title: Transparent and hard zirconia-based hybrid coatings with excellent dynamic/thermoresponsive oleophobicity, thermal durability, and hydrolytic stability.
abstract: Smooth, transparent, and extremely hard zirconia (ZrO2)-based inorganic-organic hybrid films showing excellent dynamic oleophobicity, thermal durability, and hydrolytic stability were successfully prepared through a simple combination of zirconium tetrapropoxide (Zr(O(CH2)2CH3)4) with stearic acids. In this study, we have particularly focused on the effects of stearic acid molecular architecture (linear-stearic acid (LSA) and branched-stearic acid (BSA)) on surface physical/chemical properties. Although, in each case, the resulting hybrid (Zr:LSA and Zr:BSA) films achieved by a simple spin-coating method were highly smooth and transparent, the final surface properties were markedly dependent on their molecular architectures. Thanks to the thermal stability of BSA, our Zr:BSA hybrid films displayed a greatly improved thermal effective range (maximum of 200 °C), while for Zr:LSA hybrid films, serious thermal damage to surface dewetting behavior was observed at less than 150 °C. The hardness of the Zr:BSA hybrid films were markedly increased by curing at 200 °C for 1 h (from 1.95 GPa to 3.03 GPa), while maintaining their dynamic dewettability toward n-hexadecane, when compared with Zr:LSA hybrid films (0.95-1.19 GPa). Small volume n-hexadecane droplets (5 μL) were easily set in motion, sliding across and off our best Zr:BSA hybrid film surfaces at low substrate tilt angles (<10°) without pinning. Moreover, they also showed thermoresponsive dynamic dewetting behavior, reasonable resistance to hydrolysis in an aqueous environment, and antifingerprint properties.
authors.affiliation: National Institute for Advanced Industrial Science and Technology (AIST), 2266-98, Anagahora, Shimo-shidami, Moriyama-ku Nagoya 463-8560, Japan.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Masheder
authors.forename: Chihiro
authors.initials: C
authors.lastname: Urata
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hozumi
mesh_terms: D000473:Alkanes / Q000737:chemistry; D000818:Animals; D002417:Cattle; D006868:Hydrolysis; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013229:Stearic Acids / Q000737:chemistry*; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000473:Alkanes; D013229:Stearic Acids; D012710:Serum Albumin, Bovine; D015040:Zirconium; C007932:n-hexadecane; C028541:zirconium oxide