Journal of Environmental Chemical Engineering
·
2019
·
IF 0
Limei Cao,Qian Wang,Ji Yang
A novel ultrafine Pt/Beta catalyst supported on carbon paper was prepared and applied to selective catalytic reduction of NO x by H 2 at a low temperature below 90 °C. Here, 0.8 wt.% Pt/Beta reached approximately 100 % NO conversion at 90 °C under oxygen-rich conditions (1000 ppm NO, 1 % H 2 , and 4 % O 2 ). The influence of the dispersion and particle size of Pt on the catalytic performance was investigated using Polyvinylpyrrolidone (PVP) as a structure directing agent to regulate the Pt particles. The feeding amount of PVP significantly influenced the catalytic activity of the catalysts. When the feeding amount was less than 50 mg, the Pt particle size was smaller, and the dispersion was higher, providing a higher NO conversion. However, when the feeding amount exceeded 50 mg, the dispersion no longer increased, and the activity slightly decreased. N 2 physisorption (BET) confirmed that excessive PVP decreased the specific surface area, which suppressed the catalytic activity of Pt/Beta. Moreover, the NO conversion efficiency was dependent on the dispersion and particle size of Pt and was minimally affected by the surface area of the catalysts. The Pt/Beta catalyst system was deactivated, and an irreversible poisoning phenomenon for SO 2 was observed. Zr, Ce, and V were introduced into the catalyst system as metal auxiliaries . The Ce-modified Pt-Ce/Beta catalyst prepared in this study showed resistance to SO 2 .
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
JOURNAL OF CRYSTAL GROWTH
·
2022
·
IF 1.83
Quanxiu Wang,Can Li,Lanmeng Wei,Chenglian Lu,Mengyao Chen,Hanmin Yang,Leilei Guo,Hongbin Duan
In this study, urchin-like ruthenium nanostructures (Ru NS), with an average size of approximately 30.2 nm, were successfully fabricated by reduction ruthenium chloride (RuCl 3 ) in benzyl alcohol-glycerol mixed solvents, and using Polyvinylpyrrolidone (PVP) as the stabilizing agent under microwave irradiation for 240 s. The as-synthesized Ru NS were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), ultra violet-Visible (UV–Vis) absorption spectroscopy , X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectra. The results indicated that the as-prepared urchin-like Ru NS were self-assemblies organized by smaller primary nanoparticles with an average size of about 1.7 nm. Some key factors, such as the microwave assisted heating method, and the types of solvents, were identified affecting the successful synthesis of self-assembly urchin-like Ru NS. A possible growth mechanism for the novel Ru structures has been proposed, and the urchin-like Ru NS have been formed through a self-assembly aggregation mechanism driven by an overgrowth mode.
研究领域:
材料科学
·
纳米技术
·
化学合成
✓ 已验证
产品关联
DOI
高影响因子
Materialia
·
2019
·
IF 0
Zhuangzhuang Wen,Fujian Jiang,Feng Wu,Zhuping Yin,Kulwinder Kaur,Juhi Chakraborty,Sourabh Ghosh,Shenzhou Lu
Photocurable hydrogels enable simple and fast sol-gel transformation and have broad application prospects in biomedical research. In this paper, we report the development of photoinitiated polymerization of N-Vinyl-2-pyrrolidone (NVP) monomer to Polyvinylpyrrolidone (PVP) and interpenetrating network with silk fibroin macromolecular hydrogel. This novel hydrogel material has nearly 100% light transmission and excellent mechanical properties , which opens new possibilities in targeted drug delivery, tissue regeneration, cell encapsulation, bioprinting.
研究领域:
生物材料
·
组织工程
·
药物递送
✓ 已验证
产品关联
DOI
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2020
·
IF 2.627
Yanna Wu,Jianxian Zeng,Yajie Zeng,Hu Zhou,Guoqing Liu,Jian Jian,Jie Ding
Hydrophilic modification is a promising method to inhibit fouling formation on ultrafiltration membrane. In this work, different mass concentrations (1%–16%) of hydrophilic polyvinylpyrrolidone were incorporated into polyethersulfone (PES) membranes fabricated by none-solvent induced phase separation. Then, polydopamine (PDA) coating on the surface of prepared membrane was carried out at pH 8.5. The morphology and structure, surface hydrophilicity, permeation flux, BSA rejection, antifouling and stability performances of PES and PDA/PES modified membranes were investigated in detail. The results indicated that PDA was successfully attached onto the membranes. Membrane hydrophilicity was evaluated by water contact angle measurement. The contact angles of modified membranes reduced remarkably, suggesting that the membrane hydrophilicities were significantly increased. The results of filtration tests, which were done by dead-end filtration of bovine serum albumin solution, showed that the properties of permeability and fouling resistance were obviously improved by PDA modification. When polyvinylpyrrolidone mass content reached 10%, flux recovery ratio of modified membrane was up to 91.23%, and its BSA rejection were over 70%. The results of stability tests showed that the modified membranes had good mechanical stability and chemical stability. This facile fabrication procedure and outstanding performances suggested that the modified membranes had a potential in treating fouling.
研究领域:
材料科学
·
环境工程
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Mechanical Behavior of Biomedical Materials
·
2023
·
IF 3.9
Yaoxin Wang,Zhenyu Zong,Ning Ding,Zutai Zhang
Objective This study aimed to investigate the effects of polyvinylpyrrolidone (PVP)-containing primer (PCP) on dentin bonding. Methods PVP and anhydrous ethanol were used to prepare the PCPs, which were prepared at concentrations of 0.5%, 1%, and 2% (w/v). These PCPs were subsequently applied to the dentin surface , denoted as E1, E2, and E3, respectively. In the control group, no primer was applied. Following the treatment, the dentin surfaces were subjected to analysis using Fourier-transform infrared spectroscopy (FTIR), and the micro-tensile bond strength (MTBS) was evaluated. The failure mode, nanoleakage, and bonding longitudinal section were observed utilizing scanning electron microscopy (SEM). Additionally, the effect of PCPs on matrix metalloproteinases (MMPs) activity was analyzed through an in situ zymography test. Data were subjected to statistical analysis using ANOVA tests (α = 0.05). Results Significant alterations in the infrared resonances associated with collagen cross-linking within the collagen matrix were observed across all PCP groups. The application of PCP demonstrated a noteworthy enhancement in micro-tensile bond strength (MTBS) compared to group C (p < 0.05). Notably, group C exhibited the lowest MTBS (41 ± 7.7 MPa), whereas group E2 demonstrated the highest MTBS (66 ± 11.9 MPa). Even after undergoing aging, the MTBS of the PCP groups remained superior to that of group C (p < 0.05). The resin tag length in the PCP groups was found to be greater than that of group C, and the occurrence of nanoleakage was comparatively lower in the PCP groups, both before and after aging. Additionally, PCP exhibited a dose-dependent inhibition of matrix metalloproteinases (MMPs) activity, which was statistically significant (p < 0.05). Conclusions The utilization of PCP Primer exhibits notable enhancements in bond strength, mitigates nano-leakage, and suppresses enzyme activity within the hybrid layer .
研究领域:
牙科学
·
生物材料学
✓ 已验证
DOI
高影响因子
Applied Nanoscience
·
2021
·Vol. 11
·期 8
·2271-2280
·
IF 3.674
Liu Yueqi,Li Chenxi,Chen Jia,Han Yufen,Wei Ming,Liu Jun,Yu Xiaomin,Li Fangjun,Hu Ping,Fu Lulu,Liu Yong
Rifampicin (RIF) and Isoniazid (INH) are two first-line drugs for tuberculosis treatment. Compared to isoniazid, rifampicin has poor water solubility, which results in low bioavailability. Combining the two drugs can improve the treatment effect of tuberculosis, but thier direct contact may accelerate the degradation of rifampicin, which is also considered to be another reason for RIF’s low bioavailability. In this study, the polyvinylpyrrolidone (PVP) was selected as the carrier and mixed with the loaded drug of rifampicin and isoniazid separately. The quick-released rifampicin/isoniazid-polyvinylpyrrolidone mingled fibers (RIPMF) were fabricated by the electrospinning method to promote the absorption of rifampicin. The results showed that isoniazid-polyvinylpyrrolidone (INH-PVP) nanofibers and rifampicin-polyvinylpyrrolidone (RIF-PVP) microfibers were mixed in RIPMF, instead of two drugs coexisting in one fiber. Rifampicin and isoniazid in the fibers changed from crystalline to amorphous states, which facilitated the release of the rifampicin from the fibers. The hydrophilicity of RIF-PVP fibers was not distinct, but that of RIPMF increased with the addition of INH-PVP fibers. The release rate of rifampicin in rifampicin-loaded fibers was twice as fast as rifampicin powder. Additionally, in vitro antibacterial test showed that RIPMF had an obvious inhibition effect on Staphylococcus aureus . Finally, the rifampicin-loaded fibers enhanced the release rate of rifampicin and improved its bioavailability. Increased bioavailability reduces the waste of rifampicin and prevents damage to the kidneys due to the massive metabolism of rifampicin in biomedicine.
研究领域:
药学
·
材料科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 11
·1563
·
IF 2.7
Weichen Zhang,Lu Li,Chuanyong Li,Yanhua Sun,Muhammad Dilawer Hayat,Yugeng Li,Gang Chen,Zhentao Yuan,Xiao Wang
In water-soluble binder systems, polyethylene glycol (PEG) and polymethylmethacrylate (PMMA) are often used as primary and secondary components. The PEG/PMMA binder system is clean and environmentally friendly, but the discrepancy between the crystallization temperature of PEG and the glass transition temperature of PMMA leads to the generation of pores in the feedstock. The solidification pores have an adverse impact on the final mechanical properties of the samples. Polyvinylpyrrolidone (PVP), as a crystallization inhibitor, can inhibit the formation of porosity. In this study, spherical titanium powder with a diameter of less than 45 μm was used as metal powder; the binder system consisted of PEG, PMMA and SA. Different increments of PVP (0, 10%, 20%, 30 wt.%) were added to the PEG/PMMA binder system. The uniformity of the feedstock and the open channels generated after debinding were observed using SEM. The pores’ condition before and after debinding was studied using Micro CT, and the mechanical properties of the samples were also detected. By comparing the macroscopic and microscopic morphologies of the injected samples and mechanical properties of the sintered samples, it was found that a PVP content of 20 wt.% resulted in the best properties.Keywords:metal injection molding;water-soluble binder;crystallization inhibitor;morphology;mechanical properties
研究领域:
材料科学
·
制造工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 3
·期 6
·2770-2775
·
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
✓ 已验证
DOI
Acta Biomaterialia
·
2012
·
IF 4.865
D.G. Yu,X. Wang,X.Y. Li,W. Chian,Y. Li,Y.Z. Liao
The capability of core/sheath nanofibers prepared using coaxial electrospinning to provide adjustable biphasic drug release was investigated. Using ketoprofen (KET) as the model drug, polyvinylpyrrolidone as the sheath polymer, and ethyl cellulose as the core matrix, the coaxial process could be conducted smoothly and continuously without spinneret clogging. Scanning electron microscopy and transmission electron microscopy revealed linear nanofibers with homogeneous and clear core/sheath structures. Differential scanning calorimetry and X-ray diffraction verified that the core/sheath nanofibers were nanocomposites , with the drug present in the polymer matrix in an amorphous state. Attenuated total reflectance–Fourier transform infrared spectra demonstrated that the sheath polymer and core matrix were compatible with KET owing to hydrogen bonding . In vitro dissolution tests showed that the core/sheath nanofibers could provide typical biphasic drug release profiles consisting of an immediate and sustained release . The amount of drug released in the first phase was tailored by adjusting the sheath flow rate , and the remaining drug released in the second phase was controlled by a typical diffusion mechanism. The present study shows a simple and useful approach for the systematic design and fabrication of novel biomaterials with structural characteristics for providing complicated and programmed drug release profiles using coaxial electrospinning.
研究领域:
材料科学
·
药学
✓ 已验证
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2018
·Vol. 296
·期 2
·335-340
·
IF 1.967
Hu Chang,Du Zhiping,Tai Xiumei,Mao Xuebin,Liu Xiaoying
In this paper, the physicochemical properties between sodium dodecylbenzenesulfonate (SDBS) and polyvinylpyrrolidone (PVP) in aqueous solutions were studied at 25 °C by Ubbelohde viscometer, conductivity analyzer, and fluorescence spectrophotometer. It was found that viscosity, conductivity, steady-state fluorescence, and Rayleigh scattering curve for SDBS-PVP system could be divided into three regions by two characteristic concentrations: the critical aggregation concentration (cac) and the polymer saturation point (psp). The results revealed that interactions between SDBS and PVP molecules in aqueous solutions could be explained by “necklace and bead” model. Micelle-like surfactant aggregates, formed by SDBS-free molecules, associated with PVP chains mainly by hydrophobic interaction.
研究领域:
物理化学
·
表面活性剂科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2019
·
IF 2.121
Libing Huang,Kuan Cao,Ping Hu,Yong Liu
How to improve the bioavailability of the Sanguis Draconis (SD) is an important problem in the potential clinical applications. The aim of this study was to develop a drug delivery system to achieve high bioavailability of SD, a drug with poor water solubility. It will promote the research about new formulations of the SD and the other insoluble drugs. In this study, a highly biocompatible hydrophilic polymer, polyvinylpyrrolidone (PVP), was selected as a carrier, mixed with different proportions of SD to produce SD-PVP microfibers by solution electrospinning. By orthogonal experiments, the optimal spinning conditions of the preparation of SD-PVP fibers were investigated. The morphology of different proportions of SD-PVP microfibers was observed by scanning electron microscopy, and the phase characteristics were characterized by Fourier transform infrared spectrometry, X-ray diffraction, and differential scanning calorimetry. The hydrophilic properties of SD-PVP fiber membranes with different SD content were analyzed by the water contact angle assay. In vitro dissolution experiments were carried out to observe the dissolution of drugs in SD-PVP fiber membranes. The results showed that the diameter of SD-PVP fibers increased with the enlargement of SD content. A eutectic mixture was formed after blending PVP and SD, and the hydrogen bonds were formed between the SD and PVP with no chemical reaction occurred. The dispersion of SD in the fiber decreased with the increase of SD content. The higher the content of SD in the fiber, the more hydrophobic the fiber membrane. In vitro dissolution studies revealed that the dissolution content of SD from SD-PVP microfibers was significantly higher than that of the pure or original drug SD. However, as the SD content increased from 15% to 30%, the dissolution of the drug in the SD-PVP fibers decreased. The SD-PVP fiber prepared in this study showed much higher solubility than the original drug in vitro, which has great significance for the development of new dosage forms for the clinical application of SD, and it has a useful reference for the study of similar bioavailability of poorly soluble drugs.
研究领域:
药剂学
·
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 7
·1-14
·
IF 2.8
Guo Yan,Zhang Xinxu,Zhang Rui,Li Aiyuan,Zhang Jiawen,He Hui
In this work, Bi 2 O 3 and Bi 2 S 3 nanomaterials are modified with polyvinylpyrrolidone (PVP). The products are defined as Bi 2 O 3 @PVP and Bi 2 S 3 @PVP, respectively. SEM demonstrates that the addition of PVP helps to reduce the size of Bi 2 O 3 and Bi 2 S 3 nanomaterials. XRD exhibits that the structure of Bi 2 O 3 changed from α-Bi 2 O 3 to β-Bi 2 O 3 @PVP due to the addition of PVP, while the Bi 2 S 3 configuration remained unchanged. XPS demonstrates that excess PVP leads to a partial reduction of trivalent Bi 3+ to metallic Bi 0 . Their supercapacitive performances are tested and it is found that appropriate PVP can improve the capacitive performance and cyclic stability of both Bi 2 O 3 and Bi 2 S 3 . The specific capacitance of Bi 2 O 3 @1 g PVP is 1.4 times that of the pristine Bi 2 O 3 , and the specific capacitance of Bi 2 S 3 @1 g PVP is 1.8 times that of the pristine Bi 2 S 3 . Compared with 82.0% Bi 2 O 3 and 79.6% Bi 2 S 3 , the cyclic retention is 94.7% and 95.2% for Bi 2 O 3 @1 g PVP and Bi 2 S 3 @1 g PVP after 10,000 cycles. The reason for enhancement is that PVP can support Bi 2 O 3 and Bi 2 S 3 materials, not only to support their structural stability but also to reduce their size and facilitate electron transfer and ion diffusion.
研究领域:
材料科学
·
电化学
✓ 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）