972 resultados para TERNARY ORGANOSILICON BLOCKCOPOLYMER
Resumo:
Monte Carlo simulations were used to model A/B/A-B ternary mixtures with different AB diblock copolymer volume fractions for which both the dispersed and continuous phase volume fractions were kept constant. For concentrations of the diblock copolymer below a critical value, the domain size increment of the dispersed phase decreases linearly with the copolymer concentration. This is in agreement with the predictions of Noolandi and Hong. The dependence of the domain size as a function of the copolymer volume fraction can also be fitted by the equation of Tang and Huang. Our simulations indicate, for the first time, that the micelles form before saturation of the interface occurs. This means that the formation of the micelles is not a result of the saturation of the interface.
Resumo:
A series of binary and ternary rare earth (Gd, Eu, Tb) complexes with aromatic acids and 1,10-phenanthroline have been synthesized. The lowest triplet state energies of ligands have been obtained by measuring the phosphorescence spectra of binary gadolinium complexes. By comparing the phosphorescence spectra of binary complexes with those of ternary ones, it is found that there exists another intramolecular energy transfer process from the aromatic acids to 1,10-phenanthroline besides the intramolecular energy transfer process between the aromatic acids and the central rare earth ions. The intramolecular energy transfer efficiencies have been calculated by determining phosphorescence lifetimes of binary and ternary gadolinium complexes. The luminescence properties of corresponding europium and terbium complexes are in agreement with the prediction based on energy transfer mechanism. (C) 1998 Elsevier Science S.A. All rights reserved.
Resumo:
Some novel binary and ternary complexes of rare earth(Gd, Eu,Tb) with N-Phenylanthranilic acid and 1,10-Phenanthroline were synthesized by homogenous precipitation and their compositions were characterized by,elemental analysis, IR spectra and UV-Vis spectra, The triplet state energies of N-Phenylanthranilic acid was determined to be 24 330 cm(-1) with the phosphorescence spectra of its gadolinium complexes and the energy match between the ligand and the central rare earth ions was studied. The photophysical properties such as luminescence properties and intramolecular energy transfer match between rare earth ions and ligands and between ligands were discussed. The result indicates that terbium complexes with N-Phenylanthranilic acid and 1,10-Phenanthroline have excellent luminescence properties.
Resumo:
Based on the complex crystal chemical bond theory, the formula of Liu and Cohen's, which is only suitable for one type of bond, has been extended to calculate the bulk modulus of ternary chalcopyrite A(I)B(III)C(2)(VI) and A(II)B(IV)C(2)(V) which contains two types of bonds. The calculated results are in fair agreement with the previous theoretical values reported and experimental values. (C) 1998 Elsevier Science Ltd. All rights reserved.
Resumo:
A series of rare earth (Gd, Eu, Tb) complexes with different substituent group carboxylic acids (ortho-hydroxylbenzioc acid, ortho-aminobenzoic acid and ortho-methoxy benzoic acid) and 1,10-phenanthroline were synthesized. The spectroscopic studies of the photophysical properties such as luminescence properties, energy match and intramolecular energy transfer were carried out. The lowest triplet state energies of ligands and the intramolecular energy transfer efficiencies were determined with the measurement of low phosphorescence spectra and lifetimes of Gd complexes.
Resumo:
The stability constants of M-L binary system and M-L-L' (M = La3+ similar to Yb3+, Y3+ and Ca2+; L= DL-malic aicd, L' = L-hydroxyproline) ternary system were determined by pH-(0)-tentiometric method under the simulating physiological condition(37 degrees C, I=0.15 mol/L NaCl). The complex species MpLqLr'H-s(abbr as pqrs) in the sytems were ascertained by program COMPLEX. The results show that there are three species(1101, 1100 and 1200) in M-L binary system and one species(1010) in M-L' binary system. In addition to the above four species, a new species, 1112 was found in the M-L-L' ternary system, which is the only species of mixed ligands. Rare earth ions form more stable complexes than calcium ion does and the stability differences between their complexes in the ternary system are less than that in the binary system. The distributions of all the species in La-L-L' ternary system vs pH are discussed.
Resumo:
The morphology and properties of [ PPO-PDMS-PHS](n) segmented ternary copolymers were investigated by DMA, TEM and SAXS techniques. It is shown that the continuous phase of [PPO-PDMS-PHS](n) is the compatible phase composed of PDMS, PPO and PHS segments, and that there exist two dispersed phases, i, e. the PDMS phase and a mixed phase of half hard ( PHS) and hard ( PPO) segments. The tan delta vs. T curve of the segmented ternary copolymer with 66.7% (W/W) PDMS shows a rather high plateau in the temperature range from -120 degrees C to 200 degrees C, which indicates that the copolymer has the characteristics of microphase separation as well as compatibility of block copolymers, respectively. Meanwhile, it has good tensile properties, which means that [PPO-PDMS-PHS](n) has overcome the weakness of low strength of block or segmented copolymers containing PDMS.
Resumo:
Photophysical properties (e.g. luminescence and energy transfer) of binary and ternary complexes of Gd3+, Eu3+, and Tb3+ with aminobenzoic acids and 1,10-phenanthroline were studied in connection with their spectroscopic characterization. Intramolecular energy transfer between center ions and ligands as well as between ligands is discussed in detail.
Resumo:
A series of binary and ternary rare earth complexes with para-substitued benzoic acids and 1,10-phenanthroline were synthesized. The phosphorescence spectra were measured and the lowest tripler state energies of ligands were determined, the phosphorescence lifetimes were obtained and intramolecular energy transfer mechanism between ligands was studied. The luminescence properties were also measured and were in agreement with the prediction. The energy match and intramolecular energy transfer process in these binary and ternary complexes were discussed in detail.
Resumo:
Morphology, mechanical properties, and interfacial interaction of polyamide 1010/polypropylene (PA1010/ PP) blends compatibilized with polypropylene grafted with glycidyl methacrylate (PP-g-GMA) were studied. It was found that the size of the PP domains, tensile and impact strength of ternary blends, and adhesion fracture energy between two layers of PA1010 and PP were all significantly dependent on the PP-g-GMA contents in the PP layer. Correlations between morphology and related properties were sought. The improvements in properties have been attributed to chemical and physical interaction occurring between PA1010 and PP-g-GMA. (C) 1997 Elsevier Science Ltd.
Resumo:
Ternary complexes of rare earth Eu(dbm)(3).phen and Tb(acac)(3).phen (dbm = dibenzoylmethanide, acac = acetylacetone and phen = 1,10-phenanthroline) were introduced into silica gel by the sol-gel method. The result indicated that the rare earth ions (EU3+ and Tb3+) showed fewer emission lines and slightly lower emission intensities in the silica gel than in the pure rare earth complexes. The lifetimes of rare earth ions in silica gel (Eu3+ and Tb3+) doped with Eu(dbm)(3).phen and Tb(acac)(3).phen were longer than those in purl Eu(dbm)(3).phen and Tb(acac)(3).phen. A very small amount of rare earth complexes doped in a silica gel matrix can retain excellent luminescence properties. (C) 1997 Elsevier Science S.A.
Resumo:
A series of binary and ternary rare earth (Gd, Eu, Tb) complexes with ortho hydroxyl benzoic acid, pam aminobenzoic acid, nicotinic acid and 1,10-phenanthroline were synthesized. Phosphorescence spectra and lifetimes of Gd complexes were measured and the lowest triplet state energies of gadolinium binary complexes end the intramolecular energy transfer efficiencies were determined. The luminescence properties and energy transfer process of Eu3+ and Tb3+ complexes were discussed.
Resumo:
Results of photophysical properties of the complexes of Gd3+, Eu3+ and Tb3+ with conjugated carboxylic acids (3,4-funandicarboxylic acid and nicotinic acid) and 1,10-phenanthroline are reported. Whether between central ions and ligands or between the two ligands, it is found that the intramolecular energy efficiency is a sensitive function of the relative positions of the resonance energy levels of the central ions and the lowest triplet states of the ligands. Couplings of rare earth ions to the ligands are discussed in detail. (C) 1997 Elsevier Science S.A.
Resumo:
Ternary complexes of terbium with ortho (and pam) aminobenzoic acid and 1,10-phenanthroline were introduced into silica gel by the sol-gel method. The luminescence behavior of the solid-state samples was studied during the sol-gel aging process by means of emission. excitation spectra, lifetimes and quantum efficiencies.
Resumo:
Thirteen kinds of binary and ternary complexes of rare earth (Gd, Eu,Tb) with ortho (para) aminobenzoic acid and 1.10--phenanthroline were synthesized and characterized. The phosphorescence spectra and lifetimes of gadolinium complexes were measured and the lowest triplet state energies of ligands and the energy transfer efficiencies between ligands were determined. The luminescence properties and intramolecular energy transfer of these complexes were studied in details.