NOPR Collection:

Highly active ZnS loaded TiO₂photocatalyst for mineralization of phenol red sodium salt under UV-A light

Tue, 01 Jul 2014 00:00:00 GMT

Title: Highly active ZnS loaded TiO₂photocatalyst for mineralization of phenol red sodium salt under UV-A light Authors: Dhatshanamurthi, P; Subash, B; Krishnakumar, B; Shanthi, M Abstract: ZnS loaded TiO₂ (ZnS-TiO₂) has been successfully synthesized by precipitation-cum-sol gel method. The photocatalytic activity of (ZnS-TiO₂) has been investigated for the degradation of phenol red sodium salt in aqueous solution using UV-A light. In presence of ZnS, there is a shift in the absorbance of TiO₂ in both UV and visible region. ZnS-TiO₂ is found to be more efficient than bare TiO₂, TiO₂-P25 and ZnS at pH 6.5 for mineralization of the dye under UV-A light. The effects of operational parameters such as the amount of photocatalyst and dye concentration on photomineralization of the dye have been analyzed. The mineralization has been confirmed by COD measurements. Mechanism of degradation by ZnS-TiO₂is proposed. The catalyst is found to be reusable. Page(s): 820-823

Synthesis of single crystal zeolite L rods with high aspect ratio using rice husk ash as silica source

Sat, 12 Jul 2014 10:54:28 GMT

Title: Synthesis of single crystal zeolite L rods with high aspect ratio using rice husk ash as silica source Authors: Das, Rituparna; Ghosh, Sourav; Naskar, Milan Kanti Abstract: Single crystal zeolite L rods with high aspect ratio have been prepared using rice husk ash as silica source in the presence of other aqueous-based precursors via a single-step hydrothermal process at 170 ^oC for 72 h. Crystallization behavior of the particles is studied by X-ray diffraction, and the characteristic vibration bands of zeolite L are confirmed by FTIR spectroscopy. BET surface area and total pore volume of the particles are found to be 142 m² g^-1and 0.19 cm³ g^-1, respectively. Rod-shaped morphology of zeolite L with an aspect ratio of 10-50 is observed by FESEM and TEM. Selected area electron diffraction pattern of TEM confirms the single crystal nature of the particles. Page(s): 816-819

Rheological properties of lamellar liquid crystals formed in Brij97/castor oil/water systems in the presence of soybean lecithin

Sat, 12 Jul 2014 10:53:02 GMT

Title: Rheological properties of lamellar liquid crystals formed in Brij97/castor oil/water systems in the presence of soybean lecithin Authors: Wei, Ling; Wang, Zhongni; Liu, Xin; Guo, Fumin; Fan, Jun Abstract: Phase diagrams of Brij97/castor oil (COil)/water in the presence of soybean lecithin (SL) have been determined at 37 ^oC. The lamellar phases have been investigated by polarizing optical microscopy, rheological technique and small angle X-ray scattering. With increasing SL content, the domain of the lamellar phase extends to higher COil concentration. At constant surfactant concentration, the shear viscosity increases for samples containing more SL. The storage modulus G' increases on addition of SL and reaches a maximum in the SL/COil/water system, with the smallest area of surfactant molecules at the interface. For the Brij97/SL (1:3) system, at a fixed ratio of COil/water, the dynamic moduli increases with increasing surfactant concentration. At 37 ^oC, the Brij97/SL (1:1)/water/oil systems with ethyl oleate and COil have a higher moduli and smaller a_S than with isopropyl myristate. The values of activation energy of ethyl oleate and COil systems are larger than that of isopropyl myristate system, indicating that the network in lamellar phases in ethyl oleate and COil systems are stronger than in the isopropyl myristate system. Page(s): 806-815

Catalytic activity of sulfated zirconia solid acid catalyst for esterification of myristic acid with methanol

Sat, 12 Jul 2014 10:50:49 GMT

Title: Catalytic activity of sulfated zirconia solid acid catalyst for esterification of myristic acid with methanol Authors: Saravanan, K; Tyagi, Beena; Bajaj, H C Abstract: The catalytic activity and reusability of sulfated zirconia solid acid catalyst is evaluated for esterification of myristic acid with methanol. The catalyst exhibits excellent activity with 98% conversion of myristic acid and selective formation of methyl myristate in presence of a very small amount of catalyst, i.e., 0.5 wt% (to acid) at 60 ^oC after 5 h. The re-used catalyst also shows good catalytic performance without significant difference in activity up till five reaction cycles. Characterization of the used catalyst revealed no significant change in structural and textural properties, however a slight decrease in surface acidity was observed due to deposition of carbonaceous matter on the surface acid sites. Page(s): 799-805

NOPR Collection:

Highly active ZnS loaded TiO2 photocatalyst for mineralization of phenol red sodium salt under UV-A light

Synthesis of single crystal zeolite L rods with high aspect ratio using rice husk ash as silica source

Rheological properties of lamellar liquid crystals formed in Brij97/castor oil/water systems in the presence of soybean lecithin

Catalytic activity of sulfated zirconia solid acid catalyst for esterification of myristic acid with methanol

Highly active ZnS loaded TiO₂photocatalyst for mineralization of phenol red sodium salt under UV-A light