Polymethylsiloxane (PMS) and fumed silica, alone and in a blended form (1:1 w/w), differently pretreated, hydrated, and treated again, were studied using TEM and SEM, nitrogen adsorption–desorption, 1H MAS and 29Si CP/MAS NMR spectroscopy, infrared spectroscopy, and methods of quantum chemistry. Analysis of the effects of adding water (0–0.5 g of water per gram of solids) to the blends while they are undergoing different mechanical treatment (stirring with weak (~1–2 kg/cm2) and strong (~20 kg/cm2) loading) show that both dry and wetted PMS (as a soft material) can be grafted onto a silica surface, even with weak mechanical loading, and enhanced mechanical loading leads to enhanced homogenization of the blends. The main evidence of this effect is strong nonadditive changes in the textural characteristics, which are 2–3 times smaller than additive those expected. All PMSanosilica blends, demonstrating a good distribution of nanosilica nanoparticles and their small aggregates in the polymer matrix (according to TEM and SEM images), are rather meso/microporous, with the main pore-size distribution peaks at R > 10 nm in radius and average <RV> values of 18–25 nm. The contributions of nanopores (R < 1 nm), mesopores (1 nm < R < 25 nm), and macropores (25 nm < R < 100 nm), which are of importance for studied medical sorbents and drug carriers, depend strongly on the types of the materials and treatments, as well the amounts of water added. The developed technique (based on small additions of water and controlled mechanical loading) allows one to significantly change the morphological and textural characteristics of fumed silica (hydrocompaction), PMS (drying–wetting–drying), and PMS/A-300 blends (wetting–drying under mechanical loading), which is of importance from a practical point of view.
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机译:使用TEM和SEM研究了分别预处理,水合再处理的聚甲基硅氧烷(PMS)和气相二氧化硅(分别以1:1 w / w的形式)经过不同的预处理,水合再处理的方法,氮吸附-解吸, 1 sup> H MAS和 29 sup> Si CP / MAS NMR光谱,红外光谱和量子化学方法。分析在混合物进行不同机械处理(搅拌弱(〜1-2 kg / cm 2 sup>)时,向混合物中加水(每克固体中含0-0.5 g水)的效果”高强度(约20 kg / cm 2 sup>)的负载量表明,即使是弱机械负载和增强的机械负载,干燥和湿润的PMS(作为软材料)也可以接枝到二氧化硅表面上导致共混物的均质性增强。这种影响的主要证据是质地特性发生了很强的非加性变化,比预期的加性小2-3倍。所有PMS /纳米二氧化硅共混物均表现出细孔/微孔,表明纳米二氧化硅纳米颗粒及其小聚集体在聚合物基质中分布良好(根据TEM和SEM图像),主要孔尺寸分布峰位于R> 10 nm。半径和18-25 nm的平均值。纳米孔(R <1 nm),中孔(1 nm 展开▼