| 1. |
- Zhao, Changhong, 1982, et al.
(författare)
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Synthesis of graphene quantum dots and their applications in drug delivery
- 2020
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Ingår i: Journal of Nanobiotechnology. - : Springer Science and Business Media LLC. - 1477-3155. ; 18:1
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Forskningsöversikt (refereegranskat)abstract
- This review focuses on the recent advances in the synthesis of graphene quantum dots (GQDs) and their applications in drug delivery. To give a brief understanding about the preparation of GQDs, recent advances in methods of GQDs synthesis are first presented. Afterwards, various drug delivery-release modes of GQDs-based drug delivery systems such as EPR-pH delivery-release mode, ligand-pH delivery-release mode, EPR-Photothermal delivery-Release mode, and Core/Shell-photothermal/magnetic thermal delivery-release mode are reviewed. Finally, the current challenges and the prospective application of GQDs in drug delivery are discussed.[Figure not available: see fulltext.]
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| 2. |
- Hansson, Josef, 1991, et al.
(författare)
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Bipolar electrochemical capacitors using double-sided carbon nanotubes on graphite electrodes
- 2020
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 451
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Tidskriftsartikel (refereegranskat)abstract
- The electrochemical capacitor (EC) is a key enabler for the miniaturized self-powered systems expected to become ubiquitous with the advent of the internet-of-things (IoT). Vertically aligned carbon nanotubes (VACNTs) on graphite holds promise as electrodes for compact and low-loss ECs. However, as with all ECs, the operating voltage is low, and miniaturization of higher voltage devices necessitates a bipolar design. In this paper, we demonstrate a bipolar EC using graphite/VACNTs electrodes fabricated using a joule heating chemical vapor deposition (CVD) setup. The constructed EC contains one layer of double-sided VACNTs on graphite as bipolar electrode. Compared to a series connection of two individual devices, the bipolar EC has 22% boost in volumetric energy density. More significant boost is envisaged for stacking more bipolar electrode layers. The energy enhancement is achieved without aggravating self-discharge (71.2% retention after 1 h), and at no sacrifice of cycling stability (96.7% over 50000 cycles) owing to uniform growth of VACNTs and thus eliminating cell imbalance problems.
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| 3. |
- Nylander, Andreas, 1988, et al.
(författare)
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Degradation of Carbon Nanotube Array Thermal Interface Materials through Thermal Aging: Effects of Bonding, Array Height, and Catalyst Oxidation
- 2021
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Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 13:26, s. 30992-31000
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Tidskriftsartikel (refereegranskat)abstract
- Carbon nanotube (CNT) array thermal interface materials (TIMs) are promising candidates for high-performance applications in terms of thermal performance. However, in order to be useful in commercial applications, the reliability of the interfaces is an equally important parameter, which so far has not been thoroughly investigated. In this study, the reliability of CNT array TIMs is investigated through accelerated aging. The roles of CNT array height and substrate configuration are studied for their relative impact on thermal resistance degradation. After aging, the CNT catalyst is analyzed using X-ray photoelectron spectroscopy to evaluate chemical changes. The CNT-catalyst bond appears to degrade during aging but not to the extent that the TIM performance is compromised. On the other hand, coefficient of thermal expansion mismatch between surfaces creates strain that needs to be absorbed, which requires CNT arrays with sufficient height. Transfer and bonding of both CNT roots and tips also create more reliable interfaces. Crucially, we find that the CNT array height of most previously reported CNT array TIMs is not enough to prevent significant reliability problems.
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| 4. |
- Wang, Nan, 1988, et al.
(författare)
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Improved Interfacial Bonding Strength and Reliability of Functionalized Graphene Oxide for Cement Reinforcement Applications
- 2020
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Ingår i: Chemistry - A European Journal. - : Wiley. - 1521-3765 .- 0947-6539. ; 26:29, s. 6561-6568
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Tidskriftsartikel (refereegranskat)abstract
- Poor bonding strength between nanomaterials and cement composites inevitably lead to the failure of reinforcement. Herein, a novel functionalization method for the fabrication of functionalized graphene oxide (FGO), which is capable of forming highly reliable covalent bonds with cement hydration products, and therefore, suitable for use as an efficient reinforcing agent for cement composites, is discussed. The bonding strength between cement and aggregates was improved more than 21 times with the reinforcement of FGO. The fabricated FGO also demonstrated many important features, including high reliability in cement pastes, good dispersibility, and efficient structural refinement of cement hydration products. With the incorporation of FGO, cement mortar samples demonstrated up to 40 % increased early and ultimate strength. Such results make the fast demolding and manufacture of light constructions become highly possible, and show strong advantages on improving productivity, saving cost, and reducing CO2 emissions in practical applications.
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| 5. |
- Zhang, Emma, 1985, et al.
(författare)
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Electrical monitoring of concrete using a novel structural sensor based on conductive cementitious mortar
- 2020
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Ingår i: ECCM 2018 - 18th European Conference on Composite Materials. - 9781510896932
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Konferensbidrag (refereegranskat)abstract
- This paper presents the development of a durable structural sensor based on cement-mortar modified with graphene and other carbon-based fillers. The purpose of the structural sensor is to indirectly monitor curing and service performance of concrete via electrical resistivity measurements. Electrical resistivity is an efficient parameter which can non-destructively capture intrinsic structural features of cementitious materials. The developed structural sensor is used to record electrical resistivity as a durability indicator during the whole service life of the concrete structure. To date, performance monitoring systems usually fail in the long-run before the failure of the actual monitored structure. The proposed sensor is embeddable in the interrogated structure and ensures sustainable consolidation with appropriate physico-chemical adherence and mechanical interlocking. This allows the monitoring system to surpass the expected service life of the parent concrete. Within this on-going work, the effects of different concentrations of carbon fillers on the electrical properties of cementitious mortars are reported. After an initial investigation to select the appropriate synthesis, the ability of the sensor to monitor the development of resistivity during setting and hardening was tested and the results are presented herein. Finally, the durability of the sensor was tested via electrical stability measurements under freeze-thaw cycles.
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