聚硅氧烷

Abstract(#br)Four polydimethylsiloxane (PDMS) coatings with different surface free energies have been prepared and applied to smooth and roughened aluminum plates to form hydrophobic and superhydrophobic surfaces. Their surface wettability in terms of water contact angle (CA), sliding angle (SA) and water droplet impact dynamics was studied under an ambient (50% relative humidity, RH at 25\u003cce:hsp sp=\"0.25\"/\u003e°C) and three different condensing environments (low, highly and extremely condensing, i.e. 30%, 60% and 90% RH at −10\u003cce:hsp sp=\"0.25\"/\u003e°C).

Abstract(#br)Transport properties of silica membranes derived from the oxidative thermolysis of crosslinked polydimethylsiloxane (PDMS) were studied between 35–100\u003cce:hsp sp=\"0.25\"/\u003e°C. Changes in pore morphology and transport properties were investigated for varying thermolysis and crosslinking treatments. Permeation and pressure-decay sorption measurements were made for CO 2 , H 2 , He, O 2 , N 2, and CH 4 . Physisorption data for CO 2 and N 2 were also analyzed to characterize the pore size distributions of these materials.

AbstractPolysiloxane-based polyurethane/lignin elastomers are synthesized via pre-polymerization. Isophorone diisocyanate (IPDI) reacts with polycarbonate (PCDL) and polydimethylsiloxane (PDMS) polyol to produce a linear thermoplastic elastomer. Lignin is added to the matrix of the polyurethane, where lignin not only acts as a crosslinking agent but also as filler. The effects of polysiloxane-based polyurethane/lignin elastomers on thermal properties, mechanical properties, surface hydrophobicity, and cytotoxicity in vitro are investigated.

Abstract\n\t\t\t\t\n\t\t\t\t\tIn this study, immobilizations of enzymes, invertase and glucose oxidase, were achieved in conducting copolymers of \n\t\t\t\t\t\tN-pyrrolyl terminated polydimethylsiloxane/polypyrrole (PDMS/PPy) matrices via electrochemical polymerization. The kinetic parameters, \n\t\t\t\t\t\tv\n\t\t\t\t\t\tmax (maximum reaction rate) and \n\t\t\t\t\t\tK\n\t\t\t\t\t\tm (substrate affinity), of both free and immobilized enzymes were determined.

摘要\n采用预聚法合成了聚硅氧烷基聚氨酯/木质素弹性体。异佛尔酮二异氰酸酯( IPDI )与聚碳酸酯( PCDL )和聚二甲基硅氧烷( PDMS )多元醇反应生成线性热塑性弹性体。木质素被添加到聚氨酯的基体中，其中木质素不仅作为交联剂而且作为填料。研究了聚硅氧烷基聚氨酯/木质素弹性体对其热性能、力学性能、表面疏水性和体外细胞毒性的影响。材料的耐热性、表面疏水性和机械强度得到了提高，MTT法检测发现材料对HeLa细胞的细胞毒活性降低，这与木质素的半互穿网络结构和低毒性有关。当木质素添加量为1 wt %时，细胞存活率提高到65.2 %，机械强度提高到17.1 Mpa，接触角提高到108.2°。

Novel silicone-based nanocomposites with varied elastic properties were prepared by blending standard polydimethylsiloxane (PDMS) with a lower viscosity component (hydroxyl-terminated PDMS) and integrating a graphene nanoplatelets (GNP) filler modified by strands of deoxyribonucleic acid (DNA). The curing behavior of these nanocomposites was studied by dynamic and isothermal differential scanning calorimetry.

将标准聚二甲基硅氧烷( PDMS )与低黏度组分(端羟基PDMS )共混，并与脱氧核糖核酸( DNA )链修饰的石墨烯纳米片( GNP )填料复合，制备了具有不同弹性性能的新型有机硅基纳米复合材料。采用Kissinger法和Ozawa-Flynn- Wall和Kissinger-Akahira- Sunose两种无模型等转化率方法测定了聚合反应的活化能。结果表明，采用等转化率方法可以描述固化行为的复杂趋势，对于含有标准PDMS基体的纳米复合材料，其活化能较低。同时也证明了石墨烯的DNA修饰对固化行为的作用。GNP-DNA填料的存在有利于纳米复合材料与PDMS基体的固化反应。PDMS / PDMS-OH共混物生成了硬度更软、弹性模量更低的纳米复合材料，可以通过改变填料的用量来调节。

疏水聚二甲基硅氧烷( PDMS )嵌段与亲水性聚醚段的结合对有机硅表面活性剂起着关键作用。利用双金属氰化物( DMC )催化剂，环硅氧烷与环氧化物直接(即统计)共聚是可行的。六甲基环三硅氧烷与环氧丙烷的无溶剂一锅法共聚反应生成了梯度环氧丙烷( PPO ) - PDMS共聚物。在2100 ~ 2900 g mol-1的分子量范围内，得到了分散性较低的含硅氧烷含量高达46 %的共聚物(乔  \u003c  1.2 )。通过压力监测和原位1H和原位29Si NMR谱考察了聚合动力学。接触角测量显示硅氧烷的加入显著提高了PPO- PDMS共聚物的疏水性，并使其玻璃化转变温度为-95 ℃，SiO含量为46 %。这种不寻常的共聚为有机硅/聚醚多元醇的合成提供了希望。