SYNTHESIS AND PROPERTIES OF CRYOGELS BASED ON GELLAN

Cryogel is a kind of cryogenic polymer material that consists of three-dimensional flexible polymer structures obtained by freezing-thawing. In this work, cryogels based on the natural polymer gellan were obtained by ionotropic gelation in the presence of NaCl and CaCl2. The properties of the obtained cryogels – morphological characteristics, swelling kinetics, mechanical properties and structure of the gels – are investigated. The indicators of scanning electron microscopy demonstrate a porous matrix with a system of communicating pores. There is an increase in the number of pores with an increase in the concentration of gellan. The average pore diameters of cryogels have been determined. The degree of swelling of cryogels samples is calculated. Higher values of the swelling degree of 18.2 and 19.4 g /g are observed in cryogels obtained at a higher concentration of gellan – 2%. The results of the study of the mechanical strength of cryogels show an increase in the Young's Modulus with an increase in the concentration of gellan, as well as the absence of destruction even when 99% of the compression ratio of the samples is reached. The mechanical properties of cryogels are one of the advantages of this type of materials, since they have the property of repeatedly and reversibly experiencing external mechanical effects. The chemical structure of the synthesized cryogels based on gellan is proved by the method of FTIR spectroscopy. In the IR spectra of cryogel samples, characteristic peaks of deformation and valence vibrations of functional groups that are part of the gellan were detected.

1. Ertürk G., Mattiasson B. Cryogels-versatile tools in bioseparation. – J. Chromatography A 1357, 2014. – 24-35 (In English).

2. Okay O., Lozinsky V.I. Synthesis and Structure-Property Relationships of Cryogels – Advances in Polymer Science 263. – 2014. – 103-153 (In English).

3. Plieva F.M., Oknianska A., Degerman E., Galaev I.Y., Mattiasson B. Novel supermacroporous dextran gels. – J. Biomater. Sci., Polym. Ed. 17. – 2006. – 1075-1092 (In English).

4. Arvidsson P., Plieva F.M., Lozinsky V.I., Galaev I.Y., Mattiasson B. Direct chromatographic capture of enzyme from crude homogenate using immobilized metal affinity chromatography on a continuous supermacroporous adsorbent. / J. Chromatography A 986. – 2003. – 275 (In English).

5. Lozinsky V.I., Vainerman E.S., Korotaeva G.F., Rogozhin S.V., Study of cryostructurization of polymer systems – III. Cryostructurization in organic media / Colloid Polym.Sci. 262. – 1984. – 617622 (In English).

6. Lozinsky V.I., Vainerman E.S., Ivanova S.A., Titova E.F., Shtil’man M.I., Belavtseva E.M., Rogozhin S. V., Study of cryostructurization of polymer systems. / VI. The influence of the process temperature on the dynamics of formation and structure of cross-linked polyacrylamide cryogels, ActaPolym. 37, 1986. – 142-146 (In English).

7. Tanaka Sh. and Nishinari K. Unassociated Molecular Chains in Physically Crosslinked Gellan Gels. / Polymer Journal. – Vol. 39. – 2007. – 397-403 (In English).

8. Muthukumar Th, Song J. E. and Khang G. Biological Role of Gellan Gum in Improving Scaffold Drug Delivery, Cell Adhesion Properties for Tissue Engineering Applications / Molecules, 4514, 2019. – 1-22 (In English).

9. de Souza F.S., de Mello Ferreira I.L., da Silva Costa M.A., de Lima A.L.F., da Costa M.P.M. Evaluation of different methods to prepare superabsorbent hydrogels based on deacetylated gellan / Carbohydrate Polymers 148. – 2016. – 309-317 (In English).

10. Kudaibergenov S.E., Tatykhanova G.S., Klivenko A.N. Complexation of macroporous amphoteric cryogels based on N,N-dimethylaminoethyl methacrylate and methacrylic acid with dyes, surfactant, and protein / Journal of applied polymer science. ‒ Vol. 133. – № 3. – 2016. – 1-9 (In English).

11. Tarasevich B.N. IR spectra of the main classes of organic compounds. Reference materials / Moscow: Lomonosov Moscow State University, Faculty of Chemistry, Department of Organic Chemistry. – 2012. – 55 (In Russian).