Seperation of metal alginate ionotropic gels to polymembranes with special evidence on the position of chelation in copper alginate complex

Abstract

A descending technique has been used to make multilayer ionotropic membranes within capillary structure from the gelation of macromolecular chains of alginate sol and electrolytes of divalent metal ions. A successful method was introduced to separate these polymembranes into layers. The electron‐microscopical investigation confirms that the chelation in such gel membrane complexes occurred between the divalent metal ion, and two carboxylate and two hydroxyl groups of two neighboring units of the same macromolecular chain.

Kinetics and mechanism of sol-gel transformation between some trivalent- and tetravalent-metal ions and Sodium alginate Anionic polyelectrolyte with formation of coordination Biopolymeric structure polymembranes Hydrogels of Capillary Structures Ex

“…3. The structural morphology was found to resemble that obtained for cross-linked divalent metal-alginate complexes [27]. Unfortunately, it was difficult to obtain such optical images for trivalent metal-alginate complexes owing to their poor mechanical properties in handling.…”

“…On the other hand, ionotropic gels of di-or tetravalent metal-alginate complexes can be formed in different shapes according to the direction of diffusion of electrolyte [27]. When the metal ions are allowed to diffuse upward, noncapillary gel membranes are formed.…”

“…The width in these capillaries may play an important role in the rate of exchange process during the sol-gel transformation. It is possible to separate the multilayer membranes into thin layer membranes [27]. These thin layers can be used in electrophoto conductography as cellular reinforcement screens for X-rays and photographing the electron beams of oscillographs.…”

“…The net process is an exchange reaction which leads to the formation of gel complex with definite structure and orientation. The continuity of such diffusion process leads to the formation of multilayer ionotropic gel membrane [27].…”

“…The diameter of the pores depends on several factors such as pH of electrolyte, concentration of alginate sol, the ionic radii of the interdiffused metal ion and the orientation of both coordinated water molecules and macromolecular chains of alginate toward the chelated metal ion [27].…”