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1.
采用“一锅法”制备了四氧化三铁/半胱氨酸(Fe3O4/Cys)磁性纳米微球,随后对Fe3O4/Cys进行亚氨基二乙酸(IDA)修饰得到Fe3O4/Cys/IDA磁性双功能化纳米微球。研究发现Fe3O4/Cys中的L-Cys是通过—SH基团接枝到Fe3O4表面的,随后IDA分子中的羧基与Fe3O4/Cys中的—NH2形成酰胺键,最终形成多支链多羧基的Fe3O4/Cys/IDA磁性纳米修复剂。基于修复剂表面短支链-长支链交替的多羧基结构,实现了羧基基团的高密度接枝。同时,Fe3O4/Cys/IDA磁性纳米微球对Pb2+、Cd2+、Cu2+、Co2+、Ni2+、Zn2+为专性吸附,而对Hg2+属于非专性吸附,且吸附重金属后得到的钝化产物均表现了良好的稳定性。另外,Fe3O4/Cys/IDA对重金属离子的吸附符合Langmuir模型,属于单层均相吸附,其吸附过程符合准二级动力学模型,最大吸附量为49.05 mg·g-1。  相似文献   
2.
Electrochemical oxidation of malonic esters in acetonitrile in the presence of iodides follows two different pathways depending on the nature of the cation. In the presence of Lil, alkyl 1,1,2,2,3,3-propanetetracarboxylates were obtained in 85–98% yields. In the presence of Nal, Kl, or Bu4NI, the formation of 1,1,2,2-ethanetetracarboxylates and their subsequent dehydrogenation to ethenetetracarboxylates was the main reaction pathway. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 620–623, March, 1997.  相似文献   
3.
The alcoholysis of various esters of aromatic carboxylic esters with octadecanol in the presence of lead stearate was investigated by chromatographic analysis of the reaction mixtures. The reactivity of the esters was found to be strongly affected by the substitution pattern of the aromatic nucleus as well as by the structure of the alkoxy group. Electron donating substituents in a suitable position lead to a remarkable increase in reactivity compared to the unsubstituted alkyl esters.
Herrn Prof. Dr.K. Schlögl zum 60. Geburtstag gewidmet.  相似文献   
4.
The linear additivity of free energies of ionization of substituted acids relative to the unsubstituted parent acid is described in terms of the Hammett relationship and as the weighted sums of microscopic free energies for benzenetricarboxylic acids.  相似文献   
5.
A cadmium chiral coordination polymer, formulated as [Cd(R‐cna)]n ( 1 ‐D) was constructed under hydrothermal method. Single‐crystal X‐ray diffraction analysis indicated that 1 ‐D exhibited a 2D layered structure with a point symbol of (47 · 63). 1 ‐D was further characterized by infrared spectra, powder X‐ray diffraction (PXRD), elemental analysis, thermogravimetric analysis (TGA), and circular dichroism spectra (CD). The second‐harmonic generation (SHG) property was investigated. It was also found that the luminescence of 1 ‐D can be quenched by iron ions and trinitrotoluene, indicating its potential application as luminescence sensing material.  相似文献   
6.
用钌离子催化氧化法探究了晋城15号无烟煤(J15A)的结构特征,结果表明,J15A富含紧密的芳香性结构.在温和条件下,先用H2O2对J15A进行预处理,然后用NaOCl对其氧化从而生成苯多酸.结果表明,H2O2预处理可提高NaOCl氧化J15A生成苯多酸的产率,而且该方法可以高收率、高选择性地获取苯多酸化学品.  相似文献   
7.
Cross-linking of cotton with polycarboxylic acids, applied with catalysts based on phosphorus-containing inorganic acids, produces fabrics with excellent smooth-drying properties and which release no formaldehyde at any stage of preparation or on storage. The reaction produces cellulose ester linkages and unreacted carboxylic acid groups. Fourier transform infrared spectroscopy was used to determine the degree of esterification of polycarboxylic acids that occurred on cross-linking of cotton. The height of the carbonyl peak at 1730 cm –1 was determined on the same treated fabrics after soaking in dilute acid to convert ionized groups to free acid and then in dilute base to convert free acid to carboxylate ion. The carbonyl peak for the base rinsed fabric (ester only) was ratioed against the same peak for the acid-rinsed fabric (total carbonyl, ester plus acid) to obtain a measure of the degree of esterification. This ratio minimizes the problems of different molar extinction coefficients that are encountered when peaks from different functional groups are used.  相似文献   
8.
Thermodynamic parameters for the successive ionizations of a number of monomeric polycarboxylic acids have been determined from a temperature-dependence study of the ionization constants calculated from potentiometric data obtained using cells without liquid junction. Specifically the acids are: 1,2,3-propanetri-; 1,2,3,4-butanetetra-; 1,3-benzenedi-; 1,2,3-, 1,2,4-, and 1,3,5-benzenetri-; 1,2,4,5-benzenetetra-; and 1,2,3,4,5,6-benzenehexacarboxylic acids. The data are critically discussed in terms of the common models of ionization and of reactivity effects of substituents on ionization for monomeric and polymeric polybasic acids.Abstracted from M.B.T.'s doctoral disseration, Oklahoma State University, May 1972. Copies of the computer programs and directions for their use will be available from University microfilms.  相似文献   
9.
Summary The direct esterification and gas chromatographic analysis of aromatic carboxylic acids as n-propyl esters is described.Derivatization is performed in aqueous solution with n-propanol in the presence of sulfuric acid. The n-propyl esters of benzoic, phthalic, trimellitic and pyromellitic acids permit their gas chromatographic separation from each other and from fatty acids and aliphatic dicarboxylic acids. At mode ratios of [H2O]/[n-PrOH]0.03 the water present does not interfere with the esterification reaction. At mole ratios above 0.03 anhydrous sodium sulfate is used for binding the water, at mole ratios of [Na2SO4anh.]/[H2O]=0.51–1.52 and of [H2SO4]/[Na2SO4anh.]=0.43–1.28, respectively.  相似文献   
10.
Capture and Controlled Release of Fragrances by CD Finished Textiles   总被引:4,自引:0,他引:4  
Cotton, wool and polyester fabrics finished with cyclodextrins (by the intermediateof polycarboxylic acids) were impregnated with six different fragrant molecules(-citronellol, camphor, menthol, cis-jasmone, benzyl acetate, geraniol) and citronella oil. The smell intensity of the samples has been investigated during almostone year. In most cases, the odour retention of untreated textiles towards the substratesdid not persist over one or two weeks. By contrast, most of the treated sampleskept smelling one year after the beginning of the experiment. We observed that theuse of polyacrylic acid as crosslinking agent was less effective than citric andbutanetetracarboxylic acids. The efficiency of the different CDs varied in the order-CD > -CD > -CD, and the durability of the fragranteffect was directly dependent on the amount of CD grafted onto the fabrics.  相似文献   
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