Surface-Initiated Polymerization of Superhydrophobic Polymethylene

Abstract

We report a new surface-initiated polymerization strategy that yields superhydrophobic polymethylene (PM) films from initially smooth substrates of gold and silicon. The films are prepared by assembling a vinyl-terminated self-assembled monolayer, followed by exposure of the surface to a 0.1 M solution of borane, and polymerizing from the borane sites upon exposure to a solution of diazomethane at -17 degrees C. Surface-initiated polymethylenation (SIPM) presents rapid growth in relation to other surface-initiated reactions, producing PM films thicker than 500 nm after 2 min of reaction and 3 microm after 24 h of reaction. AFM and SEM images show the presence of micro- and nanoscale features that enable the entrapment of air when exposed to water. Consistent with this result, these films exhibit advancing water contact angles greater than 160 degrees, dramatically different than 103 degrees measured for smooth PM films, and hysteresis values ranging from 2 degrees to 40 degrees, depending on the substrate and polymerization time. The superhydrophobic character of the films results in the entrapment of air at the polymer/solution interface to provide remarkable resistances greater than 10(10) Omega x cm(2) against the transport of aqueous redox probes and cause the film to behave as a "perfect" capacitor.

New Electrospun Polystyrene/Al2O3 Nanocomposite Superhydrophobic Coatings; Synthesis, Characterization, and Application

“…The static contact angle is measured according to the Wenzel and Cassie-Baxter models. The hypothesis developed by Wenzel is described in Equation (1) [47,48].…”

“…Given that θ is 151° ± 2.8°, 152° ± 1.2° and 155° ± 1.9° for PA1, PA2, and PA3 nanocomposite coatings, respectively, and θ for the PS before addition of Al2O3 equals The static contact angle is measured according to the Wenzel and Cassie-Baxter models. The hypothesis developed by Wenzel is described in Equation (1) [47,48].…”

Fabrication of Superhydrophobic and Luminescent Rare Earth/Polymer complex Films

“…Over the past decade, numerous superhydrophobic materials have been reported121314151617181920, but there are still increasing demands for novel function to further extend their practical applications. For example, rare earth complexes have been widely employed in optical displays, fluorescent probe, luminescent labels and medical diagnosis fields212223242526272829.…”

Fabrication of Mechanical Durable Polysiloxane Superhydrophobic Materials

“…One of the extreme cases of wettability, superhydrophobicity, has aroused considerable interests for many researchers inspired by the water-repellent nature of lotus leaves in recent years [2]. Heretofore, numerous methods were presented to fabricate the superhydrophobic surfaces with various materials by mimicking the surface of lotus leaves [3][4][5][6][7][8][9][10]. Due to its novel and important properties, the superhydrophobic surfaces were greatly anticipated to be used in applications such as self-cleaning coatings [11], anti-icing and fogging surfaces [12][13][14], nonwetting fabrics [15,16], and buoyancy and flow enhancement [17,18].…”