01799nas a2200169   4500008004100000022001400041245013900055210006900194260008000263300001400343490000700357520107100364100001601435700002801451700001901479856013101498       2006                        eng d  a0957-448400aConstruction of conductive multilayer films of biogenic triangular gold nanoparticles and their application in chemical vapour sensing0 aConstruction of conductive multilayer films of biogenic triangul  aDIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLANDbIOP PUBLISHING LTDcMAY  a2399-24050 v173 a<p>Metal nanoparticles are interesting building blocks for realizing films for a number of applications that include bio- and chemical sensing. To date, spherical metal nanoparticles have been used to generate functional electrical coatings. In this paper we demonstrate the synthesis of electrically conductive coatings using biologically prepared gold nanotriangles as the building blocks. The gold nanotriangles are prepared by the reduction of aqueous chloroaurate ions using an extract of the lemongrass plant (Cymbopogon flexuosus) which are thereafter assembled onto a variety of substrates by simple solution casting. The conductivity of the film shows a drastic fall upon mild heat treatment, leading to the formation of electrically conductive thin films of nanoparticles. We have also investigated the possibility of using the gold nanotriangle films in vapour sensing. A large fall in film resistance is observed upon exposure to polar molecules such as methanol, while little change occurs upon exposure to weakly polar molecules such as chloroform.</p>1 aSingh, Amit1 aChaudhary, Minakshi, V.1 aSastry, Murali  uhttps://library.ncl.res.in/content/construction-conductive-multilayer-films-biogenic-triangular-gold-nanoparticles-and-their-002243nas a2200241   4500008004100000022001400041245012400055210006900179260007100248300001600319490000800335520133000343100001901673700002401692700002301716700001801739700002501757700002801782700002501810700001801835700002001853856012801873       2013                        eng d  a0002-786300aChemically stable multilayered covalent organic nanosheets from covalent organic frameworks via mechanical delamination0 aChemically stable multilayered covalent organic nanosheets from   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV  a17853-178610 v1353 a<p>A series of five thermally and chemically stable functionalized covalent organic frameworks (COFs), namely, TpPa-NO2, TpPa-F-4, TpBD-(NO2)(2), TpBD-Me-2, and TpBD-(OMe)(2) were synthesized by employing the solvothermal aldehyde-amine Schiff base condensation reaction. In order to complete the series, previously reported TpPa-1, TpPa-2, and TpBD have also been synthesized, and altogether, eight COFs were fully characterized through powder X-ray diffraction (PXRD), Fourier transform IR (FT-IR) spectroscopy, C-13 solid-state NMR spectroscopy, and thermogravimetric analysis. These COFs are crystalline, permanently porous, and stable in boiling water, acid (9 N HCl), and base (3 N NaOH). The. synthesized COFs (all eight) were successfully delaminated using a simple, safe, and environmentally friendly mechanical grinding route to transform into covalent organic nanosheets (CONs) and were well characterized via transmission electron microscopy and atomic force microscopy. Further PXRD and FT-IR analyses confirm that these CONs retain their structural integrity throughout the delamination process and also remain stable in aqueous, acidic, and basic media like the parent COFs. These exfoliated CONs have graphene-like layered morphology (delaminated layers), unlike the COFs from which they were synthesized.</p>1 aChandra, Suman1 aKandambeth, Sharath1 aBiswal, Bishnu, P.1 aLukose, Binit1 aKunjir, Shrikant, M.1 aChaudhary, Minakshi, V.1 aBabaRao, Ravichandar1 aHeine, Thomas1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/chemically-stable-multilayered-covalent-organic-nanosheets-covalent-organic-frameworks-0