Structure-property relationships for poly（vinylidene fluoride）-graft-polystyrene sulfonic acid （PVDF-g-PSSA） fuel cell membranes prepared by a single step method involving radiation-induced grafting of sodium styr...Structure-property relationships for poly（vinylidene fluoride）-graft-polystyrene sulfonic acid （PVDF-g-PSSA） fuel cell membranes prepared by a single step method involving radiation-induced grafting of sodium styrene sulfonate （SSS） onto electron beam （EB） irradiated poly（vinylidene fluoride） （PVDF） films were established. The physico-chemical properties of the membranes such as ion exchange capacity, water swelling and proton conductivity were correlated with the degree of grafting （G, %） and the structural changes taking place in the membrane matrix during the preparation procedure. The variation in the crystallinity and the thermal stability of membranes was studied by differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA）, respectively. The membranes were found to undergo substantial structural changes in forms of ionic sites increase, hydrophilicity enhancement, hydrophobicity reduction and crystallinity decrease with the variation in G （%） and the preparation method. The structural and thermal properties of the obtained membranes were also compared with their counterparts prepared by a conventional two-steps method i.e. radiation induced grafting of styrene onto EB irradiated PVDF films followed by sulfonation. The PVDF-g-PSSA membranes obtained by a single-step method were found to have superior properties compared to those obtained by the conventional two-steps method.展开更多
Acrylonitrile-sodium styrene sulfonate copolymer/layered double hydroxides nanocomposites were prepared by in situ aqueous precipitation copolymerization of acrylonitrile （AN） and sodium styrene sulfonate （SSS） in...Acrylonitrile-sodium styrene sulfonate copolymer/layered double hydroxides nanocomposites were prepared by in situ aqueous precipitation copolymerization of acrylonitrile （AN） and sodium styrene sulfonate （SSS） in the presence of 4-vinylbenzene sulfonate intercalated layered double hydroxides （MgA1-VBS LDHs） and transferred to acrylonitrile-styrene sulfonic acid （AN-SSA） copolymer/LDHs nanocomposites as a proton-conducting polymer electrolyte. MgA1-VBS LDHs were prepared by a coprecipitation method, and the structure and composition of MgAl-VBS LDHs were determined by X-ray diffraction （XRD）, infrared spectroscopy, and elemental analysis. X-ray diffraction result of AN-SSS copolymer/LDHs nanocomposites indicated that the LDHs layers were well dispersed in the AN-SSS copolymer matrix. All the AN-SSS copolymer/LDHs nanocomposites showed significant enhancement of the decomposition temperatures compared with the pristine AN-SSS copolymer, as identified by the thermogravimetric analysis. The methanol crossover was decreased and the proton conductivity was highly enhanced for the AN-SSA copolymer/LDHs nanocomposite electrolyte systems. In the case of the nanocomposite electrolyte containing 2% （by mass） LDHs, the proton conductivity of 2.60×10^- 3 S·m^-1 was achieved for the polymer electrolyte.展开更多
Stable poly（styrene-co-sodium styrene sulfonate） （P（St-NaSS） nanoparticles with broader size distribution were synthesized by thermal emulsion polymerization without any conventional initiators and emulsifiers. T...Stable poly（styrene-co-sodium styrene sulfonate） （P（St-NaSS） nanoparticles with broader size distribution were synthesized by thermal emulsion polymerization without any conventional initiators and emulsifiers. The obtained polymer nanoparticles have higher potential, and the particle sizes have broad distribution. The stability of polymer particles originated from the addition of small amounts of ionic comonomer, NaSS, which can act as an emulsifier in somewhat. The monomer conversion could reach up to about 28 wt% in 48 h, and did not increase by further polymerization when higher polymerization temperature （120℃） was employed. This polymerization system may be give some further understand for mechanism of emulsion polymerization.展开更多
An increase of work function （0.3 eV） is achieved by irradiating poly（3,4-ethylenedioxythiophene）：poly（styrene sul- fonate） （PEDOT：PSS） film in vacuum with 254-nm ultraviolet （UV） light. The mechanism for ...An increase of work function （0.3 eV） is achieved by irradiating poly（3,4-ethylenedioxythiophene）：poly（styrene sul- fonate） （PEDOT：PSS） film in vacuum with 254-nm ultraviolet （UV） light. The mechanism for such an improvement is investigated by photoelectron yield spectroscopy, X-ray photo electron energy spectrum, and field emission technique. Sur- face oxidation and composition change are found as the reasons for work function increase. The UV-treated PEDOT：PSS film is used as the hole injection layer in a hole-only device. Hole injection is improved by UV-treated PEDOT：PSS film without baring the enlargement of film resistance. Our result demonstrates that UV treatment is more suitable for modifying the injection barrier than UV ozone exposure.展开更多
Silver nanowire(AgNW)has become one of the best candidates for flexible transparent electromagnetic(EMI)shielding materials,while the low corrosion resistance of AgNW hinders its application in environments with high ...Silver nanowire(AgNW)has become one of the best candidates for flexible transparent electromagnetic(EMI)shielding materials,while the low corrosion resistance of AgNW hinders its application in environments with high content of corrosive substances.Herein,an AgNW/poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate)(PEDOT:PSS)@nickel electrode was prepared through ultrasonic spray coating and electroplating methods.PEDOT:PSS is sprayed to improve the conductivity of the AgNW network,and a 9.8-16.5 nm Ni layer is deposited on the AgNW/PEDOT:PSS to protect the AgNWs from corrosion.The AgNW/PEDOT:PSS@Ni electrode shows a sheet resistance of 29 U·sq^(-1),a transmittance of 78.18%,an average EMI shielding efficiency of 19.64 dB and excellent corrosion resistance in Na2S solution.The resultant AgNW/PEDOT:PSS@Ni electrode is promisingly used in high corrosion resistance transparent EMI shielding film.展开更多
Flexible pressure sensors are indispensable components in wearable electronics for health monitoring and exercise management.However,existing pressure sensors face a critical trade-off between high sensitivity and wid...Flexible pressure sensors are indispensable components in wearable electronics for health monitoring and exercise management.However,existing pressure sensors face a critical trade-off between high sensitivity and wide detection range.Herein,we present novel flexible pressure sensors based on poly(3,4-ethylenedioxy-thiophene):poly(styrene sulfonate)(PEDOT:PSS)and thermoplastic polyurethane(TPU),fabricated by direct ink writing(DIW)technology with a sacrificial template strategy.The integration of the high conductivity of PEDOT:PSS,the mechanical durability of TPU,and the engineered hierarchical porous structure with irregular surface topography enables the PEDOT:PSS/TPU-based pressure sensors(PPSs)to achieve an exceptionally wide detection range(0-1044 kPa),high sensitivity(30.178 kPa^(−1)),and outstanding cycling stability(over 10,000 cycles).Leveraging these advantages,the sensors have demonstrated exceptional performance in precise physiological monitoring,effective pressure mapping through sensor arrays,and reliable operation in extreme environments(e.g.,cryogenic conditions at−196°C and underwater).Furthermore,the successful integration with LED circuits and wireless Bluetooth systems highlights their potential for next-generation wearable electronics and personalized healthcare monitoring.展开更多
基金support from the Malaysian Ministry of Science, Technology and Innovation(MOSTI) under Science Fund programThe authors also wish to thank International Atomic Energy Agency(IAEA) for the partial support under the Coordinated Research Projects(CRP) program.
文摘Structure-property relationships for poly（vinylidene fluoride）-graft-polystyrene sulfonic acid （PVDF-g-PSSA） fuel cell membranes prepared by a single step method involving radiation-induced grafting of sodium styrene sulfonate （SSS） onto electron beam （EB） irradiated poly（vinylidene fluoride） （PVDF） films were established. The physico-chemical properties of the membranes such as ion exchange capacity, water swelling and proton conductivity were correlated with the degree of grafting （G, %） and the structural changes taking place in the membrane matrix during the preparation procedure. The variation in the crystallinity and the thermal stability of membranes was studied by differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA）, respectively. The membranes were found to undergo substantial structural changes in forms of ionic sites increase, hydrophilicity enhancement, hydrophobicity reduction and crystallinity decrease with the variation in G （%） and the preparation method. The structural and thermal properties of the obtained membranes were also compared with their counterparts prepared by a conventional two-steps method i.e. radiation induced grafting of styrene onto EB irradiated PVDF films followed by sulfonation. The PVDF-g-PSSA membranes obtained by a single-step method were found to have superior properties compared to those obtained by the conventional two-steps method.
基金Supported by Program for New Century Excellent Talents in University(NCET-07-0738)
文摘Acrylonitrile-sodium styrene sulfonate copolymer/layered double hydroxides nanocomposites were prepared by in situ aqueous precipitation copolymerization of acrylonitrile （AN） and sodium styrene sulfonate （SSS） in the presence of 4-vinylbenzene sulfonate intercalated layered double hydroxides （MgA1-VBS LDHs） and transferred to acrylonitrile-styrene sulfonic acid （AN-SSA） copolymer/LDHs nanocomposites as a proton-conducting polymer electrolyte. MgA1-VBS LDHs were prepared by a coprecipitation method, and the structure and composition of MgAl-VBS LDHs were determined by X-ray diffraction （XRD）, infrared spectroscopy, and elemental analysis. X-ray diffraction result of AN-SSS copolymer/LDHs nanocomposites indicated that the LDHs layers were well dispersed in the AN-SSS copolymer matrix. All the AN-SSS copolymer/LDHs nanocomposites showed significant enhancement of the decomposition temperatures compared with the pristine AN-SSS copolymer, as identified by the thermogravimetric analysis. The methanol crossover was decreased and the proton conductivity was highly enhanced for the AN-SSA copolymer/LDHs nanocomposite electrolyte systems. In the case of the nanocomposite electrolyte containing 2% （by mass） LDHs, the proton conductivity of 2.60×10^- 3 S·m^-1 was achieved for the polymer electrolyte.
文摘Stable poly（styrene-co-sodium styrene sulfonate） （P（St-NaSS） nanoparticles with broader size distribution were synthesized by thermal emulsion polymerization without any conventional initiators and emulsifiers. The obtained polymer nanoparticles have higher potential, and the particle sizes have broad distribution. The stability of polymer particles originated from the addition of small amounts of ionic comonomer, NaSS, which can act as an emulsifier in somewhat. The monomer conversion could reach up to about 28 wt% in 48 h, and did not increase by further polymerization when higher polymerization temperature （120℃） was employed. This polymerization system may be give some further understand for mechanism of emulsion polymerization.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61076057,61376059,61171023,and 91221202,)the National Basic Research Program of China(Grant Nos.2012CB932701 and 2011CB933001)
文摘An increase of work function （0.3 eV） is achieved by irradiating poly（3,4-ethylenedioxythiophene）：poly（styrene sul- fonate） （PEDOT：PSS） film in vacuum with 254-nm ultraviolet （UV） light. The mechanism for such an improvement is investigated by photoelectron yield spectroscopy, X-ray photo electron energy spectrum, and field emission technique. Sur- face oxidation and composition change are found as the reasons for work function increase. The UV-treated PEDOT：PSS film is used as the hole injection layer in a hole-only device. Hole injection is improved by UV-treated PEDOT：PSS film without baring the enlargement of film resistance. Our result demonstrates that UV treatment is more suitable for modifying the injection barrier than UV ozone exposure.
基金supported by the Key R&D Program of Zhejiang Province of China(No.2020C01126)and the National Key R&D Program of China(2016YFB0401305).
文摘Silver nanowire(AgNW)has become one of the best candidates for flexible transparent electromagnetic(EMI)shielding materials,while the low corrosion resistance of AgNW hinders its application in environments with high content of corrosive substances.Herein,an AgNW/poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate)(PEDOT:PSS)@nickel electrode was prepared through ultrasonic spray coating and electroplating methods.PEDOT:PSS is sprayed to improve the conductivity of the AgNW network,and a 9.8-16.5 nm Ni layer is deposited on the AgNW/PEDOT:PSS to protect the AgNWs from corrosion.The AgNW/PEDOT:PSS@Ni electrode shows a sheet resistance of 29 U·sq^(-1),a transmittance of 78.18%,an average EMI shielding efficiency of 19.64 dB and excellent corrosion resistance in Na2S solution.The resultant AgNW/PEDOT:PSS@Ni electrode is promisingly used in high corrosion resistance transparent EMI shielding film.
基金the financial support from the National Natural Science Foundation of China(Nos.62288102 and 62375142)Basic Research Program of Jiangsu(No.BK20243057)+1 种基金Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(No.NY224050)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX25_1187).
文摘Flexible pressure sensors are indispensable components in wearable electronics for health monitoring and exercise management.However,existing pressure sensors face a critical trade-off between high sensitivity and wide detection range.Herein,we present novel flexible pressure sensors based on poly(3,4-ethylenedioxy-thiophene):poly(styrene sulfonate)(PEDOT:PSS)and thermoplastic polyurethane(TPU),fabricated by direct ink writing(DIW)technology with a sacrificial template strategy.The integration of the high conductivity of PEDOT:PSS,the mechanical durability of TPU,and the engineered hierarchical porous structure with irregular surface topography enables the PEDOT:PSS/TPU-based pressure sensors(PPSs)to achieve an exceptionally wide detection range(0-1044 kPa),high sensitivity(30.178 kPa^(−1)),and outstanding cycling stability(over 10,000 cycles).Leveraging these advantages,the sensors have demonstrated exceptional performance in precise physiological monitoring,effective pressure mapping through sensor arrays,and reliable operation in extreme environments(e.g.,cryogenic conditions at−196°C and underwater).Furthermore,the successful integration with LED circuits and wireless Bluetooth systems highlights their potential for next-generation wearable electronics and personalized healthcare monitoring.
