title: Surface chemical modification of poly(dimethylsiloxane)-based biomimetic materials: oil-repellent surfaces.
abstract: The oil-repellent performance of a poly(dimethylsiloxane)-based biomimetic replica (PDMS-replica) was tuned by modifying its surface chemical composition. PDMS-replica possessing a complementary combination of hierarchical roughness and mixed -CF(3) and -SiCH(3) terminal functionality was prepared in the presence of a surface-modifying agent, using nanocasting based on soft lithography. PDMS-replica showed superhydrophobicity and enhanced oil repellency, theta(oil) approximately 86 degrees . PDMS-replica was further modified with silica nanoparticles followed by chemical vapor deposition of (heptadecafluoro-1,1,2,2-tetrahydrodecyl)trichlorosilane. The -CF(3) terminal, silica-modified PDMS-replica (i.e., PDMS-replica(silica/CF(3))) showed both superhydrophobic and high oil-repellent properties (advancing theta(oil) approximately 120 degrees ). During the process of each chemical transformation, the surface pattern present on PDMS-replica was preserved and monitored using scanning electron microscopy. Surface chemical compositions of PDMS-replica and PDMS-replica(silica/CF(3)) were determined using X-ray photoelectron spectroscopy. Understanding the extent of adhesion on a biomimetic replica possessing different surface chemical compositions and roughness would provide fundamental information for various applications.
authors.affiliation: Unilever Research India, 64 Main Road, Whitefield, Bangalore, India.
authors.forename: Nilmoni
authors.initials: N
authors.lastname: Ghosh
authors.forename: Arpan
authors.initials: A
authors.lastname: Bajoria
authors.forename: Ashish Anant
authors.initials: AA
authors.lastname: Vaidya
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis* / Q000737:chemistry; D031060:Colocasia / Q000648:ultrastructure; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D009821:Oils / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D018515:Plant Leaves / Q000648:ultrastructure; D013499:Surface Properties; D017155:Wettability
chemical_list: D004129:Dimethylpolysiloxanes; D009821:Oils