Sekundarni povzetek: |
The purpose of the doctoral dissertation basically arises from the established problem that the existing antimicrobial treatment of cellulosic materials, due to permanent and excessively used antimicrobial compounds, leads to the resistance of microorganisms. From that point, functionalization of textile substrates for the development of products intendent for medicine and hygiene is particularly exiting. The trend of the development of innovative products is, therefore increasingly directed towards antimicrobial treatment of surfaces of cellulosic materials based exclusively on the use of natural, non-toxic and biodegradable substances. For this purpose, chitosan, a derivative of chitin, which exhibits excellent properties, such as good adhesiveness, biodegradability and antimicrobial efficiency, is often used.
Unfortunately, functionalization of cellulosic materials with chitosan is not always ideal in terms of reproducibility and, therefore, the reproducible reduction of pathogenic microorganisms. For this reason, one of the natural antimicrobial-acting compounds, e.g. eugenol and oleuropein, may be involved in treatment with chitosan. Both of these substances exhibit excellent biological and pharmacological properties, although these compounds have no visible role in combination with chitosan and subsequent application onto selected textile cellulose substrate. Within doctoral dissertation, chitosan was used as an antimicrobial agent to prepare new treatment formulations in combination with natural substances (eugenol, oleuropein). The purpose of incorporating these substances into the chitosan system is to upgrade and to improve chitosan functionality in regard to its antioxidant, physical-chemical and biological properties, respectively. This can be achieved in various ways, inter alia by the method of chemical and enzyme functionalization, which were used in the example of development of new functionalization formulations. Graft co-polymers obtained according to the above methods were evaluated from the point of view of the synthesis which was evaluated by various analytical methods, i.e. spectroscopy (ATR FT-IR, NMR, UV-VIS), potentiometric titration, simultaneous thermal analysis, and methods to evaluate antioxidant efficacy (FC, DPPH*, Fe3+ reduction). Furthermore, the study was carried out in the direction of application of the newly formed formulations to the selected cellulose substrate from viscose. Due to good surface activity, in terms of antimicrobial treatment, viscose was selected for this purpose as a suitable starting material for the development of new medical and hygiene materials. An impregnation-drying process was used to apply individual functionalization formulations onto the surface of viscose. After surface functionalization, the viscose samples were characterized by using ATR FT-IR spectroscopy, the C.I Acid Orange VII method, scanning electron microscopy (SEM), microbiological testing, and release kinetics, respectively.
On the basis of the obtained results, the hypothesis was fully confirmed and it is concluded that the antimicrobial and antioxidant functionalization of viscose functionalized with newly formed formulations depending on the nature of the active compound and the method of the graft co-polymer preparation. In this respect, the eugenol and the chemical functionalization of chitosan in comparison to the oleuropein and the enzymatic functionalization of chitosan have proven to be more effective. |