Diblock-Copolymer-Coated Water- and Oil-Repellent Cotton Fabrics

Abstract

A diblock copolymer consisting of a sol-gel-forming block and a fluorinated block was used to coat cotton fabrics, yielding textiles that were highly oil- and water-repellent. The coating procedure was simple. At grafted polymer amounts of as low as 1.0 wt %, water, diodomethane, hexadecane, cooking oil, and pump oil all had contact angles surpassing 150° on the coated cotton fabrics and were readily rolled. The liquids were not drawn into the interfiber space by the coated fabrics. Rather, droplets of the nonvolatile liquids such as cooking oil retained their beaded shapes for months with minimal contact angle changes. When forced into water, the coated fabrics trapped an air or plastron layer and this plastron layer was stable for months. In addition, the coating had high stability against simulated washing, and the mechanical properties were essentially identical to those of uncoated cotton fabrics.

Triblock Terpolymers Bearing a Redox-Cleavable Junction and a Photo-Cross-Linkable Block

“…The product (0.84 g) was obtained as a white precipitate in an 82% yield. 1 PEG 113 -SCOCH 3 . PEG 113 -OTs (600 mg, 1.15 × 10 −4 mol) was dissolved into anhydrous DMF (in 3.0 mL) in a round-bottom flask before potassium ethanethioate (66 mg, 5 equiv) was added to this solution.…”

“…The resultant white precipitate was dried under vacuum at room temperature, yielding 510 mg of the product in an 85% yield. 1 PEG 113 -SH. PEG 113 -SCOCH 3 was converted into PEG 113 -SH using a literature method that had been employed on organic molecules.…”

“…The resultant brown solid was dried at room temperature under vacuum for 24 h, yielding 66 mg of P1 in an 82% yield. 1 PEG 113 -S 2 -PFOEMA 10 -b-PCEMA 20 (also denoted as P2) was synthesized analogously except that PEG 113 -S 2 -PFOEMA 10 -b-PHEMA 20 was used as the precursor.…”

“…2,4,6,7 We pondered on ways to eliminate the organic solvent and to prepare coatings from water. One possibility was to use a triblock copolymer that bore a terminal sacrificial water-soluble block.…”

Fluorosilicones and Other Fluoropolymers

“…Cotton fabrics that were coated with a fluorinated azide-bearing triblock copolymer exhibited a high WCA (155°) with a copolymer concentration of only 0.25 wt%. Xiong et al reported that a fluorinated diblock copolymer bearing isopropyloxysilane groups produced superhydrophobic cotton fabrics through hydrolysis and condensation reactions between the isopropyloxysilane groups and the hydroxyl groups of the cotton substrate [140]. Meanwhile, radiation-induced graft polymerization of a fluoromonomer onto the surface of cotton fabrics provided stable coatings that retained hydrophobicity even after 50 accelerated laundering cycles, but to accomplish this the grafting degree had to exceed 10 wt% [139].…”