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1.
《Colloids and surfaces. A, Physicochemical and engineering aspects》2002,196(2-3):223-234
Penicillin potassium salt (penicillin-K) is found to show hydrotrope action, which can increase the solubility of cationic surfactant CTAB in water. Penicillin-K also shows hydrotrope-solubilization action, which makes the W/O and O/W microemulsion more stable and increases the solubilized amount of n-C5H11OH in O/W microemulsion and that of water in W/O microemulsion for CTAB/n-C5H11OH/H2O system. However, in this system, the presence of penicillin-K can decrease the stability of the lamellar liquid crystal phase due to its structure change to bicontinuous, which are proved by the mechanism of its hydrotrope-solubilization action. 相似文献
2.
《Journal of Dispersion Science and Technology》2013,34(6):763-769
Abstract The hydrolysis of cephanone in water, cetyl trimethyl ammonium bromide (CTAB) micelle, and CTAB/n‐C5H11OH/H2O O/W microemulsion was studied through UV‐VIS absorption spectroscopy. The mechanism of the hydrolysis and the effects of both the acidity of the media and the composition of O/W microemulsion on the hydrolysis were studied. The results show that the hydrolysis rate of cephanone increases with the acidity. Compared with water, CTAB micelle and CTAB/n‐C5H11OH/H2O O/W microemulsion suppress this hydrolysis. The inhibition of the hydrolysis of cephanone by CTAB micelle and CTAB/n‐C5H11OH/H2O O/W microemulsion is related to the location of cephanone in the interphases of CTAB micelles and CTAB/n‐C5H11OH/H2O O/W microemulsion droplets. 相似文献
3.
Controlled release of cephanone from hexadecyltrimethylammonium bromide (CTAB) micelles and CTAB/n-C5H11OH/H2O microemulsions was studied. The results showed that the release rate of cephanone was reduced in CTAB micelles and CTAB/n-C5H11OH/H2O microemulsions, because of the solubilization of cephanone in micelles and microemulsions. The release of cephanone from
CTAB micelles and CTAB/n-C5H11OH/H2O microemulsions was characterized by Fickian diffusion and non-Fickian diffusion. 相似文献
4.
The hydrolysis of cephanone in SDS micelle and SDS/n-C5H11-OH/H2O O/W microemulsion was studied through Uv-vis ab-sorption spectroscopy. The change of pH value in the hydrolysis of cephanone was determined. The result shows that pH value decreases in the process of the hydrolysis, and that the SDS ml-celle and SDS/n-C5H11OH/H2O O/W microemulsion accelerate the hydrolysis of cephanone compared with water. 相似文献
5.
In cetyltrimethylammonium/n-pentanol/H2O W/O (W/O = water in oil microemulsion) mixtures and bi-continuous microemulsions, phenothiazine (PTZ) molecules exist in
the membrane phase of the dispersion either with the N atom or with the S atom pointed toward the polar head of cetyltrimethylammonium
(CTAB). Cyclic voltammetry has been used to investigate the effects of the compositions and structures of the microemulsions,
pH, and the salt on the location distribution of PTZ in the membrane phase of the dispersion in CTAB/n-C5H11OH/H2O W/O and bi-continuous microemulsions. The results show that the location distribution of PTZ in the membrane phase of the
dispersion in microemulsions is mainly dependent on the hydrogen bond between PTZ and n-C5H11OH (or the counterion), and on the electrostatic attractive interaction between the N atom in PTZ and the polar head of CTAB. 相似文献
6.
Urea is found to show the hydrotrope action when the aqueous solubility of surfactant CTAB is enhanced while it will show the hydrotrope-solubilization action when the solubilized amount of n-C5H11OH in O/W microemulsion and that of water in W/O microemulsion are increased. The mechanism of the hydrotrope-sotubilization action of urea is in fact the increase of the stability of W/O and O/W microemulsion and structural transition from the lamellar liquid crystal phase to the bicontinuous structure. 相似文献
7.
Urea can enhance the aqueous solubility of surfactant CTAB (hexadecyltrimethylammonium bromide) when it shows the hydrotrope action. It will show the hydrotrope‐solubilization action when the solubilized amount of n‐C5H11OH in O/W microemulsion and that of water in W/O microemulsion are increased. The mechanism of the hydrotrope‐solubilization action of urea is the increase of the stability of W/O and O/W microemulsion and structural transition from the lamellar liquid crystalline phase to the bicontinuous structure. 相似文献
8.
Different from organic solvent, self-assemblies are environment friendly media, and moreover, if they are used as micro-reactor,
many meaningful and exciting results may be obtained. In this paper, we investigated the photoisomerization of trans-stilbene in Triton X-100/n-C5H11OH/H2O microemulsions (a kind of self-assemblies) with different compositions and structures to establish the relationship between
the reaction yields and the compositions and structures of microemulsions. The results show that the yield of cis-stilbene is increased with the increase of water content or with the decrease of Triton X-100 content, and oil in water (O/W)
structure is the best structure for this reaction, which makes it possible to decrease the pollution of environment by organic
solvent always used in organic reactions. 相似文献
9.
The diffusion coefficient of methylene blue (MB) is determined by the method of non-probe microelectrode voltammetry in sodium dodecyl sulfate (SDS)/n-C5H11OH/H2O lyotropic liquid crystal system. The results obtained show that the diffusion coefficient of MB increases with water and n-pentanol contents in the microemulsions and the lyotropic liquid crystal but decreases with SDS content. The diffusion coefficient of SDS droplet in the microemulsions and the diffusion coefficient of SDS molecule in the lyotropic liquid crystal with MB all are less than those without MB. The magnitude order of the diffusion coefficient of MB is as follows: the coefficient in the oil-in-water (O/W) microemulsion is greater than the coefficient in the water-in-oil (W/O) microemulsion which is greater than the coefficient in the lamellar liquid crystal (LLC), which is also greater than the coefficient in the Hex. 相似文献
10.
11.
A biocompatible surfactant-n-dodecylammonium α-glutamate (GDA) with biodegradable and biocompatible properties was synthesized, and the phase behavior
and the structural properties of GDA/n-pentanol/water system was studied by small-angle X-ray diffraction, electron spin resonance, and freeze-fracture transmission
electron microscopy (FF-TEM). In the ternary phase diagram of GDA/n-pentanol/water system, there exist three isotropic regions—O/W, bicontinuous, and W/O structures, and two anisotropic regions—hexagonal
liquid crystal (HEX), and lamellar liquid crystal (LLC) regions. UV irradiation causes the decrease in the interlayer space,
d, of lamellar liquid crystal and in the radius, r, of column aggregates of hexagonal liquid crystal, but it has little effect on the structure of O/W and W/O microemulsions. 相似文献
12.
The effects of penicillin potassium salt (PenK) on the solubility, Krafft temperature TK, critical micelle concentration CMC of SDS micelle and the phase behavior of SDS/n-C5H11OH/H2O system were studied. The partial phase diagrams of SDS/PenK/H2O system at different temperatures were determined. The release amounts of PenK in SDS/n-C5H11OH/H2O system and the distribution coefficient of PenK between micelle and water were measured by UV-Vis spectroscopy. The results show that in the presence of PenK, the CMC of SDS was decreased while the TK of SDS was increased and the solubility of SDS in both water and SDS/n-C5H11OH/H2O oil in water (O/W) microemulsion was decreased, but increased in water in oil (W/O) microemulsion. SDS micelles and SDS/n- C5H11OH/H20 O/W microemulsion could accelerate the release rate of PenK. The addition of SDS and water could both increase the release rate of PenK, whereas the presence of n-C5H11OH reduced the release rate of PenK. The above results were related to the electrostatic repulsion between PenK and SDS. 相似文献
13.
QIANJun-hong GUORong ZHUJun 《高等学校化学研究》2004,20(6):785-789
The hydrolysis of cephanone in Triton X-100 micelle and Triton X-100/n-C5H11OH/H2O(O/W) microemulsion were studied by means of UV-Vis absorption spectroscopy. The results show that compared with water, Triton X-100 micelle and Triton X-100/n-C5H11OH/H2O (O/W) microemulsion can inhibit the hydrolysis of cephanone. The inhibition effects of Triton X-100 micelle and Triton X-100/n-C5H11OH/H2O (O/W) microemulsion on the hydrolysis of cephanone are related to the location of cephanone in the interphases of Triton X-100 miceUes and Triton X-100/n-C5H11OH/H2O(O/W) microemulsion droplets. 相似文献
14.
IntroductionMicellesolutioncomposedofsurfactantscanaffect,adjustandcontrolmanychemicalreactionsaccordingtoitseffectsoflocalconcentration ,polarity ,charge ,microvis cosity,electrostatics ,etc ..1,2 Recently ,ithasarousedmuchattentiontoconductchemicalreactionsusingmi croemulsionasmicroreactor .3 7Theeffectofmicelleonthechemicalreactionstemsfromitsstaticelectricityandhy drophobicity .Usually ,cationicsurfactantcancatalyzethereactionbetweennucleophileandneutralmolecule ,whileanionicsurfactantsusp… 相似文献
15.
The aim of this work was to determine the structure of stable heteroassociates (HAs) with the stoichiometric ratios 1:2, 2:1,
and 4:1 of molecules formed in the HF-(C2H5)2O binary liquid system. The stretching frequencies of HF molecules found for each HA using a special procedure for processing
IR spectra were compared with the calculated frequencies V
HF of the stable molecular complexes (HF)m ((C2H5)2O)n (m = 1, 2, 4, 8; n = 1, 2) with different topologies by the density functional method (B3LYP/6-31++G(d,p)). As a result, it was shown that the most stable (among H-bonded complexes with the same stoichiometric ratio of molecules)
HAs HF((C2H5)2O)2, (HF)4 ((C2H5)2O)2, and (HF)8-((C2H5)2O)2 formed in HF solutions in diethyl ether. All of them had a cyclic structure and a common peculiarity of structure: only one
lone electron pair of the oxygen atom of the (C2H5)2O molecules is involved in hydrogen bonding. 相似文献
16.
D. A. Loginov M. M. Vinogradov Z. A. Starikova P. V. Petrovskii A. R. Kudinov 《Russian Chemical Bulletin》2007,56(11):2162-2165
The visible light irradiation of the [(η5-C6H7)Fe(η-C6H6)]+ cation (1) in acetonitrile resulted in the substitution of the benzene ligand to form the labile acetonitrile species [(η5-C6H7)Fe(MeCN)3]+ (2). The reaction of 1 with ButNC in MeCN produced the stable isonitrile complex [(η5-C6H7)Fe(ButNC)3]+ (3). The photochemical reaction of cation 1 with pentaphosphaferrocene Cp*Fe(η-cyclo-P5) afforded the triple-decker cation with the bridging pentaphospholyl ligand, [(η5-C6H7)Fe(μ-η:η-cyclo-P5)FeCp*]+ (4). The latter complex was also synthesized by the reaction of cation 2 with Cp*Fe(η-cyclo-P5). The structure of the complex [3]PF6 was established by X-ray diffraction.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2088–2091, November, 2007. 相似文献
17.
The thermotropic phase transitions in the perovskite type layer compound (n-C10H21NH3)2MnCl4 and (n-C14H29NH3)2MnCl4 were synthesized and, at the same time, a series of their mixtures C10Mn-C14Mn were prepared. The experimental binary phase diagram of C10Mn-C14Mn was established by differential thermal analysis (DTA), IR and X-ray diffraction. In the phase diagram new material (n-C10H21NH3)(n-C14H29NH3)MnCl4 and two eutectoid invariants were observed, two eutectic points temperatures are about 29.8 and 27.9°C. Contrasting other
similar system, there are three noticeable solid solution ranges (α, β, γ) at the left and right boundary and middle of the
phase diagram. 相似文献
18.
Konstantin S. Gavrichev Mikhail A. Ryumin Alexander V. Tyurin Andrey V. Khoroshilov Larisa P. Mezentseva Alexander V. Osipov Valeriy L. Ugolkov Viktor V. Gusarov 《Journal of Thermal Analysis and Calorimetry》2010,102(2):809-811
Thermal behavior of LaPO4·nH2O and NdPO4·nH2O nanopowders from room temperature to 973 K was investigated by DSC, TA/DTG, ESM, and X-ray study. Mass loss due to the release
of adsorbed and hydrate water was found in the range from 323 to 623 K. Phase transitions from hexagonal structure nanopowders
to monoclinic one for bulk specimens were found above 873 K. 相似文献
20.
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