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1.
The study presents preparation of poly methyl methacrylate (PMMA) based nanocomposite gel polymer electrolytes consisting of, salt lithium perchlorate (LiClO4), plasticizer PC/DEC and different proportions of SiO2 nanofiber by solution casting process. The effect of the composition of the electrolytes on their ionic, mechanical and thermal characteristics was investigated. Morphology of the nanocomposite electrolyte films has been observed by scanning and transmission electron microscopes. Interactions among the constituents of the composite and structural changes of the base polymer were investigated by Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. The maximum conductivity i.e. 10?3 Scm?1 at room temperature is obtained with the electrolyte composition of 0.6(PMMA)-0.15(PC + DEC)-0.1LiClO4 (wt%) containing 10 wt% SiO2 nanofiber and the temperature dependent conductivity data of the electrolyte follows Vogel-Tamman-Fulcher (VTF) behavior.  相似文献   

2.
Polythiophene/chitosan (PT/Ch) composites and PT homopolymers were chemically synthesized in the presence of anthraquinone‐2‐sulfonic acid sodium monohydrate, ACS anionic surfactant. Conductivity, FTIR, SEM, TGA, and XRD measurements were used to study the properties of the composites. The effect of the ratio of the surfactant to the Ch onto structural and physical properties of the composites was also investigated. Our experimental data show that the properties of the composites depend on the amount of both surfactant and Ch used. The highest conductivity of 9.62 × 10?3 S/cm?1 was measured for the PT/Ch2 sample. When measurements were taken for PT/Ch/ACS samples with different Ch and surfactants content, the highest conductivity and initial decomposition temperature were recorded for the PT/Ch2/ACS10 sample as 3.49 × 10?4 S/cm?1, 223°C, respectively. POLYM. ENG. SCI., 54:2632–2640, 2014. © 2013 Society of Plastics Engineers  相似文献   

3.
Composite membranes of sulfonated poly(ethersulfone)/1,1-carbonyl diimidazole/1-(3-aminopropyl)-silane/silica (SPES/CDI/AS/SiO2) with silica of various contents (3, 5 and 8 wt%) were prepared as electrolytes for direct methanol fuel cells (DMFCs). Comparison was made with pure SPES and SPES/SiO2. The properties of the composite membranes were studied by FTIR, TGA, XRD, water and methanol uptake, proton conductivity. SPES/CDI/AS/SiO2 membranes were also characterized by scanning electron microscopy (SEM), which showed good adhesion between the modified sulfonic acid (-SO3H) groups of SPES and silica because of cross-linking with covalent bond formation and reduced cavities in the composites. This effect played an important role in reducing water uptake, methanol uptake and methanol permeability of the SPES/CDI/AS/SiO2 composites. The water and methanol uptake and also methanol permeability of the SPES/CDI/AS/SiO2 composite membrane with 8% SiO2 were found in the order 3.58%, 2.48% and 1.91×10?7 (cm2s?1), lower than those of SPES and Nafion 117. In SPES membrane of 16.94% level of sulfonation, the proton conductivity was 0.0135 s/cm at 25 °C, which approached that of Nafion 117 under the same conditions. Also, the proton conductivity of the SPES/CDI/AS/SiO2 8% membrane was 0.0186 s/cm, which was higher than that of SPES at room temperature. The preparation of SPES/SiO2 composites in the presence of AS and CDI, led to 63%, 56% and 64% reduction of water uptake, methanol uptake and methanol permeability, respectively without a sharp drop in proton conductivity of the composite membranes which featured a good balance between high proton conductivity, water and methanol uptake of SPES/CDI/AS/SiO2 membranes.  相似文献   

4.
Nanocomposite polymer electrolytes (NCPE) were prepared using nano polyethylene oxide PEO doped with Magnesium (Mg) salts. Gamma irradiation was utilized to improve the PEO‐Mg salts particle sizes. Consequently, Magnesium Oxide (MgO) nanoparticles were prepared by green synthesis and incorporated into PEO‐Mg salts to improve their properties toward magnesium battery electrolyte applications. The prepared samples were examined before and after exposures to the radiation doses. Dynamic light scattering (DLS) indicated the particles size of the synthesized nano polymer‐Mg salts and MgO nanoparticles. Fourier transform infra‐red (FTIR) spectroscopic measurements, transmission electron microscopy (TEM), electrical conductivity, electrochemical properties, and thermal stability of the samples were determined. FTIR indicated the interaction between PEO with Mg salts and MgO nanoparticles which confirmed the structure. The TEM results showed a spherical nanoparticles of MgO and a good dispersion of MgO in PEO matrix. It was found that the irradiation dose 70 kGy gave the best results for the nano polymer‐Mg salts (13 nm). The electrical conductivity (σ) evaluated for NCPE, was more than three orders of magnitude of pure PEO. The liquid NCPE of 20 mL MgO NPs at 100 kGy exhibited a maximum conductivity of 3.63 × 10–3 Scm?1 at room temperature. The increase in temperature caused a slight effect on conductivity, 4.85 × 10–3 Scm?1 at temperature 250°C, at the same concentration. While un‐irradiated sample of 30 mL MgO NPs (σ) reached to 3.8 × 10?3 Scm?1 then became 5.03 × 10?3 Scm?1 by increasing temperature. From the cyclic voltammetry results, the polymer electrolytes containing MgO filler, 20 and 30 mL, for irradiated and un‐irradiated samples, respectively exhibited wider electrochemical stability window than the others due to the appearance of Mg deposition/desolution peak in CV curve showed that magnesium effectively migrating through electrolytes. Thermogravimetric analysis (TGA) was enhanced by adding Mg salts electrolyte and also MgO nanoparticles to PEO. J. VINYL ADDIT. TECHNOL., 25:243–254, 2019. © 2018 Society of Plastics Engineers  相似文献   

5.
Electrospun poly[(vinylidene fluoride)‐co ‐hexafluoropropylene]/silica (PVdF‐HFP/SiO2) nanocomposite polymer membranes (esCPMs) were prepared by incorporating different weight percentages of SiO2 nanoparticles onto electrospun PVdF‐HFP by electrospinning technique. The surface morphology of electrospun PVdF‐HFP nanocomposite membranes was characterized by scanning electron microscopy. The effect of SiO2 nanoparticles incorporation onto electrospun PVdF‐HFP polymer membranes (esPMs) has been studied by XRD, DSC, TGA, and tensile analysis. The electrospun PVdF‐HFP/SiO2 based nanocomposite membrane electrolytes (esCPMEs) were prepared by soaking the corresponding esCPMs into 1 M LiPF6 in EC:DMC (1:1 vol/vol %). The ionic conductivity of the esCPMEs was studied by AC‐impedance studies and it was found that the incorporation of SiO2 nanoparticles into PVdF‐HFP membrane has improved the ionic conductivity from 1.320 × 10?3 S cm?1 to 2.259 × 10?3 S cm?1. The electrochemical stability of the esCPME was studied by linear sweep voltammetry studies and it was found to be 2.87 V. Finally, a prototype LiCo0.2Mn1.8O4//C Li‐ion capacitor (LIC) cell was fabricated with esCPME, which delivered a discharge capacitance of 128 F g?1 at the current density of 1 A g?1 and retained 86% of its discharge capacitance even after 10,000 cycles. These results demonstrated that the esCPMEs could be used as promising polymer membrane electrolyte for LICs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45177.  相似文献   

6.
Nanoparticles of polypyrrole (PPy) in 40/60 wt % natural rubber (NR)–polystyrene (PS) blends were synthesized by emulsion polymerization using ferric sulfate [Fe2 (SO4)3], sodium dodecyl sulfate (SDS), and n‐amyl alcohol as the oxidant, surfactant, and cosurfactant, respectively. The NR/PS/PPy blends were characterized by Fourier transform infrared spectroscopy (FTIR), elemental analysis, thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FESEM). FESEM micrographs showed that NR/PS/PPy blends were homogeneous, and PPy nanoparticles were well distributed throughout the binary matrix of NR/PS. The size of PPy particles in the blends was in the range of 26–80 nm. The electrical conductivities of the pellets prepared from NR/PS/PPy blends increased as the composition of PPy nanoparticles was increased, which were in the range of 8.9 × 10?8 – 2.89 × 10?4 S/cm. Thermal stability of the blends increased as the content of PPy was increased, as shown by TGA thermograms. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

7.
Summary: We have prepared waterborne polyurethane (WBPU) thin films containing gold nanoparticles by casting WBPU/Au solutions. The effect of the Au nanoparticle contents on the microstructure and properties of the composite films was investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), field emission scanning electron microscopy (FESEM), transmittance electron microscopy (TEM), FTIR spectroscopy (FTIR) and dynamic mechanical analysis (DMA). The Au nanoparticles initially in the WBPU solution were well dispersed in the WBPU films cast and dried at 60 °C. The thermostability and mechanical properties of the polymer increased with Au contents up to 4.35 × 10?2 wt.‐%, which was believed to be a result of induced crystallization in the presence of Au nanoparticles. The Au/WBPU nanocomposite containing with 6.5 × 10?2 wt.‐% of Au resulted in the aggregation of Au particles, which leads to a worsening of the thermal and mechanical properties.

TEM micrograph of nanocomposites filled with 4.35 × 10?2 wt.‐% of Au nanoparticles.  相似文献   


8.
A series of sulfonated poly(ether sulfone) (SPES)/silica composite membranes were prepared by sol–gel method using tetraethylorthosilicate (TEOS) hydrolysis. Physico–chemical properties of the composite membranes were characterized by thermogravimetric analysis (TGA), X‐ray diffraction (XRD), scanning electron microscope–energy dispersive X‐ray (SEM–EDX), and water uptake. Compared to a pure SPES membrane, SiO2 doping in the membranes led to a higher thermal stability and water uptake. SEM–EDX indicated that SiO2 particles were uniformly embedded throughout the SPES matrix. Proper silica loadings (below 5 wt %) in the composite membranes helped to inhibit methanol permeation. The permeability coefficient of the composite membrane with 5 wt % SiO2 was 1.06 × 10?7 cm2/s, which was lower than that of the SPES and just one tenth of that of Nafion® 112. Although proton conductivity of the composite membranes decreased with increasing silica content, the selectivity (the ratio of proton conductivity and methanol permeability) of the composite membrane with 5 wt % silica loading was higher than that of the SPES and Nafion® 112 membrane. This excellent selectivity of SPES/SiO2 composite membranes could indicate a potential feasibility as a promising electrolyte for direct methanol fuel cell. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

9.
A new class of PANI/Sn(II)SiO3/FCNTs nanocomposite was synthesized by mixing polyaniline into the gel of Sn(II)SiO3 followed by FCNTs (Polyaniline/Sn(II)SiO3/Functionalized Carbon nanotubes). The physico-chemical characterization was carried out by scanning electron microscope, XRD (X-ray Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), ultraviolet–visible spectroscopy, and simultaneous thermogravimetric analysis studies. The ion-exchange capacity (1.2 meq/g) and distribution studies were also determined to understand the ion-exchange capabilities. The DC electrical conductivity studies revile it in the range of 3–5 × 10?3 S/cm. On the basis of distribution studies, ion-selective membrane electrode was designed for Hg(II). The analytical utility of this membrane was established by using it as an indicator electrode in electrometric titrations.  相似文献   

10.
The polymer electrolytes comprising of PVdF-HFP/PVAc/Mg(ClO4)2 as salt based polymer blend electrolytes derived from the addition of varying amounts of 1-ethyl – 3-methylimidazolium trifluoromethane sulfonate [EMITF], as dopant were synthesized in the form of films by solution-casting method. The XRD and FTIR patterns confirm the formation of an amorphous phase and also that complex formation between the polymers, salt and ionic liquid. The SEM images show that the polymer electrolyte exhibit a enormous pores, remarkably, the maximum ionic conductivity is obtained in the case of the typical polymer system I3 is found to be 9.122 × 10?4 Scm?1at 303 K.  相似文献   

11.
Sodium lithium sulfide (NaLiS) nanocomposite have been successfully synthesized by using microwave-irradiation (MWI) method. The study suggested that the application of microwave heating is to produce homogeneous and fine NaLiS nanocomposite which were achieved by using the precursors of lithium acetate and thioacetamide in the presence of sodium alginate biopolymer. FTIR is used to identify the structural coordination and functional groups of the prepared nanocomposite. The structural property of NaLiS particles was investigated by XRD. The surface morphology and elemental composition of synthesized material was confirmed by SEM and EDX analyses. The optical property was studied by using UV–Vis spectrophotometer. Thermal stability of as prepared sample was studied by TGA/DTG analysis. Electrical transport studies of the prepared nanocomposite have been analyzed for various temperatures. NaLiS nanocomposite has ionic conductivity of ~?10?7 S cm?1 at 35 °C which is six orders of magnitude higher than that of micro sized bulk Li2S (~?10?13 S cm?1).  相似文献   

12.
In this study, the polyethylene oxide (PEO)/SiO2 nanoparticles (NPs) nanocomposite films with various SiO2 NPs concentrations were prepared using an in situ formation of NPs in the polymer matrix for self-cleaning antireflected surface applications. The effect of SiO2 NPs in PEO/SiO2 NPs nanocomposite films on the structural, morphological, chemical, thermal, optical, and electrical properties of PEO/SiO2 NPs nanocomposite films was performed. According to the x-ray diffraction and the differential scanning calorimetry analysis, the crystallinity degree of the nanocomposite films decreases by increasing the SiO2 NPs concentrations. The bandgap energy of PEO/SiO2 NPs nanocomposite films decreases from 3.95 to 3.55 eV as the SiO2 NPs concentration increases up to 10 wt.%. The average electrical conductivity of the PEO/SiO2 NPs nanocomposite films increases from 5.1 × 10−7 to 2.0 × 10−6 S/cm as the SiO2 NPs concentration increases up to 10 wt.%. The refractive index decreases to 1.64 at 550 nm for the PEO/SiO2 NPs nanocomposite films with 10 wt.% of SiO2 NPs, and the water contact angle decreases to around 0° after thermal treatment, which confirms that the PEO/SiO2 NPs nanocomposite films can be used as self-cleaning antireflected surfaces.  相似文献   

13.
Three new polyazomethines having phenylthiourea groups were synthesized through solution polycondensation of terephthalaldehyde with 4,4′-bis(thiourea)biphenyl ether, 4,4′-bis(thiourea)biphenylmethane, and 4,4′-bis(thiourea)biphenyl sulphone. For comparison purposes, simple polyazomethines were prepared by the polycondensation of terephthalaldehyde with 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl sulphone. Poly(imine)s having phenylthiourea groups were characterized through IR and 1H-NMR spectroscopic methods and the thermal stability of the polymers were evaluated through TGA analysis. Conductivity of polyaniline synthesized in aqueous p-toluenesulfonic acid was found to be 3.83 Scm?1. The conductivity of the polymeric blends with polyaniline dopped with p-toluenesulfonic acid and HCl (20% by weight) were found to be in the range 0.16 × 10?3 ? 5.7 × 10?3 Scm?1.  相似文献   

14.
A water‐dispersible conducting polyaniline/ nano‐SiO2 composite, with a conductivity of 0.071 S cm?1 at 25°C, was prepared by the oxidative polymerization of aniline in the presence of amorphous nano‐SiO2 particles. And the structure, morphology, thermal stability, conductivity, and electroactivity of this composite were also investigated. This composite has been steadily dispersed in the aqueous solution for about 10–36 h without the need for any stabilizer. It would significantly impulse the commercial applications of conducting polyaniline/nano‐SiO2 composite as fillers for antistatic and anticorrosion coatings. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

15.
Spherical nickel oxide (NiO) nanoparticles were prepared by using nickel chloride as precursor in the ethylene glycol as solvent and urea as precipitant. The X‐ray diffraction study showed that NiO has single‐phase cubic structure with average crystallite size of 35 nm. The prepared NiO nanoparticles were incorporated into polyaniline (PANI) matrix during in situ chemical oxidative polymerization of aniline with different molar ratios of aniline: NiO (12 : 1, 6 : 1, and 3 : 1) at 5°C using (NH4)2S2O8 as oxidant in aqueous solution of sodium dodecylbenzene sulfonic acid, as surfactant and dopant under N2 atmosphere. The synthesized composites have been characterized by means of X‐ray diffraction (XRD), thermogravimetric analysis, Fourier transform infrared (FTIR), scanning electron microscopy, TEM, and vibrating sample magnetometer for its structural, thermal, morphological, and magnetic investigation. The XRD and FTIR studies show that the NiO particles are in the composite. The room temperature conductivities of the synthesized PANI, PANI/NiO (12 : 1), (6 : 1), and (3 : 1) composites were found to be 3.26 × 10?4, 1.88 × 10?4, 1.5 × 10?4, and 4.61 × 10?4 S/cm, respectively. The coercivity (Hc) and remnant magnetization (Mr) of NiO, PANI/NiO NCs (12 : 1), (6 : 1), and (3 : 1) at 5 K was found to be 8.22 × 10?2, 6.31 × 10?2, 6.42 × 10?2, 6.27 × 10?2 T, and 6.64 × 10?3, 1.83 × 10?4, 3.07 × 10?4, and 3.98 × 10?4 emu/g, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

16.
Waterborne polyurethane/polydopamine (PDA) functional reduced graphene oxide (WPU/PDRGO) nanocomposites were prepared by in situ emulsification method. The presence of a PDA layer and the partial reduction of GO by PDA were confirmed by FTIR, XRD, Raman spectra, and TGA. It was found that the interfacial PDA layers facilitated the dispersion of the PDRGO sheets in the WPU matrix and enhanced mechanical properties of the WPU matrix. The resulting WPU/PDRGO nanocomposite coatings show excellent electrical conductivity (9.9?×?10?6–1.1?×?10?4 S cm?1) corresponding to a PDRGO content of 1–16 wt%. The obtained waterborne polyurethane/graphene nanocomposite dispersions are promising for anticorrosion, antistatic, conductive, and electromagnetic interference shielding coatings.  相似文献   

17.
This paper reports the dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and ionic conductivity studies on nanosized Al2O3(aluminium oxide) filled PVA:NH4SCN:DMSO polymer composite dried gel electrolytes prepared by the wet chemistry route. Better mechanical stability and thermal behavior are noticed in the composite system. Multiple relaxation peaks seen in tangent loss measurements (in DMA studies) have been suitably correlated. Enhancement in ionic conductivity has been noticed with an optimum value of 4.02 × 10?3 Scm?1 for 4 wt% nano Al2O3 filled composite electrolytes. Temperature dependence of ionic conductivity shows a combination of Arrhenius and VTF (Vogel-Tamman-Fulcher) behavior.  相似文献   

18.
Crosslinked hydroxyl‐conductive copolymer/silica composite membranes based on addition‐type polynorbornene, poly(dodoxymethylene norbornene‐co‐norbornene‐3‐(trimethylpropyl ammonium)‐functionalized silica (QP(DNB/NB‐SiO2), were prepared by a sol–gel method. Copolymer composite membranes with different degree of quaternary ammonium functional silica, designated as QP(DNB/NB‐SiO2‐X) (X = 5, 10, 15 and 25 wt%, respectively), displayed good dimensional stabilities with low in‐plane swelling rate of 1.32–3.7%, good mechanical properties with high elastic modulus of 605.4–756.8 MPa and high tensile strength of 13.2–20 Mpa. The achieved copolymer composite membranes could self‐assemble into a microphase‐separated morphology with randomly oriented long‐range aliphatic chain/cylinder ionic channels that were imbedded in the hydrophobic PNB matrix. Among these membranes, the QP(DNB/NB‐SiO2‐25) showed the parameter with ionic conductivity of 9.33 × 10?3S cm?1, methanol permeability of 2.89 × 10?7cm2 s?1, and ion‐exchange capacity(IEC) of 1.19 × 10?3 mol g?1. A current density of 82.3mA cm?2, the open circuit voltage of 0.65 V and a peek power density of 32 mW cm?2 were obtained. POLYM. ENG. SCI., 58:13–21, 2018. © 2017 Society of Plastics Engineers  相似文献   

19.
Conductive chitosan/polypyrrole composite fibers (CS-PPy) were fabricated through pyrrole polymerization on chitosan fibers by in situ oxidation, in which chitosan fibers were obtained by the wet spinning method. The structures, the morphologies and the electroactivities of CS-PPy were characterized by FTIR, SEM, TGA, the four-probe technique and cyclic voltammetry (CV). Results showed that the diameter, thermal stability and electrical conductivity of the fiber were affected by pyrrole polymerization times. Electrical conductivity values of CS-PPy were varied from 1.60 × 10?5 to 1.31 × 10?4 S cm?1. CV of the conductive fibers presents an oxidation peak at 0.25 V in pH 7.0 PBS. Such biodegradable conductive fibers may provide new electrical stimulation materials in biomedical applications.  相似文献   

20.
Nanosize polyacrylamide/silica (PAM/SiO2) composites were prepared by water- in-oil (W/O) microemulsion process. In this system, aqueous solution of acrylamide containing disperse 10 nm size silicon dioxide was used as the dispersed phase of the microemulsion while the dispersion medium was sodium bis (2-ethylhexyl) sulfosuccinate (AOT)/toluene solution. The size of the synthesized PAM/SiO2 nanocomposites was 38–76 nm as determined by dynamic light scattering (DLS). The incorporation of nanosize silica filler reduces the particle size of PAM latex. It had also been found that the size of composite particles decreases with increasing filler loading along with better polydispersity. The presence of silica particles in the polymer latex particles and interaction of polymer chains with silica particles in hybrid nanocomposites were characterized by Fourier transform infra red spectrophotometry (FTIR), thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). The TGA results showed improved thermoresistance and high thermal stability behavior of hybrid composites. The DSC measurements revealed that the incorporation of filler favors crystallization, increases the enthalpy of melting and thermal stabilization of the synthesized composite particles. A scanning electron microscope (SEM) was used to study the morphology and topography of the prepared nanocomposites.  相似文献   

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