排序方式: 共有42条查询结果,搜索用时 187 毫秒
21.
Mandal S Selvakannan PR Roy D Chaudhari RV Sastry M 《Chemical communications (Cambridge, England)》2002,(24):3002-3003
A single step method for the synthesis of catalytically active, hydrophobic Pt nanoparticles by the spontaneous reduction of aqueous PtCl(6)2- ions by hexadecylaniline molecules at a liquid-liquid interface is described. 相似文献
22.
Methane gas sensor was fabricated based on electrocatalytic properties of the Pd/MWNT nanocomposites on indium tin oxide (ITO)glass substrates.A linear response for methane was obtained in the range of 0-16%(v/v)with a detection limit of 0.167%(v/ v)and R.S.D.of 4.1%.After 100 times sensing or stable stored more than 12 months in atmosphere,unconspicuous measurable decrease was observed.The response time was less than 60s at room temperature and ambient pressure.Some common potential interferents in samp... 相似文献
23.
Citrinal A(1),a novel tricyclic compound with a rare tetrahydro-2H-benzofuro[7-b][1,4]dioxin-9(3H)-one skeleton,along with two known related compounds,citrinin(2) and 2,3,4-trimethyl-5,7-dihydroxy-2,3-dihydrobenzofuran(3) were isolated from an algicolous fungus Penicillium sp.i-1-1.The structure and stereochemistry of 1 were determined by comprehensive spectral and biogenic analysis.Its cytotoxic effects on the A-549 and HL-60 cell lines were evaluated. 相似文献
24.
A new 3,4-seco-lanostane triterpenoid,schisanlactone G (1),was isolated from the fruits of Schisandra sphenanthera.Its structure was established on the basis of extensive spectroscopic analysis.2009 Rong Tao Li.Published by Elsevier B.V.on behalf of Chinese Chemical Society.All fights reserved. 相似文献
25.
Under mild condition,using FeCl3 as catalyst,a series of functionalized diarylmethanes were prepared efficiently from the reactions of arenes with paraformaldehyde.This catalytic system is not sensitive to air and moisture. 相似文献
26.
Triangular silver nanoprisms were prepared and applied to make colorimetric detection of cysteine based on our findings that cysteine could lead to the blue shift of the dipole plasmon resonance absorption,but other 19 kinds of natural amino acids could not.Cysteine with a concentration 160 nmol/L can result in a color change that can be discerned with naked eyes. 相似文献
27.
Selvakannan P Mandal S Pasricha R Sastry M 《Journal of colloid and interface science》2004,279(1):124-131
In addition to control over the size and monodispersity of nanoparticle, nanomaterial synthesis procedures are increasingly required to control their shape and assembly as well. We demonstrate in this paper synthesis of organically dispersible, hydrophobic gold nanoparticles of spherical shape and encased in triangular thin polyaniline shells by doing reaction under static conditions and assembly of these particles onto polymer nanorod/nanowire-like templates by varying the molar ratio of chloroaurate ions to hexadecylaniline and varying the solvent by the spontaneous reduction of aqueous chloroaurate ions by hexadecylaniline molecules in a biphasic reaction setup. Under stationary conditions (no stirring), a biphasic mixture of hexadecylaniline in toluene and chloroaurate ions in water leads to the electrostatic complexation of chloroaurate ions with hexadecylaniline at the liquid-liquid interface and their phase transfer into the organic phase, followed by their reduction by the hexadecylaniline molecules. By varying the conditions, the templating action of gold nanoparticles or the polyaniline nanodispersions can be tuned in the organic medium and resulting assembly. 相似文献
28.
Selvakannan P Mandal S Phadtare S Gole A Pasricha R Adyanthaya SD Sastry M 《Journal of colloid and interface science》2004,269(1):97-102
The synthesis of water-dispersible amino-acid-protected gold nanoparticles by the spontaneous reduction of aqueous chloroaurate ions by tryptophan is described. Water-dispersible gold nanoparticles may also be obtained by the sequential synthesis of the gold nanoparticles by borohydride reduction of chloroauric acid followed by capping with tryptophan. Comparison of the proton NMR spectroscopic signatures from the tryptophan-protected gold nanoparticles obtained by the two processes indicated that the indole group in tryptophan is responsible for reduction of the aqueous chloroaurate ions. The reduction of the metal ions is accompanied by oxidative polymerization of the indole group of the tryptophan molecules and, consequently, some degree of cross-linking of the gold nanoparticles. 相似文献
29.
An ultra-low hydrolysis sol-gel route for titanosilicate xerogels and their characterization 总被引:1,自引:0,他引:1
Toney Fernandez Gijo Jose Siby Mathew Rejikumar PR Unnikrishnan NV 《Journal of Sol-Gel Science and Technology》2007,41(2):163-168
In this work TiO2-SiO2 xerogels were prepared through an ultra low hydrolysis method using titanium and silicon alkoxide. The samples were heat
treated to 500°C. The xerogels were characterized using TGA/DTA, FTIR, XRD and TEM. The samples showed the formation of Si–O–Ti
bridges by its characteristic vibration within 925–960 cm−1 range. Si–O–Si bond angles were calculated using the central force network model. The TiO2 in all the samples crystallized on heat treatment to 500°C. The crystallite size calculated using the Scherer formula from
the XRD was verified from the Transmission Electron Micrograph. Samples heat treated to 350°C remained amorphous and hence
could be used as hosts for biomaterials and organic optical materials. 相似文献
30.
Keggin ions as UV-switchable reducing agents in the synthesis of Au core-Ag shell nanoparticles 总被引:3,自引:0,他引:3
Mandal S Selvakannan PR Pasricha R Sastry M 《Journal of the American Chemical Society》2003,125(28):8440-8441
Keggin ion-mediated synthesis of Au core-Ag shell bimetallic nanoparticles is described. Exposure of photochemically reduced aqueous (PW12O40)3- Keggin ions to AuCl4- ions leads to the formation of stable gold nanoparticles capped by the Keggin ions. The surface-bound Keggin ions may then be activated by UV irradiation and, upon exposure to Ag+ ions, reduce the metal ions to form a silver shell around the gold core. That the capping agent not only stabilizes the metal nanoparticles but also plays the role of a switchable reducing agent is a highlight of this approach with important implications in nanomaterials synthesis and catalysis. 相似文献