生物基呋喃衍生物在有机涂层中的应用

随着环境保护意识的增强,减少石油基材料的使用成为社会的共识,生物基呋喃类衍生物因其独特的性质引起了研究人员的极大兴趣,其在生物基涂层、自修复涂层和光固化涂层等领域有着极大的使用潜力,但在我国尚未有成熟的研究。基于此,本文对其在生物基涂层、自修复涂层和其他涂层的应用等方面进行了总结,介绍和分析了国内外呋喃类衍生物在有机涂层方面的最近研究成果,并指出目前呋喃类衍生物的大规模应用所存在的困难:生产成本的居高不下。最后对呋喃衍生物的其他应用,如呋喃甲基缩水甘油醚作为环氧涂层的活性稀释剂取代商业化的石油基活性稀释剂以及利用呋喃环的大π键非共价改性石墨烯再制备石墨烯/有机涂层复合材料等进行了分析和展望。     

淀粉的改性及其应用

本文简要介绍了淀粉的结构、特点以及几种淀粉衍生化的改性方法。介绍了几种淀粉衍生物及其应用，着重介绍了接枝共聚淀粉的合成并展望了其发展趋势。     

聚异丁烯丁二酸酐衍生物的合成及应用

介绍了聚异丁烯丁二酸酐衍生物的合成,并对该衍生物实际应用进行了考察.结果表明,该产品具有良好的油溶性、热稳定性和乳化性能,适用于粉状乳化炸药连续化生产线.     

胍基聚合物的合成及抗菌性能

采用熔融缩聚的方法合成了聚亚己基胍盐酸盐（PHGC）及聚亚己基双胍盐酸盐（PHBG）。应用气相渗透压法（VPO）及粘度法测定了其分子质量，应用元素分析，FT－IR，XPS分析了聚合物的化学组成，抗菌活性的研究结果表明所合成的胍基聚合物具有较强的而且广谱的抗菌性能。     

三硝基乙醇及其脂肪族衍生物研究进展

三硝基乙醇及其脂肪族衍生物具有含氧量高、密度高等优点，是一类重要的含能材料。综述了三硝基乙醇及其脂肪族衍生物等30余种三硝基乙基类含能化合物的最新研究成果，重点阐述了三硝基乙醇及其脂肪族衍生物的合成、性能及应用研究进展；并结合三硝基乙基类含能化合物的性能特点，进一步探讨了在炸药、固体推进剂等含能材料领域中的应用前景。     

三嗪衍生物的合成及其用于ABS的阻燃研究

合成了一种三嗪衍生物－－2，4－二氨基－6－羟乙胺基－1，3，5－三嗪，研究了各因素对反应的影响。将合成的这种化合物与聚磷酸铵和季戊四醇复配成ABS的膨胀型阻燃剂，表现出较好的阻燃性和抑烟性，并能在一定程度上防止熔滴现象的发生。     

新型功能材料聚烷基芴衍生物及其应用

由于新型功能高分子材料聚烷基芴的衍生物可用于制造发蓝光的二极管材料因而倍受青睐，在大面积显示领域具有广阔的应用前景。本文根据国内外研究者的报道；简要介绍了这类材料的合成，性能及其发光二极管方面的应用。     

一种含长链烷基芘类衍生物的光学压敏涂料的氧猝灭特性及热稳定性

利用芘丁醇和8-壬烯酸的酯化反应,合成了含长链烷基的芘类衍生物8-壬烯酸芘丁酯,用红外光谱(IR)和核磁共振(1H-NMR)表征其分子结构,研究了它在甲苯和硅树脂中的荧光特性和热稳定性,考察了不同芘类衍生物对光学压敏涂料热稳定性的影响。结果表明,合成的含长链烷基的芘类衍生物8-壬烯酸芘丁酯在溶液及涂料中都具有较高的氧猝灭率,随着芘类衍生物链长的增长,荧光分子在溶液及涂料中的氧猝灭率略有减小,而在涂料中的热稳定性有较大的提高。     

生物可降解材料聚苹果酸的研究进展

聚苹果酸及其衍生物是一类新型的生物高分子材料,具有良好的生物降解性和生物相容性.介绍了聚苹果酸及其衍生物的结构和性能特点,综述了它们的合成方法的研究进展,并展望了它们在药物载体及生物医用材料等领域的应用前景.     

对二甲氨基苯甲醛缩氨基硫脲及其衍生物的合成和固体荧光性质研究

合成了对二甲氨基苯甲醛缩氨基硫脲及其两种衍生物,用氢核磁共振谱、质谱、元素分析对其表征,并通过荧光测定,讨论其晶体结构与固体荧光性质的关系。发现晶体结构中π-π弱堆积的DMABNTS最接近溶液中的单体荧光发射,在有机发光材料中最具应用价值。     

Guanidine分子在燃料电池用阴离子交换膜中的应用

以壳聚糖(CS)和2,3-环氧丙基三甲基氯化铵(GTA)为原料,制备季铵化壳聚糖(QCS),将其与小分子游离胍(Guanidine)共混,借助戊二醛(GA)的化学交联作用,将季铵化壳聚糖中的氨基以及胍中的氨基交联,形成网状结构,由此制得含有不同含量Guanidine分子的交联QCS-G阴离子交换膜。实验过程中,对该膜的含水率、溶胀度、力学强度、电导率及耐碱稳定性等进行了详细的考察。结果表明,游离胍的引入可有效地提高膜的电导率和耐碱稳定性,同时降低了膜的溶胀度及含水率。其中小分子游离胍质量分数为2.5%的膜(QCS-G2.5%)在70℃时的电导率可达到6.58×10~(-2)S/cm;在10 mol/L NaOH溶液中浸渍72 h后该膜70℃测得的电导率损失仅为3.8%,离子交换量损失仅为3.82%,表明该膜的耐碱性能较好。     

Nitrogen-doped titanium dioxide photocatalysts for visible response prepared by using organic compounds

In order to utilize visible light in photocatalytic reactions, nitrogen atoms were doped in commercially available photocatalytic TiO₂ powders by using an organic compound such as urea and guanidine. Analysis by X-ray photoelectron spectroscopy (XPS) indicated that N atoms were incorporated into two different sites of the bulk phase of TiO₂. A significant shift of the absorption edge to a lower energy and a higher absorption in the visible light region were observed. These N-doped TiO₂ powders exhibited photocatalytic activity for the decomposition of 2-propanol in aqueous solution under visible light irradiation. The photocatalytic activity increased with the decrease of doped N atoms in O site, while decreased with decrease of the other sites. Degradation of photocatalytic activity based on the release of nitrogen atoms was observed for the reaction in the aqueous suspension system.     

(2-Azoniaethyl)guanidinium dichloride – A promising phase-matchable NLO material employing a simple hydrogen bond acceptor in its structure

(2-Azoniaethyl)guanidinium dichloride (AEGCl), a salt of a functional guanidine derivative, was prepared and characterised by single-crystal and powder X-ray diffraction analysis, elemental analysis and by NMR, UV–Vis and vibrational spectroscopy. The crystal structure of AEGCl, which crystallises with the symmetry of the chiral space group P2₁, is built up via simple and multicentred NH⋯Cl hydrogen bonds and further supported by CH⋯Cl contacts. The compound is thermally robust and exhibits promising NLO properties with powder SHG efficiency better than potassium dihydrogen phosphate. In contrast, (2-azoniaethyl)guanidinium salts with inorganic oxoanions such as (2-azoniaethyl)guanidinium dinitrate and diperchlorate, synthesised for a comparison, form centrosymmetric crystal assemblies having several structurally independent “molecules” in their structures.     

Matrix with high salt tolerance for the analysis of peptide and protein samples by desorption/ionization time-of-flight mass spectrometry

High concentrations of urea and guanidine hydrochloride are commonly used for the denaturation of protein, which was digested by enzymatic proteolysis for the identification by MS analysis. The presence of these contaminants seriously suppresses the ion signal of analytes in MALDI-TOF MS analysis. Herein, a novel MALDI matrix, 3, 4-diaminobenzophenone (DABP), has been found with high tolerance for these contaminants in MALDI MS analysis. The ion signal of analyte insulin can be detected in the presence of 2 M guanidine hydrochloride and 1.5 M urea using DABP as matrix. The tryptic digest of BSA (400 fmol) in 1 M guanidine hydrochloride or 1 M urea was successfully analyzed without any pretreatment prior to MS analysis. Furthermore, it has been found that this matrix can also effectively suppress the cation ion adduction of the peptides in the presence of high concentrations of metal ions in sample solution.     

Polarographic behavior of Co(II)-BSA or -HSA complex in the presence of a guanidine modifier

An extremely sensitive adsorptive wave of BSA at about -1.73 V (vs SCE) has been obtained in the solution containing 8 x 10(-)(7) mol/L CoCl(2), 0.2 mol/L guanidine hydrochloride, and 0.2 mol/L NaOH by using single-sweep polarography. The interaction of BSA with guanidine in an alkaline solution results in its Co(II) complex with a positive excess charge. Thus, the complex is strongly adsorbed by the DME as a result of static electrical attraction. The adsorption efficiently accumulates the electrochemical active complex of Co(II)-BSA onto the DME. In the following potential scan, the complex produces a sensitive adsorptive reduction peak, which can be used to determine low-level BSA. In the absence of guanidine, the complex of Co(II)-BSA with a negative excess charge is repulsed by the DME. The reduction current is very small. The peak current depends on both BSA and Co(II) ion concentrations. HSA is similar to BSA in polarographic behavior. At the optimal conditions, the peak height is linearly proportional to the BSA or HSA concentration in the range of 0.005-20 mg/L (correlation coefficient 0.999). The detection limit for BSA or HSA is 0.002 mg/L. Lysozyme, common amino acids, and metal ions have no interference with the protein determination. The new method could be useful in protein studies.     

Modification of derivatives for resolution enhancement of bands in overlapped spectra

A method for obtaining modified derivatives based on the multiplication of the Fourier image of a normal derivative of degree n by the function (-iSign(x))n has been considered. The thus-obtained modified derivatives of even, odd, and fractional degrees of symmetric functions are also even functions, which permits one to use them for obtaining spectra with a better resolution of individual bands. Also, the use of derivatives of various degrees makes it possible to considerably widen the set of functions suitable for resolving individual bands in overlapped spectra. The results of the application of modified derivatives to synthetic and experimental spectra have been considered. The conclusion has been drawn that practical application of such derivatives permits more flexible variation of the resolution in the resulting spectrum compared to the normal derivatives of only even orders.     

Potential Pharmaceutical Applications of a New Beta Cyclodextrin Derivative

Abstract

The three major natural cyclodextrins viz alpha, beta and gamma, consist of six, seven or eight glucose units, respectively (1). In addition to the natural cyclodextrins, numerous new products have been shown to have potential for the pharmaceutical industry (2,3). A clear distinction has to be made between cyclodextrin polymers, which are mainly used as separation materials in analytical chemistry (4) and cyclodextrin derivatives, which are monomers of substituted cyclodextrins (5). In the synthesis process of the latter, both the C(2) and C(3) secondary and the C(6) primary hydroxyl groups have been the target of many chemical substitutions (6), leading to the development and the characterization of cyclodextrin derivatives of pharmaceutical interest (7). Such derivatives have been successfully used in the design of new drug carrier systems (3,5), Hence, in addition to their increased solubility, these chemically modified cyclodextrins exhibit excellent complexing abilities (8). The different possibilities of modifying cyclodextrins have been reviewed by Sebille (2), Szejtli (1) and Uekama (3). Szjetli also published an extensive list of the major cyclodextrin derivatives under investigation until 1982 (1).     

Electrochemical and optical sugar sensors based on phenylboronic acid and its derivatives

Recent progress in electrochemical and optical sugar sensors based on phenylboronic acid (PBA) and its derivatives as recognition components is reviewed. PBAs are known to bind diol compounds including sugars to form cyclic boronate esters that are negatively charged as a result of the addition of OH^? ions from solution. Based on the formation of PBA charged species, sugars and their derivatives can be detected by means of electrochemical and optical techniques. For the development of PBA-based electrochemical sensing systems or sensors, PBA is modified with a redox-active marker, because PBA itself is electrochemically inactive, and ferrocene derivatives are often employed for this purpose. Ferrocene-modified PBAs have been used as redox-active additives in solution for the electrochemical detection of sugars and derivatives. PBA-modified electrodes have also been constructed as reagentless electrochemical sensors, where PBAs are immobilized on the surface of metal and carbon electrodes through mainly two routes: as a self-assembled monolayer film and as a polymer thin film. PBA-modified electrodes can be successfully used to detect sugars and derivatives through potentiometric and voltammetric responses. In addition, PBA-modified electrodes can be used for the immobilization of glycoenzymes on an electrode surface by the formation of boronate esters with carbohydrate chains in the glycoenzymes, thus resulting in enzyme biosensors. For the development of PBA-based optical sensors, a variety of chromophores and fluorophores have been coupled with PBA. Azobenzene dyes have been most frequently used for the preparation of colorimetric sugar sensors, in which the absorption wavelength and intensity of the dye are dependent on the type and concentration of added sugars. The sensitivity of the sensors is significantly improved based on multi-component systems in which alizalin red S, pyrocatechol violet, starch–iodine complex, and cyclodextrin are employed as indicators. Anthracene, pyranine, fluorescein, and rhodamine dyes have been used as fluorophores for fluorescence sensors. These dyes have been used in solution or immobilized in films, hydrogels, nanospheres, and quantum dots (QDs) to enhance the sensitivity. QDs-based sensors have been successfully applied for continuous monitoring of glucose in cells. Holographic glucose sensors have also been developed by combining PBA-immobilized hydrogels and photonic crystal colloidal arrays.     

聚苯丙抗菌乳液的制备及表征

将苯乙烯、丙烯酸丁酯、甲基丙烯酸正丁酯及末端带有碳碳双键的功能化聚六亚甲基盐酸胍进行乳液聚合反应,得到具有抗菌性能的聚苯丙乳液。分别考察了单体配比、乳化剂用量、引发剂用量及反应温度对聚苯丙抗菌乳液聚合反应的影响,以获得最佳的聚合条件。结果表明,在引发剂质量分数为0.4%~0.5%,乳化剂质量分数4%~6%,反应温度70~80℃的聚合条件下,可得到颗粒尺寸均匀适中、稳定的乳液。同时,通过红外光谱、透射电镜和激光粒度分析仪等对乳胶粒子的组成和结构进行了表征。并分别采用稀释法和扩散法测试了抗菌乳液对大肠杆菌的抗菌性能。稀释法实验表明,抗菌乳液的最低抑菌浓度可达4×10-6;扩散法实验表明,经提纯后的抗菌乳液的膜片不存在胍盐低聚物的溶出,但对大肠杆菌有明显的抑菌圈,实现了材料抗菌性能的长效性。     

Characterization of Alizarin Red S binding sites and structural changes on human serum albumin: a biophysical study

Alizarin Red S (ARS), is a water-soluble, widely used anthraquinone dye synthesized by sulfonation of alizarin. In this report, the binding of ARS to human serum albumin (HSA) was characterized by employing fluorescence, UV/vis absorption, circular dichroism (CD), and molecular modeling methods. The data of fluorescence spectra displayed that the binding of ARS to HSA is the formation of HSA-ARS complex at 1:1 stoichiometric proportion. Hydrophobic probe 8-anilino-1-naphthalenesulfonic acid (ANS) was employed and elucidated that the dye was located in subdomain IIIA. This phenomenon corroborates the result of site-specific probe displacement experiments, which demonstrate the dye is at indole-benzodiazepine site (Sudlow's site II); and it is also consistent with guanidine hydrochloride (GuHCl) induced HSA unfolding studies and molecular modeling simulations. The features of the dye, which led to structural perturbations of HSA, have also been studied in detail by methods of UV/vis, CD and three-dimensional fluorescence spectroscopy.