PVP-PdCl2-SnCl4/MontK10-PEG400的制备及催化芳香卤化物水相脱卤研究

用PVP(聚乙烯吡咯烷酮)络合双金属Pd2 ,Sn4 后，再负载于PEG400(平均式量为400的聚乙二醇)官能化的蒙脱土上，制成双金属催化剂PVP-PdCl2-SnCl4/MontK10-PEG400，用于催化不溶于水的芳香卤化物水相脱卤，对芳香氯化物呈现出高的脱氯活性和选择性，并有良好的重复使用性，通过IR，TEM，XPS等手段测定对催化剂各组分在催化脱卤中的作用进行了探讨．     

保护剂对K2PtCl6为前体合成纳米铂形状的影响

纳米粒子的性质不仅受到尺寸的影响，还与其形状密切相关，由于铂在催化及材料等领域中有重要应用，因此化学合成特定形状的纳米铂一直备受关注，具有特定表面结构的纳米粒子对于研究催化活性与表面原子结构的关系具有重要意义，目前立方体形状纳米铂已被合成，但高比例四面体形状纳米铂的合成研究很少有报道，     

水溶性非离子大分子与烷基硫酸钠同系物团簇化的比饱和簇集量

研究了烷基硫酸钠同系物(ROSO₃Na)与聚乙二醇(PEG)及聚乙烯吡咯烷酮(PVP)的γ-lgc曲线的双拐点特征,根据拟双平台现象求得烷基硫酸钠同系物对大分子的饱和簇集量Γ_∞(mmol/L)和比饱和簇集量[Γ_∞].由Γ_∞-cP回归方程的斜率得到ROSO₃Na-PEG及ROSO₃Na-PVP体系的[Γ_∞]_reg分别为0.394和0.415m/n.[Γ_∞]随表面活性剂疏水基链长、大分子分子量及浓度的变化均很小,t检验结果表明回归值[Γ_∞]_reg与实验值[Γ_∞]_exp之间无明显差异,因此超分子相互作用参数[Γ_∞]可以被视为不变量.烷基硫酸钠同系物的类胶束与大分子形成软物质团簇的作用方式为静电超分子自组装.     

Evaluation of dispersion state of the two racemic compounds of troglitazone in pharmaceutical granules using IR-to-THz imaging

Troglitazone exists as four isomers in equal amount and these isomers compose two racemic compounds, RR/SS and RS/SR. The objective of this study was to discriminate between the racemic compounds and between the crystal and amorphous forms of troglitazone in solid dispersions (SDs) using IR-to-THz imaging. SDs of troglitazone with polyvinylpyrrolidone (PVP, carrier) were prepared by the closed melting method. SDs were heated at various temperatures and water content. The mid-to-far infrared measurements for the powder samples were performed by using the synchrotron radiation source at the BL43IR in SPring-8. Crystalline RR/SS (L) and RS/SR (H) showed different spectra, that is, each form had a specific peak, respectively. However, amorphous forms prepared from each crystalline form exhibited the same spectra. Using the chemo-metric analysis, the existing component was decided in each pixel and the distribution of crystalline L, H and amorphous troglitazone in SDs could be illustrated. For the sample heated at 105 °C, 75%RH, scattered plots of H and amorphous against PVP showed the trend for H was negative; on the other hand, amorphous showed positive correlation. This result suggested that H existed separately, whereas amorphous would be dissolved in PVP. Based on these evaluations, it was clear that the physical state and distribution of troglitazone in SDs, including the discrimination between L, H, and amorphous, reflect the preparation conditions. Chemical imaging can observe a difference in the dispersed state of drug and ingredient in a visible image by performing statistical processing.     

Effect of polyvinylpyrrolidone as capping agent on Ce3+ doped flowerlike ZnS nanostructure

Nanoparticles of zinc sulfide doped with Ce³⁺ have been synthesized through a simple chemical precipitation method utilizing optimum dopant concentration (1.5 g) and employing various concentrations of polyvinylpyrrolidone (PVP, M.W: 40,000) as capping agent. The optical properties of the synthesized products were studied by UV–Vis absorption and photoluminescence measurements. The phase and size of the products were predicted by X-ray diffraction data. The existence of functional groups in the synthesized products was identified by Fourier transform infrared spectroscopy. Field emission scanning electron microscope results of Ce³⁺ doped ZnS show a uniform growth pattern of the nanorods with flowerlike structure. However, on surfactant assisted Ce³⁺ doped ZnS nanoparticles, the morphology of the products was changed from rod to spherical particles. The morphologies of the uncapped and PVP capped ZnS nanocrystals were confirmed by high resolution transmission electron microscopy.     

THE PREPARATION OF DOXORUBICIN- POLYVINYLPYRROLIDONE-NANOPARTICLES BY INVERSE EMULSION POLYMERIZATION

Doxorubicin-loaded nanoparticles, using doxorubicin (ADM) as model drug and vinylpyrrolidone as matrix, were prepared by inverse emulsion polymerization in the paper. The nanoparticles were characterized by telescope electron microscopy (TEM), laser light scattering technique (LLS) and infrared spectrum (IR). LIS test showed that the optimal prepared ADM-loaded nanoparticles had an average size 18.8nm and a narrow size distribution between 15nm and 32nm, which was consistent with the result obtained by TEM. And IR results indicated that the nanoparticles consisted of ADM and polyvinylpyrrolidone (PVP).     

Isoconversional kinetics of degradation of polyvinylpyrrolidone used as a matrix for ammonium nitrate stabilization

Thermogravimetric analyzer (TGA) has been applied to measure the kinetics of the thermal degradation of virgin polyvinylpyrrolidone (PVP) and a phase stabilized PVP–ammonium nitrate (AN) material. The PVP–AN samples have been prepared by using 20 wt.% of AN and PVP of three different molecular weights. Virgin PVP undergoes a major mass loss in the region 380–550 °C leaving a small amount of nonvolatile residue. The application of an advanced isoconversional method to the respective degradation process demonstrates that its effective activation energy increases from 70 kJ mol⁻¹ to a plateau value at 250–300 kJ mol⁻¹, which is independent of the molecular weight. The PVP–AN materials lose spontaneously 20% of their mass on heating above the glass transition temperature of the PVP matrix (160–180 °C). After the escape of AN, the remaining PVP matrix degrades in the same temperature region as virgin PVP, however, the effective activation energy of this degradation is 150–200 kJ mol⁻¹.     

Electrospinning Preparation of β-Cyclodextrin/Glutaraldehyde Crosslinked PVP Nanofibrous Membranes to Adsorb Dye in Aqueous Solution

The insoluble β-cyclodextrin/glutaraldehyde crosslinked polyvinylpyrrolidone nanofibrous membranes were prepared by electrospinning technique. The membranes were extensively characterized by various techniques including attenuated total reflectance Fourier transform infrared spectroscopy（ATR-FTIR）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and UV-visible absorption to correlate membrane characteristics with their performance. The adsorption ability of the nanofibrous membranes was tested by performing extraction of Methyl orange（MO） dye in water. It was observed that β-cyclodextrin incorporated in polyvinylpyrrolidone provided the characteristics of high adsorption capacity of polyvinylpyrrolidone. Results of sorption experiments show that the nanofibrous membranes exhibited an adsorption rate of more than 95% for MO and the MO absorbent was 39.82 mg to per gram of fl-cyclodextrin glutaraldehyde（β-CDXFM） crosslinked PVP under the optimized experimental conditions.     

聚酰亚胺的微球化

依据缩聚反应的特点, 提出了一条聚酰亚胺微球的有效制备路线, 通过在缩聚溶液和沉淀剂中加入聚乙烯基吡咯烷酮(PVP)改变体系特性. 探讨了PVP及沉淀剂对微球形貌、粒径及分布的影响. 结果表明, 在二胺与二酐缩聚溶液中加入PVP可以得到较好的球形聚合物颗粒; 增加PVP含量, 微球粒径减小且分布均匀, 而分子量有所降低; 以水为沉淀剂所得微球的形貌优于乙醇沉淀剂, 并且随着PVP用量的增加, 微球粒径减小, 均匀性亦随之提高. PVP在制备过程中分别呈现出成核、成球及分散稳定的作用, 从而实现了聚酰亚胺材料在微米尺度上的微球化.     

Synthesis and characterization of polyvinylpyrrolidone immobilized on magnetic nanoparticles modified by ionic liquid as a novel and recyclable catalyst for the three‐component synthesis of amidoalkyl naphthols

In this study, an efficient and green procedure is explained for the preparation of 1‐amidoalkyl‐2‐naphthols applying one‐pot condensation reaction of 2‐naphthol, amide and aromatic nanoparticles (Fe₃O₄@SiO₂@IL‐PVP) as a novel solid acid catalyst under solvent‐free conditions. The remarkable features of this method are short reaction time, high conversions, and high yield of product, easy workup procedures and solvent‐free conditions. The Fe₃O₄@SiO₂@IL‐PVP catalyst was characterized via Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction patterns (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), and energy‐dispersive X‐ray spectroscopy (EDS). Also, nanocatalysts could be easily recovered by a simple magnet and reused for the next reactions without significant loss of its catalytic activity.