TRIBOELECTRIC CHARGING OF HAIR 211 Probably the most important general conclusion which can be drawn from the presented data is that the combination of two factors, an increase in surface conductivity and a decrease in the electrochemical surface potential gap between the rubbing material and keratin, can provide an antistatic effect. Since the electrochemical surface potential of the fiber strongly depends on the type of modification it was subjected to, there is no single comb material which would at the same time match the electrochemical surface potential of untreated hair and that of hair modified with cationic surfactants, cationic polymers, fluorosurfactants, and silicon polymers or surfactants. It should also be stressed that the process of triboelectric charging of hair tresses during combing is much more complex as compared to the simple rubbing described in this paper. In the present experiments, the fibers were subjected to similar elongation and stress in all charge generation experiments, since the distance between the rubbing probe and the plane formed by the fibers arranged in a tress was constant. During combing, such parameters as fiber elongation, stress, and magnitude of fric- tional forces between the comb and fiber undergo variations during the movement of a comb from the upper point of a tress towards the fiber tips. Consequently, non- uniform distribution of triboelectric charge density along the length of the fiber tress is usually observed (21). This might also affect the correlation between surface modi- fication and triboelectric charging and lead to quantitatively different results than those presented in this paper. REFERENCES (1) G. XYd. Castellan, Physical Chemistry (Addison-Wesley Publishing Co., Reading, Mass, 1971), p 384. (2) D. A. Seanor, Triboelectrification of polymers--a chemist's viewpoint, Phydcochem. Aspects Polym. Surf., Proc. Int. Syrup., 1, 477 (1983). According to this reference, the electrochemical potential of electrons is strictly equal ro qb + qV s. This is, however, nor compatible with the further statement that "electrons flow from the metal of lower work function (higher chemical potential) to the metal of higher work function . . ." (p 480) if qb assumes positive values. (3) D. K. Davies, The examination of the electrical properties of insulators by surface charge measure- ment,.]. Sci. Iratram., 44(7), 521 (1967). (4) D. K. Davies, Charge generation on dielectric surfaces, Brit..]. Appl. Phys. (.]. Phys. D.), 2, 1533 (1969). (5) T. J. Lewis, "The Movement of Electrical Charge Along Polymer Surfaces," in Polymer Surfaces, D. T. Clark and XYd. J. Feast, Eds. (John Wiley and Sons, Chichister, 1978). (6) T. J. Fabish, H. M. Saltsburg, and M. L. Hair, Charge transfer in metal/atactic polystyrene contacts, .]. Appl. Phys., 47, 930 (1976). (7) T. J. Fabish, H. M. Saltsburg, and M. L. Hair, The distribution of localized electronic states in atactic polystyrene,.]. Appl. Phys., 47, 940 (1976). (8) XYd. D. Greason and I. I. Inculet, Insulator work function determination from contact charging with metals, Conference Records--IAS Annual Meeting, Vol. 10, 18-B (1975). (9) C. B. Duke and T. J. Fabish, Contact electrification of polymer: A quantitative model, .]. Appl. Phys., 49(1), 315 (1978). (10) Y. Murara, Photoelectric emission and contact charging of some synthetic high polymers, .]pn..]. Appl. Phys., 18(1), 1 (1979) Y. Murata, T. Hodoshim, and S. Kittaka, Evidence for electron transfer as the mechanism of contact charging of polyethylene with metals, .]pn..]. Appl. Phys., 18, 2215 (1979) Y. Murata, and S. Kittaka, Evidence of electron transfer as the mechanism of static charge generation by contact of polymers with merals,.]pn..]. Appl. Phys., 18(2), 421 (1979) S. Kittaka, and Y. Murata, Contact charging and photoemission of anthracene single crystal, .]pn. .]. Appl. Phys., 18(2), 295 (1979). (11) G. A. Cottrell, J. Lowell, and A. C. Rose-Innes, Charge transfer in metal-polymer contacts and the validity of'contact charge spectroscopy,'.]. Appl. Phys., 50(1), 374 (1979).

212 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (12) H. W. Gibson, J. M. Pochan, and F. C. Bailey, "Surface analyses by a triboelectric charging tech- nique, A,al. Chem., 51(4), 483 (1979). (13) H. W. Gibson, Control of electrical properties of polymers by chemical modification, Polymer, 25, 3 (1984). (14) H. W. Gibson, Linear free energy relationships. V. Triboelectric charging of organic solids, J. Am. Chem. Soc., 97, 3832 (1975). (15) H. W. Gibson, "Dye Sulfonated Polystyrene Films: Relationship of Triboelectric Charging and Molecular Orbital Energy Levels," in ModijS'cation of Polymers, Ch. E. Carraher, Jr., and J. A. Moore, Eds. (Plenum Publ. Co., 1983), p 353. (16) J. Lowell, The relationship between contact charging and the concentration of donor impurities in polymers, J. Phys. D..' Appl. Phys., 12, 2217 (1979). (17) C. Barnes, P. J. Bower, and T. J. Lewis, Electrical charge transfer at metalbiopolymer interfaces, Annual Report, Conference on Electrical Insulation and Dielectric Phenomena (IEEE Electrical Insulation Soc., 1982), p 87. (18) J. P. Crine, Open-circuit voltages and their influences on the dielectric properties of metal-dielectric- metal systems, Annual Report, Conference on Electrical Insulation and Dielectric Phenomena (IEEE Electrical Insulation Soc., 1984), p 474. (19) J. Jachowicz, G. Wis-Surel, and L. J. Wolfram, Directional triboelectric effect in keratin fibers, Text. Res. J., 54(7), 492 (1984). (20) A. J.P. Martin, Triboelectricity in wool and hair, Proc. Phys. Soc., London, 53(2), 186 (1940). (21) A. C. Lunn and R. E. Evans, The electrostatic properties of human hair, J. Soc. Cosmet. Chem., 28, 549 (1977). (22) P. Dubin and I. Levy, GPC of cationic polymers on PW gel columns, J. Chromatogr., 235, 377 (1982). (23) D. A. Seanor, Techniques for the prevention and elimination of static from polymer coatings, Polymer- Plast, Technol. Eng., 3(1), 69 (1974). (24) C. B. Duke, T. J. Fabish, and A. Paton, Influence of polarization fluctuations on the electronic structure of molecular solids, Chem. Phys. Lett., 49(1), 133 (1977). (25) G. Bush and H. Schade, Lectures on Solid State Physics (Pergamon Press, New York, 1976), p 489. (26) C. B. Duke and T. J. Fabish, Charge-induced relaxation in polymers, Phys. Rev. Lett., 37(16), 1075 (1976). (27) G. Bush and H. Schade, Lectures on Solid State Physics (Pergamon Press, New York, 1976), p 489. (28) The Handbook of Chemistry and Physics, 57th Edition, CRC Press, 1976-77. (29) P. K. Watson, "The Transport of Electrons From the Surface Into the Bulk of Polystyrene," in Polymer Surfaces, D. T. Clark and W. J. Feast, Eds. (John Wiley and Sons, Chichister, 1978), p 91. (30) P. Finkelstein and K. Laden, The mechanism of conditioning of hair with alkyl quaternary ammonium compounds, Appl. Polym. Syrup., 18, 673 (1971). (31) A. G. deBoos and E. D. Finnimore, The determination of ionic surfactants on wool, Tenside Detergents, 19, 262 (1982). (32) C. V. Patel, Antistatic properties of some cationic polymers used in hair care products, Int. J. Cosmet. Sci., 5(5), 181 (1983). (33) J. Jachowicz, G. Wis-Surel, and M. Garcia, Relationship between triboelectric charging and surface modification of human hair. Polymeric versus monomeric long alkyl chain quaternary ammonium salts, in preparation. (34) J. Jachowicz, M. Berthiaume, and M. Garcia, The effect of the amphiprotic nature of human hair keratin on the adsorption of high charge density cationic polyelectrolytes, submitted to Coll. Polym. Sci.