A surface tension study (drop volume method) was performed at 30°C on micellization and adsorbed film formation of a mixed system of a cationic Gemini-type surfactant with a cationic surfactant in comparison with another mixed system of the same Gemini-type surfactant with a nonionic surfactant. The systems studied were Bis-ammonium Gemini derived from tartaric acid dibromide salt [BAGTB, 1,4-Bis(trimethylammonio)-2,3-dodecyloxy butane dibromide] with hexadecyltrimethylammonium bromide (HTAB): BAGTB / HTAB mixed system and with n-decanoyl-N-methylglucamide (MEGA-10): BAGTB / MEGA-10 mixed system. The data of surface tension (γ ) vs logarithmic molality plots as a function of mole fraction of surfactant 2 (2 corresponds to HTAB or MEGA-10), X 2, enabled us to determine the critical micellization concentration (CMC), the surface tension at CMC (γCMC), surface excess concentration (Γt ), the mean molecular surface area (A m), the partial molecular area (PMA), and the measures of efficiency of adsorption (pC20 = -log C20) and CMC / C20 which is available for evaluating the facilitating balance between adsorption and micellization. In addition, a newly defined measure of synergism in surface activity, i.e., the minimum surface Gibbs energy (G (S)min) was employed. Based on these data, the examination of synergism in micelle formation and in surface tension reduction elucidated that the Gemini-type surfactant does not exhibit any positive synergism for either BAGTB / HTAB or BAGTB / MEGA-10 mixed systems. Most of these parameters are found to depend conspicuously on the mixing ratio for both mixtures; indicating that the state of adsorbed film is divided into three ranges of X 2; the lower, the middle and the higher. The compositions of micelles formed at CMC (Y 2) and of adsorbed film (Z 2) equilibinated with bulk solution at a fixed surface tension were estimated.
Nonionic surfactants and water-soluble polymers undergo phase transition and clouding at elevated temperature. The process can be influenced by the presence of additives. In this work, we have studied the clouding of the surfactants, TritonX 100 and Brij 56 as well as the polymers, polyvinylmethylether and a triblock co-polymer, Pluronic 85 in the presence of a number of hydrotropes, glycols and polyethylene oxides. The clouding temperatures with the additive concentration have been determined and the energetics of the process has been estimated. It has been found that the enthalpic behavior of TritonX 100 was different from that of polyvinylmethylether and Pluronic 85. The enthalpy and entropy have nicely compensated each other. The clouding of Brij 56 and TX 100 have a direct dependence on the number of ethylene groups in the glycols and the molar mass of the polyethylene oxides. The hydrotropes, on the whole, have decreased the cloud point of TX 100, polyvinylmethylether and Pluronic 85. Sodium cholate and sodium salicylate have increased the cloud point. But a correlation of the cloud points with the chemical nature of the hydrotropes is difficult to ascertain.
The halide-sensitive fluorescence probe, 6-methoxy-N-alkylquinolinium, was prepared to investigate the behavior of counterion dissociation in micellar aqueous solution. Fluorescence was quenched by halide ions based on linear Stern-Volmer plots. The plots indicated a distinct break at cmc of cationic surfactants containing halide counterions. The slope of Stern-Volmer for 6-methoxy-N-ethylquinolinium (MEQ) decreased beyond cmc owing to micellar counterion binding. The quenching efficiency of 6-methoxy-N-dodecylquinolinium (C12MQ) increased significantly beyond cmc with surfactant concentration. The fluorescence of micellar solubilized C12MQ would thus appear to be quenched effectively by halide ions at the micellar surface. These ions were found to function effectively as a quencher in cationic micelle systems, but to have no effect on amphiphilic probe fluorescence in the presence of anionic micelles. Repulsive electrostatic interactions are thus shown to occur between halide ions and anionic micelles containing probes.
We devised a damaged hair model to confirm hair-damage was caused not only by chemical stress but also by physical and environmental stress. We observed morphological changes (e.g. decreasing cuticle layers, scale lift, hair swelling) in the hair model and analyzed alterations in the hair composition (e.g. cysteic acid, protein elution, melanin granule). We devised oxidative and reductive treatments (e.g. perming, bleaching) as the chemical stresses. We also devised a system for testing physical and environmental stresses. This consisted of ultraviolet ray (UV) irradiation, brushing, treatment with detergent, drying and heating. These factors are believed to cause hair-damage during normal everyday life. Scale lift was observed and this phenomenon was propagated depending on the amount of physical and environmental stress. The amount of exfoliated cuticles and cysteic acid in the cuticles also tended to increase with the progress of the physical and environmental treatments. The tendency was more remarkable with strong chemical treatments. The swelling of the hair, protein elution and the amount of solubilized melanin granule exhibited similar trends. These trends, though, were not as remarkable as those observed in the cuticle layers. Using the damaged hair model that included physical and environmental stresses, we demonstrated that stresses from everyday life, as well as chemical stresses, effected hair damage. These influences were enhanced depending on the degree of chemical treatment. This tendency was more remarkable in cuticle layers than in the cortex and medulla parts.
To confirm the effects of hydrophilic extracts from Rosmarinus officinalis L. (HER) on oxidative and/or reductive hair-damage, we first estimated the HER antioxidant effect by doing a β-carotene decoloring test. We additionally conducted an analysis of the biochemical parameters, for example cysteic acid or chemiluminescence (CL), and observed the morphological changes (snapping and splitting frequency) after chemical and physical hair treatment. Furthermore, we compared the effect of applying HER with the effect of applying no antioxidant or the effect of a typical hydrophilic antioxidant, ascorbic acid (AsA). HER had a strong antioxidant effect in the hydrophilic radical generation system in the β-carotene decoloring test. However, HER exhibited moderate antioxidant effects in the lipophilic radical generation system. Concerning hair-damage, applying HER suppressed cysteic acid in the hair after chemical and physical treatment more than when no antioxidant is applied. In addition, HER and AsA application also suppressed CL intensity in the damaged hair in the system using 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin-3-one hydrochloride (MCLA). However, HER only exhibited a tendency for CL reduction in damaged hair when we induced CL with short time irradiation of ultraviolet rays (UV) without chemical reagents. Furthermore, HER and AsA suppressed the snapping and splitting frequency in the hair, and the suppression level of HER tended to be stronger than that of AsA. HER demonstrated the antioxidant effect in a hydrophilic radical generation system. Furthermore, HER could prevent oxidation and morphological changes in damaged hair that was subjected to oxidative and/or reductive treatment, such as perming and bleaching, as well as physical treatment, which is postulated to cause hair-damage in daily life.
We estimated levels of hair coloring and the oxidation-reduction potential (ORP) of laccase and dye precursors using cyclic voltammetry in an enzyme reaction system to understand the capability and characteristics of enzyme kinetics of polyphenol oxidase (laccase) in relation to hair dyeing. We also analyzed the correlation between these two parameters. We additionally compared the parameters of enzyme kinetics with combinations of laccase and several different dye precursors. Laccase exhibited superior capability over hydrogen peroxide (H2O2) in both the dye polymerization and hair-coloring tests. However, additional H2O2 was stoichiometrically higher than additional laccase in the enabled number of oxidative reactions. In addition, we evaluated the ORP of laccase and the dye precursors and observed a correlation between the strength of hair dyeing and the differences in the value of ORP in laccase and the dye precursors (ΔE). Furthermore, we measured the parameters of the enzyme kinetics in the reaction of laccase with several different dye precursors. Catalytic constant, kcat, tended to correlate with the strength of hair dyeing and the difference of ORP in laccase and the dye precursors. Laccase demonstrated a superior capability for hair dyeing and the enzymatic reaction generated no H2O2. Additionally, the strength of hair dyeing correlated with ΔE, and tended to correlate with kcat.
Fatty Acid Composition(%w/w)in
Total TAG PL
n-3 30.4±3.6 3.0±1.2 36.7±1.6
n-6 5.0±0.8 6.5±1.0 3.8±0.7
n-3/n-6 6.9±1.6 0.5±0.2 12.8±4.5
3 Result and Discussions section
The n-3/n-6 ratio in the PL fraction is 12.7 which is higher than that in TAG (0.5).
Fatty Acid Composition(%w/w)in
Total TAG PL
n-3 18.2±1.5 2.4±0.2 23.5±1.8
n-6 17.2±1.3 7.1±0.4 16.8±1.3
n-3/n-6 1.1±0.1 0.3±0.1 1.4±0.2
3 Result and Discussions section
The n-3/n-6 ratio in the PL fraction is 1.4 which is higher than that in TAG (0.3).