Schwaar Nadine, Benke Dominik, Retsch Markus, Goedel Werner A
Chemnitz University of Technology, Physical Chemistry, Straße der Nationen 62, 09116 Chemnitz, Germany.
University Bayreuth, Department of Chemistry, Chair of Physical Chemistry I, Universitätsstraße 30, 95447 Bayreuth, Germany.
Langmuir. 2024 Oct 29;40(43):22516-22525. doi: 10.1021/acs.langmuir.4c01232. Epub 2024 Oct 21.
Polymeric microsieves bearing elliptical pores were successfully prepared via float-casting: a dispersion comprising nonvolatile acrylate monomers and ellipsoidal polystyrene particles was spread onto a water surface. The resulting self-organized monolayer was laterally compressed, and the monomer was photopolymerized, giving rise to a membrane comprising ellipsoidal particles laterally embedded in a 0.5 μm thin polymer membrane. The particles were dissolved, leaving behind elliptical pores. These pores had an average length of the major axis of 0.87 ± 0.1 μm and of the minor axis of 0.42 ± 0.07 μm and an aspect ratio of approximately 2. The microsieve bearing these submicrometric elliptical pores was transferred to a hierarchical structure made out of microsieves bearing circular pores of 6 μm diameter on top of a microsieve with 70 μm diameter pores. The resulting hierarchically structured microsieve had a porosity of 0.13. At a pressure difference of typically 10 Pa (Reynolds number aprox. 0.002), the volumetric permeance for water was = //Δ = 0.5·10 m/s/Pa, the product viscosity·permeance is η·//Δ = 0.5·10 m. This value is lower than the corresponding values of microsieves with circular pores of similar diameter produced by the same technique. The beneficial effects of higher permeance per pore caused by the elliptical shape are countered by lower porosity caused by less efficient packing of the ellipsoidal particles.
将包含非挥发性丙烯酸酯单体和椭圆形聚苯乙烯颗粒的分散体铺展在水面上。随后对形成的自组装单分子层进行横向压缩，并使单体光聚合，得到一种膜，该膜包含横向嵌入0.5μm厚聚合物膜中的椭圆形颗粒。将颗粒溶解后留下椭圆形孔。这些孔的长轴平均长度为0.87±0.1μm，短轴平均长度为0.42±0.07μm，纵横比约为2。将带有这些亚微米级椭圆形孔的微筛转移到一种分级结构上，该分级结构由在直径为70μm孔的微筛顶部带有直径为6μm圆形孔的微筛组成。所得的分级结构微筛的孔隙率为0.13。在典型的10Pa压差（雷诺数约为0.002）下，水的体积渗透率为 = //Δ = 0.5·10 m/s/Pa，产物粘度·渗透率为η·//Δ = 0.5·10 m。该值低于用相同技术生产的具有类似直径圆形孔的微筛的相应值。椭圆形形状导致的每孔更高渗透率的有益效果被椭圆形颗粒堆积效率较低导致的较低孔隙率所抵消。
