School of Chemical and Bioprocess Engineering, University College Dublin, Belfield Dublin 4, Ireland.
ACS Appl Mater Interfaces. 2011 Feb;3(2):252-60. doi: 10.1021/am100904w. Epub 2011 Jan 13.
Composite asymmetric membranes are fabricated through the deposition of submicrometer thick (100 nm) silica (SiO(2)) and titania (TiO(2)) films onto flat nanoporous silica and zirconia substrates by magnetron sputtering. The deposition conditions for both coating types were systematically altered to determine their influence on the deposited coating morphology and thickness. Ideal He/N(2) gas selectivity was measured for all of the membranes. The TiO(2) coatings, when deposited onto a ZrO(2) support layer with a pore size of 3 nm, formed a long columnar grain structure with average column diameter of 38 nm. A similar columnar structure was observed for TiO(2) coatings deposited onto a SiO(2) support layer with a pore size of 1 nm. Under the same conditions, SiO(2) coatings, deposited onto the same SiO(2) supports, formed a closely packed spherical grain structure whereas, when deposited onto ZrO(2) supports, the SiO(2) coatings formed an open grain structure. The average SiO(2) grain diameter was 36 nm in both cases. This preliminary investigation was aimed at studying the effect of sputtering parameters on the density and morphology of the deposited coatings. For the depositions carried out, the coating material was found to be very dense. However, the presence of grain boundaries resulted in poor ideal He/N(2) separation efficiencies.
复合不对称膜是通过磁控溅射将亚微米厚（100nm）的二氧化硅（SiO2）和二氧化钛（TiO2）薄膜沉积到平板纳米多孔二氧化硅和氧化锆基底上而制备的。改变了两种涂层类型的沉积条件，以确定它们对沉积涂层形貌和厚度的影响。对所有膜都测量了理想的 He/N2 气体选择性。当 TiO2 涂层沉积在孔径为 3nm 的 ZrO2 支撑层上时，形成了具有平均柱直径为 38nm 的长柱状晶粒结构。在孔径为 1nm 的 SiO2 支撑层上沉积 TiO2 涂层时，观察到类似的柱状结构。在相同条件下，SiO2 涂层沉积在相同的 SiO2 支撑体上形成了紧密堆积的球形晶粒结构，而当沉积在 ZrO2 支撑体上时，SiO2 涂层形成了开放的晶粒结构。在这两种情况下，SiO2 晶粒的平均直径均为 36nm。这项初步研究旨在研究溅射参数对沉积涂层密度和形态的影响。对于进行的沉积，发现涂层材料非常致密。然而，由于晶界的存在，导致理想的 He/N2 分离效率很差。
