JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 23
·46351
·
IF 1.901
Li Wen,Liwen Wang,Shuyi Fang,Lei Bao,Dongdong Hu,Yuan Zong,Ling Zhao,Tao Liu
Two newly-designed hydrocarbon surfactants, that is, poly(vinyl acetate)- block -poly(1-vinyl-2-pyrrolidone) (PVAc- b -PVP) and PVP- b -PVAc- b -PVP, were synthesized using reversible addition–fragmentation chain transfer polymerization and used to form CO 2 /water (C/W) emulsions with high internal phase volume and good stability against flocculation and coalescence up to 60 h. Their structures were precisely determined by nuclear magnetic resonance, gel permeation chromatography, thermal gravimetric analysis, and differential scanning calorimetry. Besides low temperature and high CO 2 pressure, the surfactant structures were the key factors affecting the formation and stability of high internal phase C/W emulsions, including the polymerization degrees of CO 2 -philic block (PVAc) and hydrophilic block (PVP), as well as the number of hydrophilic tail. The surface tension of the surfactant aqueous solution and the apparent viscosity of the C/W emulsions were also measured to characterize the surfactants efficiency and effectiveness. The surfactants with double hydrophilic tails showed stronger emulsifying ability than those with single hydrophilic tail. The great enhancement of the emulsions stability was due to decrease of the interface tension as well as increase of the steric hindrance in the water lamellae, preventing a frequent collision of CO 2 droplets and their fast coalescence. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46351.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
POLYMER TESTING
·
2017
·
IF 2.464
Jianxi Huang,Haijun Yang,Min Chen,Te Ji,Zhengchi Hou,Minghong Wu
Systematic study of FTIR spectra was carried out on the PES/PVP blends and PES-g-PVP copolymers . In the blends, no shift of carbonyl group absorbance was observed. In the copolymers, there was an occurrence of blue-shift that increases with the grafting degree, which can be used as a compelling evidence of PVP being grafted onto PES . This phenomenon was interpreted from the stereo-hindrance effect. Besides, as the intensity of carbonyl group absorbance increased proportionally with the degree of grafting obtained by elementary analysis, FTIR, a simple and easy tool, became feasible for the quantitative determination of PVP content in the graft copolymers . Calibration curves with high correlation coefficient were established from which the quantitative relationship between the intensity of carbonyl group absorbance normalized by a chosen internal reference and the grafting degree can be obtained.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 23
·15910-15917
·
IF 3.9
Zhanjun Zhang,Qipeng Liu,Dashu Pan,Yubing Xue,Xiaojuan Liu,Jing Zhao,Yinggen Ouyang,Xiaofan Ding,Songtao Xiao,Qingyuan Yang
In order to solve the problem that UO2 in direct ethanol fuel cell anode catalysts is easily lost in acidic solution, resulting in the degradation of catalytic performance, this paper prepared a C/UO2/PVP/Pt catalyst in three steps by adding polyvinylpyrrolidone (PVP). The test results by XRD, XPS, TEM and ICP-MS showed that PVP had a good encapsulation effect on UO2, and the actual loading rates of Pt and UO2 were similar to the theoretical values. When 10% PVP was added, the dispersion of Pt nanoparticles was significantly improved, which reduced the particle size of Pt nanoparticles and provided more ethanol electrocatalytic oxidation reaction sites. The test results by electrochemical workstation showed that the catalytic activity as well as the stability of the catalysts were optimized due to the addition of 10% PVP.
研究领域:
材料科学
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电化学
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能源工程
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DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2014
·Vol. 3
·期 5
·911-918
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IF 0
Yuhua Song,Tingbin Zhang,Xiaoyan Song,Ling Zhang,Chunqiu Zhang,Jinfeng Xing,Xing-Jie Liang
The low transfection efficiency of polycations is still a major problem for successful gene therapy. To address this issue, in this study, hydrophilic poly(vinyl pyrrolidone)-graft-poly[2-(N,N-dimethylamino)ethyl methacrylate] (PVP-g-PDMAEMA) and amphiphilic poly(vinyl pyrrolidone)-graft-poly[2-(N,N-dimethylamino)ethyl methacrylate]-block-poly(methylmethacrylate) (PVP-g-PDMAEMA-b-PMMA) were synthesized via the atom transfer radical polymerization (ATRP) method, and their properties as gene vectors were investigated subsequently. PVP-g-PDMAEMA formed random coils in water and PVP-g-PDMAEMA-b-PMMA self-assembled into spherical core–shell micelles with a very low critical micelle concentration of only 6.3 × 10−3 mg mL−1. PVP-g-PDMAEMA-b-PMMA/pDNA polyplexes demonstrated an excellent gene transfection efficiency, which showed not only much higher gene transfection efficiency than PVP-g-PDMAEMA/pDNA polyplexes, but obviously surpassed 25k PEI at low N/P ratio around 3 on 293T cell lines. Hence, the results suggested that PVP-g-PDMAEMA-b-PMMA could be a highly efficient gene vector.
研究领域:
生物化学
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基因治疗
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材料科学
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DOI
PubMed
RSC Advances
·
2025
·Vol. 15
·期 8
·6162-6170
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IF 4.6
Tang Xianjie,Gan Guoyou,Chen Shouzhi,Yu Xianglei,Qian Zhuo,Li Junpeng
The majority of the current composite core–shell structure preparation and sintering processes applied to silver nanowire transparent electrodes are impractical for large-scale industrial production and primarily emphasize macroscopic performance parameters, with limited insights into the underlying sintering mechanism. This study presents a simple synthesis of AgNWs@PVP core–shell structures and investigates the effects of sintering temperature and time on their morphology. The morphology of AgNWs@PVP core–shell structures during sintering was systematically analyzed using characterization techniques, such as transmission electron microscopy and scanning electron microscopy. Subsequently, a comprehensive understanding of its sintering mechanism was summarized. This provides theoretical foundation for the preparation of AgNWs-based core–shell structures and high-temperature sintering based on core–shell structures.
研究领域:
材料科学
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纳米技术
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DOI
PubMed
高影响因子
Biomedical Materials
·
2021
·Vol. 16
·期 6
·065014
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IF 3.715
Caini Yuan,Xinyun Long,Jinghua Li,Qing Cai
As a biocompatible and biodegradable polymer, poly(lactide-co-glycolide) (PLGA) has been widely used as a carrier to achieve controlled drug delivery in various forms. Focusing on skin tumor treatment, herein 5-fluorouracil (5-FU) was embedded into the core of coaxially electrospun PLGA fibers to get a drug-loaded core–shell fibrous membrane. In the coaxial electrospinning, poly(vinylpyrrolidone) was applied in the inner flow to facilitate the formation of the core–shell structured fibers. The morphology and micro-structure of the fibers were characterized by scanning electron microscope and transmission electron microscope. The influences of the molecular weights and chemical compositions of PLGA copolymers on the release behaviors were studied. The cytotoxicity of the fibers was characterized by cell proliferation and living-dead cell staining experiments. The results showed that faster release rates would be obtained if the copolymers were of lower molecular weights and higher fraction of glycidyl unit. All the prepared 5-FU loaded fibrous membranes were non-cytotoxic, suggesting their potential applications in skin tumor treatment.
研究领域:
药学
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生物医学工程
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肿瘤学
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DOI
PubMed
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Junyu Chen,Yanqin Ma,Xinjian Cheng,Yufan Wu,Huizhi Chen,Cheng Liu
Natural polymer chitosan has many advantages, but the poor solubility limits its application. In this study, chitosan derivatives soluble in DCM, DMF, DMSO, H 2 O and other solvents were developed by introducing side chains into chitosan (CS). In addition, the fluorescent group on the side chain makes the chitosan derivative have the ability to detect 4-nitrophenol (4-NP). Firstly, a chain transfer agent containing C C (N3-NS) was synthesized with naphthalimide as the fluorescence unit. Then, using AIBN as initiator, an extensively soluble polymer with fluorescent moiety TP-NVP was synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT) method using monomer N -vinyl pyrrolidone (NVP). Finally, the C C of TP-NVP was used to react with –NH 2 on CS to prepare PVP-g-chitosan, so that more CS was “pulled” by TP-NVP into the solvent. The solubility of the synthesized CS-PVP probe can be adjusted by adjusting the amount of NVP, up to 17.6 mg/mL. At the same time, the synthesized CS-PVP had a good detection effect on 4-NP, and the detection limit (LOD) was 0.054 μM. The HOMO-LUMO energy level of the probe was calculated by cyclic voltammetry (CV). In addition, CS-PVP was successfully loaded on a low background fluorescent test paper to achieve real-time visual intelligent determination of 4-NP in real samples with the help of a color scanning APP of a smartphone.
研究领域:
材料科学
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分析化学
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生物医学工程
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DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2020
·Vol. 22
·期 9
·1-11
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IF 2.132
Wang Wei,Zhi Guowei,Liu Jijinhua,Hao Lingyun,Yang Lu,Zhao Yijie,Hu Yingfei
In the paper, the effects of polyvinylpyrrolidone (PVP) concentration and chemical wet etching on morphologies and phase composition of CuSbS 2 particles synthesized by microwave irradiation method were investigated. The phase structure, morphologies, and optical and photocatalytic properties were analyzed by using characterization techniques. The results showed that the morphology of as-prepared particles was spherical and the shape of particles etched in Na 2 S solution was tetragonal rod-like structure. The optical band gap of the particles with 1.5 g PVP after chemical etching was about 1.41 eV. The photocatalytic performance of CuSbS 2 could be significantly improved after Na 2 S chemical etching. The amounts of PVP had an obvious influence on specific surface area of as-synthesized CuSbS 2 particles. The CuSbS 2 particles with 1.5 g PVP had the best photocatalytic performance after chemical etching treatment, and the C / C 0 value reached 0.36.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 7
·1670
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IF 4.2
Jianfeng Wen,Xin Du,Feng Hua,Yiting Gu,Ming Li,Tao Tang
The aqueous instability of halide perovskite seriously hinders its direct application in water as a potential photocatalyst. Here, we prepared a new type of polyvinylpyrrolidone (PVP) passivated δ-CsPbI3(δ-CsPbI3@PVP) microcrystal by a facile method. This material can be uniformly dispersed in water and stably maintain its crystal structure for a long time, breaking through the bottleneck of halide perovskite photocatalysis in water. Under visible light, δ-CsPbI3@PVP can almost completely photodegrade organic dyes (including Rhodamine B, methylene blue, and crystal violet) in only 20 min. The efficient photocatalytic activity is attributed to the enhanced visible light absorption arising from PbI2defects in δ-CsPbI3@PVP and the intrinsic low photoluminescence quantum yield of δ-CsPbI3, which induces efficient light absorption and photocatalytic activity. We highlight δ-CsPbI3@PVP as an effective aqueous photocatalyst, and this study provides new insights into how to exploit the potential of halide perovskite in photocatalytic applications.
研究领域:
材料科学
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环境科学
·
化学
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DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2017
·
IF 3.752
Huan Liu,Quanzhen Liu,Jianzhong Zhang,Changlong Yin,Yuxin Zhao,Shumeng Yin,Chenguang Liu,Wanfu Sun
The effect of polyvinyl pyrrolidone (PVP) on the physicochemical properties and catalytic activities of unsupported NiMo catalysts was studied. The NiMo catalyst precursors were synthesized by a PVP-assisted chemical precipitation method, by adding various contents of PVP to a Ni- and Mo-containing solution. A series of techniques, including CHSN analysis, XRF , XRD, N 2 adsorption-desorption, FT-IR, SEM, TG-DSC, TPR, and XPS, were used to characterize the NiMo oxide precursors and sulfided catalysts, and the catalytic activities were tested in the hydrodesulfurization (HDS) of dibenzothiophene (DBT). The characterization results revealed that PVP was efficiently removed due to low contents in the synthesis and high solubility in water. The pore properties and hysteresis loop , the agglomeration of the nanoparticles , and the reducibility of the NiMo precursor were affected by the introduction of PVP, while the phases of the precursors and the thermal stabilities were little changed. Ni 3 S 2 and MoS 2 phases were observed in the sulfided catalysts. The catalysis results revealed that the hydrogenation pathway was predominant in the HDS of DBT. A NiMo catalyst synthesized with 0.5 g PVP showed a higher conversion of DBT than the other NiMo catalysts, possibly due to efficient formation of the ‘NiMoS’ active phase. This facile, scalable, and cost-effective route to prepare unsupported NiMo catalyst with enhanced HDS activities would be attractive in industrial applications.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
POLYMER SCIENCE SERIES A
·
2018
·Vol. 60
·期 3
·342-349
·
IF 0.729
Xiang Yanhui,Lin Haibo
Supercritical carbon dioxide (ScCO 2 ) was used as a physical foaming agent to prepare poly(vinylidene f luoride)/poly(N-vinyl pyrrolidone) (PVDF/PVP) microstructure material. The effects of foaming conditions including saturation pressure, foaming temperature and foaming time on PVDF/PVP foams morphology, thermal and electrical behavior were systematically investigated by scanning electron microscope, differential scanning calorimeter and broadband dielectric spectrometer. Small cell and low cell density were achieved at low pressure of 12 MPa, as increasing saturation pressure, the average cell size increased first, and then decreased. The competition between the cell growth and cell nucleation played an important role in average cell size, which was directly related to ScCO 2 processing conditions. With increasing foaming temperature, cell size was increased and cell density was decreased, in a nearly linear manner. The variation of foaming time was considered to be closely related to the time for cells to grow. Thus, the results revealed that the average cell size enhanced with extending foaming time. The thermal properties of PVDF/PVP composites are slightly inf luenced by foaming parameters, and the dielectric constant of PVDF/PVP composite foams decreased with increasing volume expansion ratio.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 21
·2894
·
IF 5.3
Fang Zhou,Weichang Zhou,Yujing Zhao,Li Liu
Bi2Te3has been extensively used because of its excellent thermoelectric properties at room temperature. Here, 230–420 nm of Bi2Te3hexagonal nanosheets has been successfully synthesized via a “green” method by using ethylene glycol solution and applying polyvinyl pyrrolidone (PVP) as a surfactant. In addition, factors influencing morphological evolution are discussed in detail in this study. Among these parameters, the reaction temperature, molar mass of NaOH, different surfactants, and reaction duration are considered as the most essential. The results show that the existence of PVP is vital to the formation of a plate-like morphology. The reaction temperature and alkaline surroundings played essential roles in the formation of Bi2Te3single crystals. By spark plasma sintering, the Bi2Te3hexagonal nanosheets were hot pressed into solid-state samples. We also studied the transport properties of solid-state samples. The electrical conductivityσwas 18.5 × 103Sm−1to 28.69 × 103Sm−1, and the Seebeck coefficientSwas −90.4 to −113.3 µVK−1over a temperature range of 300–550 K. In conclusion, the observation above could serve as a catalyst for future exploration into photocatalysis, solar cells, nonlinear optics, thermoelectric generators, and ultraviolet selective photodetectors of Bi2Te3nanosheet-based photodetectors.
研究领域:
材料科学
·
纳米技术
·
能源科学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）