Studies on Particulate Growth and
Oorganization in Non-Equilibrium Myelin Structure

Abstract

The interesting phenomenon of myelin formation is observed when a surfactant lamellar phase is swollen in excess solvent. Myelins are essentially long, thin finger like cylindrical structures that rapidly grow when water is brought into contact with concentrate lamellar phase of sparingly water soluble surfactants. They are well known non-equilibrium microstructures. In the present study we have reported the formation & growth mechanism of myelin structure using anionic surfactant AOT (Aerosol-OT) in aqueous medium. The effect of surfactant concentrations on the formation, growth, shape and stability of myelin structures has also been investigated. Digital video microscopy has been used to investigate the swelling & dissolution dynamics of myelin growth.
Apart from this, attempt has also been made to synthesize ultra-fine particles using these non-equilibrium myelin structures. In this work, we have successfully prepared Ca3(PO4)2 particles during the myelin formation by using AOT/water system. The formation of Ca3(PO4)2 in these systems lead to organize a chain of particles enforced by water micro flow induced by myelin growth. This new phenomenon is absent in equilibrium systems such as micelles & reverse micelles. It is also observed that increase in particle concentration causes extensive coiling of myelin structure. It is supposed to play an important role in biological systems in the formation of bones during embryonic stages.