Molecular Aggregation Structure and Surface Properties of Biomimetic Catechol-Bearing Poly[2-(perfluorooctyl)ethyl acrylate] and Its Application to Superamphiphobic Coatings

Abstract

The molecular aggregation structure and surface properties of a catechol-bearing fluoropolymer, P(FAC 8 -co-DOPAm), which was synthesized by conventional radical copolymerization of 2-(perfluorooctyl)ethyl acrylate (FAC 8 ) and N-(3,4dihydroxyphenethyl)acrylamide (DOPAm), and its application to the superamphiphobic surfaces are presented. The crystallinity of P(FAC 8 -co-DOPAm) was lower than that of poly [2-(perfluorooctyl)ethyl acrylate] (PFAC 8 ). The perfluoroalkyl (R f ) groups were ordered on the surface with CF 3 terminals exposed to air, and the R f ordering was influenced by thermal history: the thermally annealed film exhibited higher R f ordering than the unannealed one. The surface free energy was estimated to be γ = 7.32 mJ m −2 for both the unannealed and annealed films. Based on contact angle measurement, various interfacial structures of water and oils in accordance with the surface aggregation structure of R f groups were proposed. Dewetting of the PFAC 8 film at elevated temperature was suppressed by the introduction of catechol groups in the backbone. The degradation temperature of PFAC 8 was improved significantly, and the evaporation of the low molar mass-polymer was inhibited by the introduction of catechol groups under both nitrogen and air atmospheres. The hydrophobicity of the copolymer films could be healed after the surface was damaged by vacuum ultraviolet (VUV) irradiation. This copolymer was used to create superamphiphobic fabrics and halloysite nanotube (HNT)-based organic/inorganic hybrid coatings successfully. Wetting behaviors of the superamphiphobic fabrics and coatings both follow the Cassie−Baxter wetting model.

Toward bioinspired polymer adhesives: activation assisted via HOBt for grafting of dopamine onto poly(acrylic acid)

“…In the range of 300–400°C, the PAA-g-DA showed a delay in degradation compared with non-functionalized PAA. Catechol groups improving the thermal stability of polymers has been observed in prior literature and has been attributed to the hydrogen bonding and restriction of chain motion [ 52 , 53 ]. Additionally, dopamine can scavenge radicals generated by C-C bond pyrolysis, blocking depolymerization of the PAA backbone by chain scission [ 52 , 54 ].…”

Effect of N-Methylation on Dopamine Surface Chemistry

“…Modification of the R 3 position, the primary amine, has been extensively used for synthesizing DA derivatives . Various functional molecules were conjugated at this site through amide-bond-forming reactions. − However, the conjugation to the R 3 position prevents indole formation, which is another key intermediate for surface coating; thus, the coating efficiency is not as high that compared to DA. , The indole formation inhibition may be due to the decrease in nitrogen nucleophilicity. The nitrogen in amides is less nucleophilic than that in free amines because of the nitrogen lone pair resonance stabilization by the carbonyl group.…”

Surface Coating with Naphthalene Trisulfonate/Hafnium(IV) Complexes: Versatility and Post-Functionalization

“…The development of surface chemistry for endowing appropriate properties onto material surfaces has been of considerable interest in the materials chemistry field because the performance of functional materials is closely affected by their surface properties. − For example, biocompatible surface modification is a prerequisite for applying nano-/micromaterials in vivo . − In this respect, surface modification reagents, which enable the introduction of desired properties onto the surface of any material, are necessary; therefore, significant effort has been devoted to the development of a versatile surface modification reagent in the last decade. − Dopamine and tannic acid are representative molecules for such versatile surface modification. ,,, Both molecules belong to the hydroxybenzene family, which is prone to oxidation and self-assembly under mild aqueous conditions. Immersion of solid substrates in a solution of alkaline dopamine or tannic acid/metal complexes formed a polydopamine or tannic acid/metal complex coating. ,,, After the versatile surface coating properties of dopamine and tannic acid were investigated, follow-up studies have been extensively conducted, focusing on the synthesis of catechol/pyrogallol derivatives. ,− Since the catechol/pyrogallol derivatives consist of hydrophobic aromatic cores and hydrophilic hydroxyls, these molecules can bind to hydrophobic and hydrophilic solid surfaces, thereby coating diverse surfaces. Moreover, these molecules are similar in that they are transformed to large molecules via self-polymerization or metal-mediated multiple coordination bond formation .…”