Open AccessSecondary structure estimation and properties analysis of stretched Asian and Caucasian hair
Author(s) -
Zhou A. J.,
Liu H. L.,
Du Z. Q.
Publication year - 2015
Publication title -
skin research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.521
H-Index - 69
eISSN - 1600-0846
pISSN - 0909-752X
DOI - 10.1111/srt.12169
Subject(s) - protein secondary structure , raman spectroscopy , materials science , fourier transform infrared spectroscopy , hair shaft , chemistry , analytical chemistry (journal) , crystallography , composite material , optics , chromatography , biology , biochemistry , physics , hair follicle , microbiology and biotechnology
Background In this previous work, we investigated the secondary structure changes of stretched yak hairs by deconvolution, secondary derivation, and curve fitting and determined the number of bands and their positions in order to resolve the protein spectrum of Raman spectroscopy. Objectives The secondary structure estimation and properties analysis of stretched Asian and Caucasian hair were investigated by Fourier transform infrared spectroscopy, tensile curves, and measurement of density. Methods The hairs were stretched, dried, and baked at ratios 20%, 40%, 60%, 80% and 100%. Results The analysis of the amide I band indicated that the transformation from α‐helix to β‐pleated structure occured during the stretching process, which could be verified from the tensile analysis. The cysteine oxide in S–O vibration area exhibited that stretching led to the breakage of the disulfide bonds. When the stretching ratio of Caucasian hair was more than a certain ratio, the fiber macromolecular structure was destroyed because Caucasian hair had finer diameter and less medulla than Asian hair. The β turn was easier to retract compared with other conformations, resulted in the content increase. The density measurements revealed that the structure of Caucasian hair was indeed more destroyed than that of Asian hair. The cuticles characterization indicated the length of scales was stretched longer and the thickness became thinner. Caucasian hair tended to collapse to form small fragments at the early stage of stretching. With the increase in stretching ratio, the scales of Caucasian hair lifted up, then flaked off and the scale interval increased accordingly. Asian hair was more easily peeled off than Caucasian hair cuticles with the increase in stretching ratio. Conclusions The secondary structure of Caucasian hair was destroyed more easily than that of Asian hair.