INDUCTION TIME OF SURFACE NUCLEATION OF D-SCMC ON LSCMC SEED CRYSTAL AND THE GROWTH RATE OF L-SCMC SEED CRYSTAL IN DL-SCMC SUPERSATURATED SOLUTION

摘要

L-SCMC seed crystal was added into a supersaturated solution of S-Carboxymethyl-rnDL-Cysteine (DL-SCMC) which was kept on a given temperature in an agitatedrnvessel, and the change of concentrations of D-, and L-SCMC in solution wasrnobserved on batch operation. In this study, the time that required for beginning torndecrease of concentration of D-SCMC since the seed was added, was obtained as anrninduction time for surface nucleation of D-SCMC on the surface of L-SCMC seedrnand was correlated with suspension density and supersaturation ratio for the range ofrnsuspension density of 0.5~10%, supercoolingDT of 8.5~17K, pH of 0.5~2.8. Therndecreasing rate of L-SCMC concentration was also obtained by observing thernchange of concentration of L-SCMC against the operation time. The coefficient ofrncrystal growth rate of L-SCMC crystal was changed when the surface nucleation ofrnD-SCMC took place on the surface of L-SCMC seed and the phenomenon wasrndiscussed on induction time. The addition of given amount of HCl (10N) just beforernoperation time reached the induction time, was shown to affect the surfacernnucleation of D-SCMC and growth rate of L-SCMC, and it was discussed onrnoperational condition of optical resolution process.