Surface Modification And Properties Of Layered Double Hydroxides

One technique of preparation of new inorganic-organic materials is to use nano-materials to modify the organic substances. Layer double hydroxides (LDH) have a wide range of applications and potential due to their unique two-dimensional layered structure. LDHs have a positive charge in the layers, which is balanced by hydrated carbonate anions located in the interlayers. LDH can be modified by lots of organic materials. Interaction which exists between host and guest can effectively affect the optical properties of the pure fluorescent dyes and increase their photostability. What’s more, hydrotalcites can easily modified coupling agents, and further combined with substances with targetting. Thus they can develop organ-specific drug delivery system and be applied to vivo imaging.So the thesis is divided into two parts(1)In this paper, intercalations and co-intercalation of Co-Al-LDH and4-Benzoylbenzoic acid (4-BBA) and Naphthalene-2-sulfonic acid (2-NSA) can be obtained by the method of ion-exchange procedures.4-BBA and2-NSA can be intercalated or co-intercalated into Co-Al-LDH, and XRD, TG-DTA, FT-IR,X-ray photoelectron spectroscopy and photoluminescence spectra were used to characterize the structural and photophysical properties of the obtained compounds. The geometry and electronic structure of the guest molecules and their singlet vertical excitation energies and oscillator strengths were investigated at B3LYP/6-31G level by density functional theory (DFT) and time dependent DFT calculations using G03w. Fluorescence polarization method was applied to test the preferential orientation of the interlayer4-BBA and2-NSA molecules.(2) Intercalations or adsorptions of Zn-Al-LDH and disodium8-Amino-1,3,6-naphthalenetrisulfonatecan(ANTS) be obtained by the method of ion-exchange procedures. The synthesis conditions are optimized by photoluminescence spectra. They can be successfully further modified by (3-Aminopropyl) trimethoxysilane (APTS), which can be confirmed by XRD and IR spectrum. Zn-Al-CO3-LDH first modified by APTS, and then adsorbed and intercalated with ANTS can also be synthesized, and XRD and IR spectrum can confirm that they are successfully synthesized. Their optical properties can be investigated by the emission spectrum. All the products were tested by leaching test to study the stability, and their photostability was also studied by emission spectrum of compositions. The results show that ANTS can be intercalated or adsorbed by Zn-Al-CO3-LDH, and which can be further modified by APTS. Zn-Al-CO3-LDH is first modified by APTS, and then adsorbs ANTS(Zn-Al-CO3-LDH-NH2-ANTS), which can improve the optical properties. It also proves that the interaction between host and guest can improve the optical properties.The leaching test shows that Zn-Al-CO3-LDH-NH2-ANTS need further modified by chiston, which can also develop organ-specific drug delivery systems.In summary, LDH can be modified by organic materials, and interaction between host and guest and guest-guest interaction can significantly improve the optical properties of the guest. What’s more, LDHs modified by organic materials can also develop organ-specific drug delivery systems, which is meaningful for vivo image.