366 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS

EVALUATION OF HAIR DAMAGE 367 tioning may modify the fiber surface due to deposition of surfactants and particularly of conditioners. The effect of grooming on work of adhesion was established only on the sample bleached four hours in 6% H202. We chose this sample because we expected the most damaged hair to be most susceptible to secondary damage from subsequent grooming treatments. Typical traces of work of adhesion along the distance scanned are shown in Figure 13. Besides differences in wettability, the traces show qualitative differences that are nota- ble. The regularity and amplitude of "chatter" differ among the treatments, and these patterns were consistent among the samples of a given treatment. The traces for the combed only and the shampooed and combed samples are more irregular than for the ungroomed samples, which may indicate subtle physical surface changes. The chatter for samples that were shampooed, conditioned, and combed is extremely regular compared 150 t25 100 15C C12• z - 10C (b) Combed (4B1) 50 o (a) New sample (4B0) 20. I meniscus traverse, cm 0•.1 0•.2 0.,3 meniscus traverse, cm t75 , , (C) Shampooed (4B2) 150 2cr• 125 75 50 0.1 0.2 meR[scus •rQverse, cm 175 / ' (d) Shampooed/combed (4B3) 150 f _•125 .....................................................I20'125261 100t- 75 o' I 50 / (e) Shampooed/conditioned/combed (4B4) 175 150 100 75 50 0.1 0.2 0..3 0 0.1 0.2 meniscus traverse, cm meniscus traverse, cm Figure 13. Water wettability of bleached hair before and after grooming sequences.