ИСТИНА

LABILE COLLAGEN MATRIX: TRANSFORMATION OF HIERARCHICAL STRUCTURE AT NANO- AND MICRO- LEVELS INFLUENCED BY CHEMICAL TREATMENT 1 V.I. Vernadskii Institute of General & Inorganic Chemistry of the NAS of Ukraine, Palladin Pr. 32/34, 03142, Kiev, Ukraine 2 KievNationalUniversityofTechnologyandDesign,Nemirovich-Danchenko2,01011,Kiev, Ukraine 3 A.N.FrumkinInstituteofPhysicalChemistry&Electrochemistry,LeninskiiPr.31,119991, GSP-1, Moscow, Russian Federation ABSTRACT Porous structure both of natural skin and collagen matrix obtained by chemical treatment of the skin with alkaline and acidic solutions, tannage with a Cr3+-containing solution, vegetable retannage and modification with bentonite was researched using scanning and transmission electron microscopy as well as standard contact porometry. Each stripe of porogrammes has been related to elements of multilevel structure. The pores were recognized using octane as a working liquid, the results obtained by this manner were used to determine loosening-compaction and ordering-disordering at each level of the structure, which includes nanosized macromolecules, microfibrils, fibrils and primary fibres of micron size. The measurements performed in aqueous media allowed us to determine hydrophilic pores and estimate their functions, secondary fibres have been also found by this manner. As for initial skin, porometric measurements diagnosed also non-collagen hydrophobic and hydrophilic inclusions, which form their own structure between microfibrils, fibrils, primary and secondary fibres of the matrix. The structure due to these inclusions is similar to that for collagen macromolecules. Microfibrils and fibrils have been found to form both ordered and disordered structures. Contribution of porosity of each organization level into the total porosity has been estimated, changes of collagen structure caused by chemical treatment and modification of inorganic ion-exchanger have been analyzed. Recommendation dealt to obtaining of materials for sorption and membrane separation have been given.