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141.
Preparation and adsorption properties of crosslinked polystyrene-supported low-generation diethanolamine-typed dendrimer for metal ions 总被引:1,自引:0,他引:1
Two novel chelating resins, polystyrene supported G1.0 diethanolamine-typed dendrimer (PS-DEA) and G2.0 diethanolamine-typed dendrimer (PS-(DEA)2), were prepared by anchoring low-generations diethanolamine-typed dendrimer into crosslinked polystyrene in this paper. Fourier transform-infrared spectra (FTIR), scanning electron microscopy (SEM) and elemental analysis were employed to character their structures. The results of adsorption for metal ions showed that the resins had good adsorption capacities for Cu2+, Ag+ and Hg2+, especially PS-DEA for Cu2+. The adsorption kinetics and adsorption isotherms of PS-DEA for Cu2+ and PS-(DEA)2 for Hg2+ were studied. The results showed that the adsorption kinetics of the two resins can be modeled by pseudo second-order rate equation wonderfully and Langmuir and Freundlich equations could well interpret the adsorption of PS-(DEA)2 for Hg2+ and PS-DEA for Cu2+, respectively. The adsorption mechanism of the resins for Cu2+ was confirmed by X-ray photoelectron spectroscopy (XPS). 相似文献
142.
制备了外层带有荧光素基团的碳硅烷树形大分子,研究了这种树形大分子在质子化过程中的荧光增强效应。结果表明,这种树形大分子的荧光基团的紫外吸收与单荧光素参照物基本一致,而体系的荧光强度和荧光量子产率均高于参照体系。同一个树形大分子上的荧光基团之间可能存在一定的能量传递作用,从而提高了体系的荧光强度。 相似文献
143.
聚酰胺-胺树状大分子的合成与荧光性质的研究 总被引:3,自引:0,他引:3
以乙二胺为核,合成了不同代数的树状大分子,用元素分析、红外光谱、核磁共振进行了结构表征.荧光分析表明,整代的树状大分子具有荧光发光性能,通过测定与不同金属离子(M=Cu^2 ,Ni^2 ,Zn^2 ,Fe^3 ,Cr^3 ,Eu^3 )配位后的荧光性质,发现少量金属离子的加入,荧光强度变化不大.但无论是一代(1.0G)还是二代(2.0G)树状大分子,Fe^3 和Cr^3 的加入均使荧光强度明显增加. 相似文献
144.
SUNJing WANGLiyan GAOJian YUXi WANGZhiqiang 《科学通报(英文版)》2005,50(3):208-212
Two generations of earboxyl-terminated poly (aryl ether) dendrimers bearing 9,10-diphenylanthracene cores are designed and synthesized. Alternating deposition of two dendrimers and poly(4-vinylpyridine) is studied with UV-Vis spectroscopy, FT-IR spectroscopy and atomic force microscopy. Experimental results indicate that this method to introduce chromophore into multilayer film can effectively prevent desorption of dye molecule. Moreover, it is found that dendrimer can inhibit the aggregation of fluorophore in film using fluorescence spectroscopy. Increase of dendrimer‘s generation can enhance fluorescence intensity of each fluorophore. This provides a new approach to design luminescent thin film. 相似文献
145.
K. Onitsuka S. Takahashi 《复旦学报(自然科学版)》2005,44(5):823-824
1 Introduction Dendrimers possessing a regularly branched architecture and large spherical dimensions have attracted significant attention because of their unique and tunable properties as well as their potential applications. The incorporation of organometallic species into dendritic molecules has been attracting much attention, because the addition of properties characteristic of organometallic complexes, such as magnetic, electronic, and photo-optical properties, as well as reactivity may l… 相似文献
146.
Divergently synthesized carbosilane dendrimers generations 1(G1) and 2 (G2) with allyl end groups were bonded onto silica
gel. Reactions between the dendrimers and acid-processed silica gel took place, with toluene reflux and organic base as catalyst.
Chemically bonded silica gel was characterized by transmission electron microscopy (TEM), infrared (IR), and other methods.
The chemically modified silica gels were packed into high-pressure liquid chromatography (HPLC) column and their separation
characters were evaluated. G2-bonded silica gel was effective in separating homologous compounds of alcohol, alkyl-substituted
benzene, N-substituted benzene, metacrylic acid ester and phthalate.
__________
Translated from Journal of Shandong University, 2005, 40(6) (in Chinese) 相似文献
147.
ZhiJunYU QiZhenZHANG QiFengZHOU 《中国化学快报》2003,14(5):465-467
The preparation of carbosilane dendrimers with cores of myo-inositol and the outmost periphery grougs of allyl groups has been reported.By using alternate hydrosilylation and alkenyiation reactions,the dendrimer have been carried up to the third generation with 48 allyl groups on the periphery. 相似文献
148.
Barbara RomagnoliPeter R. Ashton Laurence M. HarwoodDouglas Philp David W. Price Melanja H. SmithWayne Hayes 《Tetrahedron》2003,59(22):3975-3988
A series of novel polyaromatic dendrimers that feature tris-(2-ethylamino)amine as the central core unit has been synthesized up to the third generation by employing a convergent growth strategy. The building blocks 1,3-diamino-2-hydroxypropane and 4-carboxybenzaldehyde were used for dendron construction, a process that involved the cyclic repetition of esterification, oxidation and selective amidation steps. Molecular modelling of this class of dendrimers has been used to predict potential solution state conformations employing molecular mechanics and molecular dynamic simulations. In addition, the results of preliminary metal binding studies using the first generation dendritic system are also outlined. 相似文献
149.
Yoshitaka Yamakawa Mitsuru Ueda Kazuhiko Takeuchi Michihiko Asai 《Journal of polymer science. Part A, Polymer chemistry》1999,37(18):3638-3645
Dendritic polyamides with polydispersity of 1.1–1.4 have been successfully prepared from trimesic acid, 5-aminoisophthalic acid, and 4-aminophenylpropionic acid as a core molecule, a dendron, and a spacer unit, respectively, with a one-pot procedure. This procedure involves successive activation of end carboxyl groups with the condensing agent diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (DBOP), followed by condensation of active amide with 5-aminoisopthalic acid or 4-aminophenylpropionic acid and, finally, capping of the end carboxyl groups with p-anisidine. The structure of dendritic polyamides was investigated by 1H-NMR spectroscopy, and it was found that the polymers obtained contained approximately 10% defects. Furthermore, the model reaction was studied to demonstrate the feasibility of dendritic polyamides. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3638–3645, 1999 相似文献
150.
Observations on the thermoreversible gelation of two-directional arborols in water–methanol mixtures
Keunok Han Yu Paul S. Russo Laura Younger William G. Henk Duen-Wu Hua George R. Newkome Gregory Baker 《Journal of Polymer Science.Polymer Physics》1997,35(17):2787-2793
Reversible gels of two-directional cascade polymers with hydrophilic groups covalently attached by an hydrophobic center chain were studied by light and small-angle X-ray scattering, differential scanning calorimetry, and freeze-fracture transmission electron microscopy. The long, self-assembled fibers interact side-by-side over extended regions to form bundles. A given fiber may participate in several bundles, thus forming a three-dimensional gel network. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2787–2793, 1997 相似文献