Authors: I. Portnaya, R. Khalfin, E. Kesselman, D. Danino
Affilation: Technion - Israel Institute of Technology, Israel
Pages: 221 - 224
Keywords: beta-casein, mixed micellization, synergism, block copolymers
Amphiphilic block copolymers and mixtures of amphiphiles find broad applications in numerous nano-technologies. In our previous study, we showed that interactions between a biological charged diblock copolymer, beta-casein, and a synthetic uncharged triblock copolymer, Lutrol F-127 (EO101PO56EO101) lead to the formation of mixed micelles. Here we report on synergistic effects found in some mixing ratios, and the mixed micellization characteristics. Experimental critical mixed micelles concentrations (CmMC) were obtained from Isothermal titration calorimetry. At low Lutrol mole fractions we have observed a complicated micellization process characterized by two CmMC. Positive and negative synergistic effects of Lutrol were revealed . We further found that Lutrol molecules are able to take part in mixed micelle formation even at temperatures below their critical micellization temperature. Cryogenic-transmission electron microscopy indicates some changes in the oblate micellar shape and size. Small-angle X-ray scattering and Dynamic light scattering results correlate with the microscopy data and allow to calculate aggregation numbers of the mixed micelles.For applications of the block copolymer mixtures as specific effective stabilizers or potential new nano-vehicles for delivery, understanding the components mixing characteristics are of special interest.