Terence John Swihart

XPS investigation of the dewatering of fine coal using silicone additives

Abstract The dewatering of fine coal by the use of silicone additives has been investigated with the aid of X-ray photoelectron spectroscopy (XPS), which characterizes the surface composition of the coals and detects the presence of the silicone dewatering agent on the coal surface. Emulsions of aminofunctional silicones and silicone-glycol copolymer surfactants are particularly useful. The amino functional silicones could be detected at practical concentrations in amounts consistent with an adsorbed monolayer. The co-polymer surfactants could be detected only at higher concentrations. Fractionation of active surface components of the surfactant species probably occurs at the interface in this instance. At the solid-liquid coal-water interface hydrophobing of the coal and flocculation effects are significant factors in the dewatering mechanism.

Silicones for Fabric Coating

A WIDE VARIETY of organic based compositions are utilized as coatings in the textile industry. By far the largest application is for styrene butadiene latexes for apphcation as carpet backings while acrylic based latices are utilized as back coatings for upholstery fabrics, corduroy, drapery and pile fabrics. The acrylic resins are used largely for shrinkage control and as a fiber fixative. Other materials utilized to a much lesser extent are ethylene vinyl acetates, neoprene, butyl latex, polyvinyl chloride, and polyurethanes. By contrast, silicone systems have historically found limited use in textile