show two amorphous halos around 2h 9.2 and 20.3,
and a shoulder at about 24 for the second halo, which conforms to the fact that human hair has a overall crystallinity of about 20% [54]. The shape of these curves and the peak positions do not alter much between the samples, implying that the fibrillar
Fig. 4. Variation of (a) o-Ps lifetime s3 (free volume hole size Vf), (b) o-Ps intensity I3, and (c) fractional free volume Fv as a function of UV exposure time for bleached hair sample.
Fig. 5. Effect of humidification on o-Ps lifetime s3 and intensity I3 of ‘bleached + UV exposed’ hair sample. Here, BUV200h represents a bleached (5h) + 200h UV irradiated hair; BUV200hW is a bleached (5h) + 200h UV exposed + humidified hair.