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1.
孙振文  陈晓  王庐岩  邱化玉 《化学进展》2006,18(12):1584-1591
本文综述了以类脂为基础的仿生溶致液晶体系的构建与掺杂,对掺杂物质与液晶模板之间的相互作用进行了分析,并展望了仿生溶致液晶体系在合成新型功能材料、生物学和医学等领域应用的发展前景。  相似文献   

2.
赵继宽  陈晓 《化学学报》2007,65(9):803-808
以非离子表面活性剂四氧乙烯基正十二烷基醚与氯铂酸水溶液构建层状溶致液晶, 通过电沉积技术制备了金属铂纳米线. 分别采用偏光显微镜、小角X射线散射对液晶进行结构分析, 通过透射电镜和能量弥散X射线谱分析观测产物形貌并确定其组成. 结果表明, 相对于饱和甘汞电极, 沉积电势在0.05~0.20 V范围内, 金属铂沿表面活性剂双分子层膜生长, 反应前后液晶相的长程周期性结构无明显变化; 在0.10 V沉积电势下, 随反应时间从960 s延长至3840 s, 去除表面活性剂后沉积产物分别为层状纳米粒子、层状纳米线以及长度达十几微米且致密的纳米线. 讨论了层状液晶对沉积产物的结构导向作用.  相似文献   

3.
郭睿劼  张宝泉  孙远  刘秀凤 《化学进展》2007,19(11):1695-1702
有序纳米结构材料是一类具有广泛应用前景的新材料,在分离、催化、传感器等领域的应用潜力巨大。近年来,利用溶致液晶模板合成纳米结构颗粒和薄膜材料的研究取得了一系列重要进展,包括新纳米结构金属和半导体材料的合成、由过渡金属水合物与表面活性剂构建的新液晶体系、溶致液晶与其它模板结合制备具有多级孔结构的新材料、影响液晶体系及纳米结构材料有序性与稳定性的关键因素、以及纳米结构形成机理等方面的内容。本文就上述几个方面的近期研究成果进行了总结与综述,并展望了利用溶致液晶模板合成纳米结构材料需要进一步深入开展的内容,有助于化学、化学工程和材料科学等领域的相关研究工作。  相似文献   

4.
通过壳聚糖乙酰化法制备了不同脱乙酰度的壳聚糖 ,并研究了脱乙酰度这一结构因素对壳聚糖溶致液晶性的影响 .观察到脱乙酰度为 5 0 %左右时 ,壳聚糖在水中和二氯乙酸中的溶致液晶临界浓度最高 .壳聚糖在水中的溶致液晶临界浓度远低于在二氯乙酸中的临界浓度 .  相似文献   

5.
溶致液晶是两亲分子有序组合体的一种形式.与表面活性剂相比,高分子溶致液晶的研究开展较少,其中以主链型溶致液晶为主,而侧挂型支链高分子溶致液晶报导极少[1-3],但含有离子的不同烷基侧链的高聚物在溶液中自织组成液晶的规律性和性质的研究,在基础理论和应用方面皆有重?..  相似文献   

6.
乙基氰乙基纤维素溶致性液晶的研究   总被引:7,自引:0,他引:7  
黄勇  陈鸣才  李历生 《化学学报》1988,46(4):367-371
纤维素和纤维素衍生物在适当的溶剂中可以形成溶致性液晶, 乙基氰乙基纤维素是纤维素的一种混合醚类衍生物, 本文研究了其溶致性液晶的形成, 结构以及不同溶剂对形成液晶所产生的影响.  相似文献   

7.
李祥子  魏先文 《化学研究》2006,17(2):97-101
近年来氧化铝模板电沉积功能纳米材料的技术得到了较快的发展.综述了氧化铝模板电沉积功能纳米材料的最新研究方法,介绍了国内外氧化铝模板电沉积法在制备功能纳米材料上的应用.  相似文献   

8.
以非离子型三嵌段共聚物EO106PO70EO106 (F127)/正丁醇/氯铂酸水溶液构建的溶致液晶层状相为模板, 电化学沉积制备铂纳米材料. 透射电镜和扫描电镜显示, 产物为具有高长径比的纳米线形成的束状结构, 能量弥散谱与电极电势分析证实产物为铂单质, 而循环伏安测量表明产物的比表面积约为53 m2•g−1. 对影响产物形貌的因素和产物生成的可能机理进行了分析.  相似文献   

9.
以铂微电极法测定了在SDS/n-C5H11OH/H2O溶致液晶中SDS(十二烷基硫酸钠)分子的扩散系数.结果表明,恒定质量比SDS/n-C5H11OH条件下,溶致液晶中SDS分子的扩散系数随体系中水含量的增加而增加;恒定质量比SDS/H2O,溶致液晶中SDS分子的扩散系数随正戊醇含量的增加而增加;恒定质量比H2O/n-C5H11OH ,溶致液晶中SDS分子的扩散系数随SDS含量的增加而降低.六角状液晶中SDS分子的扩散系数比层状液晶中SDS分子的扩散系数低约1个数量级,而比W/O、O/W胶束的扩散系数低3~5个数量级.  相似文献   

10.
用溶致液晶模板合成与组装纳米材料   总被引:3,自引:1,他引:3  
总结了溶致液晶作模板合成与组装纳米材料的各种方法,特别分析了近来兴起的以溶致液晶为构建支架,以纳米粒子为构建单元制备无机/有机杂合体的特点,并对未来发展趋势作了展望.  相似文献   

11.
聚酯酰胺的合成及表征   总被引:1,自引:0,他引:1  
用两种方法合成了聚酯酰胺(PEA)共聚物.一种是两步法,即先合成对苯二甲酸乙醇酰胺(BAET)单体,然后与对苯二甲酸乙二酯(BHET)共缩聚;另一种是一步法.即在酯交换反应中直接添加乙醇胺(EA).两种方法制得的聚酯酰胺(PEA)共聚物测试证明了为产物,并分析了合成中的化学反应.  相似文献   

12.
合成了以芴为取代基,P原子为核的一类新型有机膦化合物.此类化合物的HOMO值在-5.35~-5.24eV之间.在二氯甲烷中的最大紫外吸收光谱峰值在313~351nm之间,荧光光谱峰值在334~397nm之间.利用此类小分子与纯聚芴进行掺杂,制作了有机电致发光器件.低HOMO值有机膦化合物的引入有效地降低了聚芴发光器件的开启电压,提高了器件的发光效率.  相似文献   

13.
Taylor PD  Morrison IE  Hider RC 《Talanta》1988,35(7):507-512
A non-linear least-squares regression program is described which is suitable for PC-compatible microcomputers. The program is written in GWBASIC, but compiled to run with the Intel 8087 fast numeric processor. Subroutines which simulate functions are compiled separately from the main program. Parameters are optimized by a Gauss-Newton-Marquardt algorithm which can be provided with either analytically or numerically calculated partial derivatives. Multi-component potentiometric titrations are simulated and parameters optimized by using analytical derivatives. Spectrophotometric titrations are also simulated, but absorptivities are optimized by linear regression while stability constants are optimized non-linearly by using numerical derivatives. Provision is made for "global analysis" of parameters. The experimental points can be displayed on screen, along with the "best" fit and the speciation. The program is demonstrated here by the determination of the pK(a) values and stability constants of a hydroxypyridinone ligand and its complexes with Fe(III).  相似文献   

14.
聚酯酰胺的合成及表征   总被引:2,自引:0,他引:2  
 用两种方法合成了聚酯酰胺(PEA)共聚物.一种是两步法,即先合成对苯二甲酸乙醇酰胺(BAET)单体,然后与对苯二甲酸乙二酯(BHET)共缩聚;另一种是一步法.即在酯交换反应中直接添加乙醇胺(EA).两种方法制得的聚酯酰胺(PEA)共聚物测试证明了为产物,并分析了合成中的化学反应.  相似文献   

15.
Quinazoline is oxidized by xanthine oxidase initially (and rapidly) to 4-hydroxyquinazoline which subsequently is oxidized more slowly to 2,4-dihydroxyquinazoline. Both oxidative reactions are inhibited strongly by allopurinol. Quinazoline is oxidized by aldehyde oxidase to 4-hydroxyquinazoline but within a short time (3–5 minutes) the reaction ceases; the proposal that cessation of reaction is due to product inhibition is rendered untenable by our observation that 4-hydroxyquinazoline is rapidly oxidized by aldehyde oxidase to 2,4-dihydroxyquinazoline. Preincubation of aldehyde oxidase with quinazoline results in complete inhibition of the ability of the enzyme to oxidize 4-hydroxyquinazoline and the standard substrate N-methylnicotinamide. It appears therefore that quinazoline is able to react with aldehyde oxidase and inactivate it. Quinoxaline and 2-hydroxyquinoxaline are not oxidized by xanthine oxidase but are converted by aldehyde oxidase to 2,3-dihydroxyquinoxaline; all oxidations mediated by aldehyde oxidase are inhibited completely by menadione.  相似文献   

16.
Relaxation processes of surfactant adsorption and surface tension, which are characterized by two specific relaxation times, are theoretically investigated. We are dealing with fluid interfaces and small initial deviations from equilibrium. For surfactant concentrations below the critical micellization concentration (CMC), we consider adsorption under mixed barrier-diffusion control. General analytical expressions are derived, which are convenient for both numerical computations and asymptotic analysis. Series expansions for the short- and long-time limit are derived. The results imply that the short-time asymptotics is controlled by the adsorption barrier, whereas the long-time asymptotics is always dominated by diffusion. Furthermore, for surfactant concentrations above the CMC, adsorption under mixed micellization-diffusion control is considered. Again, a general analytical expression is derived for the relaxation of surfactant adsorption and surface tension, whose long- and short-time asymptotics are deduced. The derived equations show that at the short times the relaxation is completely controlled by the diffusion, whereas the long-time asymptotics is affected by both demicellization and diffusion. The micellar effect is manifested as an exponential (rather than square-root) decay of the perturbation. The derived expressions are applied to process available experimental data for the nonionic surfactant Triton X-100 and to determine the respective demicellization rate constant.  相似文献   

17.
静电纺丝技术是制备连续微纳米纤维的一种简单易行且高效的方法,所制备的纳米纤维因其独特的结构尺寸和广泛的应用领域而备受材料科学界的青睐。 作为第三代超分子主体化合物的杯芳烃及其衍生物因其独特的分子结构、优异的离子选择识别性和吸附性能而显示出广阔的应用前景。 本文简述了静电纺丝制备杯芳烃功能化纳米纤维的原理,系统地探讨了其作为吸附剂和催化剂载体的应用以及静电纺丝与杯芳烃相结合的优势。 讨论了目前静电纺丝制备杯芳烃功能化纳米纤维存在的问题,对未来的发展方向进行展望。  相似文献   

18.
Verma KK 《Talanta》1979,26(3):257-259
Arylhydrazines are detected by oxidation with N-bromosuccinimide and coupling with resorcinol to form azo-dyes which are intensely coloured in alkaline media. Hydrazones and osazones are hydrolysed to form the arylhydrazines, which are then tested for 4-Nitro- and 2,4-dinitrophenylhydrazines are tested for by forming their hydrazone with salicylaldehyde and adding alkali to produce a violet colour. The hydroxylamine formed by the hydrolysis of oximes is oxidized by iodine monochloride in the presence of sulphanilic acid; coupling with 8-hydroxyquinoline forms a dye that is red in alkali. Intense colours are immediately produced when primary, secondary and tertiary aromatic amines are mixed with diacetoxyiodobenzene. All the tests are sensitive and appear to be specific.  相似文献   

19.
A scheme using ion-exchange methods is described for the analysis of monazites and monazite concentrates. The sample is opened up with concentrated sulphuric acid, and the resultant solution is applied to a column of Zeocarb 225 resin. After phosphate has been washed out, lead, aluminium, titanium, iron, uranium, calcium and magnesium are eluted with N hydrochloric acid and determined by specific, mainly spectrophotometric, methods. Rare earth elements are eluted with 3 N hydrochloric acid. Cerium is separated from the other rare earths by solvent extraction of its nitrate with methyl iso-butyl ketone; both groups are determined gravimetrically. Thorium is eluted from the ion-exchange resin with 3.6 N sulphuric acid and determined spectrophotometrically with thorin.The sulphuric acid-insoluble minerals are brought into solution by a double fusion method, and the determinations are carried out by a combination of ion-exchange and photometric procedures. Silica, phosphorus pentoxide, tin and chromium are determined by photometric methods, using separate portions of the sample.Lanthanum, yttrium and ytterbium are determined in a 1 M perchloric acid solution of the mixed rare earth oxides (less cerium) using flame photometry. Samarium, praseodymium and neodymium are determined by spectrophotometry.  相似文献   

20.
The production of solvents from corn mash and molasses in batch fermentation usingClostridium acetobutylicum P 262 was examined. The content of saccharose of beet molasses used in experiments is determined by using the gravimetric method (52.45% saccharose). The quantities of molasses that are used in the nutrient medium are calculated after doing the above determination. The samples of fermentation liquid are taken within a certain time, the determination of saccharose is done by using the same method, and all the saccharose is converted by the microorganism to organic end products. The quantitative and qualitative determination of acetone-butanol has been made by using gas chromatography. On the other hand, using the three isolation way, three different cultures are obtained, and with microscopic observations, the cultures obtained are of the C.acetobutylicum genus. According to the literature values, the concentration of maximum mixed solvent formed during fermentation is about 2%. This is seen in this experiment. There is only a slight difference from this value. This difference is caused by another organic product that is formed during fermentation.  相似文献   

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