Study on thermal properties of poly(vinyl alcohol) and polyurethane composites with multiwalled carbon nanotubes/silica nanohybrids

2016 ◽  
Vol 30 (3) ◽  
pp. 404-415 ◽  
Author(s):  
Hongyan Xie ◽  
Qing Ye ◽  
Jin Liu ◽  
Guanglian Zhou ◽  
Wei Liu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Properties ◽  
Multiwalled Carbon Nanotubes ◽  
Vinyl Alcohol ◽  
Sol Gel ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Polyurethane Composites

Two kinds of multiwalled carbon nanotubes/silica nanohybrids (CNTs/SiO2) were synthesized via a sol–gel method by coating SiO2 on the surfaces of CNTs that had been functionalized with poly(sodium- p-styrenesulfonate) (PSS). The influence of the nanohybrids on the thermal properties of poly(vinyl alcohol) (PVA) and polyurethane (PU) composites was investigated. Characterization of CNTs/SiO2 nanohybrids, elucidated with scanning electron microscopy and X-ray diffraction, showed that PSS played a key role in the final morphology and resulted in a “core/shell” and “candied haws on a stick”-like structure. The thermal degradation and thermo-oxidation of PVA and PU composites evaluated by thermogravimetic analyses suggested that the thermal properties of PVA/(CNTs/SiO2) composites were improved at relative high temperature range when compared with pure PVA, and the improvement mainly depended on the loading fraction of the nanohybrids, while for PU/(CNTs/SiO2) composites, a small fraction of the nanohybrids increased the materials thermal properties, but the improvements were influenced by the type of CNTs/SiO2 nanohybrids.

scholarly journals Effects of Polymer Matrices and Carbon Nanotubes on the Generation of Electric Energy in a Microbial Fuel Cell

2018 ◽  
Author(s):  
Yulia Plekhanova ◽  
Sergey Tarasov ◽  
Vladimir Kolesov ◽  
Iren Kuznetsova ◽  
Maria Signore ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Power Density ◽  
Multiwalled Carbon Nanotubes ◽  
Vinyl Alcohol ◽  
Electric Energy ◽  
Poly Vinyl Alcohol ◽  
Bacterial Cells ◽  
Multiwalled Carbon

The anode of a microbial fuel cell (MFC) was formed on a graphite electrode and immobilized Gluconobacter oxydans VKM-1280 bacterial cells. Immobilization was performed in chitosan, poly(vinyl alcohol) or N-vinylpyrrolidone-modified poly(vinyl alcohol). Ethanol was used as substrate. The anode was modified using multiwalled carbon nanotubes. The aim of the modification was to create a conductive network between cell lipid membranes, containing exposed PQQ-dependent alcoholdehydrogenases, and the electrode to facilitate electron transfer in the system. The bioelectrochemical characteristics of modified anodes at various cell/polymer ratios were assessed via current density, power density, polarization curves and impedance spectres. MFCs based on chitosan at a matrix/cell volume ratio of 5:1 produced maximal power characteristics of the system (8.3 μW/cm2) at a minimal resistance (1111 Ohm cm2). Modification of the anode by multiwalled carbon nanotubes led to a slight decrease of internal resistance (down to 1078 Ohm cm2) and to an increase of generated power density up to 10.6 μW/cm2. We explored the possibility of accumulating electric energy from an MFC on a 6,800-μF capacitor via a boost converter. Generated voltage was increased from 0.3 V up to 3.2 V. Accumulated energy was used to power a Clark-type biosensor and a bluetooth transmitter with three sensors, a miniature electric motor and a light-emitting diode.

scholarly journals Effects of Polymer Matrices and Carbon Nanotubes on the Generation of Electric Energy in a Microbial Fuel Cell

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 99 ◽  
Author(s):  
Yulia Plekhanova ◽  
Sergei Tarasov ◽  
Vladimir Kolesov ◽  
Iren Kuznetsova ◽  
Maria Signore ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Power Density ◽  
Multiwalled Carbon Nanotubes ◽  
Microbial Fuel Cells ◽  
Vinyl Alcohol ◽  
Electric Energy ◽  
Poly Vinyl Alcohol ◽  
Multiwalled Carbon

The anode of a microbial fuel cell (MFC) was formed on a graphite electrode and immobilized Gluconobacter oxydans VKM-1280 bacterial cells. Immobilization was performed in chitosan, poly(vinyl alcohol) or N-vinylpyrrolidone-modified poly(vinyl alcohol). Ethanol was used as substrate. The anode was modified using multiwalled carbon nanotubes. The aim of the modification was to create a conductive network between cell lipid membranes, containing exposed pyrroloquinoline quinone (PQQ)-dependent alcoholdehydrogenases, and the electrode to facilitate electron transfer in the system. The bioelectrochemical characteristics of modified anodes at various cell/polymer ratios were assessed via current density, power density, polarization curves and impedance spectres. Microbial fuel cells based on chitosan at a matrix/cell volume ratio of 5:1 produced maximal power characteristics of the system (8.3 μW/cm2) at a minimal resistance (1111 Ohm cm2). Modification of the anode by multiwalled carbon nanotubes (MWCNT) led to a slight decrease of internal resistance (down to 1078 Ohm cm2) and to an increase of generated power density up to 10.6 μW/cm2. We explored the possibility of accumulating electric energy from an MFC on a 6800-μF capacitor via a boost converter. Generated voltage was increased from 0.3 V up to 3.2 V. Accumulated energy was used to power a Clark-type biosensor and a Bluetooth transmitter with three sensors, a miniature electric motor and a light-emitting diode.

scholarly journals Electrically Conductive Nanocomposites Polymer of Poly(Vinyl Alcohol)/Glutaraldehyde/Multiwalled Carbon Nanotubes: Preparation and Characterization

2018 ◽  
Vol 18 (3) ◽  
pp. 383 ◽  
Author(s):  
Fitri Khoerunnisa ◽  
Hendrawan Hendrawan ◽  
Yaya Sonjaya ◽  
Rizki Deli Hasanah
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Polymer Matrix ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Electrically Conductive ◽  
X Ray ◽  
Conductive Nanocomposites

Electrically conductive nanocomposites polymer of poly(vinyl alcohol)/PVA, glutaraldehyde (GA) and multiwalled carbon nanotubes (MWCNT) has been successfully synthesized. The polymer nanocomposites were prepared by mixing PVA, GA (crosslinker), and MWCNT dispersion with an aid of ultrasonic homogenizer at 50 °C. The content of MWCNT, in particular, was varied in order to determine the effect of MWCNT on electrical conductivity of polymer composites. The polymer mixture was casted into a disc to obtain thin film. The electrical conductivity, surface morphology, and mechanical properties of the composites film were investigated by means of four probes method, FTIR spectroscopy, X-ray diffraction, SEM, AFM, and tensile strength measurement, respectively. It was found that the optimum composition of PVA (10%): GA (1%): MWCNT (1%) was 20:20:3 in volume ratio. The addition of MWCNT induced the electrically conductive network on polymer matrix where the electrical conductivity of nanocomposites film significantly increased up to 8.28 x 10-2 S/sq due to reduction of the contact resistance between conductive filler. Additionally, the mechanical strength of nanocomposites polymer were significantly increased as a result of MWCNT addition. Modification of morphological structure of composite film as indicated by FTIR spectra, X-ray diffraction patterns, SEM, and AFM images verified the effective MWCNT filler network in the polymer matrix.

Synthesis and characterization of chiral poly(amide-imide) composite thin films containing functionalized multiwalled carbon nanotubes

2018 ◽  
Vol 32 (1) ◽  
pp. 76-88 ◽  
Author(s):  
Zahra Rafiee ◽  
Milad Kolaee
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Composite Films ◽  
Analysis Data ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Malachite Green Dye ◽  
Transmission Electron ◽  
Functionalized Multiwalled Carbon Nanotubes

The chiral poly(amide-imide) (PAI) was synthesized by the direct polycondensation reaction of imide-dicarboxylic acid, N-trimellitylimido-l-phenylalanine with diamine and 1,5-naphthalenediamine. Multiwalled carbon nanotubes (MWCNTs)/polymer composite films were prepared via dispersing of acid-functionalized MWCNTs (MWCNT-COOH) as reinforcement at MWCNT loadings of 5, 10, and 15 wt%. The PAI/MWCNT composite films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and transmission electron microscopy (TEM). The TEM results confirmed that the carboxylated MWCNTs were well dispersed in the polymer matrix. The thermogravimetric analysis data showed an improvement of thermal stability of composites containing the MWCNT as compared to the pure polymer. In this research, PAI/MWCNT composite 15 wt% was used as a novel and efficient adsorbent for removal of malachite green dye from aqueous solution.

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