Structural analysis of human hair single fibres by scanning microbeam SAXS.
The origin of the curliness of human hair was revealed by scanning microbeam small angle X-ray scattering (SAXS), based on the nanostructure of keratin fibre arrangement. Scanning microbeam SAXS patterns of single hair fibres have been measured across the fibres and the differences in the patterns between the inner and the outer sides of the curvature were successfully detected. The analysis of the equatorial and azimuthal scattering intensity profiles showed that the arrangement of the intermediate filaments was different between the inner and the outer sides of the curvature. From the analogy with Merino and Romny wool, it is suggested that different types of cortices exist in human hair. It is concluded that, regardless of the ethnic origins (African, Caucasian, and Asian), the macroscopic curl shape of the hair fibre originate from the inhomogeneity of the internal nanostructure, arising from inhomogeneous distribution of two types of cortices.
Kajiura
Yoshio
Y
Hair Care Research Laboratories, Kao Corporation, 2-1-3, Bunka, Sumida-ku, Tokyo 131-8501, Japan. kajiura.yoshio@kao.co.jp
Watanabe
Shunichi
S
Itou
Takashi
T
Nakamura
Koichi
K
Iida
Atsuo
A
Inoue
Katsuaki
K
Yagi
Naoto
N
Shinohara
Yuya
Y
Amemiya
Yoshiyuki
Y
D001741:Black or African American; D044466:Asian People; D005006:Ethnicity; D006197:Hair / Q000737:chemistry*; D018859:Hair Follicle / Q000737:chemistry*; D006801:Humans; D044468:Native Hawaiian or Pacific Islander; D012372:ROC Curve; D044465:White People; D014961:X-Ray Diffraction / Q000379:methods*