| 1. |
- Ajjan, Fátima, et al.
(författare)
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High performance PEDOT/lignin biopolymer composites for electrochemical supercapacitors
- 2016
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 4:5, s. 1838-1847
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Tidskriftsartikel (refereegranskat)abstract
- Developing sustainable organic electrode materials for energy storage applications is an urgent task. We present a promising candidate based on the use of lignin, the second most abundant biopolymer in nature. This polymer is combined with a conducting polymer, where lignin as a polyanion can behave both as a dopant and surfactant. The synthesis of PEDOT/Lig biocomposites by both oxidative chemical and electrochemical polymerization of EDOT in the presence of lignin sulfonate is presented. The characterization of PEDOT/Lig was performed by UV-Vis-NIR spectroscopy, FTIR infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, cyclic voltammetry and galvanostatic charge-discharge. PEDOT doped with lignin doubles the specific capacitance (170.4 F g(-1)) compared to reference PEDOT electrodes (80.4 F g(-1)). The enhanced energy storage performance is a consequence of the additional pseudocapacitance generated by the quinone moieties in lignin, which give rise to faradaic reactions. Furthermore PEDOT/Lig is a highly stable biocomposite, retaining about 83% of its electroactivity after 1000 charge/discharge cycles. These results illustrate that the redox doping strategy is a facile and straightforward approach to improve the electroactive performance of PEDOT.
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| 2. |
- Ajjan, Fátima, et al.
(författare)
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Innovative polyelectrolytes/poly(ionic liquid)s for energy and the environment
- 2017
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Ingår i: Polymer international. - : WILEY. - 0959-8103 .- 1097-0126. ; 66:8, s. 1119-1128
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Forskningsöversikt (refereegranskat)abstract
- This paper presents the work carried out within the European project RENAISSANCE-ITN, which was dedicated to the development of innovative polyelectrolytes for energy and environmental applications. Within the project different types of innovative polyelectrolytes were synthesized such as poly(ionic liquid)s coming from renewable or natural ions, thiazolium cations, catechol functionalities or from a new generation of cheap deep eutectic monomers. Further, macromolecular architectures such as new poly(ionic liquid) block copolymers and new (semi)conducting polymer/polyelectrolyte complexes were also developed. As the final goal, the application of these innovative polymers in energy and the environment was investigated. Important advances in energy storage technologies included the development of new carbonaceous materials, new lignin/conducting polymer biopolymer electrodes, new iongels and single-ion conducting polymer electrolytes for supercapacitors and batteries and new poly(ionic liquid) binders for batteries. On the other hand, the use of innovative polyelectrolytes in sustainable environmental technologies led to the development of new liquid and dry water, new materials for water cleaning technologies such as flocculants, oil absorbers, new recyclable organocatalyst platforms and new multifunctional polymer coatings with antifouling and antimicrobial properties. All in all this paper demonstrates the potential of poly(ionic liquid)s for high-value applications in energy and enviromental areas. (c) 2017 Society of Chemical Industry
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| 3. |
- Andersson, Viktor, et al.
(författare)
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Morphology of organic electronic materials imaged via electron tomography
- 2012
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Ingår i: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 247:3, s. 277-287
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Tidskriftsartikel (refereegranskat)abstract
- Several organic materials and blends have been studied with the use of electron tomography. Tomography reconstructions of active layers of organic solar cells, where various preparation techniques have been used, have been analysed and compared to device behaviour. In addition, materials with predefined structures, including contrast enhancing features, have been studied and double tilt data collection has been employed to improve reconstructions. Small changes in preparation procedures may lead to large differences in morphology and device performance, and the results also indicate a complex relation between these.
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| 4. |
- Bäcklund, Fredrik, et al.
(författare)
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Amyloid fibrils as dispersing agents for oligothiophenes: control of photophysical properties through nanoscale templating and flow induced fibril alignment
- 2014
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Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 1364-5501 .- 0959-9428 .- 2050-7526 .- 2050-7534. ; 2:37, s. 7811-7822
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Tidskriftsartikel (refereegranskat)abstract
- Herein we report that protein fibrils formed from aggregated proteins, so called amyloid fibrils, serve as an excellent dispersing agent for hydrophobic oligothiophenes such as alpha-sexithiophene (6T). Furthermore, the protein fibrils are capable of orienting 6T along the fibril long axis, as demonstrated by flow-aligned linear dichroism spectroscopy and polarized fluorescence microscopy. The materials are prepared by solid state mixing of 6T with a protein capable of self-assembly. This results in a water soluble composite material that upon heating in aqueous acid undergoes self-assembly into protein fibrils non-covalently functionalized with 6T, with a typical diameter of 5-10 nm and lengths in the micrometre range. The resulting aqueous fibril dispersions are a readily available source of oligothiophenes that can be processed from aqueous solvent, and we demonstrate the fabrication of macroscopic structures consisting of aligned 6T functionalized protein fibrils. Due to the fibril induced ordering of 6T these structures exhibit polarized light emission.
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| 5. |
- Bäcklund, Fredrik, et al.
(författare)
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Conducting microhelices from self-assembly of protein fibrils
- 2017
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Ingår i: Soft Matter. - : Royal Society of Chemistry. - 1744-683X .- 1744-6848. ; 13:25, s. 4412-4417
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Tidskriftsartikel (refereegranskat)abstract
- Herein we utilize insulin to prepare amyloid based chiral heliceswith either right or left handed helicity. We demonstrate that thehelices can be utilized as structural templates for the conductingpolymer alkoxysulfonate poly(ethylenedioxythiophene) (PEDOT-S).The chirality of the helical assembly is transferred to PEDOT-S asdemonstrated by polarized optical microscopy (POM) and CircularDichroism (CD). Analysis of the helices by conductive atomic force(c-AFM) shows significant conductivity. In addition the morphologyof the template structure is stabilized by PEDOT-S. Theseconductive helical structures represent promising candidates in ourquest for THz resonators.
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| 6. |
- Bäcklund, Fredrik, et al.
(författare)
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PEDOT-S coated protein fibril microhelices
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We show here the preparation and characterization of micrometer sized conductive helices. We utilize protein fibrils as structural templates to create chiral helices with either right or left handed helicity. The helices are coated with the conductive polymer alkoxysulfonate poly(ethylenedioxythiophene) (PEDOT-S) to create micrometer sized conductive helices. The coating acts as a stabilizer for the template structure, facilitates the preparation of solid state films and shows significant conductivity. The helices have been investigated using Circular Dichroism (CD) and scanning electron microscopy (SEM) and the conductivity have been measured for solid state films.
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| 7. |
- Bäcklund, Fredrik
(författare)
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Preparation and Application of Functionalized Protein Fibrils
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Many proteins have an innate ability to self-assemble into fibrous structures known as amyloid fibrils. From a material science perspective, fibrils have several interesting characteristics, including a high stability, a distinct shape and tunable surface properties. Such structures can be given additional properties through functionalization by other compounds such as fluorophores. Combination of fibrils with a function yielding compound can be achieved in several ways. Covalent bond attachment is specific, but cumbersome. External surface adhesion is nonspecific, but simple. However, in addition, internal non-covalent functionalization is possible. In this thesis, particular emphasis is put on internal functionalization of fibrils; by co-grinding fibril forming proteins with a hydrophobic molecule, a protein-hydrophobic compound molecule composite can be created that retains the proteins innate ability to form fibrils. Subsequently formed fibrils will thus have the structural properties of the protein fibril as well as the properties of the incorporated compound. The functionalization procedures used throughout this thesis are applicable for a wide range of chromophores commonly used for organic electronics and photonics. The methods developed and the prepared materials are useful for applications within optoelectronics as well as biomedicine.Regardless of the methodology of functionalization, using functionalized fibrils in a controlled fashion for material design requires an intimate understanding of the formation process and knowledge of the tools available to control not only the formation but also any subsequent macroscale assembly of fibrils. The development and application of such tools are described in several of the papers included in this thesis. With the required knowledge in hand, the possible influence of fibrils on the functionalizing agents, and vice versa, can be probed. The characteristic traits of the functionalized fibril can be customized and the resulting material can be organized and steered towards a specific shape and form. This thesis describes how control over the process of formation, functionalization and organization of functionalized fibrils can be utilized to influence the hierarchical assembly of fibrils – ranging from spherical structures to spirals; the function – fluorescent or conducting; and macroscopic properties – optical birefringence and specific arrangement of functionalized fibrils in the solid state. In conclusion, the use of amyloid fibrils in material science has great potential. Herein is presented a possible route towards a fully bottom up approach ranging from the nanoscale to the macroscale.
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| 8. |
- Elfwing, Anders, et al.
(författare)
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Protein nanowires with conductive properties
- 2015
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Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry. - 2050-7526 .- 2050-7534. ; 3:25, s. 6499-6504
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Tidskriftsartikel (refereegranskat)abstract
- Herein we report on the investigation of self-assembled protein nanofibrils functionalized with metallic organic compounds. We have characterized the electronic behaviour of individual nanowires using conductive atomic force microscopy. In order to follow the self assembly process we have incorporated fluorescent molecules into the protein and used the energy transfer between the internalized dye and the metallic coating to probe the binding of the polyelectrolyte to the fibril.
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| 9. |
- Fernandez-Benito, Amparo, et al.
(författare)
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Green and Scalable Biopolymer-Based Aqueous Polyelectrolyte Complexes for Zinc-Ion Charge Storage Devices
- 2023
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Ingår i: ChemElectroChem. - : WILEY-V C H VERLAG GMBH. - 2196-0216. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- Green and scalable materials are essential to fulfill the need of electrification for transitioning into a fossil-fuels free society, and sustainability is a requirement for all new technologies. Rechargeable batteries are one of the most important elements for electrification, enabling the transition to mobile electronics, electrical vehicles and grid storage. We here report synthesis and characterization of polyelectrolyte complexes of alginate and chitosan, both biopolymers deriving from the sea, for transport of zinc ions in hydrogel electrolytes. We have used vibrational spectroscopy, thermal measurements and microscopy, as well as transport measurements with ohmic or blocking contacts. The transference number for zinc ions is close to 1, the conductivity is approximate to 10 mS/cm, with stability at Zn interfaces seen through 7000 cycles in symmetric zinc//zinc cell. A zinc ion aqueous electrolyte was prepared from blends of chitosan and alginate, by using a simple and scalable route. These green zinc ion electrolytes exhibit a stability window up to 2 V, a zinc ion transference number close to 1, and electrochemical cyclability over 7000 cycles at interfaces to zinc. This biologically derived polyelectrolyte complex offers many possibilities for optimizing transport and stability at electrode interfaces.image
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| 10. |
- Johansson, Patrik, et al.
(författare)
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Electronic polymers in lipid membranes
- 2015
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 5:11242
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Tidskriftsartikel (refereegranskat)abstract
- Electrical interfaces between biological cells and man-made electrical devices exist in many forms, but it remains a challenge to bridge the different mechanical and chemical environments of electronic conductors (metals, semiconductors) and biosystems. Here we demonstrate soft electrical interfaces, by integrating the metallic polymer PEDOT-S into lipid membranes. By preparing complexes between alkyl-ammonium salts and PEDOT-S we were able to integrate PEDOT-S into both liposomes and in lipid bilayers on solid surfaces. This is a step towards efficient electronic conduction within lipid membranes. We also demonstrate that the PEDOT-S@alkyl-ammonium: lipid hybrid structures created in this work affect ion channels in the membrane of Xenopus oocytes, which shows the possibility to access and control cell membrane structures with conductive polyelectrolytes.
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