| 1. |
- Acker, Pascal, et al.
(författare)
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π-Conjugation Enables Ultra-High Rate Capabilities and Cycling Stabilities in Phenothiazine Copolymers as Cathode-Active Battery Materials
- 2019
-
Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 29:45
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, organic battery cathode materials have emerged as an attractive alternative to metal oxide–based cathodes. Organic redox polymers that can be reversibly oxidized are particularly promising. A drawback, however, often is their limited cycling stability and rate performance in a high voltage range of more than 3.4 V versus Li/Li+. Herein, a conjugated copolymer design with phenothiazine as a redox‐active group and a bithiophene co‐monomer is presented, enabling ultra‐high rate capability and cycling stability. After 30 000 cycles at a 100C rate, >97% of the initial capacity is retained. The composite electrodes feature defined discharge potentials at 3.6 V versus Li/Li+ due to the presence of separated phenothiazine redox centers. The semiconducting nature of the polymer allows for fast charge transport in the composite electrode at a high mass loading of 60 wt%. A comparison with three structurally related polymers demonstrates that changing the size, amount, or nature of the side groups leads to a reduced cell performance. This conjugated copolymer design can be used in the development of advanced redox polymers for batteries.
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| 2. |
- Ahmed, Bilal, et al.
(författare)
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i-MXenes for Energy Storage and Catalysis
- 2020
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 30:47
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Tidskriftsartikel (refereegranskat)abstract
- In 2017, a new family of in-plane, chemically-ordered quaternary MAX phases, coined i-MAX, has been reported since 2017. The first i-MAX phase, (Mo2/3Sc1/3)(2)AlC, garnered significant research attention due to the presence of chemically ordered Sc within the Mo-dominated M layer, and the facilitated removal of both Al and Sc upon etching, resulting in 2D i-MXene, Mo1.33C, with ordered divacancies. The i-MXene renders an exceptionally low resistivity of 33.2 mu omega m(-1) and a high volumetric capacitance of approximate to 1150 F cm(-3). This discovery has been followed by the synthesis of, to date, 32 i-MAX phases and 5 i-MXenes, where the latter have shown potential for applications including, but not limited to, energy storage and catalysis. Herein, fundamental investigations of i-MAX phases and i-MXenes, along with their applicability in supercapacitive and catalytic applications, are reviewed. Moreover, recent results on ion intercalation and post-etching treatment of Mo1.33C are presented. The charge storage performance can also be tuned by forming MXene hydrogel and through inert atmosphere annealing, where the latter renders a superior volumetric capacitance of approximate to 1635 F cm(-3). This report demonstrates the potential of the i-MXene family for catalytic and energy storage applications, and highlights novel research directions for further development and successful employment in practical applications.
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| 3. |
- Ail, Ujwala, et al.
(författare)
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Thermoelectric Properties of Polymeric Mixed Conductors
- 2016
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 26:34, s. 6288-6296
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Tidskriftsartikel (refereegranskat)abstract
- The thermoelectric (TE) phenomena are intensively explored by the scientific community due to the rather inefficient way energy resources are used with a large fraction of energy wasted in the form of heat. Among various materials, mixed ion-electron conductors (MIEC) are recently being explored as potential thermoelectrics, primarily due to their low thermal conductivity. The combination of electronic and ionic charge carriers in those inorganic or organic materials leads to complex evolution of the thermovoltage (Voc) with time, temperature, and/or humidity. One of the most promising organic thermoelectric materials, poly(3,4-ethyelenedioxythiophene)-polystyrene sulfonate (PEDOT-PSS), is an MIEC. A previous study reveals that at high humidity, PEDOT-PSS undergoes an ionic Seebeck effect due to mobile protons. Yet, this phenomenon is not well understood. In this work, the time dependence of the Voc is studied and its behavior from the contribution of both charge carriers (holes and protons) is explained. The presence of a complex reorganization of the charge carriers promoting an internal electrochemical reaction within the polymer film is identified. Interestingly, it is demonstrated that the time dependence behavior of Voc is a way to distinguish between three classes of polymeric materials: electronic conductor, ionic conductor, and mixed ionic–electronic conductor
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| 4. |
- Altmann, Brigitte, et al.
(författare)
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Assessment of Novel Long-Lasting Ceria-Stabilized Zirconia-Based Ceramics with Different Surface Topographies as Implant Materials
- 2017
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlag. - 1616-301X .- 1616-3028. ; 27:40
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Tidskriftsartikel (refereegranskat)abstract
- The development of long-lasting zirconia-based ceramics for implants, which are not prone to hydrothermal aging, is not satisfactorily solved. Therefore, this study is conceived as an overall evaluation screening of novel ceria-stabilized zirconia-alumina-aluminate composite ceramics (ZA8Sr8-Ce11) with different surface topographies for use in clinical applications. Ceria-stabilized zirconia is chosen as the matrix for the composite material, due to its lower susceptibility to aging than yttria-stabilized zirconia (3Y-TZP). This assessment is carried out on three preclinical investigation levels, indicating an overall biocompatibility of ceria-stabilized zirconia-based ceramics, both in vitro and in vivo. Long-term attachment and mineralized extracellular matrix (ECM) deposition of primary osteoblasts are the most distinct on porous ZA8Sr8-Ce11p surfaces, while ECM attachment on 3Y-TZP and ZA8Sr8-Ce11 with compact surface texture is poor. In this regard, the animal study confirms the porous ZA8Sr8-Ce11p to be the most favorable material, showing the highest bone-to-implant contact values and implant stability post implantation in comparison with control groups. Moreover, the microbiological evaluation reveals no favoritism of biofilm formation on the porous ZA8Sr8-Ce11p when compared to a smooth control surface. Hence, together with the in vitro in vivo assessment analogy, the promising clinical potential of this novel ZA8Sr8-Ce11 as an implant material is demonstrated.
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| 5. |
- An, Dong, et al.
(författare)
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NIR-II Responsive Inorganic 2D Nanomaterials for Cancer Photothermal Therapy : Recent Advances and Future Challenges
- 2021
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Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 31:32
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Forskningsöversikt (refereegranskat)abstract
- Non-invasive cancer photothermal therapy (PTT) is a promising replacement for traditional cancer treatments. The second near-infrared region induced PTT (NIR-II PTT, 1000-1500 nm) with less energy dissipation has been developed for deeper-seated tumor treatment in recent years compared with the traditional first near-infrared light (750-1000 nm). In addition, the use of emerging inorganic 2D nanomaterials as photothermal agents (PTAs) further enhanced PTT efficiency due to their intrinsic photothermal properties. NIR-II light stimulated inorganic 2D nanomaterials for PTT is becoming a hot topic in both academic and clinical fields. This review summarizes the categories, structures, and photothermal conversion properties of inorganic 2D nanomaterials for the first time. The recent synergistic strategies of NIR-II responsive PTT combined with other treatment approaches including chemotherapy, chemodynamic therapy, photodynamic therapy, radiotherapy are summarized. The future challenges and perspectives on these 2D nanomaterials for NIR-II responsive PTT systems construction are further discussed.
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| 6. |
- Andersson, Peter, et al.
(författare)
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Printable All-Organic Electrochromic Active-Matrix Displays
- 2007
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 17:16, s. 3074-3082
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Tidskriftsartikel (refereegranskat)abstract
- All-organic active matrix addressed displays based on electrochemical smart pixels made on flexible substrates are reported. Each individual smart pixel device combines an electrochemical transistor with an electrochromic display cell, thus resulting in a low-voltage operating and robust display technology. Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS) served as the active material in the electrochemical smart pixels, as well as the conducting lines, of the monolithically integrated active-matrix display. Different active-matrix display addressing schemes have been investigated and a matrix display fill factor of 65 % was reached. This is achieved by combining a three-terminal electrochemical transistor with an electrochromic display cell architecture, in which an additional layer of PEDOT:PSS was placed on top of the display cell counter electrode. In addition, we have evaluated different kinds of electrochromic polymer materials aiming at reaching a high color switch contrast. This work has been carried out in the light of achieving a robust display technology that is easily manufactured using a standard label printing press, which forced us to use the fewest different materials as well as avoiding exotic and complex device architectures. Together, this yields a manufacturing process of only five discrete patterning steps, which in turn promise for that the active matrix addressed displays can be manufactured on paper or plastic substrates in a roll-to-roll production procedure.
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| 7. |
- Arndt, Tina, et al.
(författare)
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Engineered Spider Silk Proteins for Biomimetic Spinning of Fibers with Toughness Equal to Dragline Silks
- 2022
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 32:23
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Tidskriftsartikel (refereegranskat)abstract
- Spider silk is the toughest fiber found in nature, and bulk production of artificial spider silk that matches its mechanical properties remains elusive. Development of miniature spider silk proteins (mini-spidroins) has made large-scale fiber production economically feasible, but the fibers’ mechanical properties are inferior to native silk. The spider silk fiber's tensile strength is conferred by poly-alanine stretches that are zipped together by tight side chain packing in β-sheet crystals. Spidroins are secreted so they must be void of long stretches of hydrophobic residues, since such segments get inserted into the endoplasmic reticulum membrane. At the same time, hydrophobic residues have high β-strand propensity and can mediate tight inter-β-sheet interactions, features that are attractive for generation of strong artificial silks. Protein production in prokaryotes can circumvent biological laws that spiders, being eukaryotic organisms, must obey, and the authors thus design mini-spidroins that are predicted to more avidly form stronger β-sheets than the wildtype protein. Biomimetic spinning of the engineered mini-spidroins indeed results in fibers with increased tensile strength and two fiber types display toughness equal to native dragline silks. Bioreactor expression and purification result in a protein yield of ≈9 g L−1 which is in line with requirements for economically feasible bulk scale production.
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| 8. |
- Asadpoordarvish, Amir, 1984-, et al.
(författare)
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Light-Emitting Paper
- 2015
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 25:21, s. 3238-3245
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Tidskriftsartikel (refereegranskat)abstract
- A solution-based fabrication of flexible and light-weight light-emitting devices on paper substrates is reported. Two different types of paper substrates are coated with a surface-emitting light-emitting electrochemical cell (LEC) device: a multilayer-coated specialty paper with an intermediate surface roughness of 0.4 μm and a low-end and low-cost copy paper with a large surface roughness of 5 μm. The entire device fabrication is executed using a handheld airbrush, and it is notable that all of the constituent layers are deposited from solution under ambient air. The top-emitting paper-LECs are highly flexible, and display a uniform light emission with a luminance of 200 cd m−2 at a current conversion efficacy of 1.4 cd A−1.
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| 9. |
- Asawa, Kenta, et al.
(författare)
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Cell Surface Functionalization with Heparin-Conjugated Lipid to Suppress Blood Activation
- 2021
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Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 31:11
-
Tidskriftsartikel (refereegranskat)abstract
- Organ transplantation leads to damage of the endothelial glycocalyx of the transplanted organ, and the activated endothelial surface induces thromboinflammation. The result is dysfunction of the transplanted organ, known as ischemia reperfusion injury (IRI). Long-term graft survival strongly depends on the regulation of IRI. Here the aim is to reconstruct the glycocalyx to regulate blood activation during IRI. Heparin-conjugated lipid (fHep-lipid) is synthesized with 0.6, 1.8, 2.7, 4.5, or 8.0 fragmented heparins per lipid to compare their anticoagulation activity. First, liposome and cells are modified with each fHep-lipid and the surface properties are evaluated. Then the hemocompatibility of the modified human mesenchymal stem cells (hMSCs) is examined in a loop model using human blood. The antithrombin-binding capacity and anti-factor Xa activity of the fHep-lipids depend on the number of conjugated heparins, with efficacy increasing with increasing number of heparins. The modified liposomes are highly negatively charged and show strong anti-factor Xa activity. In addition, the cell surfaces of human erythrocytes and hMSCs can be uniformly modified with fHep-lipid. The whole blood studies reveal that fHep-lipid on hMSCs can prevent generation of thrombin-antithrombin complexes, coagulation markers, and platelet aggregation, whereas unmodified hMSCs trigger activation of the platelet and coagulation systems.
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| 10. |
- Aziz, Shazed, et al.
(författare)
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Fast and High-Strain Electrochemically Driven Yarn Actuators in Twisted and Coiled Configurations
- 2021
-
Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 31:10
-
Tidskriftsartikel (refereegranskat)abstract
- Commercially available yarns are promising precursor for artificial muscles for smart fabric-based textile wearables. Electrochemically driven conductive polymer (CP) coated yarns have already shown their potential to be used in smart fabrics. Unfortunately, the practical application of these yarns is still hindered due to their slow ion exchange properties and low strain. Here, a method is demonstrated to morph poly-3,4-ethylenedioxythiophene:poly-styrenesulfonate (PEDOT:PSS) coated multifilament textile yarns in highly twisted and coiled structures, providing >1% linear actuation in <1 s at a potential of +0.6 V. A potential window of +0.6 V and -1.2 V triggers the fully reversible actuation of a coiled yarn providing >1.62% strain. Compared to the untwisted, regular yarns, the twisted and coiled yarns produce >9x and >20x higher strain, respectively. The strain and speed are significantly higher than the maximum reported results from other electrochemically operated CP yarns. The yarn’s actuation is explained by reversible oxidation/reduction reactions occurring at CPs. However, the helical opening/closing of the twisted or coiled yarns due to the torsional yarn untwisting/retwisting assists the rapid and large linear actuation. These PEDOT:PSS coated yarn actuators are of great interest to drive smart textile exoskeletons.
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| 11. |
- Bainsla, Lakhan, et al.
(författare)
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Ultrathin Ferrimagnetic GdFeCo Films with Low Damping
- 2022
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 32:23, s. 2111693-
-
Tidskriftsartikel (refereegranskat)abstract
- Ferromagnetic materials dominate as the magnetically active element in spintronic devices, but come with drawbacks such as large stray fields and low operational frequencies. Compensated ferrimagnets provide an alternative as they combine the ultrafast magnetization dynamics of antiferromagnets with a ferromagnet-like spin-orbit-torque behavior. However, to use ferrimagnets in spintronic devices their advantageous properties must be retained also in ultrathin films (t < 10 nm). In this study, ferrimagnetic Gdx(Fe87.5Co12.5)1−x thin films in the thickness range t = 2–20 nm are grown on high resistance Si(100) substrates and studied using broadband ferromagnetic resonance measurements at room temperature. By tuning their stoichiometry, a nearly compensated behavior is observed in 2 nm Gdx(Fe87.5Co12.5)1−x ultrathin films for the first time, with an effective magnetization of (Formula presented.) = 0.02 T and a low effective Gilbert damping constant of α = 0.0078, comparable to the lowest values reported so far in 30 nm films. These results show great promise for the development of ultrafast and energy efficient ferrimagnetic spintronic devices.
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| 12. |
- Bao, Qinye, et al.
(författare)
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Energy Level Bending in Ultrathin Polymer Layers Obtained through Langmuir-Shafer Deposition
- 2016
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 26:7, s. 1077-1084
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Tidskriftsartikel (refereegranskat)abstract
- The semiconductor-electrode interface impacts the function and the performance of (opto) electronic devices. For printed organic electronics the electrode surface is not atomically clean leading to weakly interacting interfaces. As a result, solution-processed organic ultrathin films on electrodes typically form islands due to dewetting. It has therefore been utterly difficult to achieve homogenous ultrathin conjugated polymer films. This has made the investigation of the correct energetics of the conjugated polymer-electrode interface impossible. Also, this has hampered the development of devices including ultrathin conjugated polymer layers. Here, LangmuirShafer-manufactured homogenous mono-and multilayers of semiconducting polymers on metal electrodes are reported and the energy level bending using photoelectron spectroscopy is tracked. The amorphous films display an abrupt energy level bending that does not extend beyond the first monolayer. These findings provide new insights of the energetics of the polymer-electrode interface and opens up for new high-performing devices based on ultrathin semiconducting polymers.
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| 13. |
- Bao, Qinye, et al.
(författare)
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Trap-Assisted Recombination via Integer Charge Transfer States in Organic Bulk Heterojunction Photovoltaics
- 2014
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlag. - 1616-301X .- 1616-3028. ; 24:40, s. 6309-6316
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Tidskriftsartikel (refereegranskat)abstract
- Organic photovoltaics are under intense development and significant focus has been placed on tuning the donor ionization potential and acceptor electron affinity to optimize open circuit voltage. Here, it is shown that for a series of regioregular-poly(3-hexylthiophene): fullerene bulk heterojunction (BHJ) organic photovoltaic devices with pinned electrodes, integer charge transfer states present in the dark and created as a consequence of Fermi level equilibrium at BHJ have a profound effect on open circuit voltage. The integer charge transfer state formation causes vacuum level misalignment that yields a roughly constant effective donor ionization potential to acceptor electron affinity energy difference at the donor-acceptor interface, even though there is a large variation in electron affinity for the fullerene series. The large variation in open circuit voltage for the corresponding device series instead is found to be a consequence of trap-assisted recombination via integer charge transfer states. Based on the results, novel design rules for optimizing open circuit voltage and performance of organic bulk heterojunction solar cells are proposed.
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| 14. |
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| 15. |
- Blaudeck, Thomas, et al.
(författare)
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Simplified Large-Area Manufacturing of Organic Electrochemical Transistors Combining Printing and a Self-Aligning Laser Ablation Step
- 2012
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlag Berlin. - 1616-301X .- 1616-3028. ; 22:14, s. 2939-2948
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Tidskriftsartikel (refereegranskat)abstract
- A hybrid manufacturing approach for organic electrochemical transistors (OECTs) on flexible substrates is reported. The technology is based on conventional and digital printing (screen and inkjet printing), laser processing, and post-press technologies. A careful selection of the conductive, dielectric, and semiconductor materials with respect to their optical properties enables a self-aligning pattern formation which results in a significant reduction of the usual registration problems during manufacturing. For the prototype OECTs, based on this technology, on/off ratios up to 600 and switching times of 100 milliseconds at gate voltages in the range of 1 V were obtained.
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| 16. |
- Broman, S. L., et al.
(författare)
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Dihydroazulene Photoswitch Operating in Sequential Tunneling Regime: Synthesis and Single-Molecule Junction Studies
- 2012
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 22:20, s. 4249-4258
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Tidskriftsartikel (refereegranskat)abstract
- Molecular switches play a central role for the development of molecular electronics. In this work it is demonstrated that the reproducibility and robustness of a single-molecule dihydroazulene (DHA)/vinylheptafulvene (VHF) switch can be remarkably enhanced if the switching kernel is weakly coupled to electrodes so that the electron transport goes by sequential tunneling. To assure weak coupling, the DHA switching kernel is modified by incorporating p-MeSC6H4 end-groups. Molecules are prepared by Suzuki cross-couplings on suitable halogenated derivatives of DHA. The synthesis presents an expansion of our previously reported brominationeliminationcross-coupling protocol for functionalization of the DHA core. For all new derivatives the kinetics of DHA/VHF transition has been thoroughly studied in solution. The kinetics reveals the effect of sulfur end-groups on the thermal ring-closure of VHF. One derivative, incorporating a p-MeSC6H4 anchoring group in one end, has been placed in a silver nanogap. Conductance measurements justify that transport through both DHA (high resistivity) and VHF (low resistivity) forms goes by sequential tunneling. The switching is fairly reversible and reenterable; after more than 20 ON-OFF switchings, both DHA and VHF forms are still recognizable, albeit noticeably different from the original states.
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| 17. |
- Cao, S., et al.
(författare)
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Hierachically Structured Hollow Silica Spheres for High Efficiency Immobilization of Enzymes
- 2013
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 23:17, s. 2162-2167
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the first example of a hierarchically structured hollow silica system is reported without any chemical modification to the enzyme involved in the process. The leaching of the physically adsorbed enzyme is substantially restrained in comparison to pure hollow silica supports. The hierarchical architecture is composed of the ordered hollow silica spheres with a shell-in-shell structure. This rationally integrated architecture, which serves as the host for glucose oxidase immobilization, displays many significant advantages, including increases in mechanical stability, enzyme loading, and bioactivity, and a decrease in enzyme leaching compared to existing pure hollow silica matrices. This facilitates further multifarious applications for enhanced enzyme immobilization, biosensors, and biocatalysis.
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| 18. |
- Cao, W., et al.
(författare)
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In Situ Study of FePt Nanoparticles-Induced Morphology Development during Printing of Magnetic Hybrid Diblock Copolymer Films
- 2022
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 32:4, s. 2107667-
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Tidskriftsartikel (refereegranskat)abstract
- The development of magnetic hybrid films containing diblock copolymers (DBCs) and magnetic nanoparticles (NPs) by printing is a highly promising method for scalable and low-cost fabrication. During printing, the drying and arrangement kinetics of the DBC and magnetic NPs play an important role in the film formation concerning morphology and magnetic properties. In this study, the morphology evolution of ultrahigh molecular weight DBC polystyrene-block-poly(methyl methacrylate) and magnetic iron platinum (FePt) NPs is investigated with grazing-incidence small-angle X-ray scattering (GISAXS) in situ during printing. For comparison, a pure DBC film is printed without FePt NPs under the same conditions. The GISAXS data suggest that the addition of NPs accelerates the solvent evaporation, leading to a faster film formation of the hybrid film compared to the pure film. As the solvent is almost evaporated, a metastable state is observed in both films. Compared with the pure film, such a metastable state continues longer during the printing process of the hybrid film because of the presence of FePt NPs, which inhibits the reorganization of the DBC chains. Moreover, investigations of the field-dependent magnetization and temperature-dependent susceptibility indicate that the printed hybrid film is superparamagnetic, which makes this film class promising for magnetic sensors.
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| 19. |
- Cao, Zhejian, 1991-, et al.
(författare)
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Porous Strontium Chloride Scaffolded by Graphene Networks as Ammonia Carriers
- 2021
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Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 31:30
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Tidskriftsartikel (refereegranskat)abstract
- Strontium chloride (SrCl2) as ammonia (NH3) carriers has been widely exploited due to its high ammonia uptake capacity and low energy penalty for ammonia release. However, the dramatic volume swing during absorption–desorption cycles, from SrCl2 to Sr(NH3)8Cl2 to SrCl2, imposes a challenge to structure SrCl2 for ammonia storage applications. Herein, a novel porous SrCl2 structure with SrCl2 loading up to 96 wt%, scaffolded by reduced graphene oxide (rGO) networks is reported. The optimized porous SrCl2‐rGO composite with 80 wt% SrCl2 loading maintains the macro‐ and micro‐structure accommodating the volume swing during ammonia absorption–desorption cycles without disintegration, whereas structured SrCl2 pellets disintegrates directly after the first cycle of NH3 absorption. The structured porous 80 wt% SrCl2‐rGO composite demonstrates rapid absorption–desorption kinetics, 140% faster in absorption and 540% faster in desorption compared with pure SrCl2 pellet. The enhancement of the surface area and the presence of SrCl2 particles in the pores of rGO networks result in a robust and stable structure offering rapid ammonia absorption–desorption kinetics while countermining the volume swing by self‐adjusting “breathing.”
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| 20. |
- Chateau, Denis, et al.
(författare)
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Long Distance Enhancement of Nonlinear Optical Properties Using Low Concentration of Plasmonic Nanostructures in Dye Doped Monolithic Sol-Gel Materials.
- 2016
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Ingår i: Advanced Functional Materials. - Weinheim : Wiley. - 1616-301X .- 1616-3028. ; 26:33
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Tidskriftsartikel (refereegranskat)abstract
- Monolithic sol-gel silica composites incorporating platinum-based chromophores and various types of gold nanoparticles (AuNPs) are prepared and polished to high optical quality. Their photophysical properties are investigated. The glass materials show well-defined localized surface plasmon resonance (SPR) absorbance from the visible to NIR. No redshifts of the AuNP plasmon absorption peaks due to the increase in nanoparticle doping concentration are observed in the glasses, proving that no or very small SPR coupling effects occur between the AuNPs. At 600 nm excitation, but not at 532 nm, the AuNPs improve the nonlinear absorption performance of glasses codoped with 50 × 10−3 m of a Pt-acetylide chromophore. The glasses doped with lower concentrations of AuNPs (2-5 μm average distance) and 50 × 10−3 m in chromophore, show a marked improvement in nonlinear absorption, with no or only small improvement for the more highly AuNP doped glasses. This study shows the importance of excitation wavelength and nanoparticle concentration for composite systems employing AuNPs to improve two-photon absorption of chromophores. [ABSTRACT FROM AUTHOR]
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| 21. |
- Chen, Hang, et al.
(författare)
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Modulating Carrier Kinetics in BiVO4 Photoanodes through Molecular Co4O4 Cubane Layers
- 2023
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 33:48
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the role and immobilization of molecular catalysts on photoelectrodes is essential to use their full potential for efficient solar fuel generation. Here, a CoII4O4 cubane with proven catalytic performance and an active H2O─Co2(OR)2─OH2 edge-site moiety is immobilized on BiVO4 photoanodes through a versatile layer-by-layer assembly strategy. This delivers a photocurrent of 3.3 mA cm−2 at 1.23 VRHE and prolonged stability. Tuning the thickness of the Co4O4 layer has remarkable effects on photocurrents, dynamic open circuit potentials, and charge carrier behavior. Comprehensive-time and frequency-dependent perturbation techniques are employed to investigate carrier kinetics in transient and pseudo-steady-state operando conditions. It is revealed that the Co4O4 layer can prolong carrier lifetime, unblock kinetic limitations at the interface by suppressing recombination, and enhance charge transfer. Additionally, its flexible roles are identified as passivation/hole trapping/catalytic layer at respective lower/moderate/higher potentials. These competing functions are under dynamic equilibrium, which fundamentally defines the observed photocurrent trends.
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| 22. |
- Chen, Q., et al.
(författare)
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Biopolymer-Templated Deposition of Ordered and Polymorph Titanium Dioxide Thin Films for Improved Surface-Enhanced Raman Scattering Sensitivity
- 2022
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 32:6
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Tidskriftsartikel (refereegranskat)abstract
- Titanium dioxide (TiO2) is an excellent candidate material for semiconductor metal oxide-based substrates for surface-enhanced Raman scattering (SERS). Biotemplated fabrication of TiO2 thin films with a 3D network is a promising route for effectively transferring the morphology and ordering of the template into the TiO2 layer. The control over the crystallinity of TiO2 remains a challenge due to the low thermal stability of biopolymers. Here is reported a novel strategy of the cellulose nanofibril (CNF)-directed assembly of TiO2/CNF thin films with tailored morphology and crystallinity as SERS substrates. Polymorphous TiO2/CNF thin films with well-defined morphology are obtained by combining atomic layer deposition and thermal annealing. A high enhancement factor of 1.79 × 106 in terms of semiconductor metal oxide nanomaterial (SMON)-based SERS substrates is obtained from the annealed TiO2/CNF thin films with a TiO2 layer thickness of 10 nm fabricated on indium tin oxide (ITO), when probed by 4-mercaptobenzoic acid molecules. Common SERS probes down to 10 nm can be detected on these TiO2/CNF substrates, indicating superior sensitivity of TiO2/CNF thin films among SMON SERS substrates. This improvement in SERS sensitivity is realized through a cooperative modulation of the template morphology of the CNF network and the crystalline state of TiO2.
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| 23. |
- Chen, Q., et al.
(författare)
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Cellulose-Reinforced Programmable and Stretch-Healable Actuators for Smart Packaging
- 2022
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 32:49, s. 2208074-
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Tidskriftsartikel (refereegranskat)abstract
- Biomimetic actuators are promising candidates for smart soft robotics. The applications of state-of-the-art actuators require the combination of programmable stimuli-responsiveness, excellent robustness, and efficient self-healing ability in a wide-range of working conditions. However, these properties may be mutually exclusive. Inspired by biological tissues, two kinds of polyelectrolytes including polyvinyl alcohol (PVA) and polystyrene sulfonate (PSS) are exploited as the fillers of cellulose nanofibrils (CNFs) for the fabrication of the CNF/PVA/PSS (CAS) film via the assembly of the physically-crosslinked network through multiple H-bonding and electrostatic interactions. Achieved by a casting-evaporation strategy, internal stress is stored within the polymer matrix and transforms into reversible anisotropic bending deformations in response to a humidity gradient. The speed, direction, and pitch of the bending can be programmed by tailoring the internal stresses and geometry of the samples. Moreover, the H-bonded network also contributes to the effective energy dissipation toward high toughness during tensile stretching, as well as self-healing ability during moisture saturation of the CAS films. This enables the fabrication of a humidity-sensitive flower-shaped actuator and self-healable packaging paper. This study presents a biomimetic strategy for the fabrication of multi-functional soft robotics, which holds great promise for applications in the fields of biosensors and smart packaging.
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| 24. |
- Chen, Xin, 1980, et al.
(författare)
-
Graphene Oxide Attenuates Toxicity of Amyloid-β Aggregates in Yeast by Promoting Disassembly and Boosting Cellular Stress Response
- 2023
-
Ingår i: Advanced Functional Materials. - 1616-3028 .- 1616-301X. ; 33:45
-
Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, with the aggregation of misfolded amyloid-β (Aβ) peptides in the brain being one of its histopathological hallmarks. Recently, graphene oxide (GO) nanoflakes have attracted significant attention in biomedical areas due to their capacity of suppressing Aβ aggregation in vitro. The mechanism of this beneficial effect has not been fully understood in vivo. Herein, the impact of GO on intracellular Aβ42 aggregates and cytotoxicity is investigated using yeast Saccharomyces cerevisiae as the model organism. This study finds that GO nanoflakes can effectively penetrate yeast cells and reduce Aβ42 toxicity. Combination of proteomics data and follow-up experiments show that GO treatment alters cellular metabolism to increases cellular resistance to misfolded protein stress and oxidative stress, and reduces amounts of intracellular Aβ42 oligomers. Additionally, GO treatment also reduces HTT103QP toxicity in the Huntington's disease (HD) yeast model. The findings offer insights for rationally designing GO nanoflakes-based therapies for attenuating cytotoxicity of Aβ42, and potentially of other misfolded proteins involved in neurodegenerative pathology.
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| 25. |
- Cheng, Shi, et al.
(författare)
-
A Microfluidic, Reversibly Stretchable, Large-Area Wireless Strain Sensor
- 2011
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 21:12, s. 2282-2290
-
Tidskriftsartikel (refereegranskat)abstract
- This article describes the implementation and characterization of a new self-contained large-area wireless strain sensor, operating around 1.5 GHz, based on the concept of multi-layer microfluidic stretchable radiofrequency electronics (mu FSRFEs). Compared to existing solutions, the presented integrated strain sensor is capable of remotely detecting repeated high tensile dynamic strains of up to 15% over very large surfaces or movable parts, and gets rid of all hardwiring to external storage or data processing equipment. Unlike conventional electronic devices, the major part of the sensor is a mechanically reconfigurable and reversibly deformable patch antenna, which consists of two layers of liquid metal alloy filled microfluidic channels in a silicone elastomer. A simplified radiofrequency (RF) transmitter composed of miniaturized rigid active integrated circuits (ICs) associated with discrete passive components was assembled on a flexible printed circuit board (FPCB) and then heterogeneously integrated to the antenna. The elastic patch antenna can withstand repeated mechanical stretches while still maintaining its electrical function to some extent, and return to its original state after removal of the stress. Additionally, its electrical characteristics at frequency of operation are highly sensitive to mechanical strains. Consequently, not only is this antenna a radiator for transmitting and receiving RF signals like any other conventional antennas, but also acts as a reversible large-area strain sensor in the integrated device. Good electrical performance of the standalone antenna and the RF transmitter sub-module was respectively verified by experiments. Furthermore, a personal computer (PC)-assisted RF receiver for receiving and processing the measured data was also designed, implemented, and evaluated. In the real-life demonstration, the integrated strain sensor successfully monitored periodically repeated human body motion, and wirelessly transmitted the measured data to the custom-designed receiver at a distance of 5m in real-time.
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| 26. |
- Christian Roelofs, W. S., et al.
(författare)
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Light Emission in the Unipolar Regime of Ambipolar Organic Field-Effect Transistors
- 2013
-
Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlag. - 1616-301X .- 1616-3028. ; 23:33, s. 4133-4139
-
Tidskriftsartikel (refereegranskat)abstract
- Light emission from ambipolar organic field-effect transistors (OFETs) is often observed when they are operated in the unipolar regime. This is unexpected, the light emission should be completely suppressed, because in the unipolar regime only one type of charge carrier is accumulated. Here, an electroluminescent diketopyrrolopyrrole copolymer is investigated. Local potential measurements by scanning Kelvin probe microscopy reveal a recombination position that is unstable in time due to the presence of injection barriers. The electroluminescence and electrical transport have been numerically analyzed. It is shown that the counterintuitive unipolar light emission is quantitatively explained by injection of minority carriers into deep tail states of the semiconductor. The density of the injected minority carriers is small. Hence they are relatively immobile and they recombine close the contact with accumulated majority carriers. The unipolar light output is characterized by a constant efficiency independent of gate bias. It is argued that light emission from OFETs predominantly originates from the unipolar regime when the charge transport is injection limited.
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| 27. |
- Cimenci, Cagla Eren, et al.
(författare)
-
Combined Methylglyoxal Scavenger and Collagen Hydrogel Therapy Prevents Adverse Remodeling and Improves Cardiac Function Post-Myocardial Infarction
- 2022
-
Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 32:1
-
Tidskriftsartikel (refereegranskat)abstract
- Methylglyoxal (MG) is a highly reactive dicarbonyl and the main precursor of advanced glycation end-products (AGEs). After myocardial infarction (MI), MG-derived AGEs accumulate in the heart and contribute to adverse remodeling and loss of cardiac function. In this study, the flavonoid fisetin, a dicarbonyl scavenger, is used to reduce the negative effects of MG in the post-MI heart. A fisetin-loaded collagen type I hydrogel (fisetin-HG) is injected intramyocardially in mice at 3 h post-MI, and compared to fisetin-alone, hydrogel-alone, or saline treatment. Fisetin-HG treatment increases the level of glyoxalase-1 (the main MG-metabolizing enzyme), reduces MG-AGE accumulation, and decreases oxidative stress in the MI heart, which is associated with smaller scar size and improved cardiac function. Treatment with fisetin-HG also promotes neovascularization and increases the number of pro-healing macrophages in the infarct area, while reducing the number of pro-inflammatory macrophages. Taken together, the results demonstrate that the fisetin-collagen hydrogel therapy can reduce the accumulation and negative effects of MG post-MI. This therapy may be a promising approach to limit adverse cardiac remodeling, prevent damage, and preserve function of the infarcted heart.
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| 28. |
- Cooper, Thomas M., et al.
(författare)
-
Nanoscale Organization of a Platinum(II) Acetylide Cholesteric Liquid Crystal Molecular Glass for Photonics Applications
- 2020
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 30:28
-
Tidskriftsartikel (refereegranskat)abstract
- The fabrication, molecular structure, and spectroscopy of a stable cholesteric liquid crystal platinum acetylide glass obtained from trans-Pt(PEt3)(2)(C(sic)C-C6H5-C(sic)N)(C(sic)C-C6H5-COO-Cholesterol), are described and designated as PE1-CN-Chol. Polarized optical microscopy, differential scanning calorimetry, and wide-angle X-ray scattering experiments show room temperature glassy/crystalline texture with crystal formation upon heating to 165 degrees C. Further heating results in conversion to cholesteric phase. Cooling to room temperature leads to the formation of a cholesteric liquid crystal glass. Scanning tunneling microscopy of a PE1-CN-Chol monolayer reveals self-assembly at the solid-liquid interface with an array of two molecules arranged in pairs, oriented head-to-head through the CN groups, giving rise to a lamella arrangement. The lamella structure obtained from molecular dynamics calculations shows a clear phase separation between the conjugated platinum acetylide and the hydrophobic cholesterol moiety with the lamellae separation distance being 4.0 nm. Ultrafast transient absorption and flash photolysis spectra of the glass show intersystem crossing to the triplet state occurring within 100 ps following excitation. The triplet decay time of the film compared to aerated and deoxygenated solutions is consistent with oxygen quenching at the film surface but not within the film. The high chromophore concentration, high glass thermal stability, and long triplet lifetime in air show that these materials have potential as nonlinear absorbing materials.
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| 29. |
- Corrales-Pérez, Belén, et al.
(författare)
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Alternative Metallic Fillers for the Preparation of Conductive Nanoinks for Sustainable Electronics
- 2024
-
Ingår i: Advanced Functional Materials. - : John Wiley and Sons Inc. - 1616-301X .- 1616-3028.
-
Tidskriftsartikel (refereegranskat)abstract
- The development of electronics with net zero carbon emissions through more efficient and environmentally friendly materials and processes is still a challenge. Here, alternative chemical synthesis routes of metal conductive nanoparticles, based on biodegradable materials are explored, such as nickel, iron–nickel alloy and iron nanoparticles, to be used, in the long term, as fillers in inks for inject printing. Thus, Ni and FeNi metal nanoparticles of 25–12 nm, forming aggregates of 614–574 nm, respectively, are synthesized in water in the presence of a polyol and a reducing agent and under microwave heating that enables a more uniform and fast heating. Iron nanoparticles of 120 ± 40 nm are synthesized in polyol that limits the aggregation and the oxidation degree. Commercial metal nanoparticles of iron and nickel, are coated with ethylene glycol and used for comparison. The conductivity of nanoparticles when pressed into pellets remains similar for both commercial and synthesized samples. However, when deposited on a strip line and heated, synthesized Ni, FeNi, and Fe nanoparticles show significant conductivity and interesting magnetic properties. It is demonstrated that the nanosize facilitates sintering at reduced temperatures and the capping agents prevent oxidation, resulting in promising conductive fillers for printed electronic applications.
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| 30. |
- D'Auria, Silvia, et al.
(författare)
-
Polyethylene Based Ionomers as High Voltage Insulation Materials
- 2023
-
Ingår i: Advanced Functional Materials. - 1616-3028 .- 1616-301X. ; 33:36
-
Tidskriftsartikel (refereegranskat)abstract
- Polyethylene based ionomers are demonstrated to feature a thermo-mechanical and dielectric property portfolio that is comparable to cross-linked polyethylene (XLPE), which may enable the design of more sustainable high voltage direct-current (HVDC) power cables, a crucial component of future electricity grids that seamlessly integrate renewable sources of energy. A new type of ionomer is obtained via high-pressure/high-temperature free radical copolymerization of ethylene in the presence of small amounts of ion-pair comonomers comprising amine terminated methacrylates and methacrylic acid. The synthesized ionomers feature a crystallinity, melting temperature, rubber plateau modulus and thermal conductivity like XLPE but remain melt-processable. Moreover, the preparation of the ionomers is free of byproducts, which readily yields a highly insulating material with a low dielectric loss tangent and a low direct-current (DC) electrical conductivity of 1 to 6·10−14 S m−1 at 70 °C and an electric field of 30 kV mm−1. Evidently, the investigated ionomers represent a promising alternative to XLPE-based high voltage insulation, which may permit to ease the production as well as end-of-use recycling of HVDC power cables by combining the advantages of thermoset and thermoplastic materials while avoiding the formation of byproducts.
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| 31. |
- del Pozo, Freddy G., et al.
(författare)
-
Single Crystal-Like Performance in Solution-Coated Thin-Film Organic Field-Effect Transistors
- 2016
-
Ingår i: Advanced Functional Materials. - : Wiley-Blackwell. - 1616-301X .- 1616-3028. ; 26:14, s. 2379-2386
-
Tidskriftsartikel (refereegranskat)abstract
- In electronics, the field-effect transistor (FET) is a crucial cornerstone and successful integration of this semiconductor device into circuit applications requires stable and ideal electrical characteristics over a wide range of temperatures and environments. Solution processing, using printing or coating techniques, has been explored to manufacture organic field-effect transistors (OFET) on flexible carriers, enabling radically novel electronics applications. Ideal electrical characteristics, in organic materials, are typically only found in single crystals. Tiresome growth and manipulation of these hamper practical production of flexible OFETs circuits. To date, neither devices nor any circuits, based on solution-processed OFETs, has exhibited an ideal set of characteristics similar or better than todays FET technology based on amorphous silicon. Here, bar-assisted meniscus shearing of dibenzo-tetrathiafulvalene to coat-process self-organized crystalline organic semiconducting domains with high reproducibility is reported. Including these coatings as the channel in OFETs, electric field and temperature-independent charge carrier mobility and no bias stress effects are observed. Furthermore, record-high gain in OFET inverters and exceptional operational stability in both air and water are measured.
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| 32. |
- Derewjanko, Dennis, et al.
(författare)
-
Delocalization Enhances Conductivity at High Doping Concentrations
- 2022
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 32:20
-
Tidskriftsartikel (refereegranskat)abstract
- Many applications of organic semiconductors require high electrical conductivities and hence high doping levels. Therefore, it is indispensable for effective material design to have an accurate understanding of the underlying transport mechanisms in this regime. In this study, own and literature experimental data that reveal a power-law relation between the conductivity and charge density of strongly p-doped conjugated polymers are combined. This behavior cannot consistently be described with conventional models for charge transport in energetically disordered materials. Here, it is shown that the observations can be explained in terms of a variable range hopping model with an energy-dependent localization length. A tight-binding model is used to quantitatively estimate of the energy-dependent localization length, which is used in an analytical variable range hopping model. In the limit of low charge densities, the model reproduces the well-known Mott variable range hopping behavior, while for high charge densities, the experimentally observed superlinear increase in conductivity with charge density is reproduced. The latter behavior occurs when the Fermi level reaches partially delocalized states. This insight can be anticipated to lead to new strategies to increase the conductivity of organic semiconductors.
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| 33. |
- Dev, Apurba, et al.
(författare)
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Fabrication of Periodic Nanostructure Assemblies by Interfacial Energy Driven Colloidal Lithography
- 2014
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 24:29, s. 4577-4583
-
Tidskriftsartikel (refereegranskat)abstract
- A novel interfacial energy driven colloidal lithography technique to fabricate periodic patterns from solution-phase is presented and the feasibility and versatility of the technique is demonstrated by fabricating periodically arranged ZnO nanowire ensembles on Si substrates. The pattern fabrication method exploits different interfaces formed by sol-gel derived ZnO seed solution on a hydrophobic Si surface covered by a monolayer of colloidal silica spheres. While the hydrophobic Si surface prevents wetting by the seed solution, the wedge shaped regions surrounding the contact point between the colloidal particles and the Si substrate trap the solution due to interfacial forces. This technique allows fabrication of uniform 2D micropatterns of ZnO seed particles on the Si substrate. A hydrothermal technique is then used to grow well-defined periodic assemblies of ZnO nanowires. Tunability is demonstrated in the dimensions of the patterns by using silica spheres with different diameters. The experimental data show that the periodic ZnO nanowire assembly suppresses the total reflectivity of bare Si by more than a factor of 2 in the wavelength range 400-1300 nm. Finite-difference time-domain simulations of the wavelength-dependent reflectivity show good qualitative agreement with the experiments. The demonstrated method is also applicable for other materials synthesized by solution chemistry.
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| 34. |
- Di Maria, Francesca, et al.
(författare)
-
Controlling the Functional Properties of Oligothiophene Crystalline Nano/Microfibers via Tailoring of the Self-Assembling Molecular Precursors
- 2018
-
Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 28:32
-
Tidskriftsartikel (refereegranskat)abstract
- Oligothiophenes are π-conjugated semiconducting and fluorescent molecules whose self-assembly properties are widely investigated for application in organic electronics, optoelectronics, biophotonics, and sensing. Here an approach to the preparation of crystalline oligothiophene nano/microfibers is reported based on the use of a “sulfur overrich” quaterthiophene building block, T4S4 , containing in its covalent network all the information needed to promote the directional, π–π stacking-driven, self-assembly of Y-T4S4-Y oligomers into fibers with hierarchical supramolecular arrangement from nano- to microscale. It is shown that when Y varies from unsubstituted thiophene to thiophene substituted with electron-withdrawing groups, a wide redistribution of the molecular electronic charge takes place without substantially affecting the aggregation modalities of the oligomer. In this way, a structurally comparable series of fibers is obtained having progressively varying optical properties, redox potentials, photoconductivity, and type of prevailing charge carriers (from p- to n-type). With the aid of density functional theory (DFT) calculations, combined with powder X-ray diffraction data, a model accounting for the growth of the fibers from molecular to nano- and microscale is proposed
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| 35. |
- Dick Thelander, Kimberly, et al.
(författare)
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A new understanding of au-assisted growth of III-V semiconductor nanowires
- 2005
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 15:10, s. 1603-1610
-
Tidskriftsartikel (refereegranskat)abstract
- Semiconductor nanowires of III-V materials have generated much interest in recent years. However, the growth mechanisms by which these structures form are not well understood. The so-called vapor-liquid-solid (VLS) mechanism has often been proposed for III-V systems, with a chemically inert, liquid metal particle (typically Au) acting as a physical catalyst. We assert here that An is, in fact, not inert with respect to the semiconductor material but rather interacts with it to form a variety of intermetallic compounds. Moreover, we suggest that III-V nanowire growth can best be understood if the metallic particle is not a liquid, but a solid-phase solution or compound containing An and the group III material. The four materials GaP, GaAs, InP, and InAs will be considered, and growth behavior related to their particular temperature-dependent interaction with Au.
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| 36. |
- Doryab, Ali, et al.
(författare)
-
A Biomimetic, Copolymeric Membrane for Cell-Stretch Experiments with Pulmonary Epithelial Cells at the Air-Liquid Interface
- 2021
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 31:10
-
Tidskriftsartikel (refereegranskat)abstract
- Chronic respiratory diseases are among the leading causes of death worldwide, but only symptomatic therapies are available for terminal illness. This in part reflects a lack of biomimetic in vitro models that can imitate the complex environment and physiology of the lung. Here, a copolymeric membrane consisting of poly(ε-)caprolactone and gelatin with tunable properties, resembling the main characteristics of the alveolar basement membrane is introduced. The thin bioinspired membrane (0.5 μm) is stretchable (up to 25% linear strain) with appropriate surface wettability and porosity for culturing lung epithelial cells under air–liquid interface conditions. The unique biphasic concept of this membrane provides optimum characteristics for initial cell growth (phase I) and then switch to biomimetic properties for cyclic cell-stretch experiments (phase II). It is showed that physiologic cyclic mechanical stretch improves formation of F-actin cytoskeleton filaments and tight junctions while non-physiologic over-stretch induces cell apoptosis, activates inflammatory response (IL-8), and impairs epithelial barrier integrity. It is also demonstrated that cyclic physiologic stretch can enhance the cellular uptake of nanoparticles. Since this membrane offers considerable advantages over currently used membranes, it may lead the way to more biomimetic in vitro models of the lung for translation of in vitro response studies into clinical outcome.
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| 37. |
- Doryab, Ali, et al.
(författare)
-
Evolution of Bioengineered Lung Models : Recent Advances and Challenges in Tissue Mimicry for Studying the Role of Mechanical Forces in Cell Biology
- 2019
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028.
-
Forskningsöversikt (refereegranskat)abstract
- Mechanical stretch under both physiological (breathing) and pathophysiological (ventilator-induced) conditions is known to significantly impact all cellular compartments in the lung, thereby playing a pivotal role in lung growth, regeneration and disease development. In order to evaluate the impact of mechanical forces on the cellular level, in vitro models using lung cells on stretchable membranes have been developed. Only recently have some of these cell-stretching devices become suitable for air–liquid interface cell cultures, which is required to adequately model physiological conditions for the alveolar epithelium. To reach this goal, a multi-functional membrane for cell growth balancing biophysical and mechanical properties is critical to mimic (patho)physiological conditions. In this review, i) the relevance of cyclic mechanical forces in lung biology is elucidated, ii) the physiological range for the key parameters of tissue stretch in the lung is described, and iii) the currently available in vitro cell-stretching devices are discussed. After assessing various polymers, it is concluded that natural-synthetic copolymers are promising candidates for suitable stretchable membranes used in cell-stretching models. This work provides guidance on future developments in biomimetic in vitro models of the lung with the potential to function as a template for other organ models (e.g., skin, vessels).
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| 38. |
|
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| 39. |
- Eckstein, Brian J., et al.
(författare)
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Processable High Electron Mobility pi-Copolymers via Mesoscale Backbone Conformational Ordering
- 2021
-
Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 31:15
-
Tidskriftsartikel (refereegranskat)abstract
- The synthesis and experimental/theoretical characterization of a new series of electron-transporting copolymers based on the naphthalene bis(4,8-diamino-1,5-dicarboxyl)amide (NBA) building block are reported. Comonomers are designed to test the emergent effects of manipulating backbone torsional characteristics, and density functional theory (DFT) analysis reveals the key role of backbone conformation in optimizing electronic delocalization and transport. The NBA copolymer conformational and electronic properties are characterized using a broad array of molecular/macromolecular, thermal, optical, electrochemical, and charge transport techniques. All NBA copolymers exhibit strongly aggregated morphologies with significant nanoscale order. Copolymer charge transport properties are investigated in thin-film transistors and exhibit excellent electron mobilities ranging from 0.4 to 4.5 cm(2) V-1 s(-1). Importantly, the electron transport efficiency correlates with the film mesoscale order, which emerges from comonomer-dependent backbone planarity and extension. These results illuminate the key NBA building block structure-morphology-bulk property design relationships essential for processable, electronics-applicable high-performance polymeric semiconductors.
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| 40. |
- Edberg, Jesper, et al.
(författare)
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Patterning and Conductivity Modulation of Conductive Polymers by UV Light Exposure
- 2016
-
Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 26:38, s. 6950-6960
-
Tidskriftsartikel (refereegranskat)abstract
- A novel patterning technique of conductive polymers produced by vapor phase polymerization is demonstrated. The method involves exposing an oxidant film to UV light which changes the local chemical environment of the oxidant and subsequently the polymerization kinetics. This procedure is used to control the conductivity in the conjugated polymer poly(3,4-ethylenedioxythiophene): tosylate by more than six orders of magnitude in addition to producing high-resolution patterns and optical gradients. The mechanism behind the modulation in the polymerization kinetics by UV light irradiation as well as the properties of the resulting polymer are investigated.
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| 41. |
- Ekblad, Tobias, 1979-, et al.
(författare)
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Patterned Hydrogels for Controlled Platelet Adhesion from Whole Blood and Plasma
- 2010
-
Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 20:15, s. 2396-2403
-
Tidskriftsartikel (refereegranskat)abstract
- This work describes the preparation and properties of hydrogel surface chemistries enabling controlled and well-defined cell adhesion. The hydrogels may be prepared directly on plastic substrates, such as polystyrene slides or dishes, using a quick and experimentally simple photopolymerization process, compatible with photolithographic and microfluidic patterning methods. The intended application for these materials is as substrates for diagnostic cell adhesion assays, particularly for the analysis of human platelet function. The adsorption of fibrinogen and other platelet promoting molecules is shown to be completely inhibited by the hydrogel, provided that the film thickness is sufficient (>5 nm). This allows the hydrogel to be used as a matrix for presenting selected bioactive ligands without risking interference from nonspecifically adsorbed platelet adhesion factors, even in undiluted whole blood and blood plasma. This concept is demonstrated by preparing patterns of proteins on hydrogel surfaces, resulting in highly controlled platelet adhesion. Further insights into the protein immobilization and platelet adhesion processes are provided by studies using imaging surface plasmon resonance. The hydrogel surfaces used in this work appear to provide an ideal platform for cell adhesion studies of platelets, and potentially also for other cell types.
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| 42. |
- Ekspong, Joakim, et al.
(författare)
-
Stabilizing Active Edge Sites in Semicrystalline Molybdenum Sulfide by Anchorage on Nitrogen-Doped Carbon Nanotubes for Hydrogen Evolution Reaction
- 2016
-
Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 26:37, s. 6766-6776
-
Tidskriftsartikel (refereegranskat)abstract
- Finding an abundant and cost-effective electrocatalyst for the hydrogen evolu-tion reaction (HER) is crucial for a global production of hydrogen from water electrolysis. This work reports an exceptionally large surface area hybrid catalyst electrode comprising semicrystalline molybdenum sulfi de (MoS 2+ x) catalystattached on a substrate based on nitrogen-doped carbon nanotubes (N-CNTs), which are directly grown on carbon fiber paper (CP). It is shown here that nitrogen-doping of the carbon nanotubes improves the anchoring of MoS 2+ xcatalyst compared to undoped carbon nanotubes and concurrently stabilizes a semicrystalline structure of MoS 2+ x with a high exposure of active sites for HER. The well-connected constituents of the hybrid catalyst are shown to facilitate electron transport and as a result of the good attributes, the MoS 2+ x/N-CNT/CPelectrode exhibits an onset potential of −135 mV for HER in 0.5 M H2SO4, a Tafel slope of 36 mV dec −1, and high stability at a current density of −10 mA cm −2.
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| 43. |
- Ekspong, Joakim, et al.
(författare)
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Stable Sulfur‐Intercalated 1T′ MoS2 on Graphitic Nanoribbons as Hydrogen Evolution Electrocatalyst
- 2018
-
Ingår i: Advanced Functional Materials. - : WILEY-VCH VERLAG GMBH. - 1616-301X .- 1616-3028. ; 28:46
-
Tidskriftsartikel (refereegranskat)abstract
- The metastable 1T′ polymorph of molybdenum disulfide (MoS2) has shown excellent catalytic activity toward the hydrogen evolution reaction (HER) in water‐splitting applications. Its basal plane exhibits high catalytic activity comparable to the edges in 2H MoS2 and noble metal platinum. However, the production and application of this polymorph are limited by its lower energetic stability compared to the semiconducting 2H MoS2 phase. Here, the production of stable intercalated 1T′ MoS2 nanosheets attached on graphitic nanoribbons is reported. The intercalated 1T′ MoS2 exhibits a stoichiometric S:Mo ratio of 2.3 (±0.1):1 with an expanded interlayer distance of 10 Å caused by a sulfur‐rich intercalation agent and is stable at room temperature for several months even after drying. The composition, structure, and catalytic activity toward HER are investigated both experimentally and theoretically. It is concluded that the 1T′ MoS2 phase is stabilized by the intercalated agents, which further improves the basal planes′ catalytic activity toward HER.
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| 44. |
- Elfwing, Anders, et al.
(författare)
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Conducting Helical Structures from Celery Decorated with a Metallic Conjugated Polymer Give Resonances in the Terahertz Range
- 2018
-
Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 28:24
-
Tidskriftsartikel (refereegranskat)abstract
- A method to decorate cellulose-based helices retrieved from the plant celery with a conductive polymer is proposed. Using a layer-by-layer method, the decoration of the polyanionic conducting polymer poly(4-(2,3-dihydrothieno [3,4-b]-[1,4]dioxin-2-yl-methoxy)-1-butanesulfonic acid (PEDOT-S) is enhanced after coating the negatively charged cellulose helix with a polycationic polyethyleneimine. Microscopy techniques and two-point probe are used to image the structure and measure the conductivity of the helix. Analysis of the optical and electrical properties of the coated helix in the terahertz (THz) frequency range shows a resonance close to 1 THz and a broad shoulder that extends to 3.5 THz, consistent with electromagnetic models. Moreover, as helical antennas, it is shown that both axial and normal modes are present, which are correlated to the orientation and antenna electrical lengths of the coated helices. This work opens the possibility of designing tunable terahertz antennas through simple control of their dimensions and orientation.
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| 45. |
- Engström, Joakim, et al.
(författare)
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Core–Shell Nanoparticle Interface and Wetting Properties
- 2020
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 30:15
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Tidskriftsartikel (refereegranskat)abstract
- Latex colloids are among the most promising materials for broad thin film applications due to their facile surface functionalization. Yet, the effect of these colloids on chemical film and wetting properties cannot be easily evaluated. At the nanoscale, core–shell particles can deform and coalesce during thermal annealing, yielding fine-tuned physical properties. Two different core–shell systems (soft and rigid) with identical shells but with chemically different core polymers and core sizes are investigated. The core–shell nanoparticles (NPs) are probed during thermal annealing in order to investigate their behavior as a function of nanostructure size and rigidity. X-ray scattering allows to follow the re-arrangement of the NPs and the structural evolution in situ during annealing. Evaluation by real-space imaging techniques reveals a disappearance of the structural integrity and a loss of NP boundaries. The possibility to fine-tune the wettability by tuning the core–shell NPs morphology in thin films provides a facile template methodology for repellent surfaces.
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| 46. |
- Eskilson, Olof, 1992-, et al.
(författare)
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Self-Assembly of Mechanoplasmonic Bacterial Cellulose-Metal Nanoparticle Composites
- 2020
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 30:40
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Tidskriftsartikel (refereegranskat)abstract
- Nanocomposites of metal nanoparticles (NPs) and bacterial nanocellulose (BC) enable fabrication of soft and biocompatible materials for optical, catalytic, electronic, and biomedical applications. Current BC-NP nanocomposites are typically prepared by in situ synthesis of the NPs or electrostatic adsorption of surface functionalized NPs, which limits possibilities to control and tune NP size, shape, concentration, and surface chemistry and influences the properties and performance of the materials. Here a self-assembly strategy is described for fabrication of complex and well-defined BC-NP composites using colloidal gold and silver NPs of different sizes, shapes, and concentrations. The self-assembly process results in nanocomposites with distinct biophysical and optical properties. In addition to antibacterial materials and materials with excellent senor performance, materials with unique mechanoplasmonic properties are developed. The homogenous incorporation of plasmonic gold NPs in the BC enables extensive modulation of the optical properties by mechanical stimuli. Compression gives rise to near-field coupling between adsorbed NPs, resulting in tunable spectral variations and enhanced broadband absorption that amplify both nonlinear optical and thermoplasmonic effects and enables novel biosensing strategies.
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| 47. |
- Etman, Ahmed S., et al.
(författare)
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Molybdenum Oxide Nanosheets with Tunable Plasmonic Resonance : Aqueous Exfoliation Synthesis and Charge Storage Applications
- 2019
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 29:4
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Tidskriftsartikel (refereegranskat)abstract
- Herein, a simple aqueous‐exfoliation strategy is introduced for the fabrication of a series of MoO3−x nanosheets (where x stands for oxygen vacancies) using two commercial molybdenum oxide precursors, MoO2 and MoO3. The nanosheets offer a localized surface plasmon resonance (LSPR) effect which is dependent on the structure and local environment of the nanosheets. The LSPR can be efficiently tuned by changing the weight ratio between the molybdenum oxide precursor(s) and/or by solar light irradiation using a low‐energy UV lamp (36 W). For the pristine MoO3−x nanosheets, the highest LSPR signal is obtained for nanosheets prepared using 80% MoO2. On the contrary, after solar light irradiation, the nanosheets prepared using pure MoO3 offer the highest LSPR response. The nanosheets also show an outstanding rate capability when used as binder‐free supercapacitor electrodes in an acidified Na2SO4 electrolyte. The electrodes exhibit discharge capacities of 110 and 75 C g−1 at a scan rate of 20 and 1000 mV s−1, respectively. The MoO3−x nanosheets can likewise be used as a negative electrode material for lithium‐ion batteries. The efficient eco‐friendly synthesis and the ability to tune the photochemical and electrochemical properties of the nanosheets make this approach interesting to many energy‐related research fields.
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| 48. |
- Etula, Jarkko, et al.
(författare)
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Room-Temperature Micropillar Growth of Lithium-Titanate-Carbon Composite Structures by Self-Biased Direct Current Magnetron Sputtering for Lithium Ion Microbatteries
- 2019
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 29:42
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Tidskriftsartikel (refereegranskat)abstract
- Here, an unidentified type of micropillar growth is described at room temperature during conventional direct-current magnetron sputtering (DC-MS) deposition from a Li4Ti5O12+graphite sputter target under negative substrate bias and high operating pressure. These fabricated carbon-Li2O-TiO2 microstructures consisting of various Li4Ti5O12/Li2TiO3/LixTiO2 crystalline phases are demonstrated as an anode material in Li-ion microbatteries. The described micropillar fabrication method is a low-cost, substrate independent, single-step, room-temperature vacuum process utilizing a mature industrial complementary metal-oxide-semiconductor (CMOS)-compatible technology. Furthermore, tentative consideration is given to the effects of selected deposition parameters and the growth process, as based on extensive physical and chemical characterization. Additional studies are, however, required to understand the exact processes and interactions that form the micropillars. If this facile method is further extended to other similar metal oxide-carbon systems, it could offer alternative low-cost fabrication routes for microporous high-surface area materials in electrochemistry and microelectronics.
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| 49. |
- Fabiano, Simone, et al.
(författare)
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Effect of Gate Electrode Work-Function on Source Charge Injection in Electrolyte-Gated Organic Field-Effect Transistors
- 2014
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 24:5, s. 695-700
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Tidskriftsartikel (refereegranskat)abstract
- Systematic investigation of the contact resistance in electrolyte-gated organic field-effect transistors (OFETs) demonstrates a dependence of source charge injection versus gate electrode work function. This analysis reveals contact-limitations at the source metal-semiconductor interface and shows that the contact resistance increases as low work function metals are used as the gate electrode. These findings are attributed to the establishment of a built-in potential that is high enough to prevent the Fermi-level pinning at the metal-organic interface. This results in an unfavorable energetic alignment of the source electrode with the valence band of the organic semiconductor. Since the operating voltage in the electrolyte-gated devices is on the same order as the variation of the work functions, it is possible to tune the contact resistance over more than one order of magnitude by varying the gate metal.
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| 50. |
- Fahlvik Svensson, Sofia, et al.
(författare)
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Using Polymer Electrolyte Gates to Set-and-Freeze Threshold Voltage and Local Potential in Nanowire-based Devices and Thermoelectrics
- 2015
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 25:2, s. 255-262
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Tidskriftsartikel (refereegranskat)abstract
- The strongly temperature-dependent ionic mobility in polymer electrolytes is used to freeze in specific ionic charge environments around a nanowire using a local wrap-gate geometry. This makes it possible to set both the threshold voltage for a conventional doped substrate gate and the local disorder potential at temperatures below 220 K. These are characterized in detail by combining conductance and thermovoltage measurements with modeling. The results demonstrate that local polymer electrolyte gates are compatible with nanowire thermoelectrics, where they offer the advantage of a very low thermal conductivity, and hold great potential towards setting the optimal operating point for solid-state cooling applications.
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