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61.
Sulfonated and sulfoacylated poly(styrene-divinylbenzene) copolymers as packing materials for cation chromatography 总被引:1,自引:0,他引:1
Pirogov AV Chernova MV Nemtseva DS Shpigun OA 《Analytical and bioanalytical chemistry》2003,376(5):745-752
Three different types of cation exchangers were produced from four basic poly(styrene-divinylbenzene) substrates with different properties. Porous PS-DVB resin beads were functionalized by sulfonation and sulfoacylation under various conditions to produce sulfonated resins with exchange capacities of 0.03-1.80 mM g(-1). The matrix with 50% of cross-linking is most suitable for updating by the proposed technique. Sulfuric and chlorosulfonic acids were used as the reagents for sulfonation. The sulfonating conditions, capacities, and the technique of the synthesis are given. The effects of parameters of the sulfonation reaction and the composition of the reactionary mixture on ion-exchange capacity of the sorbents were investigated. Selectivity and efficiency of the separation of some inorganic cations and derivatives of amines and hydrazines on the resins obtained are compared by ion chromatography with conductometric detection. As a result, the sulfoacylated resin was proved more efficient for the separation of these analytes. The resolution of the analytes strongly depends on the degree of functionalization. The best performance about 19,000 plates m(-1) was obtained using the sulfopropionylated beads with an ion-exchange capacity of 0.3 mM g(-1). The prepared sulfoacylated cation exchanger was compared with the commercially available Dionex CS-12 packing material. It was found that the separation of alkaline ions and 1,1-dimethylhydrazine (UDMH) were much better that those for the commercial material. 相似文献
62.
Treatment of several divalent transition-metal trifluoromethanesulfonates [M(II)(OTf)2; M(II) = Mn, Co, Ni] with [NEt4][Tp*Fe(III)(CN)3] [Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate] in DMF affords three isostructural rectangular clusters of {[Tp*Fe(III)(CN)3M(II)(DMF)4]2[OTf]2} x 2DMF (M(II) = Mn, 3; Co, 4; Ni, 5) stoichiometry. Magnetic studies of 3-5 indicate that the Tp*Fe(CN)3(-) centers are highly anisotropic and exhibit antiferromagnetic (3 and 4) and ferromagnetic (5) exchange to afford S = 4, 2, and 3 spin ground states, respectively. ac susceptibility measurements suggest that 4 and 5 exhibit incipient single-molecule magnetic behavior below 2 K. 相似文献
63.
64.
Skripnikova Tatiana A. Starikova Anna A. Shumilova Galina I. Ermolenko Yuri E. Pendin Andrey A. Mourzina Yulia G. 《Journal of Solid State Electrochemistry》2017,21(8):2269-2279
Journal of Solid State Electrochemistry - We report a new type of solid-state electrode (type I) of a simple design with polyvinyl chloride membranes based on Mn(III) tetraphenylporphyrin and with... 相似文献
65.
The boundary of the zone in which sputtered atoms are thermalized in the substrate–target drift space during the ion-plasma magnetron deposition of films is determined theoretically and experimentally. A comparison of the thicknesses of films deposited on the front and back sides of substrates situated at different distances from the target makes it possible to divide the flow of atoms sputtered toward substrates into direct and diffusion flows and to determine the dimensions of the spatial zone in which sputtered atoms are thermalized. The experimental data are in quantitative agreement with the results of a statistical simulation of the thermalization process of atomic particles during the ion-plasma deposition. This simulation enables optimization of the technology of defect-free growth of films with uniform thickness on substrates with complex 3D configuration. 相似文献
66.
Ivan S. Lonin Mikhail A. Grin Anna A. Lakhina Andrey F. Mironov 《Mendeleev Communications》2012,22(3):157-158
Chlorophyll a glycoconjugates were obtained by cross-metathesis between olefin moieties of chlorophyll derivatives and allylβ-galactopyranoside tetraacetate. 相似文献
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68.
The thermal behaviour, molecular orientation and lateral diffusion in the bilayered systems of dimyristoylphosphatidylcholine (DMPC) in the presence of poly(ethylene oxide) (PEO) were studied by NMR and DSC techniques, and it was found that PEO decreases the melting temperature (of vesicles and flat multibilayers) and affects the degree of orientation of DMPC molecules relative to the bilayer normal, but it does not influence the lateral diffusion of DMPC molecules. 相似文献
69.
70.
Andrey Kuzmin 《Liquid crystals》2013,40(7):1024-1027
The electrical conductivity of dodecylbenzenesulphonate (DoBS) ionic lyotropic liquid crystal of the systems: LiDoBS (dodecylbenzenesulphonic acid lithium salt)/water, NaDoBS (dodecylbenzenesulphonic acid sodium salt)/water, and KDoBS (dodecylbenzenesulphonic acid potassium salt)/water were investigated by impedance spectroscopy in the frequency range from 0.5 Hz to 0.5 MHz. The electrical conductivity of lyotropic LiDoBS was higher than that of isotropic phase. The electrical conductivity isotropic KDoBS and NaDoBS was higher than the conductivity of lyotropic ones. The temperature dependence of electrical conductivity was investigated in the systems LiDoBS/water and KDoBS/water for different phases. The activation energy of electrical conductivity is lowest for the normal hexagonal phase LiDoBS/water. Such systems based on anionic surfactants are of interest as the electrolyte for the supercapacitors. 相似文献