Abstract:In this study, we have investigated and compared electrical, optical, and mechanical properties of polystyrene thin films with added multi-walled carbon nanotube and carbon mesoporous. Surface conductivity ( σ), scattered light intensity ( I sc), and all the mechanical parameters of these composites have increased with increasing the content of carbon filler (multi-walled carbon nanotube or carbon mesoporous) in the polystyrene composites. This behavior in electrical, mechanical, and optical properties of the … Show more
“…31 Difference in βop values can be originated from the sample preparation and the filler–matrix compatibility. In our previous studies related with a PMMA/GNP, 42 PS/GNP 43 and P(VAc-co-BuA)/MWCNT 44 composite system, the βop value was obtained as 0.40. Figure 7.The log – log plots of I sc versus ( R – R op ) for (a) CS/GNP and (b) CS/MWCNT.…”
In this work, chitosan/graphene nanoplatelets (CS/GNP) and chitosan/multi-walled carbon nanotube (CS/MWCNT) biocomposite films were prepared using a simple, eco-friendly and low-cost method. The electrical, optical and mechanical properties of these composite films were investigated. The optical, mechanical and electrical properties of the biocomposites were significantly improved, which make them promising materials for food packaging, ultraviolet protection and biomedical applications. With the increase of carbon filler content (GNP or MWCNT) in CS biocomposites, the surface conductivity ( σ), the scattered light intensity ( I sc) and the tensile modulus ( E) increased significantly. This behaviour in the electrical, optical and mechanical properties of the CS/carbon filler biocomposites was explained by percolation theory. The electrical percolation thresholds were determined as R σ = 25.0 wt.% for CS/GNP and R σ = 10.0 wt.% for CS/MWCNT biocomposites, while the optical percolation thresholds were found as R op =12.0 wt.% for CS/GNP and R op = 2.0 wt.% for CS/MWCNT biocomposites. Conversely, the mechanical percolation thresholds for both CS/GNP and CS/MWCNT biocomposites were found to be negligibly small ( R m = 0.0 wt.%). The electrical ( β σ), optical ( β op) and mechanical ( β m) critical exponents were calculated for both CS/carbon filler biocomposites and found compatible with the applied percolation theory.
“…31 Difference in βop values can be originated from the sample preparation and the filler–matrix compatibility. In our previous studies related with a PMMA/GNP, 42 PS/GNP 43 and P(VAc-co-BuA)/MWCNT 44 composite system, the βop value was obtained as 0.40. Figure 7.The log – log plots of I sc versus ( R – R op ) for (a) CS/GNP and (b) CS/MWCNT.…”
In this work, chitosan/graphene nanoplatelets (CS/GNP) and chitosan/multi-walled carbon nanotube (CS/MWCNT) biocomposite films were prepared using a simple, eco-friendly and low-cost method. The electrical, optical and mechanical properties of these composite films were investigated. The optical, mechanical and electrical properties of the biocomposites were significantly improved, which make them promising materials for food packaging, ultraviolet protection and biomedical applications. With the increase of carbon filler content (GNP or MWCNT) in CS biocomposites, the surface conductivity ( σ), the scattered light intensity ( I sc) and the tensile modulus ( E) increased significantly. This behaviour in the electrical, optical and mechanical properties of the CS/carbon filler biocomposites was explained by percolation theory. The electrical percolation thresholds were determined as R σ = 25.0 wt.% for CS/GNP and R σ = 10.0 wt.% for CS/MWCNT biocomposites, while the optical percolation thresholds were found as R op =12.0 wt.% for CS/GNP and R op = 2.0 wt.% for CS/MWCNT biocomposites. Conversely, the mechanical percolation thresholds for both CS/GNP and CS/MWCNT biocomposites were found to be negligibly small ( R m = 0.0 wt.%). The electrical ( β σ), optical ( β op) and mechanical ( β m) critical exponents were calculated for both CS/carbon filler biocomposites and found compatible with the applied percolation theory.
“…There are various type of accessible microstructures of carbon materials, such as graphite, carbon fiber, nanotube, amorphous powders, and diamond [67]. With the persist breakthrough of nanotech in materials science, carbon nanomaterials, especially carbon nanotubes (CNT) and carbon nanofiber (CNF), have gained considerable focus in electroanalysis [68], electronic [69,70], optics [70], polymer composite [71], catalyst [72][73][74], and other related fields. In 2014, researcher Zhai Zhao Yang's team described the using graphene as solid support in synthesis the catalyst and applied in O-arylation Ullmann cross-coupling reaction.…”
“…Catalysts 2020, 10, x FOR PEER REVIEW 19 of 51 nanotubes (CNT) and carbon nanofiber (CNF), have gained considerable focus in electroanalysis [68], electronic [69,70], optics [70], polymer composite [71], catalyst [72][73][74], and other related fields.…”
Transition metal-catalyzed chemical transformation of organic electrophiles and organometallic reagents belong to the most important cross coupling reaction in organic synthesis. The biaryl ether division is not only popular in natural products and synthetic pharmaceuticals but also widely found in many pesticides, polymers, and ligands. Copper catalyst has received great attention owing to the low toxicity and low cost. However, traditional Ullmann-type couplings suffer from limited substrate scopes and harsh reaction conditions. The introduction of homogeneous copper catalyst with presence of bidentate ligands over the past two decades has totally changed this situation as these ligands enable the reaction promoted in mild condition. The reaction scope has also been greatly expanded, rendering this copper-based cross-coupling attractive for both academia and industry. In this review, we will highlight the latest progress in the development of useful homogeneous copper catalyst with presence of ligand and heterogeneous copper catalyst in Ullmann type C-O cross-coupling reaction. Additionally, the application of Ullmann type C-O cross coupling reaction will be discussed.
“…21 CNTs have low bulk density, high aspect ratio (l/d) and electrical conductivity of 10 2 -10 5 S/cm. 22 When a small amount of CNT is added as reinforcement to the composite, it creates 3-dimensional conductive percolative networks, significantly increasing the electrical, optical, mechanical, and thermal properties of the composite. [22][23][24] The final properties of the obtained composite are significantly affected by parameters such as the shape, size, intrinsic conductivity of CNT, and its distribution in the polymer matrix.…”
Section: Introductionmentioning
confidence: 99%
“…22 When a small amount of CNT is added as reinforcement to the composite, it creates 3-dimensional conductive percolative networks, significantly increasing the electrical, optical, mechanical, and thermal properties of the composite. [22][23][24] The final properties of the obtained composite are significantly affected by parameters such as the shape, size, intrinsic conductivity of CNT, and its distribution in the polymer matrix. 10 Given the numerous potential applications of biocomposites as a sustainable and transient material in optical and electronic devices, it is necessary to investigate their optical and electrical properties.…”
In recent years, as a result of increasing environmental concerns, biodegradable materials have gained great attention. With the rapid development of electronic technology, the importance of innovation and development of low-cost, sustainable, transient bioelectronics materials is increasing. In this research, the preparation of Poly(Vinyl Alcohol) (PVA), Chitosan (CS), and Multi-Walled Carbon nanotube (MWCNT) biocomposite films have been described. The solution mixing, ultrasonic mixing, and spin coating techniques were used to prepare the PVA/CS/MWCNT biocomposite thin films. UV–Vis absorption spectroscopy and two-point probe resistivity measurement techniques were used to study the optical and electrical properties of the biocomposite thin films. Optical band gap energies ( Eg) of PVA/CS/MWCNT biocomposites were obtained using the Tauc and Absorbance Spectrum Fitting (ASF) methods. Results obtained with both methods were found to be exactly the same. Experimental results have shown that with increasing MWCNT concentration, electrical conductivity (σ) increases from 1.75x10−16 S to 2.94x10−3 S, and Eg decreases significantly. At the same time, the fundamental optical parameters such as band tail (Urbach) energy ( Eu), refractive index ( n), absorption ( α), and extinction ( k) coefficient of the PVA/CS/MWCNT biocomposites were investigated in the UV-VIS range. The improvement observed in the optical and electrical properties of PVA/CS/MWCNT biocomposite films shows that these composites could be used as bioelectronics materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
