NANOTRIBOLOGICAL PROPERTIES OF HAIR 49 plied to the hair surface. Figure 6 shows histograms of all adhesive force data for damaged, damaged treated, PDMS-blend silicones (high deposition), and amino sili- cones (high deposition). Damaged treated hair shows a much larger range of adhesive force values and a normal distribution, which suggests that the conditioner layer is nonuniform in distribution and thickness. The histogram for PDMS-blend silicone treatment shows a normal distribution at the larger adhesive force values, but also shows another peak at low adhesion values. Amino silicone treated hair follows a normal distribution, but it is interesting to note the distinct groupings of the adhesion values and the spacing between them. This is further evidence that the amino silicone groups most likely attach immediately to the hair surface and are less mobile than PDMS silicone, causing distinct regions of high and low adhesion values over the cuticle surface. DISCUSSION OF SURFACE ROUGHNESS, COEFFICIENT OF FRICTION, AND ADHESIVE FORCE DATA OF VARIOUS HAIR SAMPLES Figure 7 displays a summary of the data collected for all damaged hair samples and their treatments. Table VII reviews some of the observations and corresponding mechanisms that help to explain the trends found. The application of the commercial conditioner to Q) e J2 0.5 Q) "in Q) 0.4 ..c "C IO c: 0.3 Q) ·a, iii 0.2 C: 0 � 0.1 I.! LL Damaged hair O 0 20 40 60 80 100 120 140 160 180 200 Adhesive force (nN) PDMS blend silicone (high deposition) 0.6 Q) e .$2 0.5 Q) "in Q) 0.4 ..c -0 IO � 0.3 ·a, iii 0.2 C: 0 U 0.1 � LL 0 L...-....IL..---L.'--.c==-L....J.--'--'--.L.1...--L.JL..--_ __,____, 0 20 40 60 80 100 120 140 160 180 200 Adhesive force (nN) 0.6 Q) e J2 0.5 Q) "in a, 0.4 ..c -0 IO c: 0.3 Q) ·a, iii 0.2 C: 0 U 0.1 � LL Damaged treated (commercial) 0 o 20 40 60 80 100 120 140 160 180 200 Adhesive force (nN) 0.6 Q) e J2 0.5 Q) "in Q) 0.4 ..c -0 IO � 0.3 ·a, iii 0.2 C: 0 U 0.1 � LL Amino silicone (high deposition) Adhesive force (nN) Figure 6. Adhesive force histograms for various hair specimens.

50 JOURNAL OF COSMETIC SCIENCE 2.0 ,---__,.. M=ac:..: rO�SC :.:: ale ,:.:: COeffiICi:::. ::.::c,::,:. ::.: en t Of ::.:....:.:..::::.::.::..:...:...._ friCtiOn ----,-----, C: 0 n :S 1.5 - 0 c .!1! � 1.0 Q) 8 � 0.5 X Q) .E Damaged I Damaged I BTIMC I PDM_ blend I Amino silicone I BAPDMA untrealed treated surfactant SIii Cone slX't'actant 1.19 Jcommercial1No S11iconel IOw high I low high I No Siticone 1.24 I deposition deposition I deposition deposition I i.32 0.96 0.81 0,88 0.51 T1 T2 T3 T4 TS T6 T7 0_25 ____ ...;.N ano:..::..: ;,:c sc a;;.:e:....co l effi1ci.;;.;_;,:...o :..:.::..:. ent f f ric"-o:..:.n .;;. ti .:....... __. _ __, § 0.20 � �= I o,:_:�d I ,e:;' r,1 I PD� s i ! o b� : nd I Amino silicone I =-�: �commerc181� No Silicone I � high I low hig�. I No Silicone ::: 0.15 0 c -� 0.10 !E Q) 0 0 0.05 untreated depos1bon depos11:Jon deposibon deposition I I 0.083 0.088 T1 T2 T3 T4 TS T6 T7 120 __ __,..---!..Ad:..:..;.:,::::s:!.:::.:.!.,fro�m�i.::::..:c�e:... .!: he io n o r -V.:.:o l::::.um:.:.:.::e:.=lo�t::::s� ...- BAP - DMA ---. z 100 � 80 � ,E 60 Q) -� a, 40 .c "C ( 20 82 I PDM_S blend I Amino silicone I N��f �� Damaged I D ed I BTIMC s11icone 77 untreated �c:� :iall��f����e l d �°:bon de���on ldep:lion de:��on I I I I I I I s2 I I I 50 I I I PDMS blend I Amino silicone I BAP D MA :a� I o :d I�=� I silicone I l�ourlsac,,c1aon1ne 40 E .S 30 b 1.5 E 2, 1.0 ca. 0.5 commercral) No S11!cone ,� high low high I I l deposilion depos1bon 1 depOS11ion deposition I I I I I Damaged I Damaged I BTMAC I PD� s � o �: nd I Amino silicone I B APDMA urireated lco=��lal)INS:��:!1 low high I IOw tlgh l ���:�8 I I 1.1 l d aposib on depo 1 -� tion ! deposition deposition I I o.753 o.n 0.1◄1 0.ee I 0.78 untreated T 1 T2 T3 T4 TS T6 T7 Figure 7. Coefficient of friction, adhesive force, and surface roughness plots for damaged hair with various treatments.