title: A general approach to controlling the surface composition of poly(ethylene oxide)-based block copolymers for antifouling coatings.
abstract: To control the surface properties of a polystyrene-block-poly(ethylene oxide) diblock copolymer, perfluorinated chemical moieties were specifically incorporated into the block copolymer backbone. A polystyrene-block-poly[(ethylene oxide)-stat-(allyl glycidyl ether)] [PS-b-P(EO-stat-AGE)] statistical diblock terpolymer was synthesized with varying incorporations of allyl glycidyl ether (AGE) in the poly(ethylene oxide) block from 0 to 17 mol %. The pendant alkenes of the AGE repeat units were subsequently functionalized by thiol-ene chemistry with 1H,1H,2H,2H-perfluorooctanethiol, yielding fluorocarbon-functionalized AGE (fAGE) repeat units. (1)H NMR spectroscopy and size-exclusion chromatography indicated well-defined structures with complete functionalization of the pendant alkenes. The surfaces of the polymer films were characterized after spray coating by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure spectroscopy (NEXAFS), showing that the P(EO-stat-fAGE) block starts to compete with polystyrene to populate the surface after only 1 mol % incorporation of fAGE. Increasing the incorporation of fAGE led to an increased amount of perfluorocarbons on the surface and a decrease in the concentration of PS. At a fAGE incorporation of 8 mol %, PS was not detected at the surface, as measured by NEXAFS spectroscopy. Water contact angles measured by the captive-air-bubble technique showed the underwater surfaces to be dynamic, with advancing and receding contact angles varying by >20°. Protein adsorption studies demonstrated that the fluorinated surfaces effectively prevent nonspecific binding of proteins relative to an unmodified PS-b-PEO diblock copolymer. In biological systems, settlement of spores of the green macroalga Ulva was significantly lower for the fAGE-incorporated polymers compared to the unmodified diblock and a polydimethylsiloxane elastomer standard. Furthermore, the attachment strength of sporelings (young plants) of Ulva was also reduced for the fAGE-containing polymers, affirming their potential as fouling-release coatings.
authors: Materials Department, University of California, Santa Barbara, California 93106, United States.
authors: Michael D
authors: MD
authors: Dimitriou
authors: Zhaoli
authors: Z
authors: Zhou
authors: Hee-Soo
authors: HS
authors: Yoo
authors: Kato L
authors: KL
authors: Killops
authors: John A
authors: JA
authors: Finlay
authors: Gemma
authors: G
authors: Cone
authors: Harihara S
authors: HS
authors: Sundaram
authors: Nathaniel A
authors: NA
authors: Lynd
authors: Katherine P
authors: KP
authors: Barteau
authors: Luis M
authors: LM
authors: Campos
authors: Daniel A
authors: DA
authors: Fischer
authors: Maureen E
authors: ME
authors: Callow
authors: James A
authors: JA
authors: Callow
authors: Christopher K
authors: CK
authors: Ober
authors: Craig J
authors: CJ
authors: Hawker
authors: Edward J
authors: EJ
authors: Kramer
mesh_terms: D000327:Adsorption; D002850:Chromatography, Gel; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D056951:Photoelectron Spectroscopy; D011092:Polyethylene Glycols / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry; D013499:Surface Properties
chemical_list: D011506:Proteins; D011092:Polyethylene Glycols