FORMULATION COMPOSITION ON CONDITIONING SHAMPOO PERFORMANCE 423 Figure 11. Prediction profi ler for cationic guar polymer deposition (CG0.98). Figure 12. Interaction profi le for cationic guar polymer deposition (CG0.98). CATIONIC POLYMER DEPOSITION Statistical models for cationic polymer deposition were developed for each cationic polymer. Actual versus predicted cationic polymer deposition values are compared in Figure 8. Overall, relatively good models were obtained for all cationic polymers [low P, high R2

JOURNAL OF COSMETIC SCIENCE 424 Figure 13. Prediction profi ler for cationic hydroxyethyl cellulose polymer deposition (PQ-10 1.03). (Rsq) values, and reasonable agreement between actual and predicted values]. The models are illustrated in Figures 9–13. Figure 9 shows the prediction profi ler for cationic cassia polymers deposition (CC3.0, CC2.3, and CC1.9). The results show that the cationic cassia polymer deposition decreases with increasing surfactant amount, increases with increasing micelle charge, and increases up to a maximum level with increasing ionic strength. Interactions between surfactant amount and micelle charge and between surfactant amount and cationic charge density are apparent (Figure 10). The cationic cassia polymer deposition decreases signifi cantly with increasing surfactant amount at low micelle charge and only decreases slightly with increasing surfactant amount at high micelle charge. This interaction is shown in the panel labeled 10.1 in Figure 10. In addition, the cationic cassia polymer deposition decreases with increasing surfactant amount for the low charge density cationic cassia polymer and decreases slightly with increasing surfactant amount for the high charge density cationic cassia polymer, as seen in panel 10.2 in Figure 10. Figure 11 shows the prediction profi ler for cationic guar CG0.98 deposition. The results differ from the trends observed for cationic cassia polymers. For cationic guar CG0.98, polymer deposition decreases with increasing surfactant amount, slightly increases with increasing micelle charge, and decreases with increasing ionic strength. Also, a strong interaction between micelle charge and ionic strength is observed as seen in Figure 12. At high micelle charge, an increase in the ionic strength does not affect the cationic guar deposition. But at low micelle charge, an increase in the ionic strength leads to a signifi cant decrease in cationic guar deposition (see panel 12.1). The prediction profi ler for PQ-10 1.03 polymer deposition is shown in Figure 13. The results are very different from those obtained for cationic cassia and cationic guar polymer deposition. For PQ-10 1.03, polymer deposition only decreases with increasing surfac- tant amount. Neither micelle charge nor ionic strength was observed to have a signifi cant infl uence on PQ-10 1.03 polymer cationic deposition. No interactions between micelle charge, surfactant amount, and ionic strength were statistically signifi cant. The results clearly show that the molecular interaction between cationic polymer and anionic surfactant micelles is crucial for providing effi cient silicone and cationic polymer deposition. In all cases, an increase in the amount of surfactant leads to a decrease in sili- cone or cationic polymer deposition. Higher amounts of surfactant lead to highly struc- tured micelles or micelle with high aspect ratio, such as rodlike or lamellar structure. It is also possible that there is a different interaction (or conformation) between cationic