Effect of Supersaturation Control and Heterogeneous Nucleation on Porous Membrane Surfaces in the Crystallization of l-Glutamic Acid Polymorphs

Abstract

This paper describes the crystallization of l-glutamic acid polymorphs in both quiescent and forced solution flow membrane crystallizers. The β polymorph was selectively obtained in static conditions, while the α form was preferentially grown in dynamic configuration, depending on the rate of solvent removal. According to concepts of the classical nucleation theory, the nucleation rate of the two polymorphs α and β have been calculated taking into account the quiescent/forced solution fluid dynamics regime and the homogeneous/heterogeneous nucleation activation mechanism. By this approach, the number-based polymorph fraction a, which is considered as an indication of the chance for a specific polymorphs to nucleate, was calculated. On these bases, the effect of supersaturation control and heterogeneous nucleation on the porous membrane surface was analyzed. Theoretical calculations have been compared with the experimental polymorphic outcome of the crystallization of l-glutamic acid (LGA) and an appropriate crystallization mechanism, for the different operative environments, has been formulated. Although it is obvious, classical theory was a helpful tool in describing experimental results obtained in the membrane-based equipment.

Membrane assisted cooling crystallization: Process model, nucleation, metastable zone, and crystal size distribution

“…[11][12][13] This innovative method presented an impressive performance on the reduction of the biological macromolecules nucleation barrier with various tailored membranes. 14,15 As to the industrial aspect, the membrane distillation crystallization was applied in the high concentration brine desalination and pure water recovery. [16][17][18][19][20][21] The microporous hydrophobic membranes presented both as active surfaces to promote heterogeneous nucleation (HEN) and as a masstransfer apparatus to concentrate macromolecular solutions by solvent removal in vapor phase.…”

A novel membrane distillation response technology for nucleation detection, metastable zone width measurement and analysis

“…In recent decades, membrane distillation combined crystallization (MDC) was proposed as a novel crystallization process. MDC had been applied in the separation and treatment of high concentration brine desalination Creusen et al, 2013;Curcio et al, 2010;Chung, 2012, 2013;Kim, 2011) and presented an impressive performance on the biological macromolecules with the development of membrane material and membrane process research (Profio et al, 2009(Profio et al, , 2014. The conventional crystallization (evaporative crystallization, antisolvent crystallization, etc.)…”

Polymorphism and Solvatomorphism 2009

“…In another work, the $-polymorph of (L)-glutamic acid was formed preferentially when crystallized under static conditions on a porous membrane surface, whereas the "-polymorph was obtained under more dynamic conditions. 23 The combination of scanning tunneling microscopy at the liquid-solid interface and molecular modeling has been used to study the formation of polymorphs on gold surfaces, examining the moleculesubstrate interactions that lead to the formation of two-dimensional crystals. 24 Using Schiff base compounds as models for study, it was determined that molecules could self-organize on Au(111) surfaces into columnar and dimer structures, demonstrating that the dimer-based structure was derived from molecule-surface interactions that were capable of modifying molecule-molecule interactions.…”