Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

Nono-sized organic bentonite (OMMT) was synthesized through intercalation modification process with organic phosphorus flame retardant (Cyagard RF-1) and quaternary ammonium salt (CTAB). Composite materials of polybutylene terephthalate (PBT)/OMMT, Polyamide-6 (PA6)/OMMT was prepared by a double screw extrusion. The flame retardancy and mechanical properties of these materials were characterized. Nano-sized OMMT has large interlayer spacings and good dispersion after modification. In compared with PBT and PA6, composite materials of PBT/OMMT and PA6/OMMT had high tensile strength, bending strength and notched impact strength, while their elongation decreased after addition of nano-sized OMMT, the limiting oxygen index ( LOI ) and UL94 vertical combustion of OBT/OMMT and PA6/OMMT composite materials with dosage of 3 wt% OMMT decreased slightly, in comparison with these composite metarials containing constant amounts of flame retardant.

Large-sized hydroxyapatite (HA) crystals with different morphologies, such as whisker-like, tubular and plate-form shape were prepared at different hydrothermal temperatures. Reaction solutions with small concentration of Ca2+, PO43- and OH- ions were used for HA synthesis. Phase identifications and morphological characterizations indicated that HA crystal grew along c axis under the modulation of glutamic acid adsorbent. The formation mechanism was explained according to the interfacial structures between glutamic acid and HA, as well as thermodynamic and kinetic considerations of crystal nucleation and growth. Understanding the evolution of crystal morphology in a specified reaction solution might favor to control the shape of crystals by the hydrothermal method.