Search

Polymer/fluorocarbon surfactant membranes have been reported to display excellent oleophobic/hydrophilic behavior and outstanding oil/water separation properties. In this work, multiwalled carbon nanotubes (MWNTs) enhanced poly(styrene‐alt‐maleic anhydride)/fluorocarbon surfactant (PSMA/MWNTs/FS) membrane filters were prepared by dip‐coating PSMA/MWNTs/FS on stainless steel meshes for efficient oil/water separation. The microstructure, thermal properties, wettability, oil/water separation ability, and recyclability were investigated. The results revealed that the MWNTs are suitably dispersed in the membrane, further increasing the thermal stability, oil/water separation efficiency, and recyclability. The oil/water separation efficiency of the complex membrane filter containing MWNTs was 99% initially and 97% after 20 cycles. This work provides a simple, low‐cost, and environmentally friendly approach for efficient oil/water separation. [ABSTRACT FROM AUTHOR]

Abstract Stimuli-responsive hydrogel actuators, which can swell and shrink reversibly, have attracted great attention. In this paper, a bilayer hydrogel actuator based on multi-walled carbon nanotubes (MWCNTs)/host-guest polymer composites was prepared. The surface compatibility of MWCNTs was improved by the oxidization process and vinyl functionalization. Fourier transform infrared (FTIR) and Raman analysis revealed that the modifications conferred the hydrophilic groups and disorder structures to MWCNTs, which can enhance the hydrophilicity of poly(acrylamide) matrix. The host and guest hydrogels bilayer structured actuator shows a bending movement in water, providing a new route to design and fabricate high performance hydrogel based actuators. [ABSTRACT FROM AUTHOR]

Poly (ethylene glycol)-grafted multi-walled carbon nanotubes (PEG-MWNTs) were prepared and added into poly(L-lactide) (PLLA)/aluminum nitride (AlN) composites to obtain PLLA/AlN/PEG-MWNTs nanocomposites. Microstructure and thermal conductivity of the composites were investigated on the basis of the influence of PEG-MWNTs incorporated. The results showed that PEG-MWNTs were well-dispersed in the PLLA matrix and had strong interfacial adhesion with the matrix. The addition of PEG-MWNTs improved the thermal conductivity of PLLA/AlN composites. When 3 wt.% of PEG-MWNTs and 50 wt.% of AlN were both added into the PLLA matrix, the thermal conductivity reached 0.7734 W/mK with enhancement almost by 400% as compared to a neat PLLA. However, the thermal conductivity is 0.3401 W/mK for the PLLA composite with 3 wt.% of PEG-MWNTs and 0.4286 W/mK for the one with 50 wt.% of AlN. The synergistic effect of aggregated AlN particles and well-dispersed MWNTs could form efficient thermal conductive paths for improving the thermal conductivity of PLLA composites greatly. [ABSTRACT FROM AUTHOR]

The development of shape memory polymers (SMPs) has gained remarkable attention due to their wide range of applications, from biomedical to electromechanical. In this work, we have developed and optimized an electroactive SMP based on polyvinyl alcohol/multi-walled carbon nanotubes (PVA/MWNTs) composites. When a constant voltage of 60 V was applied to the optimized sample, the polymer shape could be recovered to the original form within 35 s. Different weight fractions of MWNT/PVA composites were prepared by using a simple solution blending and transitional solution casting method, and their microstructures, electrical conductivities, thermal conductivities, and electroactive shape memory properties were investigated. According to our systematic analysis, the enhanced performance can be attributed to the reinforcement of MWNTs that led to the improved electrical and thermal conductivities of the PVA matrix. [ABSTRACT FROM AUTHOR]

Specimens of acidic multi-walled carbon nanotubes (AMWNTs) reinforced polyvinyl alcohol (PVA) nanocomposites (AMWNTs-PVA) were prepared using different amounts of AMWNTs by the traditional solution casting, involving ultrasonic wave agitation. The microstructures and tensile properties of AMWNTs-PVA were investigated by scanning electron microscopy, dynamic mechanical analysis, and quasi-static tensile testing. AMWNTs had good compatibility with PVA and dispersed evenly in the PVA matrix. The incorporation of AMWNTs improved the tensile modulus and strength of the PVA. The shape recovery testing revealed the shape recovery capacity of AMWNTs-PVA. It was observed that the recovery ratio increased, and the shape recovery rate slightly decrease with the increase of AMWNTs content. The results showed that the AMWNTs had strong interaction with the segments of the PVA and hence affected the shape recovery behavior of PVA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

In this paper, a solvent vapor-induced phase separation (SVIPS) technique was used to create a porous structure in polyvinylidene fluoride/Multi-walled carbon nanotube (PVDF/MWNTs) composites with the aim of increasing the electrical conductivity through the incorporation of MWNTs while retaining a low thermal conductivity. By using the dimethylformamide/acetone mixture, porous networks could be generated in the PVDF/MWNTs composites upon the rapid volatilization of acetone. The electrical conductivity was gradually enhanced by the addition of MWNTs. At the same time, the thermal conductivity of the PVDF film could be retained at 0.1546 W·m−1·K−1 due to the porous structure being even by loaded with a high content of MWNTs (i.e., 15 wt.%). Thus, the Seebeck coefficient, power factor and figure of merit (ZT) were subsequently improved with maximum values of 324.45 μV/K, 1.679 μW·m−1·K−2, and 3.3 × 10−3, respectively. The microstructures, thermal properties, and thermoelectric properties of the porous PVDF/MWNTs composites were studied. It was found that the enhancement of thermoelectric properties would be attributed to the oxidation of MWNTs and the porous structure of the composites. The decrease of thermal conductivity and the increase of Seebeck coefficient were induced by the phonon scattering and energy-filtering effect. The proposed method was found to be facile and effective in creating a positive effect on the thermoelectric properties of composites. [ABSTRACT FROM AUTHOR]