排序方式: 共有78条查询结果,搜索用时 31 毫秒
31.
Ariyanan Mani Subramanian Tamil Selvan Kanala Lakshminarasimha Phani 《Journal of Solid State Electrochemistry》1998,2(4):242-246
The electrochemical polymerization of benzene via the microemulsion approach yields highly crystalline and anisotropic “spherulitic”
polyparaphenylene (PPP) thin films. The crystalline order and the origin of spherulite morphology are discussed.
Received: 29 July 1997 / Accepted: 27 October 1997 相似文献
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Highly Luminescent Heterostructured Copper‐Doped Zinc Sulfide Nanocrystals for Application in Cancer Cell Labeling 下载免费PDF全文
Huixiang Ang Dr. Michel Bosman Dr. Ramesh Thamankar Muhammad Faizal B. Zulkifli Dr. Swee Kuan Yen Anushya Hariharan Dr. Thankiah Sudhaharan Dr. Subramanian Tamil Selvan 《Chemphyschem》2016,17(16):2489-2495
The structural characteristics of the seed‐mediated synthesis of heterostructured CuS–ZnS nanocrystals (NCs) and Cu‐doped ZnS (ZnS:Cu) NCs synthesized by two different protocols are compared and analyzed. At high Cu dopant concentrations, segregated subclusters of ZnS and CuS are observed. The photoluminescence quantum yield of ZnS:Cu NCs is about 50–80 %; a value much higher than that of ZnS NCs (6 %). Finally, these NCs are coated with a thin silica shell by using (3‐mercaptopropyl)triethoxysilane in a reverse microemulsion to make them water soluble. Cytotoxicity experiments show that these silica‐coated NCs have greatly reduced toxicity on both cancerous HeLa and noncancerous Chinese hamster ovary cells. The labeling of cancerous HeLa cells is also demonstrated. 相似文献
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Gole A Jana NR Selvan ST Ying JY 《Langmuir : the ACS journal of surfaces and colloids》2008,24(15):8181-8186
We describe herein studies on as-prepared hydrophobic ZnS-CdSe quantum dots (QDs) at the air-water interface. Surface pressure-area (pi-A) isotherms have been used to study the monolayer behavior. Uniform, lamellar multilayer thin films of QDs were deposited by the Langmuir-Blodgett (LB) technique. The role of two different surfactant systems commonly employed in the synthesis of these QDs (trioctylphosphine oxide-octadecylamine (TOPO-ODA) system and trioctylphosphine oxide-tetradecylphosphonic acid (TOPO-TDPA) system) on the monolayer behavior and the quality of thin films produced has been investigated. The thin films were characterized by quartz crystal microgravimetry (QCM), contact angle measurements, fluorescence spectroscopy, and transmission electron microscopy (TEM). These QD films were further modified by an amphiphilic polymer, poly(maleic anhydride-alt-1-tetradecene) (PMA). The hydrophobic interaction between the polymers and the surfactants attached to the QDs drove the self-assembly process. The carboxylic acid functional groups in the polymer were also used to immobilize avidin. We have demonstrated a proof of concept for the biosensing strategy wherein the avidin-coated QD films attracted biotinylated gold nanoparticles, resulting in fluorescence resonance energy transfer (FRET) quenching of the thin films. 相似文献
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Tomokatsu Hayakawa S. Tamil Selvan Masayuki Nogami 《Journal of Sol-Gel Science and Technology》2000,19(1-3):779-783
We have investigated the energetic correlation between rare-earth ions and semiconductor nanocrystals, using europium ion (Eu3+) doped silica (SiO2) gel with adsorbed cadmium sulfide (CdS) particles. Samples were prepared by a sol-gel technique, in which several methods for the precipitation of CdS colloids were attempted. The fluorescence intensities were compared for different gels, with and without CdS particles. The intrinsic emission lines due to 5D0 7FJ(J = 0–4) transitions of Eu3+ were observed, which were enhanced for 24 h-immersed gel (dried at 50°C). From the results on the decay dynamics of fluorescence, we proposed the model that surface-trapped electrons on CdS particles nonradiatively excited 4f electrons in Eu3+ ions due to an energy transfer process. 相似文献
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P. M. Saroja G. Immanuel G. A. G. Raj K. E. Selvan 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(3):725-730
Gracilaria edulis, an edible red marine macro algae from three high background radiation areas (Arockiapuram, Kadiapattinam and Kurumpanai)
on the southwest coast of Tamil Nadu, and one low background radiation area (Mandapam) on the southeast coast of Tamil Nadu,
in India, were studied for variations in average gross alpha and beta radiation activities. Significant variations in average
gross beta activities were observed while alpha activities showed only marginal variation. The average gross alpha activity
was recorded high (61.51 Bq kg
−1) during the post southwest monsoon season, while it recorded lowest (25.48 Bq kg
−1) during the post northeast monsoon season. Average gross beta activity varied between seasons with the lowest level (211.55 Bq Kg−1) during post southwest monsoon season and the highest (413.33 Bq kg
−1) during post northeast monsoon season. Among the four locations, the gross alpha activity was high (70.95 ± 26.74 Bq Kg−1) in Arockiapuram and low (18.74 ± 6.32 Bq Kg−1) in Mandapam, while the gross beta activity was high (442.25 ± 168.53 Bq Kg−1) in Kurumpanai and low (158.63 ± 34.37 Bq Kg−1) in Mandapam. Average gross alpha activity in G. edulis was found significantly varying in terms of locations, while average gross beta activity for the same species recorded significant
seasonal variation. 相似文献
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M. Karunakaran C.T. Vijayakumar D. Muthamil Selvan C. Magesh 《Journal of Saudi Chemical Society》2013,17(1):1-8
o-Cresol–thiourea–formaldehyde terpolymer resin was synthesized through the condensation of o-cresol and thiourea with formaldehyde in the mole ratio 1:3:5 in the presence of 2 M hydrochloric acid as a catalyst. The resulting copolymer was characterized with IR and 1H NMR spectral data. The average molecular weight of the resin was determined by Gel permeation chromatography. Thermal study of the resin was carried out to calculate the activation energy (Ea), enthalpy of activation (H3), entropy of activation (S3), free energy of activation (G3), and pre-exponential factor (A) of various steps of thermal decomposition of the terpolymer. The Dharwadkar and Kharkhanavala method has been used to calculate thermal activation energy and thermal stability. The chelation ion-exchange properties were also studied with the batch equilibrium method. The chelation ion-exchange properties of the copolymer was studied for Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+ and Cd2+ ions. The resin was proved to be selective chelating ion-exchange copolymer for certain metals. The study was carried out over a wide pH range and in media of various ionic strengths. 相似文献
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AbstractArtemether; a sesquiterpene lactone is widely used for the treatment of malaria as artemisinin-based combination therapy (ACT). The present work involves the development and validation of sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method for quantification of artemether (ART) in polymeric nanoparticles. ART was transformed to α, β-unsaturated decalones by pre-column acid treatment to enhance the sensitivity of chromophoric group lacking ART for quantification by HPLC-UV. Waters Spherisorb® 5?µm ODS(C18) column (4.6*250?mm) with gradient elution by mobile phase comprising of ACN and PBS (10?mM; pH 6.0) was used to separate acid-treated ART. The analysis was carried at λmax of 253?nm with 20?min and 20?µL run time and injection volume, respectively. The method was found to be linear in the concentration range of 0.5–10?µg mL?1 with 0.09?µg mL?1 and 0.27?µg mL?1 as LOD and LOQ respectively. Further, the method was also found to be specific for ART in presence of blank polymeric nanoparticles, accurate (% average recovery rate 101.7?±?1.68%), precise (RSD <2%), and robust. The method was successfully used to determine % entrapment efficiency and in vitro release of ART-loaded polymeric nanoparticles with HPLC using a UV-visible detector. 相似文献
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A. Rajalakshmi V. D. Nithya K. Karthikeyan C. Sanjeeviraja Y. S. Lee R. Kalai Selvan 《Journal of Sol-Gel Science and Technology》2013,65(3):399-410
Phase pure olivine type V5+ doped and un-doped LiCoPO4 (LiCo1?xVxPO4 & LiCoP1?xVxO4; x = 0.02, 0.04 and 0.06) were synthesized by combustion method. Compound formation temperature and thermal stability of the materials were studied through thermal analysis. X-ray diffraction pattern shows the prepared material possesses an orthorhombic structure with Pnmb space group. Further the functional group and vibrational analysis were carried out by Fourier Transform Infra-red and Raman spectroscopy techniques. The Scanning Electron Micrographs depicts the irregular shaped morphology with particle agglomeration of the pristine and doped LiCoPO4 materials. The structural variation on addition of dopant on both sites Co2+ & P5+ were revealed from XPS spectra. The electrochemical aspects of these materials were investigated by cyclic voltammetry studies in conjunction with electrochemical impedance spectroscopy and chronoamperommetry measurements to understand the redox reactions and their capacity contribution at higher voltages. The EIS analysis shows that the conductance value was decreased for the vanadium doped samples for both the Co site and P site, which infers that the V5+ addition doesn’t make any significant enhancement in the electrochemical performance of the LiCoPO4. 相似文献