Studies on counterion binding to ionic surfactant micelles are reviewed. The degree of counterion binding, β, is used as a measure of the number of bound counterions. The ion-selective electrode and conductivity methods and a method for estimating β from the dependence of critical micelle concentration on counterion concentration are discussed. The dependence of β on the particular kinds and concentrations of counterion and surfactant ion, micellar shape, temperature and solvent are demonstrated.

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The hydrolysis rate of p-nitrophenyl α-D-glucopyranoside was greatly enhanced in cationic micelles of hexadecyltrimethylammonium chloride (HTAC) by using phenylboronic acid (PBA) in pH 11.0 phosphate buffer. Stereospecific acceleration of hydrolysis toward the α-anomer over the β-anomer then increased to a high extent. The effect of the type of boronic acid in micelles of HTAC was examined in order to clarify the mechanism of the enhancement of the hydrolysis rate of the α-glucoside and the α/β selectivity in the presence of HTAC by the addition of PBA. The more hydrophobic boronic acid afforded the higher α/β selectivity. p-Decyloxyphenylboronic acid (C₁₀PBA) gave the highest selectivity (k_α/k_β=64) in the presence of cationic micelles. The enhancement of selectivity by the addition of 1mM C₁₀PBA was comparable to that by 7mM methylboronic acid (MBA), which is the highest selectivity obtained in the absence of cationic micelles.

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Study was conducted to improve the quality of used edible oils by membrane processing, so as to make recycling feasible. Membrane experiments were conducted on used edible oil in a flat membrane batch cell using polytetrafluoroethylene microfiltration, polymeric nanofiltration, and nonporous hydrophobic polyimid composite (NTGS-2200) membranes. For comparison, used edible oil was also improved using activated carbon.
Nanofiltration and activated carbon processing improved the color of used edible oil slightly, but did not reduce viscosity. Microfiltration failed to improve either color or viscosity of used edible oil. Color and viscosity of used edible oil were improved to the extent of fresh oil, and polar compounds and oxidation products of used edible oil were reduced by 70% and 38% respectively using the NTGS-2200 membrane. Oil stability of NTGS-2200 membrane processed oil showed no improvement over that of used edible oil. POV was found closely correlated to the viscosity of used, fresh and NTGS-2200 membrane processed oils during the same processing in the AOM test.

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In water-soluble dye, possessing -SO₃^- groups and the cationic surfactant (DTAB or CTAB) system, phase separation with precipitation and redissolution of precipitation were observed to result from cooperative-way between the dye and surfactant. On adding cationic surfactant to the dye aqueous solution, insoluble sedimentation occured. With further increase in cationic surfactant, precipitation was completely redissolved in aqueous solution. Flocculation was due to the electrostatic interaction between the dye and cationic surfactant and a hydrophobic layer would be formed on the dye since the tails of surfactant were facing the water phase. Redissolution was the cause for adsorption of cationic surfactant as micelles on the dye.
Redissolved solution in dye/DTAB or CTAB/water systems showed high viscosity. The addition of short-chain alcohol (1-propanol) lead to lower viscosity and prevention of aggregation. Surface tension, electro-conductivity and static light scattering measurements clearly indicated 1-propanol to be essential to interactions between the surfactant and dye.

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Differential scanning calorymetry (DSC) was conducted to clarify the crystallization behavior of n-hexadecane dispersed in oil-in-water emulsions (n-hexadecane : water=20 : 80). Tween 20 was used for emulsification and four sucrose fatty acid esters; sucrose laurate (L-195), sucrose palmitate (P-170), sucrose stearate (S-170) and sucrose oleate (O-170) were added to n-hexadecane. Crystallization temperature (T_c) of n-hexadecane in the emulsion system was 3.4°C and the melting temperature (T_m) was 17.4°C. T_c and T_m were 16.9°C and 18.5°C for bulk n-hexadecane, respectively. P-170 and S-170 addition resulted in considerable increase in T_c of n-hexadecane/water emulsions but L-195 had only slight effect. O-170, possessing oleic acid moieties as its hydrophobic portion had no effect on T_c of n-hexadecane/water emulsions. In bulk liquid, none of the sucrose esters showed any effect on T_c or T_m of n-hexadecane.
With the addition of P-170 and S-170, small endothermic peaks appeared at 3.6°C and 4.1°C (on heating) and exothermic peaks at -3.2 and -3.0°C (on cooling) appeared in addition to the crystallization and melting peaks of n-hexadecane. These peaks corresponded to phase transitions of molecular aggregates formed emulsion interfaces. The mechanisms for acceleration of crystallization of n-hexadecane and molecular aggregate formation are discussed with consideration to interface adsorption and mesophase formation due to sucrose fatty acid ester addition in n-hexadecane.

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Examination was made of the amount of n-3 fatty acid in freshwater fish, abundantly present in the northeastern region of Thailand. Gas-liquid chromatgraphy was conducted for this porpose for 15 species of the fish. As a result, Channa striata (Striped snake-head fish) was found to be the best source for both eicosapentaenoic acid (EPA, 20 : 5 n-3) and docosahexaenoic acid (DHA, 22 : 6 n-3) with concentration of 13.1 and 10.5%, respectively. The results showed that 185.7g of Channa striata per day can provide 1g of n-3 fatty acid as recommended by the Food and Nutrition Board of the National Research Council of USA. There could be a potential source of adequate n-3 fatty acid and healthy food in this freshwater fish.

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1, 2, 2, 2-Tetraphenylethanone (benzopinacolone) was obtained quantitatively by reaction of 1, 1, 2, 2-tetraphenyl-1, 2-ethanediol (benzopinacol) with the 4-nitropyridine N-oxide SbCl₅ (1 : 1) complex (Complex A). Benzopinacolone was also obtained along with a small amount of tetraphenylethylene oxide from benzopinacol using pyridine N-oxide-SbCl₅ (1 : 1) (Complex C) and 4-methylpyridine N-oxide-SbCl₅ (1 : 1) complex (Complex B). The Pinacol rearrangement of benzopinacol using α-OSbCl₄ pyridines followed the order :
γ-NO₂ α-OSbCl₄ pyridine>>γ-CH₃ α-OSbCl₄ pyridine≥α-OSbCl₄ pyridine

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Incorporation of the syn head-to-head cyclobutane dimer (2) of sodium ethyl 5- [2- (4-hexadecyloxyphenyl) ethenyl] -2-pyrazinylmethylphosphonate (1) in the bilayer of DPPC vesicles was noted to suppress the release of glucose entrapped in the vesicles. The release of entrapped glucose from the vesicle was accelerated by irradiation at 254nm, and also completely suppressed by irradiation at above 300nm. This acceleration-suppression cycle of the release by light was successively repeated three times. This on-and-off release control of vesicles considered due to photochromism involving monomer 1 and its dimer 2 intermolecularly and intramolecularly is reported here for the first time.

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