Fig. 1

（a） Decomposition process of a hair sample with temperature; （b） determination of strongly-bound and loosely-bound water content of the hair sample by a two-stage heat treatment"

Fig. 2

（a） DSC curves of hair stored at 50% RH at 20 ℃ （1） and of hair annealed （dried） in helium at 70 ℃ for 30 min （2）; （b） The area of the water release peak plotted vs. water content in hair after storage at different humidities and in water for 48 h; （c） DSC curves for the bleached hairs treated with leave-on conditioning products （curves 2, 3） and for the bleached hairs without treatment （curve 1）; （d） Details of the water release peaks in the DSC curves for treated and untreated hairs, and the corresponding ΔH values for water vaporization were collected for each peak"

Fig. 3

Water absorption isotherms （a） and moisture uptake as a function of time （b） for untreated （UT）, bleached （B） and permed （P） hair samples"

Fig. 4

（a） Instrument of evaporimetric measurement for hair water loss; （b） evaporimetric measurement of water loss vs. time for untreated hair sample and the hair treated with a rinse-off conditioner; （c） Water loss data of four different volunteers: W （female）, P （male）, M （child）, B （male）; inset: measurement instrument"

Fig. 5

（a） Typical tensile profile of a single hair fiber; （b） typical stress-strain curves at different relative humidities"

Fig. 6

（a） Effects of humidity on swelling of hair and on hydrogen bonds in hair; （b） Frizz image assessment at low （left） and high （right） relative humidities"

Fig. 7

Water content in human hair before and after （1-30 min） treatment with water or a 7% sorbitol solution: （a） Average brightness of near-infrared images （n=9, mean±SD） and （b） average resistance measured by an insulation resistance meter （n=5, mean±SD）"

Fig. 8

（a） Water absorption isotherms for virgin （UT） and bleached （B） hairs, and （b） for bleached hairs treated with keratin and hydrolyzed keratin"

Fig. 9

Cross sections of hair treated with fluorescent-labeled low-MW HA （a）; and effects of treatment with HA of different MW on tensile strength （b） and Young’s modulus （c） of bleached hair; TGA （d） and DSC （e） curves of untreated and treated bleached hairs with low-MW HA; （f） anti-frizz effects of low-MW HA"