L-Glu Hierarchical Structure Crystallization Using Inorganic Ions

Hierarchical organic structures have gained vast attention in the past decade owing to their great potential in chemical and medical applications in industries such as the food and pharmaceutical industries. In this paper, the crystallization of L-glu hierarchical spheres using inorganic ions, namely calcium, barium and strontium cations, is described. The anti-solvent precipitation method is used for the spherical crystallization. The L-glu microspheres are characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photo-electron microscopy (XPS) and polarized microscopy (POM). It is shown that without additives, L-glu crystallizes as flower-like structures, very different from the hierarchical spheres crystallized with the charged additives. Based on our results, we suggest a mechanism for the hierarchical sphere formation based on the crystallization and self-assembly of L-glu in emulsion droplets using charged additives.