Comparing the Capillary Rise Technique and Sessile Drop Method of Non-Porous surfaces in Determining Surface Energy of Reinforcing Powders Utilized in Polymer Composites

In present contribution two main methods of Washburn capillary rise (WCR) and sessile drop technique on non-porous and smooth surfaces are to be compared in evaluating the surface energy of powder materials. Pristine silica and silane modified powders are used to assess the influence of silane nature and silane spacer length of 3-carbon and 16-carbon chain upon the surface energy of these powders. Having examined the surface modification of silica using infrared spectroscopy, an innovative method for preparing non-penetrable surface based on a combinatory press technique encompassing hydraulic and isostatic press is introduced. Using silane of high spacer length leads to an extremely hydrophobic surface where a contact angle of 47 degree for 3-carbon silane modified silica was varied to a value of 137 degree in 16-carbon silane modified one. In an attempt to clarify the significance of accurate measurement of surface energy, silane to silica ratio was adjusted to control surface properties of silica and then the silica dispersion was expected to be similar in specimens having identical surface energy.