This study was carried out in order to check the method of obtaining reproducible streaming potential for aqueous dispersion of sulfide-type phosphor for which it was difficult to obtain reproducible results with the usual method and in order to study the relationship between dispersibility of the dispersion and zeta-potential, investigating change of zeta-potential with surface treatment of the phosphor.
The revised method of Hazel et al. for measurement of streaming potential gave us the satisfactory and reproducible linearity between streaming potential and applied pressure for the phosphor as well as a reference sample, Ti0
2. However, it was necessary to degas the red-type phosphor dispersion under reduced pressure for obtaining reproducible results.
Zeta-potential of the dispersion changed with the surface treatments of the phosphor by ball-milling, the sulfuric acid solutions and the sodium hexamethaphosphate solutions. Correspondence between zetapotential of the dispersion and dispersibility estimated from sedimentation volume of the dispersion was found.
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