cg6b01415_si_001.pdf (330.94 kB)
Crystal Growth of Salicylic Acid in Organic Solvents
journal contribution
posted on 2017-04-06, 00:00 authored by Lijun Jia, Michael Svärd, Åke C. RasmusonThe
crystal growth rate of salicylic acid has been determined by
seeded isothermal desupersaturation experiments in different organic
solvents (methanol, acetone, ethyl acetate, and acetonitrile) and
at different temperatures (10, 15, 20, and 25 °C). In situ ATR-FTIR spectroscopy and principal component analysis (PCA) were
employed for the determination of solution concentration. Activity
coefficient ratios are approximately accounted for in the driving
force determination. The results show that the dependence of the growth
rate on the solvent at equal driving force varies with temperature; e.g., at 25 °C, the growth rate is highest in ethyl
acetate and lowest in acetonitrile, while at 15 °C the growth
rate is highest in acetonitrile. The growth rate data are further
examined within the Burton Cabrera Franck (BCF) and the Birth and
Spread (B+S) theories, and the results point to the importance of
the surface diffusion step. Interfacial energies determined by fitting
the B+S model to the growth rate data are well-correlated to interfacial
energies previously determined from primary nucleation data.