Effect of cationic charge and hydrophobic index of cellulose‐based polymers on the semipermanent dyestuff process for hair

In this work, the effects of a new class of polymers generally used in hair and skin cleansing products, the SoftCAT (SofCAT SL and SoftCAT SX), on the dye uptake on the hair fibre and the fading effects has been studied. These polymers, based on quaternary ammonium salts of hydroxyethylcellulose, are cationic products that differ in viscosity, hydrophobic substitution index (HS) and/or cationic substitution (CS, % N). UV–Vis spectroscopy has been used to analyse the extracted dyes from the hair cuticle and the cortex. The results indicate that the presence of polymers in the dye bath improve both the quality of the dyeing process and the anti‐fading effect during the washing cycles. This phenomenon is postulated to be attributable to the polymers hydrophobically bonding with the dyes and so facilitating their increased penetration into the hair.     

Solution behaviour of new cationic surfactants derived from Guerbet alcohols and their use in hair conditioners

The solution behaviour of new cationic surfactants, synthesized by using long-chain Guerbet alcohols, in water was investigated by a polarizing microscopic technique, differential scanning calorimetry, and electric conductivity measurements. These surfactants show the gel–liquid crystalline phase transition to be lower than 0°C and form lamellar liquid crystals even in cold water and at low concentrations of surfactants. The sorption of cationic surfactants from aqueous solutions onto hair was determined as a function of temperature. The effect of adsorbed cationic surfactants on the critical surface tension and kinetic frictional coefficients of hair surface have been investigated. These surface characteristics of hair treated with quaternary ammonium compounds derived from Guerbet alcohols were found to be significantly improved. These results can be explained by the high ability of sorption onto hair. Hair rinses and conditioners having excellent ease of combing or brushing for wet and dry hair can be formulated by the application of these cationic surfactants.     

Silicone oil emulsions: strategies to improve their stability and applications in hair care products

Silicone oils have wide range of applications in personal care products due to their unique properties of high lubricity, non‐toxicity, excessive spreading and film formation. They are usually employed in the form of emulsions due to their inert nature. Until now, different conventional emulsification techniques have been developed and applied to prepare silicone oil emulsions. The size and uniformity of emulsions showed important influence on stability of droplets, which further affect the application performance. Therefore, various strategies were developed to improve the stability as well as application performance of silicone oil emulsions. In this review, we highlight different factors influencing the stability of silicone oil emulsions and explain various strategies to overcome the stability problems. In addition, the silicone deposition on the surface of hair substrates and different approaches to increase their deposition are also discussed in detail.     

Acetylene-derived polymers and their applications in hair and skin care

Since the introduction over 30 years ago of polyvinylpyrrolidone (PVP) as the first synthetic hairspray resin, acetylene-derived polymers have found wide and increasing applications in the cosmetics and toiletries industry. This review covers the two main classes of acetylenic polymers. In the first class, in which the chemistry may be traced back to reaction of acetylene with formaldehyde, are included PVP homopolymers and copolymers of VP with vinyl acetate, dimethylaminoethyl methacrylate, vinylcaprolactam and styrene. In the second class, stemming from reaction of acetylene with methanol, are the poly (vinyl methyl ether/maleic acid) monoester resins.     

Study of the optical properties of human hair

The optical properties of human hair were studied by photogoniometry. Starting from an optical model of hair, we developed a computerized method of decomposition of the goniophotometric curve. From our analysis we obtained structural parameters of the hair surface, average scale angle and cosmetic parameters like lustre and pigmentation. This method gave us new results in the following areas:
— the effects of bleaching on scale and internally reflected light;
— the study, from root to tip, of surface damage and hair pigmentation;
— the effects of stretching the hair on scale angle and lustre;
— the effects of sebum and dust on hair lustre.     

Grey hair: clinical investigation into changes in hair fibres with loss of pigmentation in a photoprotected population

Loss of pigmentation in hair fibres is one of the most obvious phenotypic changes with ageing and has been a topic of increasing interest in the study of follicle biology. The onset of greying brings cosmetic complaints that grey fibres are wild or difficult to manage. Of course, these perceptions may be the consequence of visual obviousness rather than underlying physical or chemical differences. Although several studies have compared pigmented and unpigmented fibres, few have tried to control genetic and ethnic difference as well as extrinsic factors such as photoexposure and chemical treatment. We have recruited subjects with salt-and-pepper hair from a population of Old Order Mennonites who, for cultural reasons, are not only prohibited from chemically treating their hair but also limit their exposure to sunlight. Hair samples were examined for elemental composition, surface energy, Young's modulus, break stress, bending modulus, shear modulus and water sorption/desorption isotherm. The parameters were evaluated statistically for global differences, individual differences and typical individual differences. Consistent with previous published literature, few global differences were found between pigmented and unpigmented hair across the population. We do find that many individual subjects had differences between pigmented and unpigmented fibres. These differences tend to be more pronounced in bulk than in surface properties. The small differences in mechanical properties and moisture uptake and loss lend support to the perception by consumers that grey hair is wilder, drier and less manageable.     

Silicones: use of substantive properties on skin and hair

Silicones have been incorporated in personal care products since the 1950s. Initially used in skin care products, and more recently in hair care applications, silicones are recognized for their lubricating properties and for the characteristic soft smooth feel they impart. With recent advances in silicone technology, these fluids can also provide substantivity and durability.
Resinous silicones such as trimethylsiloxysilicate act as effective substantivity additives when combined with dimethyl silicone in skin care formulations. In tests evaluating the number of wash cycles required to penetrate a silicone barrier, resistance to removal increases markedly as the proportion of resinous silicone to dimethyl silicone is increased. This improvement is related directly to decreased solubility of the resin.     

Application of a tensile-strength test method to the evaluation of hydrating hair products

The usual methods applied to studying the hydration state of hair (e.g. gravimetry, microscopy, evaporimetry) are mostly concerned with a limited area of the fibre. Consequently, the results obtained do not reflect the variability of the physicochemical properties of the whole fibre. Moreover, there are not many experimental methods to evaluate the hydrating power of hair care products in the literature. This study proposes a new method to measure the hydration state of treated or untreated hair by using a tensile strength test. A graphic analysis of tensile strength variation as a function of relative humidity after hair treatment allows the calculation of three hydration indexes: protection index, instant hydration index and permanent hydration index. This technique can give useful information on the behaviour of hair versus relative humidity and on the different hydrating mechanisms exhibited by hair care products.     

含聚氧乙烯链季铵盐阳离子表面活性剂对阴离子染料染色的影响

选择了几种聚氧乙烯型季铵盐阳离子表面活性剂，探讨了这些表面活性剂与酸性染料的相互作用以及对染料染色性能的影响.结果表明，含聚氧乙烯链阳离子表面活性剂能降低酸性染料的初始上染速率，并具有较好的移染性，可开发为匀染剂.为新型表面活性剂的应用和新型染色助剂的开发提供了理论依据。     

Diffusion and distribution of element-labelled surfactants in human hair

To directly follow the diffusion process of cosmetically relevant agents into human hair, a specific methodological approach is presented and elucidated for selected surfactants. For this, practically relevant anionic and cationic surfactants were synthesized with a chlorine atom at the end of their alkyl chain. The property changes of the surfactants through the modification are corresponding to an extension of the alkyl chain by about two methylene groups, thus representing a moderate increase of hydrophobicity. After the application of a modified surfactant to hair, it can be localized and quantified through its chlorine atom in cross-sections by scanning electron microscopy combined with micro X-ray fluorescence analysis. The determination of the diffusion coefficient D is realized through the application of the Matano-equation to element intensity profiles. Values for D vary within the chosen range of pH and temperature between 10(-14) and 10(-16) m(2) s(-1). The diffusion coefficients for the anionic surfactants increase with decreasing pH and increasing temperature, The temperature dependence follows in all cases the Arrhenius relationship with activation energies E(A) of 50-100 kJ mol(-1), which decrease with pH. The pH-related effects, with comparable values for D and E(A), are opposite for the cationic surfactant. These observations are consistently interpreted on the basis of ionic and hydrophobic interactions in hair.     

Rheological characterization of hair shampoo in the presence of dead sea salt

In Jordan, a growing industry has been established to produce different types of Dead Sea (DS) cosmetics that have DS salt (contains mainly NaCl, KCl, and MgCl(2)) in their formulas. In this work, the effect of DS salt on the rheology of hair shampoo containing the sodium lauryl ether sulfate as a main active matter was studied. The effects of DS salt and active matter concentration, and the temperature and time of salt mixing, on the rheological properties of hair shampoo were investigated. The salt-free shampoo showed a Newtonian behavior at 'low active matter' (LAM) and shear thinning at 'high active matter' (HAM). The presence of DS salt changed the rheological behavior of LAM shampoo from Newtonian (for the salt-free shampoo) to shear thinning. On the other hand, the behavior of HAM shampoo switched from shear thinning to Newtonian behavior in the presence of high concentration of DS salt. The addition of DS salt increased the apparent viscosity of shampoo to reach a maximum value that corresponded to a salt concentration of 1.5 wt.%. Further addition of DS salt led to a decrease in the shampoo viscosity to reach a value less than that of the salt-free sample at high salt concentration. Changing the mixing temperature (25-45 degrees C) and mixing time (15-120 min) of DS salt with shampoo has no significant influence on the rheological behavior. However, the mixing process increased the apparent viscosity of salt-free shampoo. The power law model fitted well the flow curves of hair shampoo with and without DS salt.     

黄原胶对木薯阴阳离子淀粉糊性质的影响

本文采用Brabender黏度计和哈克流变仪研究了黄原胶对木薯阴、阳离子淀粉糊黏度、冻融稳定性及流变学性质的影响。结果表明:黄原胶使木薯阴、阳离子淀粉糊的峰值黏度和崩解值均显著增加,但其起始糊化温度有所降低;添加黄原胶后,阳离子淀粉的析水率有了一定程度的提高,冻融稳定性减弱,而阴离子淀粉的析水率下降;黄原胶的加入使两种变性淀粉凝胶的tanα值降低,储能模量(G’)增大,这使得木薯阴阳离子淀粉凝胶向趋于固性的方向发展。