Wei Guohua, Bhushan Bharat
Nanotribology Laboratory for Information Storage and MEMS/NEMS, The Ohio State University, 650 Ackerman Road, Suite 255, Columbus, 43202, USA.
Ultramicroscopy. 2006 Jun-Jul;106(8-9):742-54. doi: 10.1016/j.ultramic.2005.12.009. Epub 2006 Apr 18.
Human hair ( approximately 50-100 microm in diameter) is a nanocomposite biological fiber with well-characterized microstructures, and is of great interest for both cosmetic science and materials science. Characterization of nanotribological and nanomechanical properties of human hair including the coefficient of friction and scratch resistance is essential to develop better shampoo and conditioner products and advance biological and cosmetic science. In this paper, the coefficient of friction and scratch resistance of Caucasian and Asian hair at virgin, chemo-mechanically damaged, and conditioner-treated conditions are measured using a nanoscratch technique with a Nano Indenter II system. The scratch tests were performed on both the single cuticle cell and multiple cuticle cells of each hair sample, and the scratch wear tracks were studied using scanning electron microscopy (SEM) after the scratch tests. The effect of soaking on the coefficient of friction, scratch resistance, hardness and Young's modulus of hair surface were also studied by performing experiments on hair samples which had been soaked in de-ionized water for 5 min. The nanotribological and nanomechanical properties of human hair as a function of hair structure (hair of different ethnicity), damage, treatment and soaking are discussed.
人类头发（直径约50 - 100微米）是一种具有特征明确微观结构的纳米复合生物纤维，在化妆品科学和材料科学领域都备受关注。表征人类头发的纳米摩擦学和纳米力学性能，包括摩擦系数和抗划伤性，对于开发更好的洗发水和护发素产品以及推动生物和化妆品科学发展至关重要。在本文中，使用配备Nano Indenter II系统的纳米划痕技术，测量了白种人和亚洲人头发在原始状态、化学机械损伤状态以及经护发素处理后的摩擦系数和抗划伤性。对每个头发样本的单个角质层细胞和多个角质层细胞都进行了划痕测试，并在划痕测试后使用扫描电子显微镜（SEM）研究划痕磨损轨迹。通过对在去离子水中浸泡5分钟的头发样本进行实验，还研究了浸泡对头发表面摩擦系数、抗划伤性、硬度和杨氏模量的影响。本文讨论了人类头发的纳米摩擦学和纳米力学性能随头发结构（不同种族的头发）、损伤、处理和浸泡的变化情况。
