Simultaneous EQCM and diffuse reflectance UV-visible spectroelectrochemical measurements: poly(aniline-co-o-anthranilic acid) growth and property characterization

Piezoelectric diffuse reflectance spectroelectrochemistry (PDRSEC), a new technique of diffuse reflectance spectroelectrochemistry (DRSEC) in combination with electrochemical quartz crystal microbalance (EQCM), was developed to study the electrochemical copolymerization of aniline and o-anthranilic acid in 1.0 mol l(-1) HClO4 and the properties of these copolymers. The DRSEC using an integral sphere was proven to possess a higher optical sensitivity at the unpolished piezoelectric quartz crystal electrodes used than the mirror reflectance spectroelectrochemistry mode. The copolymers grown from the copolymerization bath of different molar fractions of o-anthranilic acid (F1, relative to the total amount of the two monomers) showed intermediate properties between those of the homopolymers, which varied gradually with F1. The swelling/dissolution behavior of the copolymers vs solution pH was traced via the EQCM frequency and resistance signals, and its large dependence on F1 was found and discussed. In a HAc-NaAc buffer solution at pH 5.6, the amount of adsorbed lysozyme was found to be positively correlated with F1, via an EQCM impedance investigation, demonstrating the feasibility of using poly(aniline-co-o-anthranilic acid) as a load-adjustable immobilization matrix for cationic proteins. The novel PDRSEC method proposed is highly recommended for surface electrochemistry studies at relatively rough electrodes.     

High-throughput purification of combinatorial libraries I: a high-throughput purification system using an accelerated retention window approach

We have developed a high-throughput purification system to purify combinatorial libraries at a 50-100-mg scale with a throughput of 250 samples/instrument/day. We applied an accelerated retention window method to shorten the purification time and targeted one fraction per injection to simplify data tracking, lower QC workload, and simplify the postpurification processing. First, we determined the accurate retention time and peak height for all compounds using an eight-channel parallel LC/UV/MS system, and calculated the specific preparative HPLC conditions for individual compounds. The preparative HPLC conditions include the compound-specific gradient segment for individual compounds with a fixed gradient slope and the compound-specific UV or ELSD threshold for triggering a fraction collection device. A unique solvent composition or solvent strength was programmed for each compound in the preparative HPLC in order to elute all compounds at the same target time. Considering the possible deviation of the predicted retention time, a 1-min window around the target time was set to collect peaks above a threshold based on UV or ELSD detection. Dual column preparative instruments were used to maximize throughput. We have purified more than 500 000 druglike compounds using this system in the past 3 years. We report various components of this high-throughput purification system and some of our purification results.     

Complex dynamics in a periodically perturbed electro-chemical system

Dynamical response of a passivation model subjected to parametric periodic and stochastic perturbations is studied numerically. In response to weak periodic modulation, the system exhibits a rich variety of resonance behavior and induced dynamics, including periodically induced oscillation, birhythmicity, switching between two bistable states, selection of one of the bistable states, mixed-mode and chaotic oscillations. These phenomena are discussed in terms of the stability of saddle focus and an incomplete homoclinic connection. Our numerical results are relevant for a wide class of electro-chemical oscillatory systems, where the re-injection of unstable trajectory on the neighborhood of a saddle focus is a typical feature in the phase space.     

Single crystal tin nano-rod arrays electrodeposited by a soft template

Single crystal tin nano-rod arrays were fabricated by the electrodeposition method when amphiphilic triblock copolymer P123 was used as a soft template at a concentration much lower than that for forming a liquid crystalline phase.     

电子探针定量分析的标准样品——几种多元氧化物单晶

在很高的温度和适宜的生长条件下,分别采用熔盐籽晶法和高温引上法生长了高质量的YAP、NAB、KTP、LN、BBO、SBN等多元氧化物单晶,它们具有优良的物理化学性能,严格的化学比,固定的组成与结构以及较好的化学均匀性和电子束轰击下的稳定性。广泛地用于激光和非线性光学领域。我们选用这些晶体为原材料研制电子探针定量分析的标准样品。经过测量和标定,这些单晶标样符合中华人民共和国国家标准GB 4930-85(电子探针显微分析标准样品通用技术条件)的规定。含有稀土元素的标样如NAB和YAP能发出绿色荧光,是电子显微术中理想的阴极发光材料。     

负载咖啡因-活性炭新吸附材料对钼(VI)的吸附行为的研究

以生物碱（咖啡因）为衍生化试剂，用浸渍法使其负载于活性炭（ＡＣ）上，制成一种新的金属阴离子吸附材料———负载咖啡因－活性炭（ＣＡＣ）。用ＩＣＰ－ＡＥＳ研究了该吸附材料对金属阴离子［Ｍｏ７Ｏ２４］６－的吸附性能；考察了其化学稳定性；还研究了不同浓度硫酸和氨水对待测物吸附率和解脱率的影响及共存离子的干扰影响。     

基于交叉共轭结构的功能材料

近年来,人们对交叉共轭体系的制备、性能以及理论研究方面产生了极大的兴趣。本文综述了近期国内外在交叉共轭体系研究方面取得的一些最新进展,重点介绍了其在自组装、有机电致发光和离子检测等方面的最新发展动态。最后还对本课题组在交叉型p-n双嵌段寡聚物方面的研究作了详细的介绍,并对一些热点问题作了展望。     

Electrothermal volatilization of aluminum as 1-phenyl-3-methyl-4-benzoylpyrazolone[5] chelate for gaseous sample introduction in ICP-AES

Based on gaseous compound introduction as 1-phenyl-3-methyl-4-benzoylpyrazolone[5](PMBP) chelate of aluminum by electrothermal vaporization in ICP-AES, a method for determination of trace aluminum was developed. Trace aluminum was vaporized at temperature of 1000 degrees C, and the vaporization behavior of aluminum chelate was detailedly investigated. Under the optimum conditions, the detection limit of aluminum was 0.6 ng ml(-1), and the relative standard deviation for 0.1 mug ml(-1) aluminum was 4.7% (n=8). The proposed method was applied to the determination of trace aluminum in rice flour reference materials, and the results well agreed with the reference values.     

Synthesis, crystal structure and magnetic properties of a novel complex [Cu(NIT2Py)(PDA)(H2O)]·(CH3OH)(H2O)

A novel complex [Cu(NIT2Py)(PDA)(H₂O)]·(CH₃OH)(H₂O) has been synthesized and structurally characterized by X-ray diffraction methods. It crystallizes in the monoclinic space group P2(1)/c. The structure consists of [Cu(NIT2Py)(PDA)(H₂O)] moiety, one solvent methanol molecule and one water molecule. The copper(II) ion is in a distorted octahedral environment: one nitrogen atom and one oxygen atom from the NIT2Py, one nitrogen atom from the PDA (2,6-pyridine dicarboxylic acid) and one oxygen atom from the aqueous in the basal plane; two oxygen atoms from the PDA in the axial position. The units of [Cu(NIT2Py)(PDA)(H₂O)] were connected as one dimension chain by the intermolecular hydrogen bonds. The complex exhibits intramolecular antiferromagnetic interactions between the Cu(II) ion and the NIT2Py.