Dielectric properties of microemulsions by time domain spectroscopy

Abstract

differ drastically from those of Fe(III) lattice ions in ferrisilicate.1 234 Cations are located in the local crystal field of low symmetry and are accessible to gas-phase molecules. Figure 3 shows the ESR spectrum of Fe(III) isolated cations in H-ZSM-5. The ESR line with g = 4.27 may characterize the isolated Fe(III) ion in tetrahedral or orthorhombic coordination and the formation of ESR lines with g > 4.3 is caused by the distortion of ion environment.16•17Interaction of coordinatively unsaturated Fe(III) ions with NH3, resulting in the increase of field symmetry, provokes a complete disappearance of low-field lines with g2 = 5.8 and g3 = 6.3. At the same time the temperature dependence of the intensity for the line with g = 4.3 becomes anomalous (/20 «c =* 1017 spin/g; /_196=c 2 X 1019 spin/g).4 The sorption of xenon or hexane at room temperature is accompanied by the noticeable broadening of lines with g2 = 5.8 and g3 = 6.3, as shown in Figure 3 (dotted

Room-temperature decomposition of 2,2′-azobis(isobutyronitrile) in emulsion gels with and without silica

“…For the water/ toluene/SDS/1-butanol system, the microemulsion composition for the pseudoternary system was (by mass) 55-56% toluene, 8.5-9.0% water, and 35.5-36% surfactant/1-butanol pseudocomponent [20]. The mass ratio of the pseudocomponent (surfactant and 1-butanol) used was 1:1.5 instead of 1:2 [20]. The same compositions by mass with CTAB also formed stable transparent microemulsions.…”

Dielectric Relaxation and Solvation Dynamics of Water in Complex Chemical and Biological Systems

“…The quaternary microemulsion containing water, oil, SDS, and 1-butanol exhibits two relaxation processes. 184,185 The amplitude of the low-frequency relaxation increases with increase in the water content whereas the high-frequency process is found to be independent of hydration. The low-frequency relaxation shifts to the high-frequency range with an increase in the water content and is faster than the relaxation time of neat alcohol.…”

“…Reverse micelles refer to aggregates of surfactants (e.g., dioctyl sulfosuccinate, AOT) formed in a nonpolar solvent, in which the polar headgroups of the surfactants point inward and the hydrocarbon chains project outward into the nonpolar solvent. − Apart from liquid hydrocarbons, recently several microemulsions are reported in supercritical fluids such as ethane, propane, and carbon dioxide. − …”

“…c A9-B1 solution as given in ref ; temperature is 25 °C. d C1 solution as given in ref ; temperature is 25 °C. e 0.4 M solution in D 2 O, ref ; temperature is 20 °C.…”

“… a The weights of relaxation are given in parentheses in the second column. b A1 solution as given in ref ; temperature is 25 °C. c A9-B1 solution as given in ref ; temperature is 25 °C.…”