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1.
The influence of concentration conditions and acidity on the phase separation in non-ionic surfactants Triton X-100 solutions
in the presence of phenol was investigated. It was shown that the addition of small amounts of phenol results in the decrease
of the cloud point temperature of Triton X-100 solutions. On the other hand, the addition of phenol into the investigated
system resulted in the decrease of the hydration values of surfactant-rich phases and the increase of their hydrophobicity.
The extraction degree and distribution coefficient of phenol between the water and the surfactant-rich phases were studied.
On the basis of data obtained the molar parts of water, phenol and Triton X-100 in the non-ionic surfactant-rich phases formed
at different concentration conditions were calculated. Possibilities of the application of phenol-induced micellar extraction
for microcomponents preconcentration were estimated. 相似文献
2.
G. Geeraerts P. Joos 《Colloids and surfaces. A, Physicochemical and engineering aspects》1994,90(2-3):149-154
Considering surfactant solutions at concentrations exceeding the CMC, another relaxation process besides diffusion occurs, also affecting the dynamic surface tension. The latter equilibration process concerns a micellisation/demicellisation process, representing the disintegration of micelles into monomers. The micellisation kinetics are accounted for by adding a single source term to the diffusion equation of the free monomers.
In the present paper the integration of the diffusion equation is avoided by using the concept of the diffusion penetration depth. Nevertheless, when this approximation is made, good agreement is achieved between experiment and theory for micellar Triton X-100 solutions. Moreover, it follows that diffusion of micelles may not be neglected. 相似文献
3.
A solution phase UV-irradiation technique has been exploited to produce an AuSe nanoalloy through fusion of preformed Au (photoproduced) and Se (chemically prepared) in a micellar (TX-100) medium. 相似文献
4.
Nonionic surfactants such as Triton X-100 (TX-100) are comprised of a mixture of oligomers with a varying degree of length in the ethoxylate chain. The development of chromatographic methods for resolution of the various oligomers of TX-100 is of environmental importance, and can be useful for quality control and characterization in industrial manufacture. Capillary electrochromatography (CEC) is fast becoming a capable separation technique that combines the benefits of both high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE). This report presents a novel CEC method for separation of the various TX-100 oligomers. A comparison of monomeric vs. polymeric stationary phases for separation of TX-100 was conducted. Since the oligomers of TX-100 were better resolved on a monomeric phase as compared to polymeric phase, a systematic mobile phase tuning was performed utilizing a monomeric CEC-C18-3 microm-100 A stationary phase. Various mobile phase parameters such as acetonitrile (ACN) content, Tris concentration, pH, voltage, and temperature were manipulated in order to achieve the optimum separation of oligomers in less than 30 min. 相似文献
5.
Valdés-Díaz G Rodríguez-Calvo S Pérez-Gramatges A Rapado-Paneque M Fernandez-Lima FA Ponciano CR da Silveira EF 《Journal of colloid and interface science》2007,311(1):253-261
Ionising radiation used for sterilization can have an effect on the physicochemical properties of pharmaceutically relevant excipient systems, affecting therefore the stability of the formulation. The effect of gamma irradiation on the phase behaviour (cloud point--CP) and critical micelle concentration (CMC) of aqueous solutions of Triton X-100, used as a model nonionic surfactant, is investigated in this paper. Micellar solutions were irradiated with gamma-rays in a dose range between 0 and 70 kGy, including the sterilization range of pharmaceutical preparations. The decreased observed in CP and CMC values of micellar solutions at all absorbed doses was explained in terms of changes in molecular mass distribution of ethoxylated surfactant and the formation of cross-linked species. These results were complemented by mass spectrometry, UV-vis and NMR spectroscopy. Although the findings indicate degradation of polyethoxylated chains by water radical attacks, there was no spectroscopic evidence of radiation damage to aromatic ring or hydrocarbon tail of surfactant. Models based on Flory-Huggins theory were employed to estimate CP from changes in mass distribution and to obtain cross-linking fractions. Surface tension measurements of non-irradiated and irradiated solutions were used for estimating the effectiveness and efficiency of surfactant in the formulation. 相似文献
6.
The decomposition of the non-ionic surfactant Triton X-100 in gamma-irradiated deaerated aqueous solution is mainly attributed to the attack of OH radicals and H atoms. The mechanisms of these reactions were investigated in detail, including the influence of pH and dose rate. The RCHOH radicals formed by OH attack on alcohol molecules can decompose the surfactant in aqueous solution. 相似文献
7.
Unexpected stability of phospholipid langmuir monolayers deposited on Triton X-100 aqueous solutions
Fontaine P Fauré MC Muller F Poujade M Micha JS Rieutord F Goldmann M 《Langmuir : the ACS journal of surfaces and colloids》2007,23(26):12959-12965
We studied at the molecular level the interaction between neutral detergent Triton X-100 aqueous solution and a phospholipid Langmuir monolayer deposited on top using surface pressure measurement and grazing incidence X-ray diffraction (GIXD). Macroscopically, the detergent-phospholipid system follows the Gibbs law. However, GIXD shows that the detergent and the phospholipid segregate at the interface. The molecular organization of pure phospholipid domains is imposed by the detergent through surface pressure. Compression and expansion of the surface monolayer system in its final state reveal the stability of the phospholipids domains against dissolution by the detergent in the subphase, even above the detergent cmc. This resistance to dissolution is suppressed by an expansion of the monolayer. 相似文献
8.
The influence of micelles, formed by the aggregation of nonionic surfactant molecules, on positronium formation (combination
of e− and e+) probability is discussed in the light of radiation chemical phenomenon at the end part of the radiation track. The contribution
due to the parapositronium/narrow-component intensity in the presence of micellar aggregation and further structural reorganization
constitutes important aspects of the ortho-para conversion process. 相似文献
9.
The adsorption isotherms of nonionic surfactants Triton X-100 and Triton X-305 from water and cyclohexane on carbon black have been determined at 15 and 30°C. The Langmuir-type and BET-type isotherms are obtained for adsorption of Triton X-100 and Triton X-305 from water and cyclohexane respectively. Both the contact angles of water for graphite/water/air and graphite/water/cyclohexane decrease monotonously with increasing surfactant concentration. From these results, it is proposed that the adsorption of Triton X-100 and Triton X-305 on carbon black or graphite from water is monolayer. For the adsorption from cyclohexane solutions, the ethyleneoxide group of the surfactant molecules may be adsorbed onto the polar spot at the surface of carbon black, and the hydrophobic group of adsorbed molecules may direct toward the liquid phase or attaches to the nonpolar surface region around the polar spot. As the concentration increases, the ethylene oxide groups of the adsorbed molecules can be aggregated with each other via polar interactions to form hemi-reversed micelle. 相似文献
10.
The partitioning behavior of silica particles was investigated in the Triton X-100/dextran/water system. It was found that both electrostatic effects and interactions between phase-component species and the solid surface played important roles in determining the distribution of solids. Silica partition was highly pH-dependent, which was interpreted in terms of the pH dependence of the Triton X-100/SiO(2) interaction and the weak acidity of dextran. The presence of sodium dodecyl sulfate (SDS) moved the particles from the top surfactant-rich phase to the interface and the bottom phase, while dodecyltrimethylammonium bromide (DTAB) had the opposite effect. These trends are attributable to the electrostatic interaction between the charged mixed micelles in the top phase and the particles and to the fact that the ionic surfactants modified the adsorption density of the nonionic surfactant on silica. 相似文献
11.
The influences of Triton X-100 on hemoglobin (Hb) behaviors were studied by the methods of UV-Vis spectrum, fluorescence spectrum, HPLC, conductivity, zeta potential and negative-staining transmission electron microscope in Hb/acyclovir/Triton X-100/H2O system. With the increase of Triton X-100 concentration in the system, the percentage of the free acyclovir increased from 58%--63% to 90%--94%. The static quenching constant and the association number of acyclovir to Hb decreased. The fluorescence spectrum, conductivity, zeta potential, fluorescence polarization and negative-staining morphology of Hb tended to recover to those of the original state of Hb in the same concentration of Hb. The interaction between Triton X-100 and Hb is stronger than that between acyclovir and Hb. Most Triton-X-100 was associated with Hb at low Triton X-100 concentration. But the interaction of Triton X-100 with Hb was apparently dominant in high Triton X-100 concentration. The Hb structure was unfolded and finally denatured. 相似文献
12.
13.
表面活性剂在非水溶剂中聚集态的研究所见的报导与水体系相比要少得多.然而近年来对非水体系的研究日益增多.这是因为表面活性剂在非水溶剂中的应用日趋增加,但与水体系相反,对非水体系的性质了解甚少.对表面活性剂非水体系的研究还有助于对其聚集体的共溶剂效应有更深的认识.TritonX-100(以下简写为TX-100)是典型的非离子表面活性剂,在工业上有着广泛的应用.乙二醇在多醇中与水的化学结构最相近问,然而它却是水结构的破坏剂,加入少量的乙二醇会使水的冰点急剧下降.乙二醇又是蛋白质的变性溶剂.表面活性剂在乙二醇中的胶… 相似文献
14.
Pulse radiolysis of deaerated aqueous solutions of 4·10–5–2.4·10–3 mol dm–3 Triton X-100 gives rise to a transient species originating from the reactions of OH radicals and H atoms. The rate constants of these reactions were found to be 8.8·109 mol–1·dm3·s–1 and 1.25·109 mol–1·dm3·s–1, respectively, for Triton X-100 concentrations below CMC. The corresponding transient species were found to decay according to second order kinetics. The mechanism of the reactions involved including concentration effects is discussed. 相似文献
15.
Brites CD Freitas VT Ferreira RA Millán A Palacio F Carlos LD 《Langmuir : the ACS journal of surfaces and colloids》2012,28(21):8190-8196
Stable, cost-effective, brightly luminescent, and metal-free organosilica nanoparticles (NPs) were prepared using the St?ber method without any thermal treatment above 318 K. The white-light photoluminescence results from a convolution of the emission originated in the NH(2) groups of the organosilane and oxygen defects in the silica network. The time-resolved emission spectra are red-shifted, relative to those acquired in the steady-state regime, pointing out that the NPs emission is governed by donor-acceptor (D-A) recombination mechanisms. Moreover, the increase of the corresponding lifetime values with the monitored wavelength further supports that the emission is governed by a recombination mechanism typical of a D-A pair attributed to an exceptionally broad inhomogeneous distribution of the emitting centers peculiar to silica-based NPs. These NPs exhibit the highest emission quantum yield value (0.15 ± 0.02) reported so far for organosilica biolabels without activator metals. Moreover, the emission spectra and the quantum yield values are quite stable over time showing no significant aging effects after exposure to the ambient environment for more than 1 year, stressing the potential of these NPs as metal-free biolabels. 相似文献
16.
Jie Zhu Xiang Guang Meng Hai Dong Wang Shan Dong Liu Qin Hui Pang Juan Du Xian Cheng Zeng 《中国化学快报》2007,18(3):349-351
The oxidative coupling reaction of 2,6-dimethylphenol with H2O2 catalyzed by a copper(Ⅱ) Schiff complex in aqueous and Triton X-100 micellar solution under mild conditions was investigated. The kinetics of formation of 3,3′,5,5′-tetramethyl-4,4′-diphenoquinone (DPQ) was studied. Rate constant k2 were obtained. The optimum pH for DPQ generation reaction is 7.25. The main product was DPQ in aqueous buffer solution, but PPE and the oxidized products of PPE remained in Triton X-100 micellar solution. 相似文献
17.
Two samples of Triton X-100 (TX100) were compared. The "old sample," manufactured by Rohm and Haas, has a mean degree of ethoxylation of 10.1. The "new sample," manufactured by Union Carbide, has a mean degree of ethoxylation of 9.6. The cmc values near room temperature (23 degrees C, old sample; 24.6 degrees C, new sample), as determined from surface tension measurements, are similar. Dynamic light scattering measurements on the new sample gave hydrodynamic radii at different temperatures in reasonable accord with those reported a number of years ago. In contrast, time-resolved fluorescence quenching (TRFQ) experiments using a pyrene-labeled triglyceride as a probe gave aggregation numbers N(agg) near room temperature that were similar to those determined previously by light scattering; however, the N(agg) of the new sample was larger, and the difference was outside of experimental error to one standard deviation. More troubling was that the TRFQ experiment failed to give meaningful results on solutions exposed to air, as in the case of the older TX100 sample. To get useful data by TRFQ measurements, one had to first remove oxygen from the solution. Copyright 2000 Academic Press. 相似文献
18.
The influence of UV-irradiation on the interaction of hemoglobin (Hb) with Triton X-100 is investigated by UV–Vis absorption spectroscopy, fluorescence spectroscopy and freeze-fractured transmission electron microscopy. It is found that in Triton X-100/H2O systems Hb can convert to hemichrome but heme is not present, whereas in Triton X-100/n-C5H11OH/H2O microemulsion Hb can convert to hemichrome and then induce the heme monomer to leave the hydrophobic cavity of Hb. UV-irradiation can also convert Hb to hemichrome, and subsequently make heme to be photodegraded, in which the conversion rate depends on the structure of the surfactant aggregates. Furthermore, in order to understand the mechanism of photostabilization of Hb in Triton X-100 systems, the photostabilization of heme in the Triton X-100 aqueous solutions and Triton X-100/n-C5H11OH/H2O microemulsions has been studied. 相似文献
19.
20.
M. Romero-Cano A. Martín-Rodríguez F. de las Nieves 《Colloid and polymer science》2002,280(6):526-532
An experimental study on the electrophoretic mobility (µe) of polystyrene particles after adsorption of Triton X-100 (TX100) is described. Three polystyrene particles with different functionality (sulphate, carboxyl and amidine) were used as solid substrate for the adsorption of the surfactant. The electrophoretic mobility of the polystyrene-TX100 complexes at different electrolyte concentrations has been studied versus the amount of adsorbed surfactant. The presence of TX100 onto the colloidal particles seems to produce a slight shifting of the slipping plane. This is observed for electrolyte concentrations above ~10-3 M. On the other hand, the electrophoretic mobilities of the latex-surfactant complexes with maximum surface coverage were measured versus pH and salt concentration. Specific ion interactions between H+/carboxyl groups and OH-/amidine groups appeared at extreme pH which explain the anomalous electrophoretic behaviour encountered in the region where surface charge change. 相似文献