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WETTING CHARACTERIZATION OF HAIR FIBERS 41 (10) B. J. Carroll, Droplet formation and contact angles of liquids on mammalian hair fi bres, J. Chem. Soc. Faraday Trans., 85, 3853–3860 (1989). (11) J. A. Swift and J. R. Smith, Microscopical investigations on the epicuticle of mammalian keratin fi bres, J. Microscopy, 204, 203–211 (2001). (12) X. F. Wu, A. Bedarkar, and K. A. Vaynberg, Droplets wetting on fi lament rails: Surface energy and morphology transition, J. Colloid Interface Sci., 341, 326–332 (2010).