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91.
Xiyang Zhou Guoyong Wang Tao Lei 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):701-710
Abstract A lactobionamide-based trisiloxane surfactant (Si3N2–LA) was prepared via a two-step method. Structure characterization of Si3N2–LA was performed by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H NMR). Surface activity and aggregation behavior in aqueous solution of Si3N2–LA were investigated by surface tension measurements, dynamic light scattering (DLS) and negative-stained transmission electron microscopy (TEM). The results show that the surfactants can self-assemble into spherical vesicles with diameters in the range from 50 to 150 nm due to the introduction of trisiloxane tail. 相似文献
92.
Chen Chen Xiangheng Niu Yan Chai Hongli Zhao Minbo Lan Yonggang Zhu Gang Wei 《Electroanalysis》2013,25(6):1446-1452
This work presents a disposable bismuth‐antimony film electrode fabricated on screen‐printed electrode (SPE) substrates for lead(II) determination. This bismuth‐antimony film screen‐printed electrode (Bi‐SbSPE) is simply prepared by simultaneously in situ depositing bismuth(III) and antimony(III) with analytes on the homemade SPE. The Bi‐SbSPE can provide an enhanced electrochemical stripping signal for lead(II) compared to bismuth film screen‐printed electrodes (BiSPE), antimony film screen‐printed electrodes (SbSPE) and bismuth‐antimony film glassy carbon electrodes (Bi‐SbGC). Under optimized conditions, the Bi‐SbSPE exhibits attractive linear responses towards lead(II) with a detection limit of 0.07 µg/L. The Bi‐SbSPE has been demonstrated successfully to detect lead in river water sample. 相似文献
93.
M. N. Chai 《International Journal of Polymer Analysis and Characterization》2013,18(4):280-286
Electrical impedance spectroscopy was used to measure the conductivity of solid polymer electrolytes. From the impedance study, the highest ionic conductivity of solid polymer electrolytes based on carboxyl methylcellulose as polymer host and oleic acid as the doping salt, prepared by the solution casting method at room temperature, σr.t, is 2.11 × 10?5 S cm?1 for the sample containing 20 wt.% of oleic acid. Transference number measurement was performed to correlate the diffusion phenomena to the conductivity behavior of carboxyl methylcellulose-oleic acid solid polymer electrolytes. From the transference number measurement study, the conduction species carrier of the cation (+) is higher than that of the anion (?). Thus, the results proved that the samples are proton-conducting solid polymer electrolytes. 相似文献
94.
Mengbo Zhou Li Song Feng Niu Kangying Shu Wenxiang Chai 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(5):463-466
In the title CuII complex, [Cu(C19H14O3P)2(C3H7NO)(H2O)2], the molecule is bisected by a twofold axis relating the two 2‐(diphenylphosphoryl)benzoate (ODPPB) ligands. The asymmetric unit consists of a CuII metal centre on the symmetry axis, an ODPPB ligand, one water ligand and one dimethylformamide (DMF) ligand (disordered around the twofold axis). The CuII ion has fivefold coordination provided by two carboxylate O atoms from two ODPPB ligands, two O atoms from two coordinated water molecules and another O atom from a (disordered) DMF molecule, giving a CuO5 square‐pyramidal coordination geometry. The ODPPB ligand adopts a terminal monocoordinated mode with two free O atoms forming two strong intramolecular hydrogen bonds with the coordinated water molecules, which may play a key role in the stability of the molecular structure, as shown by the higher release temperature for the coordinated water molecules than for the coordinated DMF molecule. The optical absorption properties of powder samples of the title compound have also been studied. 相似文献
95.
Huachang Chen Dongying YuanYiya Li Mingjie DongZhihua Chai Juan KongGuoqi Fu 《Analytica chimica acta》2013
Surface imprinting over nanosized support materials is particularly suitable for protein templates, considering the problems with mass transfer limitation and low binding capacity. Previously we have demonstrated a strategy for surface protein imprinting over vinyl-modified silica nanopartiles with lysozyme as a model template by polymerization in high-dilution monomer solution to prevent macrogelation. Herein, the synthesis process was further studied toward enhancement of the imprinting performance by examining the effect of several synthesis conditions. Interestingly, the feed crosslinking degree was found to have a great impact on the thickness of the formed imprinting polymer layers and the recognition properties of the resulting imprinted materials. The imprinted particles with a crosslinking degree up to 50% showed the best imprinting effect. The imprinting factor achieved 2.89 and the specific binding reached 23.3 mg g−1, which are greatly increased compared to those of the lowly crosslinked imprinted materials reported previously. Moreover, the relatively high crosslinking degree led to no significant retarding of the binding kinetics to the imprinted particles, and the saturated adsorption was reached within 10 min. Therefore, this may be a promising method for protein imprinting. 相似文献
96.
97.
We are reviewing the state of electrochemical sensing of H2O2 based on the use of metal nanoparticles. The article is divided into subsections on sensors based on nanoparticles made from Ag, Pt, Pd, Cu, bimetallic nanoparticles and other metals. Some sensors display high sensitivity, fast response, and good stability. The review is subdivided into sections on sensors based on heme proteins and on nonenzymatic sensors. We also discussed the challenges of nanoscaled sensors and their future aspects. Figure
Sensing mechanism of (A) mediator-based enzyme biosensor, (B) mediator-less enzyme biosensor and (C) nonenzymatic sensors with metal nanoparticles for the electrocatalytic reduction toward H2O2 相似文献
98.
Dianlong Zhang Xiang Li Guojin Li Guoyong Wang 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(11):1817-1820
The aggregation behavior of tetrasiloxane-lactobionamide (Si4N2-LA) in aqueous solution has been characterized by dynamic light scattering (DLS), negative-stained transmission electron microscopy (TEM) and X-ray Diffraction methods. Compared with the micellar sizes 7.0 nm of n-dodecyllactobionamide (C12Glu2), the Si4N2-LA molecule can self-assemble into spherical vesicle with diameters in the range from 60 to 300 nm. 相似文献
99.
Yulin Ren Francisco Jiménez Ricardo García Milciades Mejía Heebyung Chai Norman R. Farnsworth Djaja D. Soejarto A. Douglas Kinghorn 《Tetrahedron letters》2013
A new sesquiterpene lactone, rufescenolide C (1), the first furanoheliangolide dimer, was isolated from the leaves of Piptocoma rufescens, collected in the Dominican Republic. Its structure was determined by interpretation of its spectroscopic data, with the absolute configuration being established by analysis of the CD spectrum. A plausible biogenesis of this dimer is proposed. This compound showed potent cytotoxicity with an IC50 value of 150 nM, when tested against HT-29 human colon cancer cells. 相似文献
100.
Xu-Feng Tan Li-Yong Yuan Chang-Ming Nie Kui Lui Zhi-Fang Chai Wei-Qun Shi 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):281-288
Electrochemical behaviors of U(VI) in 1-butyl-3-methylimidazolium chloride (C4MimCl) with various water contents investigated by chronopotentiometry and cyclic voltammetry. The electrochemical reduction of U(VI) was identified to follow two processes: a lower valence intermediate U(V) was initially formed at the potential of ca. ?0.2 V(vs. Ag wire). Then, further deposition of UO2 was followed at around ?0.8 V. Little amount of water (1–4 wt%) in C4MimCl, however, has an effect on the U(VI) reduction by changing the current density of the redox reaction and the diffusion coefficient of U(VI) in C4MimCl. The deposited product by potentiostatic electrolysis on the surface of stainless steel electrode was characterized by the scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) methods. Although the electrodeposited black film was amorphous, the electrochemical reduced product of U(VI) can be still confirmed to be UO2 by XRD after the crystallization of the amorphous deposits at 1,073 K in nitrogen atmosphere. 相似文献