Transparent, abrasion-insensitive superhydrophobic coatings for real-world applications

Superhydrophobic surfaces and surface coatings are of high interest for many applications in everyday life including non-wetting and low-friction coatings as well as functional clothing. Manufacturing of these surfaces is intricate since superhydrophobicity requires structuring of surfaces on a nano- to microscale. This delicate surface structuring makes most superhydrophobic surfaces very sensitive to abrasion and renders them impractical for real-life applications. In this paper we present a transparent fluorinated polymer foam that is synthesized by a simple one-step photoinitiated radical polymerization. We term this material "Fluoropor". It possesses an inherent nano-/microstructure throughout the whole bulk material and is thus insensitive to abrasion as its superhydrophobic properties are not merely due to a thin-layer surface-effect. Due to its foam-like structure with pore sizes below the wavelength of visible light Fluoropor appears optically transparent. We determined contact angles, surface energy, wear resistance and Vickers hardness to highlight Fluoropor's applicability for real-word applications.

Protein-stabilized foams and emulsions

This review is a survey of studies on protein-stabilized foams and emulsions in relatively simple, well-defined systems (rather than in food products per se). The emphasis is on the extent of basic understanding developed, particularly in terms of the physicochemical properties involved. The stability of the system, its formation, and its rheology are covered. Unfortunately, much work is of limited fundamental value because of poorly designed experimental approaches and the failure to measure key parameters. Reasonable generalization can be made concerning the effects of a number of variables, particularly protein solubility, pH, protein structure and the presence of small molecule surfactants. However, several possible explanations of these effects in terms of surface properties remain tenable. A number of observations can fairly confidently be ascribed to the influence of rheology on flow processes within foams and emulsions.