Figure 3 - Coacervation effect shown by red 80 dye intensity
‣ 3 % Cola Moist 200 and water only at three test sites , and left a fourth untreated as a control . Skin moisturisation was measured with visual grading and Corneometer at baseline , and at four , eight and 12 hours after application . The results ( Figure 1 ) showed that the body wash with ColaMoist 200 significantly improved moisturisation over all other conditions throughout the 12-hour period of the study .
Measuring coacervates
More recently , CCI has evaluated its products for their ability to form dilution-activated coacervates and improve combing in an anionicbased two-in-one cleansing system . A standard anionic system was created , containing 11.5 % sodium laureth-2 sulfate , 2.6 % disodium cocoamphodiacetate , 0.5 % polyquaternium-10 ( JR-400 ) as the conditioning quat and citric acid to pH 6.0 . Three endpoints were evaluated :
• Turbidity
• Rubine dye deposition
• Comb force reduction , measured on wet , lightly bleached brown hair For turbidity , the key performance indicator for coacervate formation and potential performance is the cloudiness of the product over a range of dilutions at ambient temperature . We diluted each of the test products in stepwise amounts and measured the clarity of the resultants dilution using a HACH turbidimeter in NTUs . The higher the turbidity , the more coarcervate has been formed and the greater deposition onto the hair or skin . PolySuga Quat S1210P showed peak performance at around 0.3 %; there was little benefit at 0.6 % and 2.0 % ( Figure 2a ). The broad curve of the results show that this product is quite forgiving and the dilution effect in the product means that there will be a high level of deposition . PolySuga Quat TM8610-P is the product with the highest charge density in the range . This means much more turbidity in the formulation and much more of the cationic PQ-10 coming out of the solution and being deposited on the surface ( Figure 2b ). Even at 2 % concentration , the NTU level is almost twice as high as that of PolySuga Quat S1210P . Finally , ColaMoist 200 proved to be three times as effective as PolySuga Quat S1210P , achieving 750 NTUs at 2 % concentration . Again , there is a very broad curve , meaning a high level of cationic quat deposition as the product is diluted in use ( Figure 2c ). To back up these findings , we wanted to prove that the PQ-10 and our cationic products were actually depositing onto the surface of the hair . We did this by using a rubine dye test , which predicts cationic polymer deposition by measuring the amount of an anionic red dye that gets deposited on a wool swatch , wash it and compare it to the same material washed without the cationic polymer .
46 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981