改性SiO_2粒子制备超疏水表面的研究

通过改性SiO2粒子和其他几种物质共混配制涂料,在PVC膜材上进行涂层烘干并焙烘,获得超疏水涂层表面。讨论了几种物质的用量对表面性能及形态的影响;初步探索了表面微结构对接触角的影响。利用改性SiO2粒子成功制备出了超疏水表面;获得了最佳涂层工艺条件;结构的粗糙度对接触角有着直接的影响。     

Some synergistic properties of N- Alkyl- 2- pyrrolidones,a New class of surfactants 1

N-Alkylpyrrolidones, a new class of commercial surfactants, interact synergistically with anionic surfactants. Mixtures of the N-2-ethylhexyl-(C2,6P), N-octyl-(C8P), N-decyl-(ClOP), and N-dodecyl-(C12P) pyrrolidones with commercial linear sodium alkylbenzenesulfonate (LAS) were investigated. Measurements of the molecular interaction parameters,β ^a, and β^M, for mixed monolayer formation and mixed micelle formation, respectively, in these mixtures indicated that the first three compounds show synergism in surface tension reduction efficiency and all four compounds show synergism in surface tension reduction effectiveness, when mixed in the proper proportions with LAS. This was confirmed experimentally. The N-alkylpyrrolidone-LAS mixtures also exhibit synergism in Ross-Miles foaming and in Draves (skein) wetting. Presented at the 70th annual meeting of the American Oil Chemists’ Society, Phoenix, Arizona, May 9, 1988. JAOCS, Vol. 66, no. 7 (July 1989)     

阻聚剂在乳液聚合中的行为(Ⅱ)——第Ⅰ类动力学体系?〈〈 0.5)

本文研究了水溶性阻聚剂(O_2)和油溶性阻聚剂(TBC)在第I类动力学乳液聚合体系(以醋酸乙烯乳液聚合为例)中的行为,它与第Ⅱ类动力学的乳液聚合有较大的差别.对油溶性阻聚剂的影响进行了数学模拟,模拟结果与实验结果比较吻合.     

TiO2-SiO2复合材料的制备和表征

采用水解法在SiO2表面包覆纳米TiO2,制备出TiO2-SiO2复合材料,并用IR、SEM、XRD及化学分析手段进行表征.结果表明:复合材料由纳米锐钛矿型TiO2和SiO2组成,它们之间有Ti-O-Si键形成,且该键对锐钛矿型TiO2起了稳定作用.试验研究并讨论了制备条件对包覆效果的影响.     

真空脱水法制备无水氯化铈的研究

研究了七水氯化铈真空脱水法制备无水氯化铈工艺.介绍了脱水过程的理论依据,考察了原料配比、脱水温度、脱水时间、真空度4个因素对无水氯化铈纯度的影响.综合单因素考察得到最佳脱水条件:氯化铵用量(氯化铵占氯化铵与七水氯化铈混合物的质量分数)为30%,真空度为0.04 MPa,脱除结构水的温度为160 ℃,真空脱水时间为200 min.在最佳脱水条件下,无水氯化铈纯度超过93%.     

Calculating structures and free energies of complex molecules: combining molecular mechanics and continuum models

A historical perspective on the application of molecular dynamics (MD) to biological macromolecules is presented. Recent developments combining state-of-the-art force fields with continuum solvation calculations have allowed us to reach the fourth era of MD applications in which one can often derive both accurate structure and accurate relative free energies from molecular dynamics trajectories. We illustrate such applications on nucleic acid duplexes, RNA hairpins, protein folding trajectories, and protein-ligand, protein-protein, and protein-nucleic acid interactions.     

超支化聚磷酸酯改性PP的研究

以新型的超支化聚磷酸酯(HPPE)对聚丙烯(PP)进行共混改性,研究了HPPE的用量和分子量对PP/HPPE复合材料性能的影响,还通过扫描电子显微镜(SEM)观察其试样冲击断面的微观形态并研究其增韧机理.结果表明,HPPE对PP/HPPE复合材料的冲击强度影响明显,当HPPE-1用量为3份时冲击强度可提高143.56%;熔体流动速率也有提高,但拉伸强度、弯曲强度和维卡软化点温度有微小下降,其增韧机理为两相"海-岛"结构增韧.     

改性SiO2在防污自洁表面处理中的应用

以硅烷偶联剂(KH570)为改性剂,采用溶胶-凝胶的方法制备出改性SiO2粉体;以DMF为溶剂,PVDF为主要成分,共混入拒水拒油剂和改性SiO2粉体,制备出可应用于软质PVC基材的防污自洁表面处理剂.实验结果表明:拒水拒油剂降低了基材的表面张力,改性SiO2粉体的加入起到提高基材表面微观粗糙度的作用,从而成功实现了在聚合物表面模拟荷叶效应的目的.     

Preparation of organic/inorganic hybrid nanomaterials using aggregates of star block copolymer consisting of poly(stearyl methacrylate) and poly(3‐(trimethoxysilyl) propyl methacrylate) as precursor

A series of star block copolymer consisting of poly(stearyl methacrylate) and poly(3‐(trimethoxysilyl)propyl methacrylate) was synthesized via atom transfer radical polymerization technique. The resultant polymers were characterized by gel permeation chromatography and ¹H NMR. The copolymer can self‐assemble into the aggregates in selective solvents, the resulting aggregates can be used as precursor to prepare hybrid nanomaterials conveniently via the hydrolysis reaction of ? Si(OCH₃)₃ groups and the condensation reaction of ? Si(OH)₃ groups. Moreover, the effect of the star copolymer‐solvent interaction on the aggregation behavior was also discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

预涂层处理技术在建筑膜材中的应用

为提高聚氯乙烯(PVC)膜材的剥离强度,采用较低黏度的PVC浆料对涤纶基材进行预涂层处理,研究了预涂层工艺对膜材剥离强度、拉伸强度、撕破强力的影响,并对膜材试样进行了电镜分析。结果表明:涤纶基材经预涂层处理后,可显著提高膜材的剥离强度,而对膜材的拉伸强度和撕破强力影响较小。