Facile fabrication of non-fluorine polymer brush/loop surfaces for oil/water separation and self-cleaning applications

Polydimethylsiloxane (PDMS), a low surface energy material, is widely used in the preparation of various (super)hydrophobic materials. Nevertheless, the impact of PDMS chain architectures (i.e., linear, branched, difunctional and monofunctional PDMS) on surface properties, such as hydrophobicity and self-cleaning, has received limited attention. In this work, we constructed PDMS chains on stainless steel mesh/polyester fiber/silica surfaces to form both looped and linear topological structures. Surfaces with looped structure showed higher roughness and stronger hydrophobicity in air and water, compared to the surfaces with linear structures. Surface force measurements demonstrated that the silica surface with looped structure exhibited stronger hydrophobic forces in water than the surfaces with linear structure. The looped structure coatings also exhibited superior self-cleaning and faster water sliding compared to the linear structure coatings. Additionally, both looped and linear PDMS coated stainless steel mesh/polyester fibers showed efficient separation of oil/water mixture. This study sheds light on the influence of polymer topology on surface properties and advances the development of applications in oil/water separation and self-cleaning.