JOURNAL OF COSMETIC SCIENCE 154 Beyond a styling spray, the acrylates/hydroxyesters acrylates copolymers can be incorpo- rated into a hair gel. The acrylates/hydroxyesters acrylates copolymers are also non-fl aking as can be observed after combing through a bundle of Brazilian hair, where we compared the acrylates hair fi xative to a polyvinylpyrrolidone-based hair fi xative. The PVP based product has signifi cant fl aking on the hair and residue on the comb. By having a contin- uous ‘non-fl aking’ fi lm on the hair, there is a smoother, shinier surface. The PVP fi lm tends to crack and fl ake, giving a discontinuous fi lm that appears matte or dull (see Figures 4a and 4b). The rheology modifi er, acrylates/steareth-20 methacrylate crosspolymer, is used to thicken the hair gel. These are multifunctional by providing thickening and viscosity control and inherent fi lm formation. The rheology modifi ers have the ability to provide hold and style control as well as humidity resistance in clear hair gels as shown in Table III below. ZINC OXIDE AND JOJOBA OIL RESULTS FOR COLOR PROTECTION Zinc oxide offers broad spectrum absorption across the whole solar UV range (UVA + UVB). Traditionally, zinc oxide has been formulated into sunscreens for the sun care mar- ket. Although an effective UV fi lter, its lack of transparency limited its use. A new mi- cron sized zinc oxide product in combination with jojoba oil offers opportunity to expand the use of zinc oxide beyond sunscreens and in hair care products. zinc oxide and jojoba oil deliver color protection, enhanced feel and anti-frizz control. Jojoba oil is natural product and non-greasy. It is commonly used in hair treatments, especially hair that is dry or damaged, has split ends and is prone to breakage and tangling. Jojoba is considered moisturizing oil since its molecules are small enough to penetrate the hair cuticle. Using products with jojoba oil as a hair treatment will give your hair a healthy shine and con- ditioned feel. To demonstrate the attributes of zinc oxide and jojoba oil in a styling cream, bleached hair was dyed using L’Oreal Cherry CordialTM (Manufactured by L’Oreal Group Cosmetic Company), treated with zinc oxide and jojoba oil comparable to those in a commercial control Figure 4. (a) Acrylates RM and HF hair gel. (b) Commercial hair gel. Table III % Curl Retention after 8 hrs at 90% RH and 30°C Initial 4 hrs 8 hrs PVP/carbomer commercial hair gel (control) 100 50 10 Acrylates/steareth-20 methacrylate crosspolymer 100 75 50 Acrylates/steareth-20 methacrylate crosspolymer and acrylates/hydroxyesters acrylates copolymer 100 90 85

2010 TRI/PRINCETON CONFERENCE 155 cream, then exposed to UV using parameters from Table IV below. After exposure the zinc oxide and jojoba oil-treated tresses had barely perceptible color loss compared to a commercial control claiming to prevent color loss, which had very distinctive and percep- tible color loss (Figure 5). AFM RESULTS FOR ZINC OXIDE AND JOJOBA OIL Hair tresses were evaluated using atomic force microscopy before and after exposure to UV for 7 days (see Figures 6a, b, c, and d). The hair samples were imaged by two different types of microscopy, atomic force micros- copy and scanning electron microscopy. For the most part there is a great deal of overall agreement of the morphology of the hair obtained by the two techniques. Where a feature Figure 5. (a) Exposed area on hair tresses treated with commercial control: Very distinctive and perceptible color loss (b) Exposed area on hair tresses treated with zinc oxide and jojoba oil: Very slightly perceptible color loss compared to commercial control. Figure 6. (a,b) Untreated control. (c,d) Tress treated with zinc oxide and jojoba oil. Table IV UV Exposure Parameters Settings Hair Program 313 nm light, no water Irradiance - 0.35 W/m2 @ 340 nm Panel temp 60°C, 168 continuous hrs European, bleached Colored with Couleur Experts 6.6 Bright Autumn by L’Oreal