Journal of Physical Chemistry C
·
2021
·
IF 4.126
Haoting Zheng,Guojie Xu,Kun Wu,Liang Feng,Rongguang Zhang,Yiliang Bao,Han Wang,Kunxin Wang,Zhencai Qu,Jun Shi
A series of poly(vinylidene fluoride) (PVDF)/poly(vinyl alcohol) (PVA) composite films with different ratios were prepared by electrospinning. Because of the intermolecular interaction force, the highest thermal conductivity of the above film is 2.434 W m–1 K–1, which is about 60% higher than that of the pure PVDF film without a strong intermolecular interaction force. Infrared and wide-angle X-ray diffraction (WXAD) proved that PVDF as a thermal bridge enhances the internal interaction force and makes the internal structure more regular. The laser method shows that the film with strong intermolecular interaction has higher thermal diffusivity. Using molecular dynamics to explore the thermal expansion rate of the system, it is found that the intermolecular interaction force and the thermal bridge can effectively inhibit the activity of the molecular chain and reduce its free volume. After an in-depth study of the influence of the intermolecular interaction force and the thermal bridge on polymers, it is found that electrospinning can conveniently and effectively improve the ordering of the polymer structure. Integration of the electrospinning method and intermolecular interaction leads to the remarkable improvement of intrinsic thermal conductivity for polymer blends.
研究领域:
材料科学
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热传导研究
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DOI
高影响因子
Journal of Water Process Engineering
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2022
·
IF 7.34
Lin Chen,Fangqing Li,Longjie Jiang,Fudong He,Yufei Wei
Polytetrafluoroethylene (PTFE) hydrophobic membranes used in direct contact membrane distillation (DCMD) processes were prone to fouling and wetting by oil and surfactants, which hampered their broad industrial application. In this work, a new Janus composite membrane was developed by modifying UiO-66-NH 2 with polyvinyl alcohol (PVA) as a cross-linking agent and immobilizing the modified UiO-66-NH 2 on the PTFE membrane by vacuum filtration. By tuning the ratio of PVA to MOF , an optimally proportioned Janus membrane was obtained, and its performance was tested in DCMD experiments through the use of a sodium chloride feed solution containing hexadecane and sodium dodecyl sulfate. The top layer of this Janus membrane exhibited underwater oleophobicity (130.1 ± 0.96°) and hydrophilicity in the air (54.0 ± 0.92°), while the bottom layer is hydrophobic (132.3 ± 0.97°). Compared to the pristine PTFE membrane, the modified Janus membrane demonstrated promising resistance to both membrane fouling and wetting of oils and surfactants. The desalination rate of 99.99% was still achieved within 24 h with the conductivity remaining lower than 10 μS/cm and the flux maintained at 21.3 L/(m 2 ·h). As a result, the Janus composite membrane developed in this study was shown to be a prospective alternative for treating wastewater containing oily substances and surfactants in a resourceful manner.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2024
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IF 4.2
Xin Zhang,Shanpeng Qiao,Hong Zhang,Bo Wang,Xu Zeng,Bo Ren,Xiaodong Yang
The literature on polyvinyl alcohol (PVA) films is extensive, however, these methods often necessitate intricate synthesis processes or the addition of plasticizers to modify the strength and water solubility of the PVA material. A high-strength UV radiation-resistant composite film by chelating Fe 3+ with lignin and PVA, which exhibits excellent hydrolysis resistance is developed. This composite film is prepared simply by incorporating a small amount of dealkalized lignin (APPL) and ferric chloride (FeCl 3 ) into PVA through a straightforward composite process. During the scanning test, it is noted that the film exhibits a high density of uniformly dispersed particles, endowing it with efficient ultraviolet absorption capabilities. The infrared and anti-dissolution tests reveal that the coordination of Fe 3+ with lignin imparts an outstanding hydrolysis resistance to the film, obviating the need for any extender, curing agent, acid or base. The tensile fracture strength reaches an impressive 187.81Mpa in the tensile test. UV and indicator card tests unequivocally demonstrate that the film achieves a remarkable 100% anti-UV efficiency. This Fe 3+ chelated lignin/PVA composite film, with its facile preparation, environmental sustainability, high strength, and outstanding anti-ultraviolet efficiency, can be deployed across diverse applications requiring robust protection against ultraviolet radiation.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
FIBERS AND POLYMERS
·
2015
·Vol. 16
·期 8
·1772-1780
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IF 0.881
Zhou Yingsong,Yu Junrong,Wang Xuexin,Wang Yan,Zhu Jing,Hu Zuming
Melamine-formaldehyde/polyvinyl alcohol (MF/PVA) composite membranes modified by nano silica (SiO 2 ) and silane coupling agent KH570 modified SiO 2 (KH570-SiO 2 ) were prepared. The surface properties and morphology of KH570-SiO 2 were characterized using fourier transform infrared spectrometer (FTIR), thermogravimetric analysis (TGA), contact angle measurement instrument and X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and particle size analyzer. The morphology and properties of nanoparticles modified MF/PVA membranes were also studied with scanning electron microscopy (SEM), TGA, dynamic mechanical analysis (DMA) and tensile tester. The results show that KH570 is grafted on the surface of nano SiO 2 . KH570-SiO 2 has better dispersion in MF/PVA resin than that of unmodified SiO 2 . The thermal stability, mechanical and crystallizing properties of MF/PVA membrane are increased after modified with nano SiO 2 . KH570-SiO 2 makes MF more compatible with PVA resin, and further increases the mechanical properties and thermal stability of MF/PVA membrane.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
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2019
·
IF 6.044
Jun Wu,Xueyu Du,Zhibing Yin,Shuang Xu,Shuying Xu,Yucang Zhang
Coconut waste husks were effectively utilized in this study as a promising cellulose source for production of purified coir cellulose (PCC) after multiple treatments, e.g., ultrasonic-assisted solvent immersion, alkaline treatment, bleaching, etc. As to upgrade the self-value of coir cellulose based products and further broaden their applications in light of biorefinery, coir cellulose nanofibrils (CCNF) with an average diameter of 5.6 ± 1.5 nm were prepared by selection of a milder TEMPO-mediated oxidation system (TEMPO/NaClO/NaClO 2 , pH = 4.8) accompanied by subsequent ultrasonic treatment. The cellulose nanofibrils were comprehensively characterized in terms of their functional groups, crystallinity, morphology, and thermal stability. The potential reinforcement of CCNFs as a filler for biodegradable PVA based films was investigated and the main properties including tensile strength, elongation at break, and thermal stability of CCNF/PVA composite films were significantly enhanced especially when 3% of CCNF (based on dry film weight) was applied.
研究领域:
材料科学
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环境科学
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生物工程
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Qingsong Zheng,Shaoran Shi,Yang Gu,Pamela Owusu Osei,Lei Wang,Xiaorong Duan,Xiaomeng Wu,Xiaojun Liao
This study utilized deep eutectic solvents (DES) based on choline chloride/lactic acid (ChCl/LA) to deconstruct coconut fibers. The effects of DES with different temperatures and molar ratios on the yield of lignin, recovery rate of residues, structural changes in lignin and solid residues, and saccharification efficiency were investigated. The results showed that acidic DES treatment effectively deconstructed the coconut fibers, resulting in a high lignin yield of 68.51 % while enhancing the enzymatic saccharification of cellulose, reaching a glucose yield of 85.88 %. The structural characterization of lignin revealed that acidic DES primarily cleaved β-O-4 bonds, yielding coconut fiber lignin with lower molecular weight and higher phenolic hydroxyl groups. Uniform and smooth coconut fiber lignin nanoparticles (CFLNPs) with excellent antioxidant activity were finally obtained by antisolvent method. Furthermore, PVA/CFLNPs nanocomposite films were prepared based on acidic DES CFLNPs. The results of the structural and functional analysis showed that CFLNPs significantly improved the thermal stability, mechanical properties, hydrophobicity, antioxidant and antibacterial activity of the nanocomposite films. In general, this work achieved efficient deconstruction of coconut fibers, providing insights for biorefining in the future, and more importantly, the potential to use the CFLNPs as a choice for active food packaging.
研究领域:
材料科学
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食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Wei Chen,Pengfei Wang,Weike Jia,Huidan Zeng
Silicalite-1 zeolites/polymer composite membranes are among the most reliable materials for the pervaporation separation of m-X from xylene isomers. However, the separation factors of the present silicalite-1 zeolites/polymer composite membrane are low. This work has succeeded in fabricating dense and defect-free silicalite-1/PVA composite membrane for first improving the pervaporation separation performance of m-X/p-X isomers. The silicalite-1/PVA composite membrane was prepared by combining solution scraping and vacuum thermal crosslinking methods with fumaric acid as a crosslinker (denoted as silicalite-1/PVA-V). The silicalite-1/PVA-V composite membrane with a thickness of 15.3 μm, prepared with a fumaric acid/monomeric unit of PVA molar ratio of 0.05 after vacuum thermal crosslinking at 160 ℃ for 2 h, exhibited dense and defect-free structure with extremely low xylene swelling degree, good structural stability and mechanical properties as well as excellent pervaporation separation performance. Compared to the pure PVA membrane, the silicalite-1/PVA-V composite membrane exhibited better selective separation performance of m-X isomer. The temperature, amount of fumaric acid, crosslinking degree and membrane thickness significantly influenced the pervaporation separation performance. The optimum selective separation factor of m-X/p-X isomers and the corresponding total permeate flux were about 9.85 and 59.15 g·m −2 ·h −1 (60 ℃), respectively. The pervaporation experiments of long-time and repetitively prepared membrane demonstrated that the silicalite-1/PVA-V composite membrane had long-term structural stability and reproducibility. To demonstrate scalability, we showed that our strategy could produce large-size silicalite-1/PVA-V composite membrane with an area of 1000 cm 2 , which exhibited m-X separation performance similar to that of small membrane coupons. The present work provided a potentially scalable method for producing high-quality silicalite-1/PVA composite membrane for enhancing the pervaporation separation performance of m-X from xylene isomers.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 40
·12518-12522
·
IF 6.641
Yongqi Yang,Jianyu Xu,Yi Li,Guanghui Gao
Rewritable paper exhibits the potential to replace conventional paper due to its reusable properties. However, compared to conventional paper, rewritable paper can fade, making it impossible to store information stably for a long time in a daily environment, which limits its application. Here, a series of photochromic gelatin/polyvinyl alcohol (PVA) composited films containing polyoxometalate were prepared. The addition of PVA had a significant effect on the mechanical, transparent, photochromic and fading properties of the film. The addition of PVA significantly inhibited the fading process of the film after photochromism. This was due to the increase of crosslink density in the film and the existence of hydrogen bonding between PVA and inorganic photochromic ammonium molybdate. Despite this, the film was able to achieve complete fading in 1.5 days in a humid environment and the fading time could be further accelerated to 2 h by heating. This film could display information stably over a long time while being rewritable. It was expected that this simple and effective design strategy is conducive to the development of a new generation of rewritable paper.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Membranes
·
2016
·Vol. 6
·期 4
·47
·
IF 0
Ningen Hu,Tonghu Xiao,Xinhai Cai,Lining Ding,Yuhua Fu,Xing Yang
In this study, a nonsolvent thermally-induced phase separation (NTIPS) method was first proposed to fabricate hydrophilically-modified poly(vinylidene fluoride) (PVDF) membranes to overcome the drawbacks of conventional thermally-induced phase separation (TIPS) and nonsolvent-induced phase separation (NIPS) methods. Hydrophilically-modified PVDF membranes were successfully prepared by blending in hydrophilic polymer polyvinyl alcohol (PVA) at 140 °C. A series of PVDF/PVA blend membranes was prepared at different total polymer concentrations and blend ratios. The morphological analysis via SEM indicated that the formation mechanism of these hydrophilically-modified membranes was a combined NIPS and TIPS process. As the total polymer concentration increased, the tensile strength of the membranes increased; meanwhile, the membrane pore size, porosity and water flux decreased. With the PVDF/PVA blend ratio increased from 10:0 to 8:2, the membrane pore size and water flux increased. The dynamic water contact angle of these membranes showed that the hydrophilic properties of PVDF/PVA blend membranes were prominently improved. The higher hydrophilicity of the membranes resulted in reduced membrane resistance and, hence, higher permeability. The total resistanceRtof the modified PVDF membranes decreased significantly as the hydrophilicity increased. The irreversible fouling related to pore blocking and adsorption fouling onto the membrane surface was minimal, indicating good antifouling properties.Keywords:nonsolvent thermally-induced phase separation (NTIPS);PVDF/PVA blend membrane;hydrophilic modification;membrane resistance;antifouling property
研究领域:
材料科学
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环境工程
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产品关联
DOI
PubMed
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Qi Xin,Huiwen Li,Wan Sun,Xuezhi Li,Xianqin Lu,Jian Zhao
Lignin, as an amorphous three-dimensional aromatic polymer, was able to self-assemble into lignin nanoparticles (LNPs) to realize valorization of lignin. Here, lignin-xylan extractives were extracted from grape seed (GS) and poplar by acidic THF at room temperature, and effectively produced lignin-xylan nanospheres via spin evaporation. The morphology and chemical properties of nanospheres were determined by its natural origins, consequently influencing its application. For the lignin-xylan extractive from grape seed, the lignin was composed of guaiacyl (G) and p -hydroxylphenyl (H) units and the hollowed nanospheres (GS-LNPs) with 362.72 nm diameter was produced. The extractive from poplar was composed of G-syringyl (S) typed lignin (80.30 %) and xylan (12.33 %), that can assemble into LNPs with smaller size (229.87 nm), better PDI (0.1), and light color. The hybrid particles showed the qualities of lignin and xylan, that properties led to the LNPs@PVA composite films with UV-blocking capability, strong mechanical strength and hydrophobicity, and transparency ability of visible light. P-LNPs showed better performance as the film additives, due to its lower particles size and high content of unconjugated -OH from xylan. Xylan was significant in the composite films, and lowering the xylan content resulted in the decrease of the composite film's mechanical properties and hydrophobicity.
研究领域:
材料科学
·
生物质化学
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产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Jiawei Cheng,Peizhi Wang,Xinyang Zhou,Zhilin Zhang,Jinxin Yao,Jiachen Xie,Yongchen Zong,Jun Ma,Wei Wang
The lack of robust distillation membranes to resist scaling/wetting remains a significant barrier to applying membrane distillation (MD) for hypersaline wastewater treatment. Constructing a functional surface layer was demonstrated to be a promising strategy against membrane scaling/wetting. However, conventional surface coating processes could increase water transport resistance and low compatibility between the surface layer and hydrophobic substrate, deteriorating membrane efficacies and stabilities. Herein, we successfully developed a surfactant-tailored PVDF/PVA composite membrane (SPCM) with a robust embedded interlocking structure. SPCM not only exhibited outstanding mechanical stabilities and anti-scaling/wetting capabilities during hypersaline wastewater treatment but also showed marvelous water permeability (exceeding the intrinsic permeability of hydrophobic substrate, ∼17%). We systematically investigated the effect of surfactant integration on the microstructural evolution and operational efficacies of functional surface layers. Detailed mechanisms of water transport enhancement were revealed by instrument characterization and experimental design. The embedded structure of surface layer, which decreased the water transfer distance and enhanced the evaporation area at the gel-layer/hydrophobic-substrate interface, was demonstrated to be the key to water flux enhancement. Besides, the post-treatment could further optimize the chemical structure of hydrogel networks and increase the proportion of intermediate water (IW) at the evaporation interface, facilitating water evaporation. SPCM also demonstrates outstanding efficiency and stability in the long-term cycle concentration of desulfurization wastewater. The high mechanical stability and exceptional operational efficiency of the SPCM, combined with the simplified membrane preparation process, endowed the SPCM with tremendous application potential for hypersaline water treatment.
研究领域:
环境工程
·
膜科学
·
水处理技术
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2023
·
IF 2.7
Haoting Hou,Miao Wu,Mao Wang,Xirui Miao,Haichao Li,Yang Chen,Xudong Yang
Carbon dots have been widely noticed due to their excellent optical properties, such as good photostability and a wide excitation wavelength range. However, the emission peaks of most known carbon dots (CDs) are in the blue region, which hinders their extensive applications in long-wavelength emission. In this study, red-emitting carbon dots (RCDs) that are pH-responsive are synthesized using citric acid and urea as precursors, and their fluorescence intensity increased gradually with increasing solution pH from 1 to 12. A new mechanism based on H aggregation and Fermi energy level transfer is proposed to explain the pH-responsive emission of RCDs. In contrast to the narrow response range of most pH-sensitive CDs reported so far, the pH-responsive range of RCDs is large, especially in the alkaline range, and their pronounced red light emission is well visualized. The prepared carbon dots have the advantages of non-toxicity, low cost, and a wide pH response range. In addition, “rose” test paper and carbon dot PVA composite film, RCDs-PVA film, are made to demonstrate the visualization of carbon dots in pH detection. The “rose” test paper and carbon dot PVA still have good fluorescence intensity. The prepared carbon dots have good application prospects for pH detection.
研究领域:
材料科学
·
分析化学
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纳米技术
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环境科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）