Liquid crystal colloidal structures for increased silicone deposition efficiency on colour‐treated hair

Abstract

An approach is described to increase the deposition efficiency of silicone conditioning actives from a shampoo on colour-treated hair via liquid crystal (LC) colloidal structures, created with a high charge density cationic polymer, poly(diallyldimethyl ammonium chloride) and negatively charged surfactants. LCs are materials existing structurally between the solid crystalline and liquid phases, and several techniques, including polarized light microscopy, small angle X-Ray analysis, and differential scanning calorimetry, were used to confirm the presence of the LC structures in the shampoo formula. Silicone deposition from the LC-containing shampoo and a control shampoo was measured on a range of hair substrates, and data from inductively coupled plasma optical emission spectroscopy analysis and ToF-SIMS imaging illustrate the enhancement in silicone deposition for the LC shampoo on all hair types tested, with the most pronounced enhancement occurring on hair that had undergone oxidative treatments, such as colouring. A model is proposed in which the LC structure deposits from the shampoo onto the hair to: (i) provide 'slip planes' along the hair surface for wet conditioning purposes and (ii) form a hydrophobic layer which changes the surface energy of the fibres. This increase in hydrophobicity of the hair surface thereby increases the deposition efficiency of silicone conditioning ingredients. Zeta potential measurements, dynamic absorbency testing analysis and ToF-SIMS imaging were used to better understand the mechanisms of action. This approach to increasing silicone deposition is an improvement relative to conventional conditioning shampoos, especially for colour-treated hair.

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

“…Silicone deposition on the hair substrates was measured from the LC-containing shampoo in comparison with control shampoo [64]. The results proposed that LC structure deposited on the hair through electrostatic and hydrophobic interactions, which caused increase in hydrophobicity of the hair surface and resultantly increased deposition of silicone.…”

“…There was also a successful approach to increase the silicone deposition on hair from a shampoo containing liquid crystal (LC) colloidal structures that were produced by cationic polymer [poly (diallyldimethylammonium chloride)] and surfactants with negative surface charge. Silicone deposition on the hair substrates was measured from the LC-containing shampoo in comparison with control shampoo [64]. The results proposed that LC structure deposited on the hair through electrostatic and hydrophobic interactions, which caused increase in hydrophobicity of the hair surface and resultantly increased deposition of silicone.…”

Oil drop deposition on solid surfaces in mixed polymer-surfactant solutions in relation to hair- and skin-care applications

“…The resulting electrostatic repulsion suppresses the oil-drop deposition on the substrate [8]. To overcome this undesired effect, the respective personal-care formulations contain also a cationic polymer, which serves as a mediator of the drop-to-substrate adhesion [9][10][11][12][13][14][15]. In the bulk of solution, the surfactant and polymer form joint aggregates, sometimes called "coacervates" [16].…”

A novel preparation method for silicone oil nanoemulsions and its application for coating hair with silicone

“…As yet, there are no other methods to overcome this issue. [1][2][3][4][5][6][7][8][9][10][11] Hair fibers have a structure consisting of several layers. From the outside, they are the cuticle layer, hydrolipid emulsion layer, cortex layer, and medulla layer.…”

“…From the outside, they are the cuticle layer, hydrolipid emulsion layer, cortex layer, and medulla layer. 1,2 The cuticle is composed of several layers of flat and thin cells laid out and overlapping one another like roof shingles. These hair scales are opened by hot water or alkali.…”