Dr. Mees et al., FORMATION OF SELENIUM COLLOIDS USING SODIUM ASCORBATE AS THE REDUCINGAGENT, Journal of colloid and interface science, 170(1), 1995, pp. 254-260
Selenium colloid was synthesized to quantitative yield from selenous a
cid using sodium ascorbate as the reducing agent. When pure ascorbate
is used, the presence of an added surfactant is required to obtain sta
ble suspensions. Alternatively, exposure of ascorbate solutions to oxy
gen at elevated temperatures produces surface-active components which
can substitute as effective stabilizers. The progress of the reaction
with respect to change in particle number, growth, and conversion can
be followed spectrophotometrically. A growth phase, in the absence of
new particle formation, was observed from approximately 4 to 40 h. The
resulting colloid exhibits long-term colloidal stability, and the int
ernal structure of the particles exhibits no tendency to revert from t
he amorphous to the crystalline state. (C) 1995 Academic Press, Inc.