Langmuir-Blodgett (L-B) films prepared from 18,18,18-trifluorooctadecanoic acid [CF3(CH2)(16)-COOH], perfluorotetradecanoic acid [n-C13F27COOH], or octadecanoic acid [n-C17H35COOH] were used as target surfaces for hyperthermal ion-surface collisions. The synthesis of 18,18,18-trifluorooctadecanoic acid and the preparation of the L-B film from this compound using a subphase containing Al3+ are reported in this paper. The Ion-surface collision results show that the outermost surface group, namely CF3 vs CH3, is the main determinant for the efficiency of both energy transfer and electron transfer during low-energy(e.g., 10-100 eV) polyatomic ion-surface collisions. For atomic projectile ions, there is evidence of penetration into a depth of the films.