Polymeric Janus thin films were synthesized using a facile, one-step, vapor-based approach. The resultant films are comprised of two ultrathin surface layers of poly(1H,1H,2H,2H-perfluorodecyl acrylate) and poly(dimethyl amino ethyl methacrylate) hydrogel, covalently linked to a highly crosslinked bulk of poly(ethylene glycol diacrylate). Such an architecture allows distinct wetting behavior on the two surfaces while enabling the film integrity and mechanical robustness to be simultaneously achieved. Owing to the strong support from the crosslinked bulk, the Young's modulus and hardness of the Janus film were significantly improved compared with those of the polymers composing the two surface layers. The film is highly transparent across the visible light spectrum. The Janus film was further micropatterned using a templated vapor deposition method and transferred to nonplanar substrates.

Layered polymer nanocoatings consisting of a reactive polyisocyanate primer and grafted functional top were synthesized by single-step vapor phase polymerization deposition. The rationally designed coating architecture enables strong coating adhesion and highly enriched surface functionality, resulting in superhydrophilic and underwater superoleophobic surfaces with unprecedented durability. With a coating thickness as thin as 130 nm, the coated wool fabric exhibits an excellent oil–water separation efficiency above 99.99%, which is maintained after a series of harsh durability tests, including washing and abrasion against sandpaper for up to 150 cycles. The layered nanocoating is applicable to substrates regardless of their geometry, including highly porous fabrics for ultrafast free oil–water separation and microporous PVDF membranes for efficient gravity-driven oil-in-water emulsion separation.

Anti-biofouling poly(N-vinyl pyrrolidone) (PVP) coatings with tailored crosslinking degrees were synthesized and grafted onto planar and microporous substrates via a one-step vapor-based approach. N-Vinyl pyrrolidone was copolymerized with ethylene glycol diacrylate at different ratios in the vapor phase, resulting in conformal PVP coatings with a wide spectrum of crosslinking degrees. The synthesized coatings were immobilized onto substrates either through covalent bonding with pretreated surfaces, or by first generating a highly crosslinked polymer prime layer on untreated surfaces, followed by in situ grafting from the reactive sites of the prime coating. The surface hydrophilicity of the resultant coatings along with their protein and bacteria repellency increased monotonically with the decrease of the crosslinking degree. Coatings on planar surfaces with the lowest crosslinking degree showed a water contact angle of 33 ± 1°, comparable to the reported PVP-grafted surfaces, while coatings on microporous membranes exhibited “superwettability” with water contact angles close to 0°. The least crosslinked coatings also adsorbed 92% less bovine serum albumin compared to the control, and readily prevented the attachment of Escherichia coli cells. The grafted coatings are robust against continuous washing and ultrasonication. We expect this vapor-based grafting technique to provide a practical means for imparting surface hydrophilicity and anti-biofouling properties to substrates regardless of their surface chemistry or geometry.

Anti-biofouling poly(N-vinyl pyrrolidone) (PVP) coatings with tailored crosslinking degrees were synthesized and grafted onto planar and microporous substrates via a one-step vapor-based approach. N-Vinyl pyrrolidone was copolymerized with ethylene glycol diacrylate at different ratios in the vapor phase, resulting in conformal PVP coatings with a wide spectrum of crosslinking degrees. The synthesized coatings were immobilized onto substrates either through covalent bonding with pretreated surfaces, or by first generating a highly crosslinked polymer prime layer on untreated surfaces, followed by in situ grafting from the reactive sites of the prime coating. The surface hydrophilicity of the resultant coatings along with their protein and bacteria repellency increased monotonically with the decrease of the crosslinking degree. Coatings on planar surfaces with the lowest crosslinking degree showed a water contact angle of 33 ± 1°, comparable to the reported PVP-grafted surfaces, while coatings on microporous membranes exhibited “superwettability” with water contact angles close to 0°. The least crosslinked coatings also adsorbed 92% less bovine serum albumin compared to the control, and readily prevented the attachment of Escherichia coli cells. The grafted coatings are robust against continuous washing and ultrasonication. We expect this vapor-based grafting technique to provide a practical means for imparting surface hydrophilicity and anti-biofouling properties to substrates regardless of their surface chemistry or geometry.

Layered polymer nanocoatings consisting of a reactive polyisocyanate primer and grafted functional top were synthesized by single-step vapor phase polymerization deposition. The rationally designed coating architecture enables strong coating adhesion and highly enriched surface functionality, resulting in superhydrophilic and underwater superoleophobic surfaces with unprecedented durability. With a coating thickness as thin as 130 nm, the coated wool fabric exhibits an excellent oil–water separation efficiency above 99.99%, which is maintained after a series of harsh durability tests, including washing and abrasion against sandpaper for up to 150 cycles. The layered nanocoating is applicable to substrates regardless of their geometry, including highly porous fabrics for ultrafast free oil–water separation and microporous PVDF membranes for efficient gravity-driven oil-in-water emulsion separation.