Co-deposition of fine particles on glass surfaces

Abstract

The deposition of latex particles on glass surfaces in the presence of a CaF 2 precipitant has been studied in the impinging jet cell. The initial flux of latex particles in 5 × 10 −4 M CaCl 2 solution was increased by a factor of thirty when the glass collector surface was modified by contact with CaF 2 precipitant. However, after a period of time necessary to dissolve the positively charged CaF 2, the flux had declined and eventually the previously deposited particles were washed out. Small amounts of the CaF 2 precipitant added to the latex solution also promoted deposition, although in this case the flux increase was not as large as it was previously. Significant influence of the CaF 2 precipitant on the latex particles flux to the glass collector was noted even for quantities of CaF 2 which should have dissolved after being added to the latex suspension. For very small amounts of CaF 2 precipitant, the initially constant flux declined sharply after some period of time. However, one could not see the escape of the deposited particles. The experimental data presented herein indicate a great number of possible interactions during the deposition process from binary mixtures of chemically dissimilar colloid particles. This paper also briefly presents a theory of the phenomenon.