NISCAIR Online Periodicals Repository Collection: IJCT Vol.11(5) [September 2004]

Synthesis of glycylcalix[6]arene and its applicability as resin for separation and preconcentration of trace transition metals

Sun, 29 Aug 2004 22:58:59 GMT

Title: Synthesis of glycylcalix[6]arene and its applicability as resin for separation and preconcentration of trace transition metals

Authors: Bhatt, H; Agrawal, Y K

Abstract: A new glycylcalix[6]arene is synthesized by the reaction of glycine ethyl ester hydrochloride with acid chloride of p-carboxycalix[6]arene. Its physical properties, void volume, density, swelling, cation exchange capacity and t_1/2 have been determined. The glycylcalix[6]arene is used as resin and its metal ion exchange capacities are determined. Mn(II), Fe(II), Co(II), Cu(II), Ni(II) and Zn(II) were absorbed at 5.5, 4.5, 6.0, 4.0, 4.8 and 5.0 pH, respectively. These were eluted with NaF, H₂SO₄, acetic acid, tartrate and HCl_. The chromatographic separation of Mn(II), Fe(II) Co(II), Ni(II), Cu(II) and Zn(II) from each other was studied. These metals were preconcentrated on resin and determined in blood plasma and in the environment samples.

Page(s): 688-694

Ethylation of benzene over AFI type molecular sieves

Sun, 29 Aug 2004 22:58:59 GMT

Title: Ethylation of benzene over AFI type molecular sieves

Authors: Raj, K Joseph Antony; Vijayaraghavan, V R

Abstract: Large pore aluminophosphate-based molecular sieves, MgMnAPO-5 and MnZnAPO-5, were synthesized by hydrothermal methods. The samples were characterised by the techniques of XRD, FT-IR, ³¹P and ²⁷Al MAS-NMR spectra, BET-surface area, n-butylamine-TPD and ICP-MS chemical analysis. The catalytic performance of these materials has been examined for ethylation of benzene with ethanol in the vapour phase. The products were ethylbenzene, p-diethylbenzene, m-diethylbenzene, o-diethylbenzene and PAB[(1,2,4 and 1,3,5-triethylbenzene) and (1,2,4,5-tetraethylbenzene)]. Maximum conversion (20.6%) was observed at 400^oC over MnZnAPO-5.

Page(s): 678-682

Decolourization of synthetic dyes using rice straw attached pleurotus ostreatus

Sun, 29 Aug 2004 22:58:59 GMT

Title: Decolourization of synthetic dyes using rice straw attached pleurotus ostreatus

Authors: Neelamegam, R; Baskaran, V; Dhanasekar, R; Viruthagiri, T

Abstract: Preliminary studies were conducted to assess the degree of decolourization of different dyes such as Malachite green, Indigo carmine, Xylidine ponceau, Bismark brown, Congo red and Methyl orange using the white rot fungus Pleurotus ostreatus. The effect of initial concentration of different dyes on the decolourization was studied. The effect of pH and biomass concentration during decolourization were also observed for all the dyes. The time course of decolourization was also characterised for all the dyes at their optimum concentrations. An improved percent decolourization [95%] was achieved for Xylidine ponceau, Methyl orange, Congo red and Bismark brown with the rice straw attached Pleurotus ostreatus

Page(s): 622-625

Phlogiston: The rise and fall of a theory

Sun, 29 Aug 2004 22:58:59 GMT

Title: Phlogiston: The rise and fall of a theory

Authors: Wisniak, Jaime

Abstract: The phlogiston theory was born around 1700 and lasted for about one hundred years. It provided for the first time a unifying approach to widely different chemical and physical phenomena and as such was adopted by the most famous European scientists, particularly the French ones. Its demise came with Lavoisier’s new insights into the phenomena of chemical reactions in general and combustion in particular, as well as about the composition of air. Lavoisier’s results disproved the phlogiston theory and established the applicability of the principle of mass conservation to chemical reactions.

Page(s): 732-743