Preparation and Characterization of Kynurenic Acid Occluded in Sol-Gel Silica and SBA-15 Silica as Release Reservoirs
Figure 2
(a) Chemical structure of kynurenic acid and its functional groups: carboxyl (1), hydroxyl (3), amine (2), and C=C double bonds of aromatic rings (4). (b) Schematic of the interactions between silica surface and KYNA molecules. Dotted lines represent hydrogen bonds.
