title: Robust superamphiphobic coatings based on silica particles bearing bifunctional random copolymers.
abstract: Reported herein is the growth of bifunctional random copolymer chains from silica particles through a "grafting from" approach and the use of these copolymer-bearing particles to fabricate superamphiphobic coatings. The silica particles had a diameter of 90 ± 7 nm and were prepared through a modified Stöber process before atom transfer radical polymerization (ATRP) initiators were introduced onto their surfaces. Bifunctional copolymer chains bearing low-surface-free-energy fluorinated units and sol-gel-forming units were then grafted from these silica particles by surface-initiated ATRP. Perfluorooctyl ethyl acrylate (FOEA) and 3-(triisopropyloxy)silylpropyl methacrylate (IPSMA) were respectively used as fluorinated and sol-gel-forming monomers in this reaction. Hydrolyzing the IPSMA units in the presence of an acid catalyst yielded silica particles that were adorned with silanol-bearing copolymer chains. Coatings were prepared by spraying these hydrolyzed silica particles onto glass and cotton substrates. A series of four different copolymer-functionalized silica particles samples bearing copolymers with similar FOEA molar fractions (fF) of ~80% but with different copolymer grafting mass ratios (gm) that ranged between 12.3 wt% and 58.8 wt%, relative to silica, were prepared by varying the polymerization protocols. These copolymer-bearing silica particles with a gm exceeding 34.1 wt% were used to coat glass and cotton substrates, yielding superamphiphobic surfaces. More importantly, these particulate-based coatings were robust and resistant to solvent extraction and NaOH etching thanks to the self-cross-linking of the copolymer chains and their covalent attachment to the substrates.
authors.affiliation: Guangzhou Institute of Chemistry, Chinese Academy of Sciences , Guangzhou, People's Republic of China , 510650.
authors.forename: Ganwei
authors.initials: G
authors.lastname: Zhang
authors.forename: Shudong
authors.initials: S
authors.lastname: Lin
authors.forename: Ian
authors.initials: I
authors.lastname: Wyman
authors.forename: Hailiang
authors.initials: H
authors.lastname: Zou
authors.forename: Jiwen
authors.initials: J
authors.lastname: Hu
authors.forename: Guojun
authors.initials: G
authors.lastname: Liu
authors.forename: Jiandong
authors.initials: J
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Meilong
authors.initials: M
authors.lastname: Hu