Polyaniline （PANI）/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, ...Polyaniline （PANI）/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, which indicated that PANI and face-centered-cubic silver were synthesized under γ-ray irradiation. The reaction mechanism were discussed, which revealed that the PANI was formed by the reaction of aniline cation radicals formed by the reaction of aniline cation and -OH, and Ag was formed by the reaction of Ag＋ and eaq. The morphology of the composite consisted of PANI nanofibers and Ag nanoparticles, and the mechanism of the morphology formation was discussed, which revealed that the rapid mixing like polymerization process might play an important role. It was revealed that the transport behavior of the composite well fitted with the variable-range-hopping model in 80-300 K and deviated from the model below 80 K.展开更多
Poly(vinylidene fluoride)(PVDF) is a semi-crystalline thermoplastic polymer with excellent thermal stability,electrochemical stability and corrosion resistance, which has been widely studied and applied in industrial ...Poly(vinylidene fluoride)(PVDF) is a semi-crystalline thermoplastic polymer with excellent thermal stability,electrochemical stability and corrosion resistance, which has been widely studied and applied in industrial nonmetallic heat exchanger and piezoelectric-film sensor. In this study, polyaniline(PANI) nanofibers were synthesized using dodecylbenzene sulfonic acid as the surfactant. The obtained PANI nanofibers were blended in PVDF matrix to enhance thermal conductivity and tensile strength of composite materials. Electric field was applied for the orientation of membrane structure during membrane formation. Scanning electron microscope(SEM) images exhibited that the PANI nanofibers were well-dispersed in the composite membranes. The structure of composite membranes was more orderly after alignment. X-ray diffraction(XRD) and differential scanning calorimetry(DSC) indicated that the content of PANI nanofibers contributed to the transformation of PVDF from α-phase to β-phase. Both the tensile strength and thermal conductivity of composite membranes were significantly improved. This tendency was further enhanced by the application of electric field. The maximum tensile strength was obtained when the content of PANI nanofibers was 3 wt%, which was 46.44% higher than that of pure PVDF membrane. The maximum thermal conductivity of composite membranes after alignment was 84.5% greater than that of pure PVDF membrane when the content of PANI nanofibers was 50 wt%. The composite membrane is a promising new potential material in heat transfer field and the mechanism explored in this study would be informative for further development of similar thermal conductive polymeric materials.展开更多
Electrospun nanofibers of a polyaniline(PANi)/(+)-camphor-10-sulfonic acid(HCSA)/poly(ethylene oxide)(PEO)composite doped with different variants of graphene oxide(GO)were fabricated and evaluated as chemiresistor gas...Electrospun nanofibers of a polyaniline(PANi)/(+)-camphor-10-sulfonic acid(HCSA)/poly(ethylene oxide)(PEO)composite doped with different variants of graphene oxide(GO)were fabricated and evaluated as chemiresistor gas sensors operating at room temperature.A new strategy for enhancing PANi/PEO gas sensor performance is demonstrated using GO dopants reduced via thermal(trGO)or chemical(crGO)routes.By varying the chemical reduction duration(6 h,crGO-6 or 24 h,crGO-24),tunable enhancement of sensor response was achieved.Upon exposure to short-chain aliphatic alcohol vapors,the partially reduced crGO-6 dopant exhibited higher response than GO and crGO-24,suggesting that the dopant enhances sensor performance via increased electrical conductivity over neat GO,and enhanced hydrogen bonding capability over the further-reduced crGO-24 variant.Sensor arrays consisting of PANi/PEO doped with trGO,crGO-6 or crGO-24 moieties successfully identified methanol,ethanol,and 1-propanol vapors using principal component analysis(PCA).展开更多
文摘Polyaniline （PANI）/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, which indicated that PANI and face-centered-cubic silver were synthesized under γ-ray irradiation. The reaction mechanism were discussed, which revealed that the PANI was formed by the reaction of aniline cation radicals formed by the reaction of aniline cation and -OH, and Ag was formed by the reaction of Ag＋ and eaq. The morphology of the composite consisted of PANI nanofibers and Ag nanoparticles, and the mechanism of the morphology formation was discussed, which revealed that the rapid mixing like polymerization process might play an important role. It was revealed that the transport behavior of the composite well fitted with the variable-range-hopping model in 80-300 K and deviated from the model below 80 K.
基金Supported by the Science and Technology Project of Tianjin(Grant No.12ZCZDSF02200)the Innovation Service Platform Project of Desalination and Comprehensive Utilization(Grant No.CXSF2014-34-C)
文摘Poly(vinylidene fluoride)(PVDF) is a semi-crystalline thermoplastic polymer with excellent thermal stability,electrochemical stability and corrosion resistance, which has been widely studied and applied in industrial nonmetallic heat exchanger and piezoelectric-film sensor. In this study, polyaniline(PANI) nanofibers were synthesized using dodecylbenzene sulfonic acid as the surfactant. The obtained PANI nanofibers were blended in PVDF matrix to enhance thermal conductivity and tensile strength of composite materials. Electric field was applied for the orientation of membrane structure during membrane formation. Scanning electron microscope(SEM) images exhibited that the PANI nanofibers were well-dispersed in the composite membranes. The structure of composite membranes was more orderly after alignment. X-ray diffraction(XRD) and differential scanning calorimetry(DSC) indicated that the content of PANI nanofibers contributed to the transformation of PVDF from α-phase to β-phase. Both the tensile strength and thermal conductivity of composite membranes were significantly improved. This tendency was further enhanced by the application of electric field. The maximum tensile strength was obtained when the content of PANI nanofibers was 3 wt%, which was 46.44% higher than that of pure PVDF membrane. The maximum thermal conductivity of composite membranes after alignment was 84.5% greater than that of pure PVDF membrane when the content of PANI nanofibers was 50 wt%. The composite membrane is a promising new potential material in heat transfer field and the mechanism explored in this study would be informative for further development of similar thermal conductive polymeric materials.
基金The authors would like to acknowledge financial support from United States NSF(CHE-1413449).
文摘Electrospun nanofibers of a polyaniline(PANi)/(+)-camphor-10-sulfonic acid(HCSA)/poly(ethylene oxide)(PEO)composite doped with different variants of graphene oxide(GO)were fabricated and evaluated as chemiresistor gas sensors operating at room temperature.A new strategy for enhancing PANi/PEO gas sensor performance is demonstrated using GO dopants reduced via thermal(trGO)or chemical(crGO)routes.By varying the chemical reduction duration(6 h,crGO-6 or 24 h,crGO-24),tunable enhancement of sensor response was achieved.Upon exposure to short-chain aliphatic alcohol vapors,the partially reduced crGO-6 dopant exhibited higher response than GO and crGO-24,suggesting that the dopant enhances sensor performance via increased electrical conductivity over neat GO,and enhanced hydrogen bonding capability over the further-reduced crGO-24 variant.Sensor arrays consisting of PANi/PEO doped with trGO,crGO-6 or crGO-24 moieties successfully identified methanol,ethanol,and 1-propanol vapors using principal component analysis(PCA).
