Chinese Physics B
·
2016
·Vol. 25
·期 7
·078106
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IF 1.436
Xu Yan,Miao Yu,Wen-Peng Han,Ming-Hao You,Jun-Cheng Zhang,Rui-Hua Dong,Hong-Di Zhang,Yun-Ze Long
Electrospun nanofibers with designed or controlled structures have drawn much attention. In this study, we report an interesting new closed-loop structure in individual cerium nitrate/polyvinyl alcohol (Ce(NO3)3/PVA) and NaCl/PVA fibers, which are fabricated by electrospinning with a nail collector. The electrospinning parameters such as voltage and Ce(NO3)3 (or NaCl) concentration are examined for the formation of the closed-loop structure. The results suggest that the increase of the spinning voltage or addition of Ce(NO3)3 (or NaCl) is favorable for the formation of the closed-loop structure, and the increase of loop numbers and the decrease of loop size. Further analyses indicate that the formation mechanism of the closed-loop fibers can be predominantly attributed to the Coulomb repulsion in the charged jets.
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 11
·110510
·
IF 4.316
Ning Yan,Lei Ding,Tong Wu,Sihang Zhang,Feng Yang,Ya Cao,Ming Xiang
The thermal shutdown of the separator is the crucial feature for hindering thermal runaway of lithium-ion batteries. Because the temperature within the cell continues to rise rather than drop immediately after shutdown, the separator should be capable of maintaining adequate dimensional stability up to a specific range above the shutdown temperature to prevent internal short circuits. Based on this, a composite separator with high shutdown temperature and a wider shutdown temperature window was fabricated based on the non-solvent induced phase separation process of poly ethylene-vinyl alcohol sulfonate lithium (EVOH-SO3Li) and poly (vinyl alcohol) (PVA). The scanning electron microscope, pore size analysis, and wettability test results show that the composite separator possesses a uniform micron-sized porous structure and excellent electrolyte affinity owing to the abundant hydroxyl and sulfonic acid groups. Hence, the composite separator obtains the optimized electrochemical performances. The cell assembled with the composite separator also exhibits superior discharge C-rate capacity and cycle stability. In addition, the composite separator displays a higher shutdown function of 155 °C and maintained sufficient dimensional integrity below 213 °C, which is conducive to fabrication of lithium-ion batteries with adequate security feature and ideal cycle ability.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 7
·1400
·
IF 4.967
Mengwen Sun,Yajuan Wang,Lihui Yao,Ya Li,Yunxuan Weng,Dan Qiu
In this study, porous scaffold materials based on polyvinyl alcohol (PVA) and gelatin (Gel) were successfully fabricated and characterized. The mechanism of the reaction, morphology, and crystallinity were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In addition, thermogravimetric analysis (TGA) was performed together with differential scanning calorimetry (DSC) for examining the thermostability and phase transformation of the scaffolds. Degradation and swelling studies of PVA/Gel composite scaffold materials were performed in phosphate-buffered saline. Finally, the mechanical performances had been determined. According to the results, the polymer matrix that was formed by the combination of PVA and gelatin had better thermal stability. The synthesized composite scaffold was amorphous in nature. The addition of gelatin did not affect the fishbone-like microstructure of PVA, which ensures the excellent mechanical properties of the PVA scaffold. The denaturation temperature and elastic modulus of the PVA scaffold were improved by the gelatin addition, but the physical and chemical properties of the PVA scaffold were weakened when the gelatin content exceeded 10%. In addition, the PVA-10G sample has suitable degradability. Therefore, the PVA/Gel composite scaffold might potentially be applied in the field of tissue engineering that demands high strength.Keywords:polyvinyl alcohol;gelatin;porous scaffold
研究领域:
生物材料学
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组织工程学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 11
·9338-9343
·
IF 3.289
X. W. Chen,S. M. Dong,Y. M. Kan,H. J. Zhou,J. B. Hu,Y. S. Ding
Boron carbide (B4C) powder was synthesized by heating a gel precursor with pyrolysis and carbothermal processes. The gel precursor was prepared by the condensation reaction of boric acid (H3BO3) and polyvinyl alcohol (PVA) at a weight ratio of 1/2 with the addition of various amounts of glycerine. The effects of glycerine addition on the synthesis of B4C powder were studied. It was observed that glycerine could promote the condensation reaction and resulted in a pyrolyzed precursor with a much finer distribution of B2O3 in the carbon matrix. This led to a significant reduction of residual free carbon in the B4C powder. Moreover, the morphology of the B4C powder was also found to be closely related to the glycerine addition.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CyTA-Journal of Food
·
2019
·
IF 1.605
Min Pang,Lulu Cao,Lili Cao,Yi She,Hualin Wang
The properties of manufactured nisin-ZrO2/poly (vinyl alcohol)-wheat gluten (ZPWG) films were characterized. The formation of hydrogen bonds among the PVA, WG, and ZrO2 units were detected and caused a decrease in the film crystallinity. Also, the degradation rate was increased with WG content. As expected, the addition of WG and ZrO2 influenced the light transmission, tensile properties, gas permeability and water vapor permeability of the films. Nisin-loaded films presented a low initial burst release of the antimicrobial agent, followed by a gradual release. The initial diffusion of nisin (Mt/M∞<2/3) from the ZPWG film was formulated by the Fickian diffusion equation, showing a linear relationship (R2 > 0.998) between Mt/M∞ and t1/2, and the diffusion coefficient D increased with increasing WG content. Antimicrobial activity testing of nisin-ZPWG films with 40 wt% WG showed excellent inhibitory activity against Staphylococcus aureus, indicating its potential as a new active food packaging material.
研究领域:
食品科学
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材料科学
✓ 已验证
DOI
高影响因子
Journal of Nano Research
·
2015
·
IF 0.564
Jing Jing Shi,En Long Yang
The present study reports green electrospinning of polyvinyl alcohol (PVA) / citric acid nanofiber membranes, and the membranes were then crosslinked by heat treatment. The electric conductivity of the PVA aqueous solution increases rapidly and the growth slows down along with the increase of citric acid content. The viscosity of 13 wt% PVA aqueous solutions with citric acid had a small increase and remained stable in one week, which was suitable for electrospinning fibers. Porous, interconnected nonwoven nanofiber membranes were electrospun from a thoroughly mixing of PVA/ citric acid aqueous solution. The membranes were then heat treated at 140 °C for 2 h. The postelectrospinning crosslinked nanofiber membranes were insoluble in water, while the non-crosslinked electrospun nanofiber membranes dissolved instantaneously. FT-IR spectrum, X-ray diffraction, and DSC thermograms reveal that crosslinking of PVA nanofiber membranes occurred through esterfication reaction during heat treatment.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
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2016
·
IF 1.272
Jiang Haiyan,Zhao Qiuxiang,Zeng Ying
In this study, modified polyvinyl alcohol (PVA) was prepared and characterized by element analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and surface area and proximity analysis. The isotherms and thermodynamic parameters of the modified PVA adsorption process were estimated. The data indicate that the adsorption process is exothermic, feasible, spontaneous, and fit to the Langmuir isotherm model. The maximum adsorption capacities for Cd(II) and Pb(II) were calculated to be 1.19 and 1.48 mmol/g, respectively. Sorption was rapid, with the removal percentage higher than 98% after 10 min. Adsorption behavior mechanisms were analyzed using pseudo-first-order and pseudo-second-order models, which were highly fitted to pseudo-second-order model. This suggests the main adsorption mechanism is a chemical adsorption, involving ion exchange and valence forces through sharing or exchange of electrons between metal ions and modified PVA. The modified PVA is a good reusable sorbent, enhancing the economics of practical application for the removal of Cd(II) and Pb(II) from water and wastewater.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 16
·6916-6928
·
IF 3.5
Tan Xiansheng,Liang Caiying,Bai Shihang,Lan Pei,Ren Yan,Zhao Jianhao,Rong Jianhua
Due to the good biocompatibility, polyvinyl alcohol (PVA) hydrogels have attracted the attention of many biomaterial researchers. However, the low strength and poor toughness of pure PVA hydrogel prepared by freeze–thaw method limit the application. In this study, silica was used to enhance the performances of PVA hydrogel. Different from previous PVA/SiO 2 hydrogels, urea was used to regulate the formation and distribution of silica in PVA, which greatly improved the mechanical properties of hydrogels. The tensile stress and toughness of the obtained PVA(Urea)/SiO 2 hydrogels reached 8.10 MPa and 44.45 MJ/m 3 , which were 39 times and 212 times as that of pure PVA hydrogel, respectively. In PVA(Urea)/SiO 2 hydrogels, SiO 2 had both strengthening and toughening effects on hydrogels, which is very different from the ordinary composite hydrogels. In addition, PVA(Urea)/SiO 2 hydrogels showed unique self-reinforcing characteristics with increasing the number of tensile recoveries in cyclic stretching and recovery tests. Thus, PVA(Urea)/SiO 2 hydrogel with high strength and toughness, constructed by a simple strategy, is a potential candidate in cartilage repair.
研究领域:
生物材料
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材料科学
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医学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Ruofei Sun,Dongshu Chen,Wanting Li,Bai Wang,Jianshe Hu
In recent years, flexible sensors have attracted much attention due to their wide range of applications. Eutectogel solved the problems of water loss and phase separation of conventional hydrogels. In this work, a purely natural polymer, sodium alginate (SA), was used to construct the network structure of the gel with MXene, PVA and deep eutectic solvent (DES) were used to initiate the physical cross-linking, and an antimicrobial eutectogel was synthesised by one-pot method, which possessed excellent mechanical properties (fracture strain of about 1350 % and fracture toughness of about 2.50 MJ/m 3 ) and a high gauge factor (GF = 7.66). In addition, the resulting gels had good environmental stability (−20 °C–60 °C, maintained a highly repeatable response signal) and enabled wireless sensing. The sensor was capable of sensitively monitoring human joint movements and micro-expressions, which offered a wide range of application prospects for the development of wearable electronic products suitable for human movement.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2020
·
IF 3.862
Shaobai Wang,Kangzhou Xie,Donglin Tang
Polyvinyl alcohol (PVA) is a reactive polymer since there are abundant hydroxyl groups so various chemical transitions are feasible for PVA. In this study, we utilized the oxidation of PVA followed with a ketalization to achieve the configuration of reversible polyketal networks. The oxidation of PVA was performed by using a benign oxidation system in which hydrogen peroxide acts as the green oxidant and p -toluene sulfonic acid (TSA) as the catalyst. Both fully oxidized PVA (polyketone, PK) and partially oxidized PVA (PVA-OXI) were obtained by controlling the oxidation time. Polyketals (PKLs) were prepared by ketalization of PVA with PK, or by self-ketalization of PVA-OXI. Under the catalysis TSA , only dark PKLs were obtained. However, with ionic liquid [BMIm]HSO 4 as the catalyst, PKLs were colorless and transparent. The PKLs originated from a feed ratio of PVA/PK = 4/1 (w/w) seems tougher than other samples. When the PKL films were hydrolysed at 90 °C and recasted, the recycled (or reprocessed) PKL films appears the same as the fresh one, from the appearance to the chemical structure, and further to the mechanical properties. PKLs can be prepared by self-ketalization as well from PVA-OXI but the mechanical properties of the obtained PKLs seem not as good as those from ketalization of PVA and PK. The discoveries in this work open a door to easy but efficient modification of OH-abundant polymers, especially for polysaccharides.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 20
·
IF 1.86
Bo Shi,Liang Liang,Hui Yang,Liming Zhang,Fuan He
Spirulina–poly(vinyl alcohol) (PVA)–glycerol (SPG) films with improved mechanical performance, especially tensile strength (TS) and the elongation at break (EAB), are fabricated by a casting method. The integrity, color, solubility, microstructure, thermal properties, tensile strength, and compatibility of the SPG films are assessed. SPG films became smooth, homogeneous, and flexible after plasticizing with glycerol. The presence of PVA and hydrogen bonding of PVA with glycerol and spirulina protein improves the water resistance of SPG films by decreasing water absorption of spirulina protein and decreasing water diffusion through the films. The amount of carbonaceous residues decreases from 31% to 14% because of the co-pyrolysis of spirulina, PVA, and glycerol. TS increases from 2.5 to 26 Mpa and modulus from 53 to 610 Mpa with increasing PVA content. Glycerol enhances film flexibility and EAB up to 50%. Spirulina can be composited with hydrophilic polymers to fabricate compatible, processable and thermally recyclable films with desirable mechanical performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44842.
研究领域:
材料科学
·
生物工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Wei Wan,Meizhen Tao,Hailin Cao,Yuqing Zhao,Junrong Luo,Jian Yang,Tai Qiu
Exploring flexible dielectrics with high dielectric constant and low loss is pertinent for many applications in electronic devices. In the present work, a non-ferroelectric polymer, polyvinyl alcohol (PVA), was used to fabricate homogeneous dielectric composite films with a relatively high dielectric constant and a low dielectric loss by using 2D nano sheets (Ti 3 C 2 T x MXene) as the filler. To limit dielectric loss, SiO 2 was coated onto the surface of MXene to provide interfacial barrier effect and suppress dielectric loss. MXene@SiO 2 /PVA composite films showed lower dielectric losses at low frequencies (from 20 Hz to ~ 10 kHz) compared with MXene/PVA composite films. MXene@SiO 2 /PVA composite films with 2.5 wt% MXene loading and 5 wt% (with respect to MXene content) SiO 2 coating had a dielectric constant of 27.2 (a 292.5% rise compared to neat PVA film) and a dielectric loss of only 0.057 (a 259.6% reduction compared to MXene/PVA composite film) at 100 Hz and room temperature (RT). In addition, this SiO 2 -coated composite film had stable dielectric properties (dielectric constant and loss change from 27.2 to 29.3 and 0.057 to 0.104, respectively) in the temperature range of RT to 60 °C. This work provides a promising way to fabricate PVA-based dielectric composites with excellent dielectric properties for practical applications in electronics.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）