Fabrication of intercalated p-aminobenzoic acid into Zn-Ti layered double hydroxide and its application as UV absorbent

An organic ultraviolet (UV) ray absorbent, p-aminobenzoic acid (PABA) was intercalated into a Zn-Ti layered double hydroxide (LDH) precursor by an anion-exchange reaction to obtain ZnTi-PABA-LDH, a new organic-inorganic nanocomposite. The structure and the thermal stability of ZnTi-PABA-LDH were characterized by XRD, FT-IR and TG-DTA. The results indicate ZnTi-PABA-LDH, synthesized by this method, exhibit relatively high crystallinity, and markedly enhanced thermal stability of PABA after intercalation into ZnTi-LDH. The UV-vis-NIR spectrophotometric and ESR data show excellent UV ray resistance and greatly decreased photocatalytic activity when PABA is intercalated into the interlayers of the ZnTi-LDH. The studies suggest that ZnTi-PABA-LDH may have potential applications as safe sunscreen materials. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.