Table I Analysis Summary Table Tension (g) Dose (ppm) Average angle (degree) Standard deviation sin θ Adhesive tangential force (μN) cos θ Adhesive normal force (μN) Low-load static coeffi cient of friction Angle 90 (%) Virgin 26 6.4 0.44 2.2 0.89 0.5 0 4X bleached 29 7.1 0.48 2.4 0.87 0.6 0 Relaxed 31 7.0 0.51 2.6 0.85 0.6 0 Virgin 10 29 6.7 0.47 2.4 0.87 0.5 0 Virgin 50 25 5.8 0.42 2.1 0.90 0.5 0 Silicone quat 1000 47 15.0 0.71 3.5 0.66 1.1 0 3000 53 27.2 0.71 3.5 0.55 1.3 12 Amino Abn 1000 49 19.2 0.71 3.6 0.62 1.2 4 3000 71 28.5 0.83 4.2 0.32 2.6 22 Aminosilicone 1000 46 20.4 0.66 3.3 0.67 1.0 4 3000 70 35.7 0.77 3.9 0.32 2.4 28 Silicone gum 3000 117 42.6 0.68 3.4 −0.32 1.6 68 2008 TRI/PRINCETON CONFERENCE 267

JOURNAL OF COSMETIC SCIENCE 268 solvent affects the fi nal spatial distribution of silicones on the hair sample and does not lead to a totally random distribution. The strength of hair fi ber–fi ber interactions was the lowest for silicone quat (lowest slid- ing angle), and it was the highest for silicone gum (highest angle) (Figure 7). The silicone quat, the amino ABn and the aminosilicone treatment showed a rather low percentage of angles higher than 90° (column 11, Table I). These treatments were characterized by an increased adhesive tangential force from 2.6 μN (untreated) to 3.5–4.2 μN (column 7, Table I). In contrast, the silicone gum treatment wais characterized by a very high per- centage of angles higher than 90° and a strong normal adhesion 1.6 μN (column 9, Table I). Figure 5. Sliding angle histograms of untreated hair and silicone-treated hair (N = 50, X-axis: angle in degrees). Treated hair has 1000 ppm of silicone quat. [Note: Test data. Actual results may vary.] Figure 6. Sliding angle histograms of hair treated with different silicones at constant silicone dose of 3000 ppm (N = 50, X-axis: angle in degrees). Black line is the normal distribution fi t. [Note: Test data. Actual results may vary.]