Pengaruh Garam-Garam Nitrat Terhadap Konsentrasi Miselisasi Kritis (CMC, Critical Micellization Concentration) Saponin

Abstract

Effect of nitrate salts [NaNO₃, KNO₃, Mg(NO₃)₂ and Sr(NO₃)₂], on the critical micellization concentration (cmc) of  saponin, as  a natural non-ionic surfactant, which isolated from Sapindus Rarak D.C, have been conducted by a tensiometric method. Results showed that (1) the higher of concentration of the added nitrate salts, the lower cmc reached; (2) the more electropositive of added cation of added salts, the lower cmc reached; (3) the salt effect on the decreasing of  cmc and cations binding to micelles becomes more pronounced in the order Na⁺< K⁺< Mg²⁺< Sr²⁺; and (4) cmc decreasing of nitrat salts Na, K, Mg, dan Sr. were favorable enough, while nitrate salts of Mg and Sr at concentration of  ≥ 0,06M, showed a constant decreasing cmc relatively.

Key Words: garam-garam  nitrat [NaNO₃, KNO₃, Mg(NO₃)₂ dan Sr(NO₃)₂], cmc, serta saponin.