Micronization of curcumin with biodegradable polymer by supercritical anti-solvent using micro swirl mixer

Curcumin is a hydrophobic polyphenol compound exhibiting a wide range of biological activities such as anti-inflammatory, anti-bacterial, anti-fungal, anti-carcinogenic, anti-human immunodeficiency virus, and anti-microbial activity. In this work, a swirl mixer was employed to produce the micronized curcumin with polyvinylpyrrolidone (PVP) by the supercritical anti-solvent process to improve the bioavailability of curcumin. The effects of operating parameters such as curcumin/PVP ratio, feed concentration, temperature, pressure, and CO₂ flow rate were investigated. The characterization and solubility of particles were determined by using scanning electron microscopy, Fourier Transform Infrared spectroscopy, and ultra-violet-visible spectroscopy. The result shows that the optimal condition for the production of curcumin/PVP particles is at curcumin/PVP ratio of 1:30, feed concentration of 5 mg·mL⁻¹, temperature of 40 °C, pressure of 15 MPa, and CO₂ flow rate of 15 mL·min⁻¹. Moreover, the dissolution of curcumin/PVP particles is faster than that of raw curcumin.     

交联聚乙烯吡咯烷酮的生产应用与市场前景

概述了交联聚乙烯吡咯烷酮的理化性质、制备、应用情况及其市场前景。     

Synergistic enhancement of polyvinylpyrrolidone-modified TiO2 and graphene oxide on the corrosion resistance of waterborne epoxy

Waterborne epoxy (WEP) resins have garnered significant interest due to their potential application as anticorrosion coatings for steel materials. However, it has been reported that defects in the cured coatings generated during the curing process lead to the level of anticorrosion not meeting the expected effects. In this study, TiO₂ and GO were selected to be modified by polyvinylpyrrolidone (PVP) to obtain PT and PG, and used to improve the anticorrosion performance of WEP. The obtained PT and PG were characterized using Fourier transform infrared, Raman, and x-ray photoelectron spectroscopy. The morphology of PT and PG before and after modification was observed using scanning electron microscopy, and the differences were described. The analysis results of laser confocal scanning microscopy and water contact angle (WCA) indicate that there are differences in surface roughness and WCA of the WEP coatings with or without PT and PG. Electrochemical impedance spectroscopy was used to evaluate the anticorrosion performance of the coatings. The results showed that WEP coatings containing PT and PG exhibited better anticorrosion performance. The synergistic enhancement of PT and PG on the anticorrosion performance was proposed, which can be attributed to the comprehensive effect of the hydrophobicity of the coating surface and the barrier effect of PT and PG within the coatings.     

Purification and structural characterisation of lipid transfer protein from red wine and grapes

Lipid transfer proteins (LTP) play a major role in plant defence and are of particular interest due to their known ability to cause allergic reactions. These proteins are expressed in grapes and also remain detectable after vinification, especially in red wine. However, it remains unknown whether the protein undergoes any changes during the vinification process. Here, we present a purification method for LTPs from Dornfelder grapes and wine. By liquid-chromatography–mass spectroscopy (LC–MS/MS) we identified LTPs from two different species (Vitis vinifera and Vitis aestivalis). Additionally, the purified LTPs were characterised using spectrometric methods, confirming their high purity and structural stability during vinification. We conclude that LTPs are resistant to the alcohol content (13.5 vol%), acidic milieu of wine and other ingredients present during the vinification process, indicating that the allergenic potential of grape LTP is not diminished by the vinification process.     

黏附剂对预涂厌氧胶性能的影响

以黏附剂种类及含量作为试验因素,以预涂厌氧胶A组分和预涂螺栓的外观、预涂螺栓装配时的状态、初固时间和扭矩强度等为考核指标,采用单因素试验法优选出制备预涂厌氧胶的最优方案。研究结果表明:当PVP(聚乙烯吡咯烷酮)-K30为黏附剂、w(PVP-K30)=2.0%(相对于厌氧胶总质量而言)时,预涂厌氧胶的综合性能相对最好。     

Preparation of Polymer-stabilized Palladium–silver Bimetallic Nanoparticles by γ-irradiation and their Catalytic Properties for Hydrogenation of cis,cis-1,3-Cyclooctadiene

Polyvinypyrrolidone (PVP)-stabilized Pd-Ag bimetallic colloids were successfully prepared in an acetone:2-propanol solution mixture of palladium acetate and silver perchlorate, and in an aqueous solution of palladium nitrate and silver nitrate by γ-irradiation. The prepared PVP-stabilized bimetallic nanoparticles were characterized by UV, TEM, XRD, and XPS. In Pd–Ag bimetallic nanoparticles, the XPS data indicated that the constituent elements were in the metallic state, and the palladium atoms were concentrated on the surface of the alloy cluster. These PVP-stabilized bimetallic nanoparticles were used as catalysts for hydrogenation of cis,cis-1,3-cyclooctadiene (COD).     

聚乙烯吡咯烷酮的合成及其在定型剂啫喱中的应用

N-乙烯基吡咯烷酮(NVP)通过自由基溶液聚合方法合成聚乙烯基吡咯烷酮(PVP),通过调节引发剂偶氮二异丁腈(AIBN)的用量和催化剂NaHCO3溶液浓度调控PVP的质均分子量,制备出适用于定型剂啫喱所需的PVP。结果表明,当m(AIBN)∶m(NVP)为0.4%、NaHCO3溶液浓度为0.4 mol/L、聚合温度70℃、聚合时间2 h条件下,合成的PVP质均分子量为66 829;其所配制的定型剂啫喱对头发卷曲保持率为86.9%,且具有光泽度好、易清洗、不易发粘、梳理性好等性能。     

Comparison of relative viscosity measurement of polyvinylpyrrolidone in water by glass capillary viscometer and differential dual‐capillary viscometer

The relative viscosity (RV) of polyvinylpyrrolidone (PVP) with different molecular weights was measured with a glass capillary viscometer and with a differential dual‐capillary viscometer in water at different concentrations. For the differential dual‐capillary viscometer, RV increases with a decreasing flow rate, especially for high molecular weight PVP at a 1% concentration. A good agreement in the RV between the two methods can be obtained for PVP with different molecular weights and at various concentrations if an appropriate flow rate is selected for the differential dual‐capillary viscometer. Special precaution is needed when using the differential dual‐capillary viscometer to measure the viscosity of a pure solvent. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1312–1315, 2002     

花片状钌纳米颗粒的控制合成

以三氯化钌为前驱体、聚乙烯吡咯烷酮（PVP）为稳定荆、三缩四乙二醇（TEG）和Zn粉为还原剂,于170℃反应2h。再加入适量十六烷基三甲基溴化铵（CTAB）,继续反应4h成功制得花片状Ru纳米颗粒。反应体系中最适宜RuCl2：PVP：CTAB：Zn（摩尔比）为1：20：1：1．5。产物用透射电子显微镜（TEM）、X-射线粉末衍射（XRD）、紫外可见吸收光谱（UV—Vis）等进行了表征。     

聚乙烯吡咯烷酮对PESA-H2O-SiC悬浮液流变性能的影响

研究了聚乙烯吡咯烷酮(PVP)对聚环氧琥珀酸(PESA)稳定的水基碳化硅(SiC)悬浮液流变性能的影响.结果表明,在pH值为9.0时,添加一定比例的少剂量的二元分散剂即可改善SiC悬浮液的分散性.当分散剂总添加量为0.4wt％,PESA与PVP的质量之比为3∶1时,悬浮液的流变性最佳.固含量为40vo1％时,PESA稳定的SiC悬浮液完全絮凝,而添加PVP作为第二分散剂可使体系较好的分散.此外,添加二元分散剂PESA/PVP显著提高了SiC悬浮液的抗电解质性能.