353 Silicone Reduce Combing Force, Flyaway, Damage in Shampoo stage, S2 (0.21% amodimethicone) and S3 (0.42% amodimethicone) showed significant lower combing force both at first half and second half of the rinsing stage compared to S1. In addition, at the second-half rinsing stage, much lower combing force was observed for both S2 and S3. This indicated that the amodimethicone deposited onto hair provided a lubrication benefit to the hair surface, which is consistent with the literature data (11). Furthermore, S3 showed even lower combing force than S2 at both the first and second half of the rinsing stage this indicated that much more amodimethicone was deposited on the hair and provided even more lubrication benefit to the hair surface. This was demonstrated by our deposition data. For S4, shampoo with 0.18% silicone quaternium-18, we didn’t observe a significant difference for combing force at either the first or second rinsing stage compared to S1. As silicone quaternium-18 is also a cationic polymer, we suppose that it could form coacervates with surfactant too the silicone deposition should be even larger than with amodimethicone, which was demonstrated in our deposition data. We hypothesized the hydrophilic moiety of polyether in the silicone backbone may affect the lubrication benefit to hair during the rinsing stage. This needs to be further confirmed. At after the rinse stage (wet stage), S3 showed significant lower combing force (about 42% reduction) than S1, but no significant difference was found among S1, S2, and S4. Data for S4 were similar to the combing-force data during the first and second rinse stages we are not sure why S2 didn’t show combing force improvement. At the dried stage, S2, S3, and S4 showed significant lower combing force (about 20% reduction) than S1, but no significant difference among S2, S3, and S4. It is widely known that anionic surfactant and cationic polymer forms a polymer-surfactant complex called coacervate while diluted on the hair during shampoo application, the coacervate will precipitate and form a lubricating film on the hair surface, thus improving the combing during rinsing (14). In addition, this coacervate can also help silicone ingredients deposit on the hair surface, and the small silicone particles can be more easily entrapped in coacervate and deposit more easily onto the damaged hair (15), thus providing more smoothness (less combing force) during rinsing (11). Furthermore, amodimethicone 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Lathering First half of the rinsing stage Second half of the rinsing stage After Rinse Dried S1 S2 S3 S4 *p 0.05 n=3 ************Figure 5. Hair dynamic combing test results on Asian damaged hair swatches. Means +/− SD. S1: base shampoo without silicone S2: shampoo with 0.21% amodimethicone S3: shampoo with 0.42% amodimethicone S4: shampoo with 0.18% silicone quaternium-18. Required Combing Force Blank =1.00 Good-----combing-----Bad

354 JOURNAL OF COSMETIC SCIENCE contains the hydrophilic moiety NH 2 ,and it shows some cationic properties, which aids deposition to the damaged part of the hair surface, as the damaged part of hair normally is negatively charged and shows relatively hydrophilic properties. Therefore, the combing force reduction during rinsing for S2 and S3 was a synergy of polymer-surfactant complex and amodimethicone deposited on the hair surface. Silicone quaternium-18 is a silicone quat it is cationic and may form coacervate with surfactants during rinsing, resulting in increased deposition on damaged hair. We observed that S4 showed significantly lower combing force than S1 at the dry stage, which indicated that it may be difficult to observe the combing benefit for silicone quaternium-18 at the rinsing and wet stages it did deposit on hair and reduce dry combing force. The hydrophilic moiety of polyether in the silicone quaternium-18 molecular backbone may affect the lubrication effect of silicone quaternium-18 at the rinsing and wet stages. Because of the microemulsion state of amodimethicone and silicone quaternium-18, the particle size of emulsion is very small. We expected their distribution on the hair surface can be very uniform after surfactants are clearly rinsed off. This uniform silicone deposition on the hair surface improved the wet (amodimethicone) and dry (both amodimethicone and silicone quaternium-18) combing even at lower concentrations. The wet and dry combing force reduction were due to the synergy deposition of both cationic polymer and silicones. Due to the low surface tension of silicones and small particle size in the microemulsion state, the uniform deposition of amodimethicone and silicone polyquaternium-18 may contribute more combing force reduction than cationic polymer, especially at the wet stage. This is consistent with the dimethicone results in reference (11). Figure 6 shows the results of flyaway area average change (left) and total volume area average change (right) for damaged hair after each shampoo. Our hypothesis was that the deposition of amodimethicone and silicone quaternium-18 could help control flyaway of damaged hair. The hair swatches washed with the base shampoo (S1) showed a flyaway area increase after shampoo, while hair swatches washed by S2 shampoo (0.21% amodimethicone), S3 shampoo (0.42% amodimethicone), and S4 shampoo (0.18% silicone quaternium-18) showed a significant decrease of flyaway area. There was no difference observed among hair swatches washed by S2, S3, and S4, indicating that a small quantity of amodimethicone and silicone quaternium-18 added in shampoo can decrease the flyaway. For total volume average change, the hair swatches washed by base shampoo (S1) showed a total volume area increase -70.00 -60.00 -50.00 -40.00 -30.00 -20.00 -10.00 0.00 10.00 20.00 S1 S2 S3 S4 -40.00 -30.00 -20.00 -10.00 0.00 10.00 20.00 S1 S2 S3 S4 Figure 6. Volume area average change after each shampoo. Left, flyaway area average change right, total volume area average change. Means +/− SD. S1: base shampoo without silicone S2: shampoo with 0.21% amodimethicone S3: shampoo with 0.42% amodimethicone S4: shampoo with 0.18% silicone quaternium-18. Average Change in Flyaway Area Average Change inTotal Volume Area %