Goedel Werner A, Gläser Kerstin, Mitra Dana, Hammerschmidt Jens, Thalheim Robert, Ueberfuhr Peter, Baumann Reinhard R
Physical Chemistry , Chemnitz University of Technology , Straße der Nationen 62 , 09111 Chemnitz , Germany.
Department of Digital Printing and Imaging Technology , Chemnitz University of Technology , Reichenhainer Straße 70 , 09126 Chemnitz , Germany.
Langmuir. 2019 Feb 12;35(6):2196-2208. doi: 10.1021/acs.langmuir.8b03252. Epub 2019 Jan 18.
This article describes the preparation of hierarchically structured microsieves via a suitable combination of float-casting and inkjet-printing: A mixture of hydrophobized silica particles of 600 nm ± 20 nm diameter, a suitable non-water-soluble nonvolatile acrylic monomer, a nonvolatile photoinitiator, and volatile organic solvents is applied to a water surface. This mixture spontaneously spreads on the water surface; the volatile solvents evaporate and leave behind a layer of the monomer/initiator mixture comprising a monolayer of particles, each particle protruding out of the monomer layer at the top and bottom surface. Photopolymerization of the monomer converts this mixed layer into a solid composite membrane floating on the water surface. Onto this membrane, while still floating on the water surface, a hierarchical reinforcing structure based on a photocurable ink is inkjet-printed and solidified. In contrast to the nonreinforced membrane, the reinforced membrane can easily be lifted off the water surface without suffering damage. Subsequently, the silica particles are removed, and thus, the reinforced composite membrane is converted into a reinforced microsieve of 350 nm ± 50 nm thickness bearing uniform through pores of 465 nm ± 50 nm diameter. This reinforced microsieve is mounted into a filtration unit and used to filter model dispersions: its permeance for water at low Reynolds numbers is in accordance with established theories on the permeance of microsieves and significantly above the permeance of conventional filtration media; it retains particles exceeding the pore size, while letting particles smaller than the pore size pass.
将直径为600 nm±20 nm的疏水化二氧化硅颗粒、合适的非水溶性非挥发性丙烯酸单体、非挥发性光引发剂和挥发性有机溶剂的混合物施加到水表面。该混合物在水表面自发铺展；挥发性溶剂蒸发，留下一层由单层颗粒组成的单体/引发剂混合物，每个颗粒在顶面和底面突出于单体层之外。单体的光聚合将该混合层转化为漂浮在水表面的固体复合膜。在该膜仍漂浮在水表面时，基于可光固化油墨的分层增强结构通过喷墨打印并固化。与未增强的膜相比，增强后的膜可以很容易地从水表面提起而不损坏。随后，去除二氧化硅颗粒，从而将增强复合膜转化为厚度为350 nm±50 nm、带有直径为465 nm±50 nm均匀通孔的增强微筛。该增强微筛安装在过滤单元中用于过滤模型分散体：其在低雷诺数下对水的渗透率符合关于微筛渗透率的既定理论，并且显著高于传统过滤介质的渗透率；它截留尺寸超过孔径的颗粒，同时让尺寸小于孔径的颗粒通过。
