Marico R&D Center, Andheri (E), Mumbai, India.
Department of Applied Mechanics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
Int J Cosmet Sci. 2022 Jun;44(3):289-298. doi: 10.1111/ics.12774. Epub 2022 May 13.
The present study is intended to characterize the surfactant damage suffered by the hair cortex in routine washing and the mechanistic effect of Coconut Based Hair Oils (CBHO) to mitigate the damage.
Surfactants which diffuse into the hair structure solubilize protein moieties, leading to an increase in porosity and internal surface area as well as the pore volume. The changes in hair pores occurring in the hair cortex are measured by nitrogen sorption method in line with the Brunauer-Emmett-Teller (BET) theory. Single fiber tensile parameters were measured using Diastron MTT 175. Color protection was measured quantitatively using spectrophotometer as well as visual rating by trained panelists.
The pore surface area data clearly show the benefit of introducing coconut-based hair oils (CBHO) into the hair by preventing increase in hair porosity. A statistically significant decrease in break stress and toughness were observed and the same were reversed by the application of CBHO. A pronounced color protection effect was also recorded with the application of CBHO.
The porosity reduction effect seen with the use of CBHO is attributed to the CBHO molecules blocking the diffusion pathways in the endocuticle and the matrix part of the cortical cells, limiting protein surfactant interaction resulting in reduced solubilization and loss. Since, the color molecules are likely to be much smaller than the protein moieties, a pronounced color protection effect suggests that the penetrated CBHO molecules form a dense diffusion barrier in the matrix, cell membrane complex (CMC) and the endocuticle regions of hair - which are the main diffusion pathways out of hair. The study confirms the damage repair potential of CBHO and that it works by increasing the hydrophobicity of hair - both on the hair surface and in the cortex.
本研究旨在描述常规洗发过程中头发皮质层所遭受的表面活性剂损伤，以及椰基发油（CBHO）减轻这种损伤的机械作用。
表面活性剂扩散到头发结构中，溶解蛋白质部分，导致孔隙率和内表面积以及孔体积增加。通过氮气吸附法，根据 Brunauer-Emmett-Teller（BET）理论，测量头发皮质层中头发孔隙的变化。使用 Diastron MTT 175 测量单纤维拉伸参数。使用分光光度计和经过培训的评估小组进行视觉评估，对颜色保护进行定量测量。
孔表面积数据清楚地表明，通过将椰基发油（CBHO）引入头发中，可以防止头发孔隙率增加，从而带来益处。观察到断裂应力和韧性的统计学显著下降，而通过应用 CBHO 可以逆转这种情况。应用 CBHO 还记录到明显的颜色保护效果。
使用 CBHO 看到的孔隙率降低效果归因于 CBHO 分子阻止了内角质层和皮质细胞基质部分的扩散途径，限制了蛋白质表面活性剂的相互作用，从而减少了溶解和损失。由于颜色分子可能比蛋白质部分小得多，因此明显的颜色保护效果表明，穿透的 CBHO 分子在基质、细胞膜复合物（CMC）和头发的内角质层区域形成致密的扩散屏障 - 这些是头发中主要的扩散途径。该研究证实了 CBHO 的损伤修复潜力，并且它通过增加头发的疏水性来发挥作用 - 无论是在头发表面还是在皮质层。
