The measurement of contact angle between a solid and a liquid presents difficulties when the solid is a powder.   The Washburn method uses capillary flow to measure this contact angle of powders, but has some drawbacks.   One drawback is the extreme difficulty inadapting this method to pressures greater than atmospheric.  Heat flow microcalorimetry offers an opportunity to measure the contact angle at elevated temperatures andpressures.  In this poster, we describe heat flow microcalorimetry measurements of a hydrophobic silica with water containing three different surfactants types; non-ionic, cationic and anionic surfactants at three different temperatures, 40�C, 75�C and 125�C.

Measurements of enthalpy of immersion for hydrophobic fumed silica nanospheres at elevated temperatures and pressures

247th National Meeting (2014)

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