http://hdl.handle.net/2289/149 Search the Channel search http://dspace.rri.res.in:8080/jspui/simple-search http://hdl.handle.net/2289/5375 Title: Porphyrin aggregates in the form of nanofibers and their unusual aggregation induced emission<br/><br/>Authors: Pandey, Rakesh K.; Chitgupi, U.; Lakshminaryanan, V.<br/><br/>Abstract: We present here the simple procedure for synthesizing elongated fibers like porphyrin aggregates. Usually whenever the aggregation in dye molecules takes place the emission always tends to quench. In this work we explore and discuss the unusual enhanced emission property of these aggregates. The nanofibers of porphyrin were characterized with the help of atomic force microscopy and UV-vis spectroscopy whereas photoluminescence spectroscopy was used to check their emission property.<br/><br/>Description: Restricted Access. Mon, 29 Oct 2012 22:58:59 GMT http://hdl.handle.net/2289/5372 Title: Methyl 4-benzyloxy-2-hydroxybenzoate<br/><br/>Authors: Palakshamurthy, B.S.; Srinivasa, H.T.; Vijith, Kumar; Sreenivasa, S.; Devarajegowda, H.C.<br/><br/>Abstract: In the title compound, C15H14O4, the dihedral angle between the benzene rings is 67.18 (8)_. The Ca—Cm—O—Ca (a = aromatic and m = methylene) torsion angle is 172.6 (3)_ and an intramolecular O—H_ _ _O hydrogen bond generates an S(6) ring. In the crystal, molecules are linked by C—H_ _ _O hydrogen bonds into zigzag chains propagating in [001] and C—H_ _ __ interactions also occur.<br/><br/>Description: Restricted Access. Sat, 29 Oct 2011 22:58:59 GMT http://hdl.handle.net/2289/5336 Title: Modulated phases of phospholipid bilayers induced by tocopherols<br/><br/>Authors: Kamal, M.D. Arif; Raghunathan, V. A.<br/><br/>Abstract: The influence of α-, γ‐ and δ-tocopherols on the structure and phase behavior of dipalmitoyl phosphatidylcholine (DPPC) bilayers has been determined from X-ray diffraction studies on oriented multilayers. In all the three cases the main-transition temperature (Tm) of DPPC was found to decrease with increasing tocopherol concentration up to around 25 mol%. Beyond this the main transition is suppressed in the case of γ‐tocopherol, whereas Tm becomes insensitive to composition in the other two cases. The pre-transition is found to be suppressed over a narrow tocopherol concentration range between 7.5 and 10 mol% in DPPC‐γ-tocopherol and DPPC-δ‐tocopherol bilayers, and the ripple phase occurs down to the lowest temperature studied. In all the three cases a modulated phase is observed above a tocopherol concentration of about 10 mol%, which is similar to the Pβ phase reported in DPPC–cholesterol bilayers. This phase is found to occur even in excess water conditions at lower tocopherol concentrations, and consists of bilayers with periodic height modulation. These results indicate the ability of tocopherols to induce local curvature in membranes, which could be important for some of their biological functions<br/><br/>Description: Restricted Access. Mon, 29 Oct 2012 22:58:59 GMT http://hdl.handle.net/2289/5333 Title: Ethanol electrocatalysis on gold and conducting polymer nanocomposites: A study of the kinetic parameters<br/><br/>Authors: Pandey, Rakesh K.; Lakshminarayanan, V.<br/><br/>Abstract: The study attempts to compare the electrocatalytic effect of gold nanoparticles dispersed conjugated polymers using activation energy, Tafel slopes and reaction orders for the evaluation of their performance. A simple and rapid in situ chemical and electrochemical method was adopted for the synthesis of gold and different conducting polymers nanocomposites on electrode surfaces. The method involves the polymerization of the monomer to yield the polymer nanocomposite film with dispersed gold nanoparticles. Polyaniline, polypyrrole, polythiophene and poly(3,4-ethylenedioxythiophene) are the four polymers studied in this work. A systematic comparison among the nanocomposites reveals that although all the conducting polymers have good catalytic activity in alkaline medium however polyaniline dispersed with gold nanoparticles has the best catalytic properties among them as evidenced by its very low activation energy, low onset potential and reproducible currents.<br/><br/>Description: Restricted Access. Sun, 29 Jul 2012 22:58:59 GMT