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A novel mesoporous bioactive glass (MBG) of composition 64SiO 2 -26CaO-10P 2 O 5 (mol %) was prepared by hydrothermal method using H 3 PO 4 as a precursor for P 2 O 5 . The effect of use of organic triethylphosphate (TEP) and inorganic H 3 PO 4 in MBG synthesis on glass transition temperature (T g ), crystallinity, morphology and bioactivity of MBGs was studied. Phase purity determination and structural analysis were done using powder X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, respectively. XRD revealed that MBG prepared from H 3 PO 4 (MBG-H 3 PO 4 ) when sintered at 700°C was partially glassy/amorphous in nature and contained a mixture of crystalline apatite, wollastonite, calcium phosphate and calcium silicate phases. Calcined MBG prepared from TEP (MBG-TEP) contained only wollastonite and calcium silicate phases. Particle size and surface area determined by BET surface area analysis showed higher surface area (310 m 2 g -1 ) for MBG-H 3 PO 4 as compared to MBG-TEP (86 m 2 g -1 ). It also had a smaller particle size (20 nm) and 70 % higher pore volume (0.88 cm 3 g -1 ) for MBG-H 3 PO 4 as compared to MBG-TEP (60 nm particle size and 0.23 cm 3 g -1 pore volume). Thermal studies showed that use of H 3 PO 4 decreases T g and increased DT (difference between T g and crystallization initiation temperature Tc o ). Low T g and high DT also enhanced bioactivity of MBGs. Bioactivity was determined by immersion in a simulated body fluid for varying time intervals for a maximum period of 14 days. It revealed enhanced bioactivity, as evident by the formation of apatite layer on the surface, for MBG-H 3 PO 4 as compared to MBG-TEP. Scanning electron microscopy and FTIR spectroscopy also supported this observation. Antibacterial studies with Escherichia Coli bacteria, MBG-H 3 PO 4 showed better antibacterial behaviour than MBG-TEP.

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The present work deals with the synthesis of the metal-doped titanium dioxide/silica composite by using the sol-gel method. The structure, morphology, and composition of the prepared samples were characterized by using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The prepared composites were used for the photodegradation of methylene blue dye in sunlight. Different parameters like pH, time, and catalytic concentration were varied to optimize the reaction conditions. Maximum 99.8% degradation was observed with the Ni-doped composite. The results indicate extraordinary efficiency of all metal-doped composites for the removal of the harmful organic pollutant like methylene blue.

The preparation of hexamethylated and hexabenzylated arylene or heteroarylene bridged dinuclear di(cyclopentadienyltitanium) compounds from the reaction of the corresponding hexachlorides with methyllithium or benzylmagnesium chloride is described. The spacers between the cyclopentadienyl rings consist of one, two or three phenylene groups, a dioctyloxyphenylene group or a 2,2'-bithienylene group. The corresponding hexachlorides and hexaisopropoxides have also been prepared.

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