共查询到20条相似文献,搜索用时 15 毫秒
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Gh. Dragon 《Journal of Thermal Analysis and Calorimetry》1986,31(4):941-954
The solubility behaviour of several hydrated and anhydrous sulphates has been studied isothermally (26.2±0.06 °C) by using the high-resolution calorimeter previously described. The notion of behaviour recently defined in terms of topoenergetic principles was adopted for these experiments by establishing standard experimental conditions (SEC), mainly covering the geometry of the measuring cell and the figure of merit of the overall calorimetric system. The previously defined parameters from the heat flow recorded at normal and high speed clearly show the oscillatory behaviour generally predicted by the topoenergetic theory. The measuring system used also allows the demonstration of a difference in behaviour for size fractions of the same solute. The overall solubility behaviour under the same SEC for all values of solute mass can be defined in accordance with the universal topoenergetic procedure applied to a large variety of composite and measuring systems. The resulting data associated with the individual (ontogenic) and the group (phylogenic) behaviour can provide Data Banks for general use. 相似文献
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Gh. Dragon 《Journal of Thermal Analysis and Calorimetry》1987,32(1):293-300
The process of dilution of aqueous concentrated solutions of the series XSO4 (X=Cu, Na2, Fe, Ni, Mn, Mg) was studied calorimetrically by considering the peak height and area as eigenvalues and the initial concentration as governing potential. The experiments were carried out under standard conditions imposed by topoenergetic principles. The results obtained with the universal procedure recently established define the individual (ontogeny) and the group (phytogeny) behaviour of all the considered solutions with respect to the overall measuring system. These data agree with many other experimental facts showing the following increasing sequence of their power: Mg< Mn < Ni < Fe< Na < Cu. The initial concentration of hydrogen-bonds can be determined by means of standard experiments with the universal topoenergetic procedure proposed for the creation of Data Banks.
Zusammenfassung Der Proze\ der Verdünnung konzentrierter wÄssriger Lösungen der Serie XSO4 (X=Cu, Na2, Fe, Ni, Mn, Mg) wurde kalorimetrisch untersucht, indem Höhe und FlÄche des Peaks als Eigenwerte und die Ausgangskonzentration als dominierendes Potential angesehen wurden. Die Experimente wurden unter von topochemischen Prinzipien auferlegten Standardbedingungen ausgeführt. Die mit der kürzlich eingeführten universellen Prozedur erhaltenen Ergebnisse kennzeichnen das (ontogene) individuelle und das (phylogene) Gruppenverhalten aller in Betracht genommenen Lösungen in Bezug auf das Gesamtme\system. Diese Daten stimmen mit anderen experimentellen Fakten überein. Die von den Kationen ausgehende Wirkung nimmt in der Reihenfolge Mg< Mn < Ni < Fe < Na < Cu zu. Die Ausgangskonzentration der Wasserstoffbindungen kann mittels Standardexperimenten nach der für die Schaffung einer Datenbank vorgeschlagenen universellen topoenergetischen Prozedur bestimmt werden.
XSO4 (X=u, Na2, Fe, Ni, Mn, Mg), , — . . , , () () . , Mg < Mn < Ni < Fe < Na < u. , .相似文献
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The interaction between molecular oxygen and bile salts, previously observed using chemiluminescence techniques, is studied in this paper by electrochemical techniques to further highlight the nature of the interaction. A shift of half-wave potential of the first polarographic wave for the reduction of molecular oxygen was observed in solutions in the presence of bile salts. The shift could be related to different phenomena, such as adsorption of bile salt molecules on the mercury electrode, irreversibility of the oxygen reduction reaction, pH of the solution. Experimental results suggest the exclusion of the above mentioned processes and outline the occurrence of a direct interaction between oxygen and bile salts, where the hydrophobic face of bile salt monomers and/or small aggregates are involved, enhancing so dismutation of superoxide ion produced at the electrode. The presence of bile salts in solutions containing triphenylphosphine oxide, a hydrophobic surfactant, increases also the wave of reduction of molecular oxygen. As a consequence bile salts, beside the well-assessed physiological roles, can behave as oxygen carrier and as antioxidant, preventing the oxidation of biological compounds by superoxide ion. 相似文献
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The heats of mixing of the DNA-AD, Duplex I-AD and Duplex II-one systems were measured at 298.15 ± 0.005 K by using an LKB batch type twin microcalorimeter with a help of spectral measurements. From the results of DNA-AD system obtained, the interaction between DNA and AD is mainly caused by intercalation manner by referring to the result of spectral measurement. And, we estimated the thermodynamic quantities based on the intercalation process. While, from the results of Duplex I-AD and Duplex II-one systems, we concluded that the interactions of these systems may be corresponded to an electrostatic force as binding process rather than an intercalation process. 相似文献
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In this work, the interaction of an ionic liquid (IL) 1-octyl-3-methylimidazolium chloride ([Omim]Cl) and L-tryptophan was investigated with fluorescence spectroscopic method. The quenching mechanism and binding characteristics of [Omim]Cl with L-tryptophan at different temperatures were studied from fluorescence measurement. The thermodynamic parameters such as free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS), were calculated by thermodynamic equations. The experimental results indicated that [Omim]Cl and L-tryptophan had weak interaction and the mechanism of quenching belonged to static quenching. Hydrogen bonds and van der Waals interactions played important roles in the binding of [Omim]Cl with L-tryptophan. 相似文献
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Wang Fang Sheng Shenjun Ge Xuefeng Huang Heyong Ma QingYu 《Journal of Thermal Analysis and Calorimetry》2019,135(5):2849-2856
Journal of Thermal Analysis and Calorimetry - Exploring the mechanism of the interaction between milrinone drug and lysozyme is important for us to understand the transportation in vivo, metabolism... 相似文献
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E. Chiessi M. D'Alagni G. Esposito E. Giglio 《Journal of inclusion phenomena and macrocyclic chemistry》1991,10(4):453-469
The structure of sodium deoxycholate (NaDC) micellar aggregates has been previously reported to be helical, and two helical models have been proposed for the micellar aggregates of sodium taurodeoxycholate (NaTDC). Here we report NMR and UV-VIS studies on the interaction between acridine orange (AO) and NaDC or NaTDC aqueous micellar solutions. AO is known to aggregate in aqueous solutions. The addition of NaDC or NaTDC causes the breaking of the AO aggregates, although the binding geometry of the two bile salts with AO seems to be slightly different. The cationic dye interacts mainly with the C18 and C,9 methyl groups of the bile salt molecules. This result agrees with one of the two NaTDC helical models and with some of its possible aggregates, and confirms again the helical structure attributed to the NaDC micellar aggregates within the limits of the experimental conditions tested by us.Devoted to Professor Giovannai Battista Marini Bettolo Marconi on the occasion of his 75th birthday. 相似文献
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《Fluid Phase Equilibria》2006,244(1):68-77
Heat capacities for nine ionic liquids (IL) have been determined with the “three-step” method using two different differential scanning calorimeters (DSC). In addition, the heat capacities of these ionic liquids have been studied by the modulated-temperature differential scanning calorimetry (MDSC™). The measurements cover a temperature range from 315 to 425 K. 相似文献
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The interactions between an organic polymer with plasticizing activity and a model surface (CaCO3), with a surface activity similar to the cement one, have been analysed by volumetric analysis and thermal analysis: TG/DTG
and DSC. The synthesized polymer has a negative link site (carboxylate) that is able to interact with the substrate and a
long ethylene oxide chain that contribute to the dispersing activity. The pattern of the adsorption isotherm suggests the
occurring of a step like adsorption, initially characterised by a coil conformation of PEO chain followed by a more PEO strained,
linear, conformation as the amount of polymer increases. The polymer adsorption appears to modify the crystalline phase and
morphology of the CaCO3 surface as the thermal analysis puts in evidence through the CaCO3 decomposition temperature shifts. SEM analysis confirms the morphology changes induced by polymer adsorption. 相似文献
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Lu Y Wang G Tang W Hao X Xu M Li X 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,82(1):247-252
The binding properties of amino phosphate ester derivatives, compound 1 and 2 with calf thymus DNA (CT-DNA) were investigated by UV spectra, fluorescence spectra, molecular modeling and isothermal titration calorimetry (ITC). The intrinsic binding constants Kb of compound 1 and 2 with CT-DNA were determined by fluorescence spectroscopy and ITC, respectively. The results indicated that the two compounds bind to CT-DNA with different binding affinity, which is in the order of compound 1 > compound 2. At the same time, fluorescence spectra suggested that the mechanism of the binding of the two compounds to CT-DNA is a static enhancing type. According to the ethidium bromide displacement experiments, UV spectra, molecular modeling and ITC studies, it can be concluded that compound 1 and 2 are intercalators that can slide into the G–C rich region of CT-DNA. Furthermore, ITC data showed that compound/DNA binding is enthalpy controlled. 相似文献
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芳香反离子与离子表面活性剂胶团的相互作用 总被引:5,自引:0,他引:5
用紫外吸收光谱的方法研究了多种芳香反离子与离子表面活性剂胶团之间的相互作用。发现阳离子表面活性剂和阴离子表面活性剂胶团对芳香反离子的吸收光谱有着显著不同的影响,芳香反离子结构的细微变化可导致光谱特性显著不同。这被解释为阳离子表面活性剂胶团与芳香环之间的阳离子-π相互作用。阳离子-π相互作用需要阳离子表面活性剂分子与芳香反离子具有合适的相对位置与距离。通过测定各混合体系的吸附量证明,不同的芳香反离子在胶团表面有不同的排列方式。NMR的实验结果支持了上述解释。 相似文献
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