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
A hierarchically‐structured nylon 6 (PA6) nanofiber membrane decorated with silver nanoparticles (Ag NPs) was fabricated by electrospinning and impregnation methods. The as‐fabricated hierarchically‐structured Ag/P...A hierarchically‐structured nylon 6 (PA6) nanofiber membrane decorated with silver nanoparticles (Ag NPs) was fabricated by electrospinning and impregnation methods. The as‐fabricated hierarchically‐structured Ag/PA6 nanofiber membrane (HS‐Ag/PA6 NM) exhibits a morphology in which Ag NPs are deposited on the surfaces of both thick fibers and thin fibers. The content and size of theAg NPs can be controlled by varying the concentration of the silver colloid solution. Compared with the non‐hierarchically‐structured Ag/PA6 nanofiber membrane, HS‐Ag/PA6 NM has a higher specificsurface area and exhibits a higher degradation rate for methylene blue of 81.8%–98.1% within2 h. HS‐Ag/PA6 NM can be easily recycled and exhibits good reusability. It retains a degradation rate for methylene blue of 83.5% after five consecutive cycles. The hierarchically‐structured nanofiber membrane is therefore a potential nanocatalyst.展开更多
In this work,we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers(BCF)as a template.Silver(Ag)nanoparticles with an average diameter of 1...In this work,we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers(BCF)as a template.Silver(Ag)nanoparticles with an average diameter of 1.5 nm were well dispersed on BCF via a simple in situ chemical-reduction between AgNO3and NaBH4at a relatively low temperature.A growth mechanism is proposed that Ag nanoparticles are uniformly anchored onto BCF by coordination with BC-containing hydroxyl groups.The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by several techniques including transmission electron microscopy,X-ray diffraction,thermogravimetric analyses,and ultraviolet-visible(UV-Vis)absorption spectra.The antibacterial properties of Ag/BCF hybrid nanofibers against Escherichia coli(E.coli,Gram-negative)and Staphylococcu saureus(S.saureus,Gram-positive)bacteria were evaluated by using modified Kirby Bauer method and colony forming count method.The results show that Ag nanoparticles are well dispersed on BCF surface via in situ chemical-reduction.The Ag/BCF hybrid nanofiber presents strong antibacterial property and thus offers its candidature for use as functional antimicrobial agents.展开更多
With the rapid development of smart wearable devices, flexible and biodegradable sensors are in urgent needs. In this study, ‘‘green" electrically conductive Ag nanowire (Ag NW)/cellulose nanofiber (CNF) hybrid...With the rapid development of smart wearable devices, flexible and biodegradable sensors are in urgent needs. In this study, ‘‘green" electrically conductive Ag nanowire (Ag NW)/cellulose nanofiber (CNF) hybrid nanopaper was fabricated to prepare flexible sensors using the facial solution blending and vacuum filtration technique. The amphiphilic property of cellulose is beneficial for the homogeneous dispersion of Ag NW to construct effective electrically conductive networks. Two different types of strain sensors were designed to study their applications in strain sensing. One was the tensile strain sensor where the hybrid nanopaper was sandwiched between two thermoplastic polyurethane (TPU) films through hot compression, and special micro-crack structure was constructed through the pre-strain process to enhance the sensitivity. Interestingly, typical pre-strain dependent strain sensing behavior was observed due to different crack densities constructed under different pre-strains. As a result, it exhibited an ultralow detection limit as low as 0.2%, good reproducibility under different strains and excellent stability and durability during 500 cycles (1% strain, 0.5 mm/min). The other was the bending strain sensor where the hybrid nanopaper was adhered onto TPU film, showing stable and recoverable linearly sensing behavior towards two different bending modes (tension and compression). Importantly, the bending sensor displayed great potential for human motion and physiological signal detection. Furthermore, the hybrid nanopaper also exhibited stable and reproducible negative temperature sensing behavior when it was served as a temperature sensor. This study provides a guideline for fabricating flexible and biodegradable sensors.展开更多
Stretchable color-changing fibers are urgently demanded for smart textiles/clothing due to their perfect implantability,permeability of vapor and heat,and flexibility/stretchability.Herein,stretchable electrothermochr...Stretchable color-changing fibers are urgently demanded for smart textiles/clothing due to their perfect implantability,permeability of vapor and heat,and flexibility/stretchability.Herein,stretchable electrothermochromic fibers were fabricated with unconventional stretchable conductive fibers as core layers and thermochromic coatings as shell layers.In the stretchable conductive fibers,hierarchical porous structures with percolative one-dimensional(1 D)conductive networks were constructed through phase inversion of carbon nanotube/polyurethane(CNT/PU)solutions.With the deposition of silver nanoparticles(AgN Ps)on the surface of micro-pores,electrically conductive dual-pathways consisting of0 D AgN Ps and 1 D CNTs were formed to significantly enhance the electric conductivity and thus improve the electrothermal performance of the fibers.More importantly,because of the connective CNTs and AgN Ps,such dual-pathways ensured the electron transport under the stretching state,preventing the sharp decay of conductivity and electrothermal performance.Through the continuous wet-spinning method,the stretchable conductive fibers can be easily obtained with the length up to several meters.At last,stretchable electrothermochromic fibers were prepared with two color-changing modes and implanted into textile perfectly,advancing their applications in wearable display and military adaptive camouflage of smart clothing.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 National Natural Science Foundation of China (51673148)National Basic Research Program of China (2014CB660813)+2 种基金National Key Technology Support Program (2015BAE01B03)Innovation Fund for Technology of China (14C26211200298)Innovation Fund for Technology of Tianjin (14TXGCCX00014,14ZXCXGX00776)~~
文摘A hierarchically‐structured nylon 6 (PA6) nanofiber membrane decorated with silver nanoparticles (Ag NPs) was fabricated by electrospinning and impregnation methods. The as‐fabricated hierarchically‐structured Ag/PA6 nanofiber membrane (HS‐Ag/PA6 NM) exhibits a morphology in which Ag NPs are deposited on the surfaces of both thick fibers and thin fibers. The content and size of theAg NPs can be controlled by varying the concentration of the silver colloid solution. Compared with the non‐hierarchically‐structured Ag/PA6 nanofiber membrane, HS‐Ag/PA6 NM has a higher specificsurface area and exhibits a higher degradation rate for methylene blue of 81.8%–98.1% within2 h. HS‐Ag/PA6 NM can be easily recycled and exhibits good reusability. It retains a degradation rate for methylene blue of 83.5% after five consecutive cycles. The hierarchically‐structured nanofiber membrane is therefore a potential nanocatalyst.
基金Supported by the National Natural Science Foundation of China（21206076） the Natural Science Foundation of Jiangsu Province（BK2012401 and BK2011715） National High Technology Research and Development Program of China（2011AA050701）
文摘In this work,we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers(BCF)as a template.Silver(Ag)nanoparticles with an average diameter of 1.5 nm were well dispersed on BCF via a simple in situ chemical-reduction between AgNO3and NaBH4at a relatively low temperature.A growth mechanism is proposed that Ag nanoparticles are uniformly anchored onto BCF by coordination with BC-containing hydroxyl groups.The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by several techniques including transmission electron microscopy,X-ray diffraction,thermogravimetric analyses,and ultraviolet-visible(UV-Vis)absorption spectra.The antibacterial properties of Ag/BCF hybrid nanofibers against Escherichia coli(E.coli,Gram-negative)and Staphylococcu saureus(S.saureus,Gram-positive)bacteria were evaluated by using modified Kirby Bauer method and colony forming count method.The results show that Ag nanoparticles are well dispersed on BCF surface via in situ chemical-reduction.The Ag/BCF hybrid nanofiber presents strong antibacterial property and thus offers its candidature for use as functional antimicrobial agents.
基金supported by the National Natural Science Foundation of China(51803191)the China Postdoctoral Science Foundation(2018M642782)the 111 project(D18023)
文摘With the rapid development of smart wearable devices, flexible and biodegradable sensors are in urgent needs. In this study, ‘‘green" electrically conductive Ag nanowire (Ag NW)/cellulose nanofiber (CNF) hybrid nanopaper was fabricated to prepare flexible sensors using the facial solution blending and vacuum filtration technique. The amphiphilic property of cellulose is beneficial for the homogeneous dispersion of Ag NW to construct effective electrically conductive networks. Two different types of strain sensors were designed to study their applications in strain sensing. One was the tensile strain sensor where the hybrid nanopaper was sandwiched between two thermoplastic polyurethane (TPU) films through hot compression, and special micro-crack structure was constructed through the pre-strain process to enhance the sensitivity. Interestingly, typical pre-strain dependent strain sensing behavior was observed due to different crack densities constructed under different pre-strains. As a result, it exhibited an ultralow detection limit as low as 0.2%, good reproducibility under different strains and excellent stability and durability during 500 cycles (1% strain, 0.5 mm/min). The other was the bending strain sensor where the hybrid nanopaper was adhered onto TPU film, showing stable and recoverable linearly sensing behavior towards two different bending modes (tension and compression). Importantly, the bending sensor displayed great potential for human motion and physiological signal detection. Furthermore, the hybrid nanopaper also exhibited stable and reproducible negative temperature sensing behavior when it was served as a temperature sensor. This study provides a guideline for fabricating flexible and biodegradable sensors.
基金supported by the National Natural Science Foundation of China(51672043)Donghua University Distinguished Young Professor Program(LZB2019002)+1 种基金Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2017QNRC001)the Fundamental Research Funds for the Central Universities(CUSF-DH-D-2018006)。
文摘Stretchable color-changing fibers are urgently demanded for smart textiles/clothing due to their perfect implantability,permeability of vapor and heat,and flexibility/stretchability.Herein,stretchable electrothermochromic fibers were fabricated with unconventional stretchable conductive fibers as core layers and thermochromic coatings as shell layers.In the stretchable conductive fibers,hierarchical porous structures with percolative one-dimensional(1 D)conductive networks were constructed through phase inversion of carbon nanotube/polyurethane(CNT/PU)solutions.With the deposition of silver nanoparticles(AgN Ps)on the surface of micro-pores,electrically conductive dual-pathways consisting of0 D AgN Ps and 1 D CNTs were formed to significantly enhance the electric conductivity and thus improve the electrothermal performance of the fibers.More importantly,because of the connective CNTs and AgN Ps,such dual-pathways ensured the electron transport under the stretching state,preventing the sharp decay of conductivity and electrothermal performance.Through the continuous wet-spinning method,the stretchable conductive fibers can be easily obtained with the length up to several meters.At last,stretchable electrothermochromic fibers were prepared with two color-changing modes and implanted into textile perfectly,advancing their applications in wearable display and military adaptive camouflage of smart clothing.
