渗透

Abstract(#br)Silicones have innumerable applications in many areas of life. Polydimethylsiloxane (PDMS), which belongs to the class of silicones, has been extensively used in the field of analytical chemistry owing to its favourable physicochemical properties. The use of PDMS in analytical chemistry gained importance with its application as a stationary phase in gas chromatographic separations.

Abstract(#br)Thin film composite (TFC) reverse osmosis (RO) membranes are semipermeable membranes that are utilized in water purification or water desalination systems. Discarding these membranes after end-of-life leads to environmental problems. Reusing old TFC-RO membranes is one way to solve this problem. For this reason, in this study, used TFC-RO membranes were coated with polydimethylsiloxane (PDMS) for CO 2 /N 2 gas separation application. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was utilized to confirm the crosslinking of coated PDMS.

Abstract(#br)Supercritical carbon dioxide (scCO 2 ) is used in the food industry as a water-extracting drying agent. Once saturated with water, the scCO 2 needs to be regenerated. A promising way of drying scCO 2 is by using H 2 O permeable membranes. Ideally, these membranes demonstrate low CO 2 permeability. Here, we investigated the CO 2 permeability of three types of dense membranes, Nafion, Natural Rubber and PDMS, of which the latter in more detail because of its ease of handling.

Abstract(#br)By means of chemical combination between the Polydimethylsiloxane (PDMS) layer and Polyethersulfone (PES) layer, a kind of PDMS/PES composite membrane was prepared for separation of the light hydrocarbon components from the drilling mud. Meanwhile, its separation performance of the light-hydrocarbon components from the drilling mud was investigated and evaluated quantitatively. Results showed that the prepared PDMS/PES composite membrane had good mechanical performance, and it was resistant to corrosion of the water-based drilling mud.

摘要\n聚合物在生物材料方面的应用越来越引起人们的兴趣。研究人员一直在尝试将金属氧化物或金属纳入聚合物中，以获得显著提高所得到聚合物材料的理想性能，如导电性和抗菌活性。这类材料的一个很有前途的技术是原子层沉积( ALD )。通过沉积一层非常薄的金属或金属氧化物薄膜，人们可以在不损失聚合物独特的本体性能的前提下利用这些材料的特性，然而，由于表面和亚表面薄膜的生长，这种材料在聚合物上的沉积在一定程度上变得困难。\n本研究在O2等离子体处理和非等离子体处理的PDMS上，研究了TiO2在聚二甲基硅氧烷( PDMS )上成核和生长初期的原子层沉积( ALD )，采用X射线近边结构吸收、扫描电子显微镜/能量色散X射线能谱和X射线光电子能谱对材料进行表征。结果表明，等离子体处理的PDMS表面发生了类ALD的TiO2表面生长，对于非等离子体处理的原始PDMS，TiO2在聚合物亚表面得到了明显的有利扩散/浸润，至少前25个ALD循环没有明显的外表面沉积。

摘要\n膜分离的主要挑战之一是塑化效应降低选择性。为了更好地理解这一现象，了解混合物各组分的吸附行为是必要的。为此，成功设计了吸附式热虹吸仪( STA )，并进行了气体吸附测试。与实际其他方法相比，STA方法的主要优点之一是利用热虹吸管记录压力衰减情况，保证顶空浓度均匀。平衡条件在取样过程中不受干扰，允许在吸附实验结束时保留准确数据。为了验证新体系的有效性，通过STA等实验技术获得了纯CO2和CH4以及CO2 / CH4 ( 50 / 50 )混合物在聚二甲基硅氧烷( PDMS )中的吸附、扩散和渗透系数，与文献数据吻合较好。

单个二甲苯异构体的分离仍然具有挑战性和能量密集型。由于膜分离的利用可以带来改进，我们比较了渗透汽化和萃取两种相关的膜分离方法在40  ℃下用聚二甲基硅氧烷( PDMS )和三醋酸纤维素( CTA )膜分离p ‑二甲苯/ m ‑二甲苯混合物的效果。在渗透汽化过程中，PDMS对p ‑二甲苯几乎没有选择性，而在甲醇富集的条件下，PDMS的选择性达到1.40。CTA对所有混合溶剂的萃取效果均优于PDMS，在进料中不含甲醇的熔融共晶混合物的萃取选择性最高，为1.93。选择性增强的可能原因是与甲醇增塑聚合物中极性基团的异构体特异性相互作用。总体而言，简单改变从渗透汽化到渗透萃取的操作方式，使用膜夹带剂，可以显著提高普通可靠膜材料的p ‑二甲苯对m ‑二甲苯的选择性。

本文利用聚二甲基硅氧烷( PDMS )的亲有机疏水膜，以疏水性离子液体( ILs ) 1 -丁基-3 -甲基咪唑双(三氟甲基)磺酰基)酰亚胺( [ bmim ] [ Tf2N ] )、1 -辛基-3 -甲基咪唑双(三氟甲基)磺酰基)酰亚胺( [ omim ] [ Tf2N ] )和三己基十四烷基膦酰亚胺( [ P6，6，6，14 ] [ DCA ] )为萃取相，对一种从水溶液中回收稀释香兰素的萃取体系进行了实验和理论研究。建立了适用于描述ILs萃取体系中水相中香兰素的传质模型。根据该模型，确定PDMS膜提供的主要传质阻力，其次是IL。[ P6，6，14 ] [ DCA ]实验表明，与[ Tf2N ]阴离子型ILs相比，跨膜通量增加了13 %，但也表现出较高的水跨膜通量。在这方面，[ omim ] [ Tf2N ]被发现具有更好的香草醛/水选择性。渗透汽化体系提取香兰素的跨膜通量优于文献报道的数据。另一方面，根据COSMO-RS中的筛选，将阴离子DCA、SCN、TCC、Otf、PFBS、Tf2N、Pf2NyPF6与吡咯烷、哌啶、膦基阳离子结合，适宜增加香草醛提取性能。