Ultrasonic modification of micelle nanostructures #16

Abstract

The tremendous attention given to micelles in recent technological advancements and industries is due to its amazingly stable and flexible physicochemical properties exhibited upon exposure to different stimuli. A concise review of micelle structures and the effects of various stimuli on the structural properties of micelles with a particular focus on the effect of ultrasound are provided. While the use of conventional stimuli such as temperature, shear, etc., for controlling micelle structures is widely reported, the use of ultrasound as a stimulus has not been studied extensively. For this reason, a detailed discussion on the possibility of designing a variety of micelle nanostructures using ultrasound is provided. Using ultrasound as a stimulus is an advantage as it eliminates the need for adding external chemicals to the micellar system and the experimental parameters could be easily controlled. A case study of using cetyltrimethylammonium salicylate (CTASal) prepared from ion exchange process of equimolar mixture of cetyltrimethylammonium bromide (CTABr) and sodium salicylate (NaSal) is used in order to evaluate the efficiency of ultrasonics on controlling the micelles’ aggregational structures. Further experiments and discussion imply that the transformation is mainly driven by the physical effect generated from sonication. Evidence from cryo-TEM indicates that the structural transformation took place according to the reptation and reaction Model proposed before.