Journal of Materials Chemistry A
·
2014
·Vol. 3
·期 6
·2770-2775
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IF 0
Muhua Luo,Yuanchen Hong,Weifeng Yao,Cunping Huang,Qunjie Xu,Qiang Wu
The synthesis of colloidal Pt and Pt alloy nanoparticles (NPs) requires surfactants and capping agents to inhibit the overgrowth and aggregation of NPs. These reagents are also needed in the shape control synthesis of NPs to vary crystal growth rates in selected directions. Polyvinylpyrrolidone (PVP) is one of the most common water soluble capping agents for use in the synthesis of colloidal particles. However, PVP strongly adsorbed onto the surface of nanoparticles is detrimental when the NPs are used as catalysts, because surface adsorbed PVP blocks the access of reactant molecules to the active sites of nanoparticles. In this paper, we report a facile NaBH4/tert-butylamine (TBA) treatment technology for the effective removal of PVP from the surface of colloidal Pt–Pd nanocubes (NCs). This method does not change the morphology of the NPs. After treatment, the catalytic activity of Pt–Pd NCs significantly improves due to greater particle surface areas available for catalytic reactions. This facile method will find extensive applications in the fields of fuel cells, water electrolysis and photocatalytic hydrogen production.
研究领域:
材料科学
·
催化化学
·
燃料电池技术
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DOI
JOURNAL OF NANOPARTICLE RESEARCH
·
2017
·Vol. 19
·期 7
·1-13
·
IF 2.02
Liu Mei,Chen Qian,Wang Sheng,Bai Linfeng,Sang Min,Jiang Wanquan,Xuan Shouhu,Gong Xinglong
We develop a modified method to improve the rheological performance of SiO 2 -based shear thickening fluid (STF). Directly adding surfactant into STF is the most common method to improve the rheological performance of SiO 2 -based STF. However, the final viscosity increases quickly with the increase of shear rate, which is against for the practical applications. In this work, SiO 2 nanospheres are firstly modified by PVP K30 through an ethanol refluxing method and the modified SiO 2 nanospheres are used to prepare PVP@SiO 2 -STF. Compared with the unmodified SiO 2 based STF (SiO 2 -STF), the PVP@SiO 2 -STF presents an obvious increase of shear thickening (ST) effects and the maximum viscosity increases by 7 times and the critical shear rates decrease about 10 times approximately. A reasonable explanation is proposed to interpret the influence of the modification methods on the rheological properties of STF. This work provides a new way to control the shear thickening behavior and also contributes to understand the mechanism of ST effect, which has an important significance to develop controllable STF.
Figure PVP immobilized SiO 2 based shear thickening fluid shows a dramatic improvement in shear thickening behavior (a, b, and c) and the illustration of the enhanced mechanism of shear thickening (d).
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
FIBERS AND POLYMERS
·
2024
·
IF 2.2
Zhou Xinnan,Xin Binjie,Gao Di,Newton Md. All Amin
In the purification of oily wastewater, polyvinylidene fluoride (PVDF) nanofiber membranes have attracted widespread attention for their excellent water–oil separation performance. And chitosan (CS), as a natural polymeric alkaline polysaccharide containing many functional groups interacting with heavy metal ions, such as –NH 2 and –OH, has been widely used to treat heavy metal ions in wastewater. However, a few studies have been conducted on superhydrophilic and underwater hydrophobic PVDF composite membranes for the simultaneous removal of heavy metal ions and oil from wastewater. In this paper, PVDF/PVP composite membranes were used as the substrate of separation membranes, and PVDF/PVP-modified membranes were prepared by surface coating with PDA and CS in turn. Among them, CS can be coated on the surface of PVDF/PVP composite membrane by cross-linking the amino group on the molecule with the quinone structure in the PDA molecule to form a stable CS/PDA gel layer. Compared with other modified membranes, CS/PDA-PVDF/PVP has better hydrophilicity and underwater oleophobicity. The underwater OCA of dichloromethane could reach 161°, and the OCA of other oils were above 140°. The water flux was 14,171 L m −2 h −1 . After 15 mixture and emulsion separation tests, the separation efficiency was higher than 99% and 98%, respectively. The adsorption efficiency for Cu 2+ , Pb 2+ , and Cr 3+ aqueous solutions with concentrations of 10–60 mg/L reached more than 80%. Therefore, this method has great potential in treating oily wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 41
·48045
·
IF 2.188
Wei Lu,Qingwei Meng,Chuanrui Qin,Jinliang Li,Guansheng Qi,Biao Kong,Zhenglong He
A binary emulsion system via combination of sodium dodecylbenzenesulfonate (SDBS) and polyvinyl pyrrolidone (PVP) was employed to prepare microcapsules containing isophorone diisocyanate. The effect of different concentrations of SDBS and PVP on the size and distribution of capsules was investigated. The results showed that uniform and size-controllable capsules were synthesized by synergistic function of SDBS and PVP. Characteristics of capsule were studied by optical microscopy, Fourier transform infrared spectrometry, scanning electron microscopy, thermal gravimetric analysis, and 1 H NMR. The results revealed that the core content and yield of the spherical capsules were approximately 65.7 and 79 wt %, respectively, at the capsule diameter of ~115 μm. The residue core content of microcapsules was approximately 44.7 wt % after immersion in water for 10 days. And its self-healing epoxy coatings showed excellent corrosion resistance performance after accelerated corrosion tests. These results exhibited the feasibility and great application prospect of the multiemulsifiers system in the microcapsule synthesis process. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48045.
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
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2020
·Vol. 37
·期 3
·411-418
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IF 1.063
Huang Libing,Liu Yueqi,Sang Xinyu,Song Jinghui,Hu Ping,Liu Yong
T he alum-borneol nanoemulsion(ABN), which combines the mineral medicine alum and the botanical medicine borneol, has been applied for approximately 40 years in the clinical treatment of burns, scalds, radiation dermatitis and shingles, and has a good curative effect. However, the current formula and dosage form of ABN pose problems of low borneol content and ease of precipitation, which greatly affects the efficacy of the drug. In this study, polyvinylpyrrolidone(PVP) was selected as a carrier mixed with different proportions of alum and borneol to produce alum-borneol-PVP fibers(ABPF) by electrospinning. The results showed that the stable system with good drug dispersion was 2:3(alum:borneol). The dissolution content of borneol from the ABPF was about 80% in 4 h, which was much higher than that of the alum-borneol liquid(ABL) and ABN. The ABPF membrane showed a more significant inhibitory effect on Staphylococcus aureus than the ABL and ABN. The composite fiber markedly increased the drug content of borneol, which was 800 times of that in ABN. The fiber had a higher solubility than the nanoemulsion in vitro , which is of great importance for the development of new forms for the clinical application of alum and borneol.
研究领域:
药剂学
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材料科学
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生物医学工程
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产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2012
·
IF 2.234
Hucheng Zhang,Dong Xu,Jianji Wang
High fluorescence efficiency is desired for the practical applications of semiconductor nanocrystals (NCs) in many fields. However, reducing photoluminescence (PL) efficiency is usually observed after ligand exchanges on nanocrystal surfaces due to the generation of surface defects. Here, we report the preparation of polyvinylpyrrolidone-capped CdSe NCs (CdSe/PVP), and show the PL enhancement of CdSe/PVP NCs under UV radiation in the air. The experimental results indicate that the PL-enhanced mechanism of the NCs in methanol results from passivation of the lyates in that they act as the hole-acceptors. By screening of hole scavenger, furthermore, it is found that ditertbutyl peroxide is a better passivators of surface defects, and promotes the PL efficiency of CdSe/PVP NCs to achieve a value 110 times higher than that of as-prepared CdSe/PVP NCs. The photopassivation in the presence of organic molecules provides a prefertial, inexpensive path to harvest NCs with high PL efficiency.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
Recent Patents on Nanotechnology
·
2023
·Vol. 19
·期 3
·453-465
·
IF 2
Muhammad Ali,Ya Li,Ji-Huan He
BackgroundBipolymeric nanofibers have gained significant attention in various fields due to their enhanced functionality, improved mechanical properties, and controlled release capabilities. However, the fabrication of these composite fibers with a well-defined polymer-polymer interface remains a challenging task.MethodsThe double bubble electrospinning setup was developed and simulated using Maxwell 3D to analyze the electric field. PVP and PVA polymers were electrospun simultaneously to create bipolymer nanofibers with an interface. The resulting nanofibers were compared with nanofibers made from pure PVA, PVP, and a PVA/PVP blend. The characterization of the nanofibers was performed using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA).ResultsThe SEM images showed the formation of PVA/PVP interfacial nanofibers aligned side by side, with a diameter of a few thousand nanometers on each side. By increasing the voltage from 20 kV to 40 kV during electrospinning, the diameter of the nanofibers on the PVA and PVP sides was successfully reduced by 60.8% and 66.3%, respectively. FTIR analysis confirmed the presence of both PVA and PVP in the bipolymeric interfacial nanofibers. TGA analysis demonstrated a weight retention of 14.28% compared to PVA, PVP, and the PVA/PVP blend even after degradation at 500°C. The Maxwell simulation of double bubble electrospinning revealed a stronger and more uniform electric field pattern at 40 kV compared to 20 kV.ConclusionThe study has demonstrated the potential of double bubble electrospinning for the fabrication of bipolymer nanofibers with an interface, opening new avenues and patents for the development of functional nanofibers.
研究领域:
材料科学
·
纳米技术
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DOI
高影响因子
JOURNAL OF POWER SOURCES
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2019
·
IF 7.467
Qian Yang,Xue Lang Gao,Hong Yue Wu,Yuan Yuan Cai,Qiu Gen Zhang,Ai Mei Zhu,Qing Lin Liu
Herein, a novel strategy to improve the performance of anion exchange membranes (AEMs) is adopted to build a crosslinked structure by tethering the rigid poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) backbone and the flexible poly(4-vinylphenol) (PVP) backbone using an oscillational chain. The incompatibility between the PPO and PVP backbones makes them self-aggregated resulting in occurrence of distinct microphase separation and development of ion transport channels in the AEMs to facilitate the transport of hydroxide ion. The microphase separation of the as-prepared AEMs has been revealed by transmission electron microscopy (TEM) and DI multimode atomic force microscopy (AFM). The existence of the hydrophilic PVP chain also ensures sufficient water uptake to enhance the conductivity of the AEMs. A maximum ionic conductivity of 134 mS cm −1 is achieved at 80 °C by the PPO-c-PVP-40% (40% is the molar content of PVP chains) membrane. A maximum power density of 173 mW cm −2 at 80 °C is obtained by a H 2 /O 2 single cell using the PPO-c-PVP-40% membrane electrode assembly . The PPO-c-PVP-40% membrane also exhibits robust alkaline stability (retains about 90% ionic conductivity after 480 h alkaline stability test) and excellent mechanical property. Those render the AEMs a potential membrane electrode material for fuel cell applications .
研究领域:
材料科学
·
能源化学
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产品关联
DOI
高影响因子
APPLIED ENERGY
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2022
·
IF 11.446
Rui-Long Wang,Ming-Jia Li,Dong Li,Yi-Wen Yang
In this paper, a novel microalgal attached membrane photobioreactor based on the modified polyvinylidene difluoride (PVDF) / polyvinyl pyrrolidone (PVP) composite membrane for microalgae direct air carbon capture is developed and optimized. The Computational Fluid Dynamics (CFD) simulation, molecular dynamic study (MDS) and experimental study are adopted to investigate the synergy between light transmission and fluid flow, CO 2 transmission mechanism inside the membrane and microalgae cells. The modified composite membrane is proposed and processed to improve the carbon sequestration rate of the microalgal attached membrane photobioreactor (AM-PBR). First, the synergy angle between the light transmission direction and fluid flow direction of the flat-plate photobioreactor (FP-PBR) is analyzed. To improve the synergy of light and fluid flow, the AM-PBR is proposed. Secondly, for the MDS part, the models of PVDF membrane and polytetrafluoroethylene (PTFE) membrane are developed. A three-layer simulation model is proposed to reveal the transmission mechanism of CO 2 from the gas-liquid layer to the microalgae cell membrane layer. Several parameters including CO 2 diffusion coefficient, CO 2 concentration profile and velocity profile of CO 2 are analyzed to compare the performance of different membranes and working conditions. Then, for verification of the simulation work, AM-PBR experiments are designed. To further enhance the CO 2 transmission and microalgae attached performance, different PVDF/PVP composite membranes are assessed. The carbon sequestration rate of the modified membrane is improved according to the experiments. Finally, the novel microalgae membrane photobioreactor with the modified PVDF/PVP membrane is developed and the carbon sequestration rate of the PBR system is improved. The results showed that the best ratio for PVDF and PVP is 2:1 with 20 wt% solution, and with this modified membrane the carbon sequestration rate of the PVDF/PVP-based AM-PBR is 18.61% higher than the original PVDF-based AM-PBRs. The proposed novel AM-PBR is especially useful for low-concentration CO 2 direct air carbon capture.
研究领域:
环境科学
·
生物技术
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产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Jiwen Li,Yaqian Duan,Linlin Wang,Jingjun Ma
The poor light absorption and low carrier separation efficiency of Titanium dioxide (TiO 2 ) limit its further application. The introduction of plasma metal Ag have the potential to solve these drawbacks owing to its plasma resonance effect. Thus core-shell structure Ag@TiO 2 plasma photocatalysts was prepared by using facile reduction method in this work. More specifically, Ag@TiO 2 composite catalysts with different Ag loading amounts were prepared in the presence of surfactant PVP. Ag@TiO 2 demonstrates excellent light absorption performance and photoelectric separation efficiency compared with pure TiO 2 . As a result, it displays excellent performance of Cr(VI) reduction under visible light. The optimal composite catalysts Ag@TiO 2 –5P achieves exceptional visible-light-driven photocatalytic Cr(VI) reduction efficiency of 0.01416 min −1 that is 2.29 times greater than pure TiO 2 . To investigate the role of PVP, we also synthesized Ag@TiO 2 -5 without PVP. The experimental results show that although Ag@TiO 2 -5 Cr(VI) reduction performance is superior to pure TiO 2 , it significantly decreases compared with Ag@TiO 2 –5P. The results of TEM and optoelectronic testing show that agglomeration of Ag particles leads to a decrease in the photoelectric separation efficiency of Ag@TiO 2 -5. The smaller Ag particles provide more active sites and demonstrating a stronger overall local surface plasmon resonance (LSPR) effect. DMPO spin-trapping ESR spectra testing indicates that ∙O 2 − and ∙OH are the main reactive species. This research provides a potential strategy to prepare Ag-based plasma photocatalysts for environment protection.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
COLLOID AND POLYMER SCIENCE
·
2020
·Vol. 298
·期 10
·1285-1291
·
IF 1.536
Xie Chuanbao,Leng Kangwei,Sheng Jie,Wang Xuemei,Li Qianmin,Song Liang,Liu Lei,Sun Hejing,Huang Xiaowen,Wang Zhongwei,Yu Qing
Poly(methyl methacrylate) (PMMA) microspheres were synthesized through visible light–induced photopolymerization of methyl methacrylate (MMA). 2,4,6-Trimethylbenzoyldipenylphosphine oxide (TPO), polyvinylpyrrolidone (PVP), and light-emitting diodes (LEDs) were used as the photoinitiator, stabilizer, and light source, respectively. No other additive was involved. The effect of LEDs, TPO, and PVP was discussed. Results showed that PMMA microspheres with the size of 0.5–0.8 μm could be obtained when LED@385 nm was the light source, and the content of TPO and PVP was 2 wt% and 30 wt% of MMA. Moreover, the possible formation pathway of PMMA microspheres was proposed based on the investigation of reaction time and addition method of PVP.
Graphical abstract
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2025
·
IF 6
Jing Chen,Yaqin Shi,Wenli Xue,Wenjing Liu,Rongfang Ma
Catechol is an important fine chemical raw material, and is widely used in the production of chemicals. However, this compound has low degradability and high toxicity, and was highly susceptible to release into the environment during production and application, posing a potential threat to ecosystems and human health. Therefore, in this paper, a PVP-functionalized NH 2 -Ti-MOF was synthesized using PVP as a shape-controlling agent, NH 2 -BDC as an organic ligand, and TBOT as a metal source. A sensor for dual-mode detection of catechol was constructed based on the interaction between catechol and PVP-NH 2 -Ti-MOF. When catechol was added to the probe solution, the fluorescence intensity at 428 nm was found to decrease based on the static quenching effect. At the same time, it was found that a new ultraviolet absorption peak appeared at 282 nm in the ultraviolet absorption spectrum, and the absorption peak intensity increased with the increase of catechol concentration, thus realizing the dual mode detection of catechol. Compared with the single-mode sensor, the dual-mode sensor is more accurate, fast and sensitive, which provides a new idea for the detection of catechol in water samples.
研究领域:
环境化学
·
材料科学
·
传感器与生物传感器
·
分析化学
✓ 已验证
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）