Papers by Keyword: Layered Double Hydroxide (LDH)

Abstract: Layered double hydroxides (abbreviated as LDHs) are one of the nanoordered layered compounds. The importance of layered compound is based on their ability to retain chemical species with electrical charges compatible to those of the layers. In this study we have reported the synthesis of nanosized layered double hydroxide (LDH) by co-precipitation method using two different surfactants as cetyl trimethyl ammonium bromide (CTAB) and octadecyl trimethyl ammonium bromide (ODTMA) having different critical micelle concentration (CMC) /chain length and its comparative results on calcined surface modified LDH (CS-LDH). The structure of surface modified layered double hydroxide (CS-LDH) synthesized is unique and has important advantages to the photocatalytic activity. LDH has significant number of application due to their structural, chemical properties etc., these compounds can be used as catalyst, adsorbents, anion exchanger. The photocatalytic activity of prepared surface modified CS-LDH was tested on degradation of the methylene blue (MB) dye in an aqueous solution. The surface characteristics of LDH and CS-LDH were examined using Energy Dispersive X-ray (EDX), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and UV-Visible spectrophotometer for Photocatalytic activity under visible light using MB dye. It was observed that highly exfoliated and basal spacing in CS-LDH-ODTMA which enhanced photocatalytic activity (Approx. 60% degradation) than that of comparison to CS-LDH-CTAB (Approx. 32% degradation).

Abstract: Usage of Hybrid nanocomposite materials provides a greater opportunity to replace the conventional materials due to their properties such as light weight and high strength to based on weight ratio. In this synergitic study, nanosized clay particle and layered double hydroxide particles are used. nanoclay and LDH particles were mixed on the bases of weight percentage (1wt% to 5wt%) by ultra sonication technique. The composite material was fabricated by one of the most common method known as hand lay-up technique. The composite materials was prepared in the form of plate with 4mm of thickness.The characterization of tensile and flexural property of the nanoclay, LDH and combination of both was analysis by tensile test using universal testing machine and three point bending test respectively. The tensile and three point bending test specimens were cut to size as per ASTM standard.The morphology of composite was studied using SEM analysis.

Abstract: This work focused on the preparation of poly (vinyl alcohol) (PVA)/ layered double hydroxide (LDH) and LDHSA nanocomposites by casting method. The morphology and interlayer spacing of the composites were characterized. The mechanical properties and the photochemical stability of the film of PVA, PVA/LDH and PVA/LDHSA have been studied and compared with PVA/MMT nanocomposites reported in previously. The results indicated that the thermal stability and dynamic mechanical properties of the PVA matrix in the PVA/LDH films and PVA/MMT films was enhanced. PVA/LDH films and PVA/OMMT films were shown stable photochemically more than those of pure PVA.

Abstract: A novel aminotriacetic acid (NTA) intercalated MgAl-LDHs have been successfully synthesized by anion exchange method with MgAl-NO₃-LDHs as precursor. The XRD pattern implies that NTA anions have replaced NO₃^- in the interlayer of LDHs. The FT-IR spectra also indicates that NTA anions have intercalated into layers’ space of LDHs, and the carboxyl groups of NTA have been converted into carboxyl anions after intercalation process. When comparing IR spectra of MgAl-NTA-LDHs and MgAl-CO₃-LDHs, higher and stronger absorption was observed in the range of 1428-1250 cm^-1, especially in the range of 1111-909 cm^-1.