Template induced crystallization: A relation between template properties and template performance

A relation between template properties and template performance has been established: template particles with a surface layer of cinnamic acid molecules, either adsorbed or covalently bonded, promote crystallization of cinnamic acid, while particles without such a layer do not. The BET surface area and dynamic light scattering (DLS) particle size were measured to gain control over the total surface area of added template particles (ZrO2, TiO 2, TiO2-SiO2, and SiO2-CAH). Zeta-potential measurements indicated whether adsorption of cinnamate on particles occurred, while the loading of the surface layer with cinnamic acid molecules was determined by adsorption isotherm measurements and spectrophotometry. The template performance was evaluated using induction time measurements. Scanning electron microscopy (SEM) images revealed that effective templates not only improve nucleation rates, but may also affect the size and shape of crystals. Template induced crystallization (TIC), where template particles promote crystallization, can be used as an in-situ product removal (ISPR) tool in fermentation processes to alleviate inhibitory and/or toxic constraints which are due to high product titers. The established relation between template properties and template performance can be used to predict which materials are effective templates for a specific (fermentation) product. © 2009 American Chemical Society.