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Please use this identifier to cite or link to this item: https://dspace.lboro.ac.uk/2134/3263

Title: Surface energy measurements of coated titanium dioxide pigment
Authors: Lim, B.C.
Thomas, Noreen L.
Sutherland, I.
Keywords: titanium dioxide
surface energy
contact angle
organic coating
Issue Date: 2008
Publisher: © Elsevier
Citation: LIM, B.C., THOMAS, N.L. and SUTHERLAND, I., 2007. Surface energy measurements of coated titanium dioxide pigment. Progress in organic coatings, 62 (2), pp. 123-128
Abstract: In this study surface energy measurements have been carried out on titanium dioxide pigments coated with different types of organic compound. The organic coatings investigated were polymethylsiloxane and octyl triethoxy-silane. The level of coating applied was increased from 0.2 up to 1.5 weight %. Contact angles were measured using an advancing sessile drop method. To allow for the fact that measurements were made on pressed discs of particles rather than on a perfectly flat surface, a correction was applied to convert each measured contact angle to the true Young’s contact angle. Surface energies were calculated from the corrected contact angles using the Owens and Wendt equation. From the values of surface energy it was possible to determine at what coating level the surface characteristics changed from hydrophilic to hydrophobic and hence when complete coverage had taken place. For both the siloxane and the silane coatings it was found that complete coating coverage occurred at an addition level of around 0.8 weight %. The surface energies of all the coated pigments were found to correlate well with their dispersion behaviour in liquid paraffin. Keywords: In this study surface energy measurements have been carried out on titanium dioxide pigments coated with different types of organic compound. The organic coatings investigated were polymethylsiloxane and octyl triethoxy-silane. The level of coating applied was increased from 0.2 up to 1.5 weight %. Contact angles were measured using an advancing sessile drop method. To allow for the fact that measurements were made on pressed discs of particles rather than on a perfectly flat surface, a correction was applied to convert each measured contact angle to the true Young’s contact angle. Surface energies were calculated from the corrected contact angles using the Owens and Wendt equation. From the values of surface energy it was possible to determine at what coating level the surface characteristics changed from hydrophilic to hydrophobic and hence when complete coverage had taken place. For both the siloxane and the silane coatings it was found that complete coating coverage occurred at an addition level of around 0.8 weight %. The surface energies of all the coated pigments were found to correlate well with their dispersion behaviour in liquid paraffin. Keywords: Titanium dioxide; surface energy; contact angle; organic coating; surface energy; contact angle; organic coating
Description: This article was published in the journal, Progress in organic coatings [© Elsevier]. The definitive version is available at: http://www.sciencedirect.com/science/journal/03009440
URI: https://dspace.lboro.ac.uk/2134/3263
ISSN: 0300-9440
Appears in Collections:Published Articles (Materials)

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