Preparation Of L-Amino Acid Intercalated Layered Double Hydroxides And Investigations On Their Properties

In this thesis, several kinds of L- amino acid were intercalated into layered double hydroxides. The supramolecular structure and properties of intercalated materials have been investigated particularly. Controllable synthesis on layered double hydroxides was made, and two new applications: "molecular container" and "molecular reactor" have been proposed.L-aspartic acid was intercalated into the layered double hydroxides by coprecipitation. Two kinds of well-crystallized materials were obtained by controlling the value of pH in reaction. They were characterized by XRD, FT-IR and elemental analysis. The schematic models and the reasonable explanation of two intercalation structures with different basal spacings were given. Furthermore, the mechanism of thermolysis of L-aspartic acid intercalated layered double hydroxides has been investigated firstly and detailedly by in situ FT-IR, in situ HT-XRD, TG-DTA, TPDE and GC-MS. It is found that the thermolysis of L-Asp LDH is quite different from that of the pristine L-Asp studied as a reference sample.L-tyrosine has been intercalated into a magnesium-aluminum, zinc-aluminum and nickel-aluminum respectively layered double hydroxide by coprecipitation. They were characterized by XRD, FT-IR and elemental analysis. The specific optical rotation of L-tyrosine decreases significantly on exposure to sunlight, heat, or UV light because of partial racemization. However, intercalation of L-tyrosine in nickel-aluminum layered double hydroxide can prevent racemization under the same conditions. Therefore, this layered material may have potential application as a "molecular container" for storing or transporting unstable chiral biomolecules or pharmaceutical agents.The L-cysteine intercalated layered double hydroxides with two basal spacings were obtained firstly by coprecipitation and ion exchange respectively with different value of pH in reaction. The L-cystine intercalated layered double hydroxide was also made. Dioxide water as oxidizer, L-cysteine was supposed to be turned to L-systine in the layers for the design of "molecular reactor".