The g-C3N4 Nanosheets Separated by PS for Photocatalytic Degradation of Dye

Polymerization of styrene (St) stabilized by graphitic carbon nitride (g-C3N4) nanosheets, containing hydrophobic conjugated structure and hydrophilic oxygen-containing functional groups, is conducted at varying styrene concentration. It is found that the morphology of polystyrene (PS)/g-C3N4 nanocomposites tends to transform from g-C3N4 nanosheets coated PS nanospheres to g-C3N4 nanosheets separated by PS with irregular morphology by further increasing the concentration of St. The strong interaction between PS and g-C3N4 nanosheets, suggesting by FT-IR, XRD patterns and UV–vis spectra results, and the amount of St are responsible for the structure and morphology of the final product. The g-C3N4 nanosheets separated by PS exhibit the highest photocatalytic efficiencies towards degradation of methylene blue (MB), due to the specific structure and morphology. The PS separates g-C3N4 nanosheets, obstructs the aggregates of g-C3N4 nanosheets. On the other hand, the PS as a collector gathers the MB, which is benefit for the close contact between g-C3N4 nanosheets and MB, achieving the collective effect to greatly increase the photocatalytic efficiency.

PHOTOACTIVE GOLD NANOPARTICLE SOFTOXOMETALATES (SOM) USING A KEPLERATE FOR SYNTHESIS OF POLYSTYRENE LATEX MICROSPHERES BY PHOTOPOLYMERIZATION

In this paper, a green and facile synthetic protocol for the preparation of photoactive gold nanoparticle-soft oxometalates ( AuNP-SOM ) using a unique keplarate type oxomolybdate cluster viz. { Mo 132}, is reported. The as-synthesized AuNP-SOMs are fully characterized by electronic absorption spectroscopy, Raman spectroscopy and high resolution transmission electron microscopy (HR-TEM). We further demonstrate that by merely tuning the ratio of the precursors in solution it is possible to control the morphology of AuNP-SOM nanostructures. Moreover, these photoactive AuNP-SOMs are employed as photocatalysts for the photopolymerization of styrene to generate colloidal monodisperse polystyrene microspheres in a controllable way in the absence of any external co-initiator or inert atmosphere. Effect of styrene concentration on the size of microspheres is studied using DLS and optical microscopy. Finally, the role of AuNP-SOMs as efficient photocatalyst is established through several control experiments and a reaction pathway is proposed.

Nanocomposites of Carbonated Hydroxyapatite/Poly (4-vinyl pyridine-co-styrene): Synthesis, Characterization and its Application

nanocarbonated hydroxyapatite/Poly (4-vinyl pyridine-co-styrene) composites of varying composition for biomaterial applications have been synthesized. The nanocarbonated hydroxyapatite/Poly (4-vinyl pyridine-co-styrene) composite materials were characterized by XRD, FTIR, 31P NMR, TGA, DTA and FESEM. Carbonated Hydroxyapatite nanorod embedded composite was prepared using Poly (4-vinyl pyridine-co-styrene) as a matrix with different weight percentages (wt %). The results indicated that the size and crystallinity of Carbonated hydroxyapatite nanoparticles decreases with increase in Poly (4-vinyl pyridine-co-styrene) concentration in the composite. SEM confirms the presence of carbonated hydroxyapatite nanorod crystals in Poly (4-vinyl pyridine-co-styrene) matrix. nanoCarbonated hydroxyapatite/ Poly (4-vinyl pyridine-co-styrene) composites were screened for antimicrobial activity and anti inflammatory activity.

Preparation of Three-Dimensional Ordered Macroporous Perovskite-Type LaFeO3 Oxides

Polystyrene spheres were prepared by soap free emulsion polymerization method. The effects of styrene concentration, polymerization time and self-assemble methods on the diameter of the polystyrene spheres were investigated. Different size of polystyrene microspheres could be obtained by changing styrene concentration and polymerization time. Polystyrene templates with good uniform and highly ordered can be assembled by means of vertical deposition method. Based on this template, three-dimensional ordered macroporous (3DOM) perovskite-type oxides LaFeO3 were successfully prepared which were confirmed by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was also found that 1mol/L metal precursor solution which used ethanol solution of metal nitrates with citric acid addition gave the best 3DOM perovskite-type LaFeO3 oxides. The pores are uniform, flexible and arranged in a highly ordered form.

RADIATION GRAFTING OF STYRENE ONTO PTFE FILM

Radiation grafting of styrene monomer onto poly(tetrafluoroethylene) (PTFE) film has been investigated. This research is emphasized on the conditioning of PTFE film. It was irradiated by -ray radiation at various irradiation dose from 2.5 - 12.5 kGy with dose rate 1.9 kGy/hour. Irradiated copolymer was then grafted by styrene monomer under various conditions. The results showed that degree of grafting increased by increasing irradiation dose, solvent concentration, temperature and time of grafting. The optimum condition of radiation grafting relatively was obtained at irradiation dose of 10 kGy, 2-propanol solvent, styrene concentration of 40 volume%, temperature and time of grafting of 70 oC and 6 hours each. Keywords: Radiation grafting, PTFE, Fuel cell