发胶中润湿性检测方案(表面张力仪)

Application Report Wetting of single hair samples Application report： AR101e Industry section： Cosmetics Author：L e e G i l m a n Method： Force Tensiometer-K14 Keywords： Hair， wetting， silicone polymer， advancing/receding contact angle Evaluating Silicone Hair Treatments Samples Liquids were silicone polymers with viscosity below 500 mPas. The solids were samples of dry， bleached hair. Method Measure two cycles of advancing and receding contact angle for each of the silicone polymers against dry， bleached hairusing the Single Fiber Tensiometer K14 and the K121 Dynamic Contact Angle Software. Wetted length of the hair sampleswas also measured using hexane as the wetting liquid. Results and discussion The two silicone polymers have significantly different surface tension. One is 20.7 mN/m and the other is 25.5 mN/m. Thehigher surface tension silicone contained more polar groups on the side chains. On the basis of surface tension only， wewould expect to get poorer wetting from the higher surface tension silicone. Examining the plots of force versus position for the two， we see in Figure 1 that the higher surface tension silicone musthave adsorbed more strongly onto the hair fiber. Advancing contact angle for this sample shows a substantial reductionbetween the first and the second dipping. The lower surface tension silicone (Figure 2) shows nearly the same advancingcontact angle on the first and second dip. Data for this latter sample is not so easy to decipher. However， it shows that thehysteresis (distance between the advancing and receding contact angle) remains fairly constant during the first andsecond dipping cycle. Wetted length must be measured on hair using a wetting liquid rather than calipers. Hair is often elliptical and has somesurface structure. This is evident in Figure 3 which was used to determine wetted length. This change in fiber diameteralong the length of the fiber shaft contributes to the apparent variation in contact angle observed for these samples. Figure 1 Figure 2 Figure 3 KRUSS GmbH|Borsteler Chaussee Hamburg| Germany|www.kruss.de|