Primary nucleation of vanillin explored by a novel multicell device

A novel multicell apparatus is designed, constructed, and used to investigate crystal nucleation of vanillin in water/2-propanol solution (20 mass % of 2-propanol on a solute-free basis). The device contains 15 nucleation cells, with volumes of about 6 cm³ each, in which the induction times for nucleation are measured simultaneously. The nucleation in the cells is continuously video-recorded and analyzed offline. The induction time for nucleation of vanillin is determined at various levels of supersaturation and temperature, and by classical nucleation theory the solid-liquid interfacial energy is estimated to 7.3 ± 0.2 m^-2. A large variation in the experimental data is observed, and this variation is analyzed by statistical methods.