Herein,a modified screen printed carbon electrode(SPCE)based on a composite material,graphene oxide-gold nanoparticles(GO-AuNPs),and poly(3-aminobenzoic acid)(P3ABA)for the detection of paraquat(PQ)is introduced.The m...Herein,a modified screen printed carbon electrode(SPCE)based on a composite material,graphene oxide-gold nanoparticles(GO-AuNPs),and poly(3-aminobenzoic acid)(P3ABA)for the detection of paraquat(PQ)is introduced.The modified electrode was fabricated by drop casting of the GO-AuNPs,followed by electropolymerization of 3-aminobenzoic acid to achieve SPCE/GO-AuNPs/P3ABA.The morphology and microstructural characteristics of the modified electrodes were revealed by scanning electron microscopy(SEM)for each step of modification.The composite GO-AuNPs can provide high surface area and enhance electroconductivity of the electrode.In addition,the presence of negatively charged P3ABA notably improved PQ adsorption and electron transfer rate,which stimulate redox reaction on the modified electrode,thus improving the sensitivity of PQ analysis.The SPCE/GOAuNPs/P3ABA offered a wide linear range of PQ determination(10^(−9)-10^(−4) mol/L)and low limit of detection(LOD)of 0.45×10^(−9) mol/L or 0.116μg/L,which is far below international safety regulations.The modified electrode showed minimum interference effect with percent recovery ranging from 96.5%to 116.1%after addition of other herbicides,pesticides,metal ions,and additives.The stability of the SPCE/GO-AuNPs/P3ABA was evaluated,and the results indicated negligible changes in the detection signal over 9 weeks.Moreover,this modified electrode was successfully implemented for PQ analysis in both natural and tapped water with high accuracy.展开更多
In this paper, poly （acrylamide-co-acrylic acid） （P（AM-co-AA）） hydrogel was pre- pared in an aqueous solution by using glow-discharge electrolysis plasma （GDEP） induced copoly- merization of acrylamide （AM） ...In this paper, poly （acrylamide-co-acrylic acid） （P（AM-co-AA）） hydrogel was pre- pared in an aqueous solution by using glow-discharge electrolysis plasma （GDEP） induced copoly- merization of acrylamide （AM） and acrylic acid （AA）, in which N,N＇-methylenebisacrylamide （MBA） was used as a crosslinker. A mechanism for the synthesis of P（AM-co-AA） hydrogel was proposed. To optimize the synthesis condition, the following parameters were examined in detail： the discharge voltage, discharge time, the content of the crosslinker, and the mass ratio of AM to AA. The results showed that the optimum pH range for cationic dyes removal was found to be 5.0-10.0. The P（AM-co-AA） hydrogel exhibits a very high adsorption potential and the ex- perimental adsorption capacities for Crystal violet （CV） and Methylene blue （MB） were 2974.3 mg/g and 2303.6 mg/g, respectively. The adsorption process follows a pseudo-second-order kinetic model. In addition, the adsorption mechanism of P（AM-co-AA） hydrogel for cationic dyes was also discussed.展开更多
Nosocomial infections affect implanted medical devices and greatly challenge their functional outcomes,becoming sometimes life threatening for the patients.Therefore,aggressive antibiotic therapies are administered,wh...Nosocomial infections affect implanted medical devices and greatly challenge their functional outcomes,becoming sometimes life threatening for the patients.Therefore,aggressive antibiotic therapies are administered,which often require the use of last-resort drugs,if the infection is caused by multi-drug-resistant bacteria.Reducing the risk of bacterial contamination of medical devices in the hospitals has thus become an emerging issue.Promising routes to control these infections are based on materials provided with intrinsic bactericidal properties(i.e.,chemical action)and on the design of surface coatings able to limit bacteria adhesion and fouling phenomena(i.e.,physical action),thus preventing bacterial biofilm formation.Here,we report the development and validation of coatings made of layer-by-layer deposition of electrospun poly(vinylidene fluoride-co-trifluoro ethylene)P(VDF-TrFE)fibers with controlled orientations,which ultimately gave rise to antifouling surfaces.The obtained 10-layer surface morphology with 90°orientation fibers was able to efficiently prevent the adhesion of bacteria,by establishing a superhydrophobic-like behavior compatible with the Cassie-Baxter regimen.Moreover,the results highlighted that surface wettability and bacteria adhesion could be controlled using fibers with diameter comparable to bacteria size(i.e.,achievable via electrospinning process),by tuning the intra-fiber spacing,with relevant implications in the future design of biomedical surface coatings.展开更多
π -Conjugated poly( p -phenyleneethynylene) with the interruption of the conjugation by a butylene unit was synthesized. Its absorption, PL and EL spectra were investigated respectively. The spectral peaks shifted to...π -Conjugated poly( p -phenyleneethynylene) with the interruption of the conjugation by a butylene unit was synthesized. Its absorption, PL and EL spectra were investigated respectively. The spectral peaks shifted to the higher energy side with the interruption of the conjugation lengths. The model compound was synthesized, by which the results were proved. The thermal characteristics of the polymer was determined by DSC and TGA, indicating that the polymer has a good thermal stability. The electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.展开更多
A central problem in the study of complexity is the measure of nonuniform complexity classes. BPPP/poly has been proved by Aldman, and EXPSPACEP/poly by Kannan. We propose the definition of approximate acceptance with...A central problem in the study of complexity is the measure of nonuniform complexity classes. BPPP/poly has been proved by Aldman, and EXPSPACEP/poly by Kannan. We propose the definition of approximate acceptance with which we discuss the nonuniform complexity of the K sized complete subgraph problem. The method of modal theory is used and the K sized complete subgraph problemP/poly, co NPP/poly and NPP/poly is proved. This paper solves the Karp Lipton′s open problem: “NPP/poly?”展开更多
Piezoelectric materials that generate electrical signals in response to mechanical strain can be used in tissue engineering to stimulate cell proliferation. Poly （vinylidene fluoride-trifluoroethylene） （P（VDF-TrF...Piezoelectric materials that generate electrical signals in response to mechanical strain can be used in tissue engineering to stimulate cell proliferation. Poly （vinylidene fluoride-trifluoroethylene） （P（VDF-TrFE））, a piezoelectric polymer, is widely used in biomaterial applications. We hypothesized that incorporation of zinc oxide （ZnO） nanoparticles into the P（VDF-TrFE） matrix could promote adhesion, migration, and proliferation of cells, as well as blood vessel formation （angiogenesis）. In this study, we fabricated and comprehensively characterized a novel electrospun P（VDF-TrFE）/ZnO nanocomposite tissue engineering scaffold. We analyzed the morphological features of the polymeric matrix by scanning electron microscopy, and utilized Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry to examine changes in the crystalline phases of the copolymer due to addition of the nanoparticles. We detected no or minimal adverse effects of the biomaterials with regard to blood compatibility in vitro, biocompatibility, and cytotoxicity, indicating that P（VDF-TrFE）/ZnO nanocomposite scaffolds are suitable for tissue engineering applications. Interestingly, human mesenchymal stem cells （hMSCs） and human umbilical vein endothelial cells cultured on the nanocomposite scaffolds exhibited higher cell viability, adhesion, and proliferation compared to cells cultured on tissue culture plates or neat P（VDF-TrFE） scaffolds. Nanocomposite scaffolds implanted into rats with or without hMSCs did not elicit immunological responses, as assessed by macroscopic analysis and histology. Importantly, nanocomposite scaffolds promoted angiogenesis, which was increased in scaffolds pre-seeded with hMSCs. Overall, our results highlight the potential of these novel P（VDF-TrFE）/ZnO nanocomposites for use in tissue engineering, due to their biocompatibility and ability to promote cell adhesion and angiogenesis.展开更多
Paclitaxel （PTX）, one of the most effective cytotoxins for the treatment of breast and lung cancer, is limited by its severe side effects and low tumor selectivity. In this work hollow-poly（4-vinylpyridine） （holl...Paclitaxel （PTX）, one of the most effective cytotoxins for the treatment of breast and lung cancer, is limited by its severe side effects and low tumor selectivity. In this work hollow-poly（4-vinylpyridine） （hollow-p4VP） nanoparticles （NPs） have been used for the first time to generate PTX@p4VP NPs, employing a novel technique in which a gold core in the center of the NP is further oxidized to produce the hollow structure into which PTX molecules can be incorporated. The hollow-p4VP NPs exhibit good physicochemical properties and displayed excellent biocompatibility when tested on blood （no hemolysis） and cell cultures （no cytotoxicity）. Interestingly, PTX@p4VP NPs significantly increased PTX cytotoxicity in human lung （A-549） and breast （MCF-7） cancer cells with a significant reduction of PTX ICs0 （from 5.9 to 3.6 nM in A-549 and from 13.75 to 4.71 nM in MCF-7）. In addition, PTX@p4VP caused a decrease in volume of A-549 and MCF-7 multicellular tumor spheroids （MTS）, an in vitro system that mimics in vivo tumors, in comparison to free PTX. This increased antitumoral activity is accompanied by efficient cell internalization and increased apoptosis, especially in lung cancer MTS. Our results offer the first evidence that hollow- p4VP NPs can improve the antitumoral activity of PTX. This system can be used as a new nanoplatform to overcome the limitations of current breast and lung cancer treatments.展开更多
Effect of the device fabrication conditions on photovoltaic performance of the polymer solar cells based on poly（3-hexylthiophene） （P3HT） as donor and indene-C70 bisadduct （IC70BA） as acceptor was studied system...Effect of the device fabrication conditions on photovoltaic performance of the polymer solar cells based on poly（3-hexylthiophene） （P3HT） as donor and indene-C70 bisadduct （IC70BA） as acceptor was studied systematically. The device fabrication conditions we studied include pre-thermal annealing temperature, active layer thickness, and the P3HT ： IC70BA weight ratios. For devices with a 188-nm-thick active layer of P3HT ： ICToBA （1 ： 1, w ＇ w） blend film and pre-thermal annealing at 150 ℃C for 10 rain, maximum power conversion efficiency （PCE） reached 5.82% with Voc of 0.81 V, Isc of 11.37 mA/cm2, and FF of 64.0% under the illumination of AM1.5G, 100 mW/cm2.展开更多
This work explores the use of poly（3- hexylthiophene） （P3HT） modified carbon nanotubes （CNTs@P3HT） for the cathodes of hole transporter free, mesoscopic perovskite （CH3NH3PbI3） solar cells （PSCs）, simultaneo...This work explores the use of poly（3- hexylthiophene） （P3HT） modified carbon nanotubes （CNTs@P3HT） for the cathodes of hole transporter free, mesoscopic perovskite （CH3NH3PbI3） solar cells （PSCs）, simultaneously achieving high-performance, high stability and low-cost PSCs. Here the thin P3HT modifier acts as an electron blocker to inhibit electron transfer into CNTs and a hydrophobic polymer binder to tightly cross-link the CNTs together to compact the carbon electrode film and greatly stabilize the solar cell. On the other hand, the presence of CNTs greatly improve the conductivity of P3HT. By optimizing the concentration of the P3HT modifier （2 mg/mL）, we have improved the power conversion efficiencies （PCEs） of CNTs@P3HT based PSCs up to 13.43% with an average efficiency of 12.54%, which is much higher than the pure CNTs based PSCs （best PCE 10.59%） and the sandwich-type P3HT/CNTs based PSCs （best PCE 9.50%）. In addition, the hysteresis of the CNTs@P3HT based PSCs is remarkably reduced due to the intimate interface between the perovskite and CNTs@P3HT electrodes. Degradation of the CNTs@ P3HT based PSCs is also strongly retarded as compared to cells employing the pure CNTs electrode when exposed to the ambient condition of 20%- 40% humidity.展开更多
A series of model polymerization are carried out via the one-pot externally initiated Kumada catalyst-transfer polycondensation （KCTP） of 2-bromo-5-chloromagne- slum thiophene monomers, and the excess amount of init...A series of model polymerization are carried out via the one-pot externally initiated Kumada catalyst-transfer polycondensation （KCTP） of 2-bromo-5-chloromagne- slum thiophene monomers, and the excess amount of initiators or catalysts are found no need to be isolated during the polycondensation process. Especially, the impacts of the nickel catalyst loading variation on regioregularity （rr）, yield, molecular weight （Mn）, polydispersity （PDI） and initiation efficiency of poly（3-hexylthiophene） （P3HT） are systematically investigated. The IH NMR, size-exclusion chromatography （SEC）, and MALDI-TOF mass spectroscopy results indicated that an excess amount of catalyst does not influence yield, rr, Mn, and PDI of P3HT, nor the initiation efficiency. However, the PDI of the product is broad, and the Mn and rr values decreased in the absence of 1,3-bis （diphenylphosphino）propane （dppp）. It can be concluded that the in-situ KCTP polymerization of P3HT is a practical and effective process. These results are especially valuable for the synthesis of all-conjugated block copolymers where macroinitiators are used.展开更多
Nowadays, muifichannel nerve guidance conduit （NGC） was designed by mimicking the architecture of nerve fascicles, and it was used to reduce dispersion of regenerating axons within the NGC lumen. In this paper, gela...Nowadays, muifichannel nerve guidance conduit （NGC） was designed by mimicking the architecture of nerve fascicles, and it was used to reduce dispersion of regenerating axons within the NGC lumen. In this paper, gelatin was used to prepare multichannel inner layer of NGC by freeze-drying, and poly （ L-lactic add-co-ε- caprolactone） （P（LLA-CL）） was used to fabricate nanofiber outer layer of NGC by electrospinning. The morphology of dual-layer mtlltichannel NGC was observed by scanning electron microscopy （SEM）. In vitro degradation experiment of the NGC demonstrated that the inner layer of NGC had the faster degradation rate than the outer layer of NGC. tell viability assay indicated that Schwann cells （SCs） showed better proliferation on dual-layer multichannel NGC than hollow NGC, because the multichannel structure introduced contact guidance for direct cell migration. Therefore, it was suggested that the dual-layer multichannel NGC had the potential for nerve lissue regeneration.展开更多
Polymer-based solid electrolytes have been extensively studied for solid-state lithium metal batteries to achieve high energy density and reliable security.But,its practical application is severely limited by low ioni...Polymer-based solid electrolytes have been extensively studied for solid-state lithium metal batteries to achieve high energy density and reliable security.But,its practical application is severely limited by low ionic conductivity and slow Li+transference.Herein,based on the“binary electrolytes”of poly(vinylidene fluoride-chlorotrifluoroethylene)(P(VDF-CTFE))and lithium salt(LiTFSI),a kind of eutectogel hybrid electrolytes(EHEs)with high Li+transference number was developed via tuning the spontaneous coupling of charge and vacated space generated by Li-cation diffusion utilizing the Li6.4La3Zr1.4Ta0.6O12(LLZTO)dopant.LLZTO doping promotes the dissociation of lithium salt,increases Li+carrier density,and boosts ion jumping and the coordination/decoupling reactions of Li+.As a result,the optimized EHEs-10%possess a high Li-transference number of 0.86 and a high Li+conductivity of 3.2×10–4 S·cm–1 at room temperature.Moreover,the prepared EHEs-10%composite solid electrolyte presents excellent lithiumphilic and compatibility,and can be tested stably for 1,200 h at 0.3 mA·cm–2 with assembled lithium symmetric batteries.Likewise,the EHEs-10%films match well with high-loading LiFePO4 and LiCoO2 cathodes(>10 mg·cm–2)and exhibit remarkable interface stability.Particularly,the LiFePO4//EHEs-10%//Li and LiCoO2//EHEs-10%//Li cells deliver high rate performance of 118 mAh·g–1 at 1 C and 93.7 mAh·g–1 at 2 C with coulombic efficiency of 99.3%and 98.1%,respectively.This work provides an in-depth understanding and new insights into our design for polymer electrolytes with fast Li+diffusion.展开更多
Ferroelectric field-effect transistors(FeFET)with nondestructive readout capability have emerged as an attractive candidate for next-generation nonvolatile memory technology.Herein,we demonstrate ferroelectric-gated n...Ferroelectric field-effect transistors(FeFET)with nondestructive readout capability have emerged as an attractive candidate for next-generation nonvolatile memory technology.Herein,we demonstrate ferroelectric-gated nonvolatile memory featuring a top gate architecture by combining multi-layer ReS_(2)with ferroelectric poly(vinylidene fluoride-trifluoroethylene)(P(VDF-TrFE))copolymer films.The ReS_(2)FeFET using hBN as substrate shows a large memory window of~30 V.Repeated write/erase operations are successfully performed by applying pulse voltage of±25 V with 1 ms width to the ferroelectric P(VDF-TrFE),and an ultra-high write/erase ratio of~107 can be achieved.Furthermore,the ReS_(2)FeFET shows stable data retention capability of longer than 2,000 s and reliable endurance of greater than 2,000 cycles.These characteristics highlight that such ferroelectricgated nonvolatile memory has great potential in future non-volatile memory applications.展开更多
基金supported by the ProgramManagement Unit on Area Based Development (PMUA),Thailand (No.4594393)the National Science and Technology Development Agency (NSTDA),Thailand (No.P2250367).
文摘Herein,a modified screen printed carbon electrode(SPCE)based on a composite material,graphene oxide-gold nanoparticles(GO-AuNPs),and poly(3-aminobenzoic acid)(P3ABA)for the detection of paraquat(PQ)is introduced.The modified electrode was fabricated by drop casting of the GO-AuNPs,followed by electropolymerization of 3-aminobenzoic acid to achieve SPCE/GO-AuNPs/P3ABA.The morphology and microstructural characteristics of the modified electrodes were revealed by scanning electron microscopy(SEM)for each step of modification.The composite GO-AuNPs can provide high surface area and enhance electroconductivity of the electrode.In addition,the presence of negatively charged P3ABA notably improved PQ adsorption and electron transfer rate,which stimulate redox reaction on the modified electrode,thus improving the sensitivity of PQ analysis.The SPCE/GOAuNPs/P3ABA offered a wide linear range of PQ determination(10^(−9)-10^(−4) mol/L)and low limit of detection(LOD)of 0.45×10^(−9) mol/L or 0.116μg/L,which is far below international safety regulations.The modified electrode showed minimum interference effect with percent recovery ranging from 96.5%to 116.1%after addition of other herbicides,pesticides,metal ions,and additives.The stability of the SPCE/GO-AuNPs/P3ABA was evaluated,and the results indicated negligible changes in the detection signal over 9 weeks.Moreover,this modified electrode was successfully implemented for PQ analysis in both natural and tapped water with high accuracy.
基金supported by National Natural Science Foundation of China(No.21367023)Natural Science Foundation of Gansu Province,China(No.1208RJZA161)Key Project of Young Teachers’ Scientific Research Promotion of Northwest Normal University of China(Nos.NWNU-LKQN-10-16 and NWNU-LKQN-12-9)
文摘In this paper, poly （acrylamide-co-acrylic acid） （P（AM-co-AA）） hydrogel was pre- pared in an aqueous solution by using glow-discharge electrolysis plasma （GDEP） induced copoly- merization of acrylamide （AM） and acrylic acid （AA）, in which N,N＇-methylenebisacrylamide （MBA） was used as a crosslinker. A mechanism for the synthesis of P（AM-co-AA） hydrogel was proposed. To optimize the synthesis condition, the following parameters were examined in detail： the discharge voltage, discharge time, the content of the crosslinker, and the mass ratio of AM to AA. The results showed that the optimum pH range for cationic dyes removal was found to be 5.0-10.0. The P（AM-co-AA） hydrogel exhibits a very high adsorption potential and the ex- perimental adsorption capacities for Crystal violet （CV） and Methylene blue （MB） were 2974.3 mg/g and 2303.6 mg/g, respectively. The adsorption process follows a pseudo-second-order kinetic model. In addition, the adsorption mechanism of P（AM-co-AA） hydrogel for cationic dyes was also discussed.
文摘Nosocomial infections affect implanted medical devices and greatly challenge their functional outcomes,becoming sometimes life threatening for the patients.Therefore,aggressive antibiotic therapies are administered,which often require the use of last-resort drugs,if the infection is caused by multi-drug-resistant bacteria.Reducing the risk of bacterial contamination of medical devices in the hospitals has thus become an emerging issue.Promising routes to control these infections are based on materials provided with intrinsic bactericidal properties(i.e.,chemical action)and on the design of surface coatings able to limit bacteria adhesion and fouling phenomena(i.e.,physical action),thus preventing bacterial biofilm formation.Here,we report the development and validation of coatings made of layer-by-layer deposition of electrospun poly(vinylidene fluoride-co-trifluoro ethylene)P(VDF-TrFE)fibers with controlled orientations,which ultimately gave rise to antifouling surfaces.The obtained 10-layer surface morphology with 90°orientation fibers was able to efficiently prevent the adhesion of bacteria,by establishing a superhydrophobic-like behavior compatible with the Cassie-Baxter regimen.Moreover,the results highlighted that surface wettability and bacteria adhesion could be controlled using fibers with diameter comparable to bacteria size(i.e.,achievable via electrospinning process),by tuning the intra-fiber spacing,with relevant implications in the future design of biomedical surface coatings.
基金Supported by the National Natural Science Foundation of China(No.2 99740 2 5 ) and Zhejiang Provincial Natural Science Foundation of China(No.5 9910 0 ) State Key L aboratory of Silicon Materials,L aboratory of Organic Solids,Institute ofChemistry,Chine
文摘π -Conjugated poly( p -phenyleneethynylene) with the interruption of the conjugation by a butylene unit was synthesized. Its absorption, PL and EL spectra were investigated respectively. The spectral peaks shifted to the higher energy side with the interruption of the conjugation lengths. The model compound was synthesized, by which the results were proved. The thermal characteristics of the polymer was determined by DSC and TGA, indicating that the polymer has a good thermal stability. The electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.
文摘A central problem in the study of complexity is the measure of nonuniform complexity classes. BPPP/poly has been proved by Aldman, and EXPSPACEP/poly by Kannan. We propose the definition of approximate acceptance with which we discuss the nonuniform complexity of the K sized complete subgraph problem. The method of modal theory is used and the K sized complete subgraph problemP/poly, co NPP/poly and NPP/poly is proved. This paper solves the Karp Lipton′s open problem: “NPP/poly?”
文摘Piezoelectric materials that generate electrical signals in response to mechanical strain can be used in tissue engineering to stimulate cell proliferation. Poly （vinylidene fluoride-trifluoroethylene） （P（VDF-TrFE））, a piezoelectric polymer, is widely used in biomaterial applications. We hypothesized that incorporation of zinc oxide （ZnO） nanoparticles into the P（VDF-TrFE） matrix could promote adhesion, migration, and proliferation of cells, as well as blood vessel formation （angiogenesis）. In this study, we fabricated and comprehensively characterized a novel electrospun P（VDF-TrFE）/ZnO nanocomposite tissue engineering scaffold. We analyzed the morphological features of the polymeric matrix by scanning electron microscopy, and utilized Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry to examine changes in the crystalline phases of the copolymer due to addition of the nanoparticles. We detected no or minimal adverse effects of the biomaterials with regard to blood compatibility in vitro, biocompatibility, and cytotoxicity, indicating that P（VDF-TrFE）/ZnO nanocomposite scaffolds are suitable for tissue engineering applications. Interestingly, human mesenchymal stem cells （hMSCs） and human umbilical vein endothelial cells cultured on the nanocomposite scaffolds exhibited higher cell viability, adhesion, and proliferation compared to cells cultured on tissue culture plates or neat P（VDF-TrFE） scaffolds. Nanocomposite scaffolds implanted into rats with or without hMSCs did not elicit immunological responses, as assessed by macroscopic analysis and histology. Importantly, nanocomposite scaffolds promoted angiogenesis, which was increased in scaffolds pre-seeded with hMSCs. Overall, our results highlight the potential of these novel P（VDF-TrFE）/ZnO nanocomposites for use in tissue engineering, due to their biocompatibility and ability to promote cell adhesion and angiogenesis.
文摘Paclitaxel （PTX）, one of the most effective cytotoxins for the treatment of breast and lung cancer, is limited by its severe side effects and low tumor selectivity. In this work hollow-poly（4-vinylpyridine） （hollow-p4VP） nanoparticles （NPs） have been used for the first time to generate PTX@p4VP NPs, employing a novel technique in which a gold core in the center of the NP is further oxidized to produce the hollow structure into which PTX molecules can be incorporated. The hollow-p4VP NPs exhibit good physicochemical properties and displayed excellent biocompatibility when tested on blood （no hemolysis） and cell cultures （no cytotoxicity）. Interestingly, PTX@p4VP NPs significantly increased PTX cytotoxicity in human lung （A-549） and breast （MCF-7） cancer cells with a significant reduction of PTX ICs0 （from 5.9 to 3.6 nM in A-549 and from 13.75 to 4.71 nM in MCF-7）. In addition, PTX@p4VP caused a decrease in volume of A-549 and MCF-7 multicellular tumor spheroids （MTS）, an in vitro system that mimics in vivo tumors, in comparison to free PTX. This increased antitumoral activity is accompanied by efficient cell internalization and increased apoptosis, especially in lung cancer MTS. Our results offer the first evidence that hollow- p4VP NPs can improve the antitumoral activity of PTX. This system can be used as a new nanoplatform to overcome the limitations of current breast and lung cancer treatments.
基金This work was supported by the National Natural Science Foundation of China （Nos. 20821120293 and 50933003） and Chinese Academy of Sciences.
文摘Effect of the device fabrication conditions on photovoltaic performance of the polymer solar cells based on poly（3-hexylthiophene） （P3HT） as donor and indene-C70 bisadduct （IC70BA） as acceptor was studied systematically. The device fabrication conditions we studied include pre-thermal annealing temperature, active layer thickness, and the P3HT ： IC70BA weight ratios. For devices with a 188-nm-thick active layer of P3HT ： ICToBA （1 ： 1, w ＇ w） blend film and pre-thermal annealing at 150 ℃C for 10 rain, maximum power conversion efficiency （PCE） reached 5.82% with Voc of 0.81 V, Isc of 11.37 mA/cm2, and FF of 64.0% under the illumination of AM1.5G, 100 mW/cm2.
文摘This work explores the use of poly（3- hexylthiophene） （P3HT） modified carbon nanotubes （CNTs@P3HT） for the cathodes of hole transporter free, mesoscopic perovskite （CH3NH3PbI3） solar cells （PSCs）, simultaneously achieving high-performance, high stability and low-cost PSCs. Here the thin P3HT modifier acts as an electron blocker to inhibit electron transfer into CNTs and a hydrophobic polymer binder to tightly cross-link the CNTs together to compact the carbon electrode film and greatly stabilize the solar cell. On the other hand, the presence of CNTs greatly improve the conductivity of P3HT. By optimizing the concentration of the P3HT modifier （2 mg/mL）, we have improved the power conversion efficiencies （PCEs） of CNTs@P3HT based PSCs up to 13.43% with an average efficiency of 12.54%, which is much higher than the pure CNTs based PSCs （best PCE 10.59%） and the sandwich-type P3HT/CNTs based PSCs （best PCE 9.50%）. In addition, the hysteresis of the CNTs@P3HT based PSCs is remarkably reduced due to the intimate interface between the perovskite and CNTs@P3HT electrodes. Degradation of the CNTs@ P3HT based PSCs is also strongly retarded as compared to cells employing the pure CNTs electrode when exposed to the ambient condition of 20%- 40% humidity.
文摘A series of model polymerization are carried out via the one-pot externally initiated Kumada catalyst-transfer polycondensation （KCTP） of 2-bromo-5-chloromagne- slum thiophene monomers, and the excess amount of initiators or catalysts are found no need to be isolated during the polycondensation process. Especially, the impacts of the nickel catalyst loading variation on regioregularity （rr）, yield, molecular weight （Mn）, polydispersity （PDI） and initiation efficiency of poly（3-hexylthiophene） （P3HT） are systematically investigated. The IH NMR, size-exclusion chromatography （SEC）, and MALDI-TOF mass spectroscopy results indicated that an excess amount of catalyst does not influence yield, rr, Mn, and PDI of P3HT, nor the initiation efficiency. However, the PDI of the product is broad, and the Mn and rr values decreased in the absence of 1,3-bis （diphenylphosphino）propane （dppp）. It can be concluded that the in-situ KCTP polymerization of P3HT is a practical and effective process. These results are especially valuable for the synthesis of all-conjugated block copolymers where macroinitiators are used.
基金National Natural Science Foundations of China(Nos.31470941,31271035)Science and Technology Commission of Shanghai Municipality,China(Nos.15JC1490100,15441905100)+2 种基金National Major Research Program of China(No.2016YFC1100200)Ph.D.Programs Foundation of Ministry of Education of China(No.20130075110005)Light of Textile Project,China(No.J201404)
文摘Nowadays, muifichannel nerve guidance conduit （NGC） was designed by mimicking the architecture of nerve fascicles, and it was used to reduce dispersion of regenerating axons within the NGC lumen. In this paper, gelatin was used to prepare multichannel inner layer of NGC by freeze-drying, and poly （ L-lactic add-co-ε- caprolactone） （P（LLA-CL）） was used to fabricate nanofiber outer layer of NGC by electrospinning. The morphology of dual-layer mtlltichannel NGC was observed by scanning electron microscopy （SEM）. In vitro degradation experiment of the NGC demonstrated that the inner layer of NGC had the faster degradation rate than the outer layer of NGC. tell viability assay indicated that Schwann cells （SCs） showed better proliferation on dual-layer multichannel NGC than hollow NGC, because the multichannel structure introduced contact guidance for direct cell migration. Therefore, it was suggested that the dual-layer multichannel NGC had the potential for nerve lissue regeneration.
基金This work was supported by the International Cooperation Projects of Sichuan Provincial Department of Science and Technology(No.2021YFH0126)Quzhou Science and Technology Bureau Project(No.2021D006)+2 种基金the Fundamental Research Funds for the Central Universities(No.A030202063008029)The China Postdoctoral Science Foundation(Nos.2021T140433,2020M683408)the Natural Science Foundation of Shaanxi Province(No.2021JQ-538).
文摘Polymer-based solid electrolytes have been extensively studied for solid-state lithium metal batteries to achieve high energy density and reliable security.But,its practical application is severely limited by low ionic conductivity and slow Li+transference.Herein,based on the“binary electrolytes”of poly(vinylidene fluoride-chlorotrifluoroethylene)(P(VDF-CTFE))and lithium salt(LiTFSI),a kind of eutectogel hybrid electrolytes(EHEs)with high Li+transference number was developed via tuning the spontaneous coupling of charge and vacated space generated by Li-cation diffusion utilizing the Li6.4La3Zr1.4Ta0.6O12(LLZTO)dopant.LLZTO doping promotes the dissociation of lithium salt,increases Li+carrier density,and boosts ion jumping and the coordination/decoupling reactions of Li+.As a result,the optimized EHEs-10%possess a high Li-transference number of 0.86 and a high Li+conductivity of 3.2×10–4 S·cm–1 at room temperature.Moreover,the prepared EHEs-10%composite solid electrolyte presents excellent lithiumphilic and compatibility,and can be tested stably for 1,200 h at 0.3 mA·cm–2 with assembled lithium symmetric batteries.Likewise,the EHEs-10%films match well with high-loading LiFePO4 and LiCoO2 cathodes(>10 mg·cm–2)and exhibit remarkable interface stability.Particularly,the LiFePO4//EHEs-10%//Li and LiCoO2//EHEs-10%//Li cells deliver high rate performance of 118 mAh·g–1 at 1 C and 93.7 mAh·g–1 at 2 C with coulombic efficiency of 99.3%and 98.1%,respectively.This work provides an in-depth understanding and new insights into our design for polymer electrolytes with fast Li+diffusion.
基金supported by the National Key Research&Development Projects of China(Nos.2016YFA0202300 and 2018FYA0305800)National Natural Science Foundation of China(Nos.61888102 and 51772087)+2 种基金Strategic Priority Research Program of Chinese Academy of Sciences(CAS,No.XDB30000000)Youth Innovation Promotion Association of CAS(No.Y201902)CAS Project for Young Scientists in Basic Research(No.YSBR-003).
文摘Ferroelectric field-effect transistors(FeFET)with nondestructive readout capability have emerged as an attractive candidate for next-generation nonvolatile memory technology.Herein,we demonstrate ferroelectric-gated nonvolatile memory featuring a top gate architecture by combining multi-layer ReS_(2)with ferroelectric poly(vinylidene fluoride-trifluoroethylene)(P(VDF-TrFE))copolymer films.The ReS_(2)FeFET using hBN as substrate shows a large memory window of~30 V.Repeated write/erase operations are successfully performed by applying pulse voltage of±25 V with 1 ms width to the ferroelectric P(VDF-TrFE),and an ultra-high write/erase ratio of~107 can be achieved.Furthermore,the ReS_(2)FeFET shows stable data retention capability of longer than 2,000 s and reliable endurance of greater than 2,000 cycles.These characteristics highlight that such ferroelectricgated nonvolatile memory has great potential in future non-volatile memory applications.
