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101.
The Surface‐enhanced Raman scattering of benzenesulfonamide and sulfanilamide adsorbed on silver sols was studied. On the basis of the noticeable shifts observed for wavenumbers of the νs(OSO), ν(CS), and ν(SN) vibrations with respect to the Raman spectra of the solids and the ionic solutions, we conclude that these molecules are adsorbed on silver nanoclusters at pH ≥ 7 with the aminosulfonyl groups partially deprotonated. The benzenesulfonamide links to the metal through the nitrogen atom of the corresponding azanion, while the sulfanilamide interacts in turn through the nitrogen atoms of the –NH2 and –SO2NH groups in the para‐position. Additionally, it was found that the most enhanced surface‐enhanced Raman scattering bands, especially the 8a;νring mode, are related to the presence of the charge transfer mechanism. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
102.
硫化锌胶体标准溶液稳定性研究   总被引:1,自引:0,他引:1  
采用去离子除氧水,由淀粉、乙酸锌、氯化钠、硫化钠等配制了硫化锌胶体标准溶液。实验结果表明,硫化锌胶体标准溶液的吸光度与硫化钠标准溶液基本一致,可以替代硫化钠标准溶液。采用t检验对硫化物胶体标准溶液稳定性进行了检验,表明该法配制的硫化锌胶体标准溶液在室温下可稳定保存2个月,解决了硫化物标准溶液只能现配现标现用的问题。  相似文献   
103.
The oxidation of Mn(II) by bromine is an autocatalytic reaction, which seems to be important for a detailed elucidation of chemical oscillators, based on manganese chemistry. With regard to the mechanism proposed previously, an alternative reaction mechanism is proposed, based on a micro-heterogeneous oxidation of Mn(II) ion, adsorbed on a surface of the MnO2 colloid. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
104.
高磺化度聚苯胺体系中的分形结构研究   总被引:6,自引:0,他引:6  
通过透射电镜的观察研究发现磺化聚苯胺的胶体聚集体和胶粒内部结构都具有分形体的特征 ,从而将分形的概念及其数学模型引入共轭导电聚合物体系之中 .磺化聚苯胺胶体的聚集体为很不均匀的分支状开放结构 ,其形成过程可用扩散控制集团聚集模型 (DLCA)进行模拟 ,计算机模拟生成的图形及其分形维数都与实验观测结果相当吻合 .胶粒由于是在分散介质所形成的平均化场中生成 ,屏蔽效应减弱 ,是比由它组成的聚集体要致密的球形结构 ,该结构的生成可用随机雨点模型模拟且结果相近 .  相似文献   
105.
After characterizing digoxin immunogens and antibodies, we investigated the assay performances of enzyme immunoassay (EIA), biotin–streptavidin mediated enzyme immunoassay (B-Av EIA), and immunostrip test and compared the effectiveness of these tests for detecting the presence of digoxin and its analogues. The clinical use of digoxin is very complicated due to its narrow therapeutic range. Thus, the development of a rapid and simple detection device has been needed. In our study, we determined digoxin levels by EIA and B-Av EIA, and compared these tests with the immunotest strip to determine the possibility of personal monitoring at the bedside. Three kinds of digoxin antibodies were produced from various digoxin–BSA immunogens (digoxin/BSA molar ratio of 15:1, 50:1, and 200:1 in their preparation step). The antibodies produced were purified by the immunoaffinity chromatography using digoxin–KLH or digoxin–BSA as the affinity ligand. Antibody #7 and its matching coating ligand of digoxin–KLH were selected by titration and sensitivity studies for use in EIA and B-Av EIA. Colloidal gold-labeled antibody #7 on a glass fiber membrane and digoxin–BSA on a nitrocellulose membrane were selected for the immunostrip preparation. The EIA and B-Av EIA could detect 0.01 ppb digoxin within 2.5 h, but the immunostrip could detect 0.01 ppm within 3 min, which was three orders less sensitive than EIA or B-Av EIA.  相似文献   
106.
The highly fluorescent natural dye berberine can be easily identified in microscopic textile samples by surface‐enhanced Raman spectroscopy employing citrate‐reduced Ag colloid. The ordinary Raman (OR) and SERS spectra of berberine are presented and discussed in the light of a DFT calculation. Using FT‐Raman and FT‐SERS we could reliably compare relative intensity shifts and investigate the adsorption geometry of berberine on Ag nanoparticles. The significant enhancement in the FT‐SERS spectrum of the out‐of‐plane ring system bending deformation mode at 729 cm−1 relative to a group of in‐plane vibrations at around 1500 cm−1 was interpreted as evidence of a ‘flat‐on’ adsorption geometry. SERS was successfully used to identify berberine in silk fiber samples coated with colloidal Ag following a pretreatment with HCl vapor. The SERS method allowed us to detect berberine in a microscopic sample of a single silk fiber from a severely degraded and soiled 17th Century Chinese textile fragment. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
107.
PS胶体粒子表面逐层自组装固定化SOD及其生物活性   总被引:3,自引:0,他引:3  
通过逐层自组装技术成功地把超氧化物歧化酶(SOD)吸附在聚苯乙烯(PS)胶体粒子表面.zeta电位和TEM证明了聚阳离子或聚阴离子型SOD与相反电荷的聚电解质在PS胶体粒子表面的交替吸附.通过测定SOD被胶体粒子吸附后上清液的生物活性,得到聚阴离子型SOD(pH=8.0)和聚阳离子型SOD(pH=4.3)在PS胶体粒子表面的吸附量分别为12和51IU,相对活性分别为23.4%和2.9%.聚阴离子型SOD在PS胶体粒子表面能形成平滑规整的膜,导致较高的相对活性.研究结果表明,通过调节pH值,可以优化自组装固定化酶的聚集状态和生物活性  相似文献   
108.
硼砂作稳定剂时胶体Sb2O5制备条件的优化   总被引:1,自引:0,他引:1  
硼砂作稳定剂时胶体Sb2O5制备条件的优化  相似文献   
109.
Au nanoparticles, which were photoreduced by a Nd:YAG laser in HAuCl4 solution containing TiO2 colloid and accompanied by the TiO2 particles, were deposited on the substrate surface. The film consisting of Au/TiO2 particles was characterized by the absorption spectra, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The adhesion between the film and substrate was evaluated by using adhesive tape test. It was found that the presence of TiO2 dramatically enhanced the adhesion strength between the film and the substrate, as well as the deposition rate of film. The mechanism for the deposition of Au/TiO2 film was also discussed.  相似文献   
110.
This paper describes a metal–metal bonding technique using metallic Cu nanoparticles prepared in aqueous solution. A colloid solution of metallic Cu particles with a size of 54 ± 15 nm was prepared by reducing Cu2+ (0.01 M (CH3COO)2Cu) with hydrazine (0.6 M) in the presence of stabilizers (5 × 10?4 M citric acid and 5 × 10?3 M cetyltrimethylammonium bromide) in water at room temperature in air. Discs made of metallic materials (Cu, Ni/Cu, or Ag/Ni/Cu) were successfully bonded under annealing at 400 °C and pressurizing at 1.2 MPa for 5 min in H2 gas with help of the metallic Cu particle powder. Shear strength required for separating the bonded discs was 27.9 ± 3.9 for Cu discs, 28.1 ± 4.1 for Ni/Cu discs, and 13.8 ± 2.6 MPa for Ag/Ni/Cu discs. Epitaxial crystal growth promotes on the discs with a good matching for the lattice constants between metallic nanoparticles and metallic disc surfaces, which leads to strong bonding. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
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