ABSTRACT

Abstract ................................................................................................... 39 4.1 Introduction .................................................................................... 40 4.2 Experimental Part ........................................................................... 42 4.3 Results ............................................................................................ 45 4.4 Discussion and Conclusion ............................................................ 46 Keywords ................................................................................................ 48 References ............................................................................................... 48

ABSTRACT

Highly porous cellulose samples (aerocellulose), obtained by the processing of stitched and not stitched original gel with supercritical carbon

dioxide have been studied by the spin probes technique of electron paramagnetic resonance. The width of the distribution in rotational correlation time of spin probe (τ) and its average value at room temperature have been determined by the comparison of experimental and calculated electron paramagnetic resonance spectra. These parameters characterize porous polymer structure. The data obtained in this work show that the width of the Gaussian distribution in τ value at 1/e part of it height (α) after processing of the original gels by supercritical CO2 may be as much as 2-3 orders of magnitude. The greatest value of α is typical for the sample obtained from previously stitched original gel (5 orders of magnitude). The results show that the cellulose with different porous structure can be obtained by processing of the original gels with supercritical CO2, varying the concentration of polymer in the gel, and introducing cross-linkers.