Processes occurring in the NaCMC/glauconite suspension under the cold plasma treatment. Influence of plasma on adsorptive and stabilizing properties of the system.

The paper presents the studies on the processes at the interface of the colloidal suspensions composed of clay mineral - glauconite (GT) and polysaccharide - sodium carboxymethyl cellulose (NaCMC) with the cold plasma treatment (CPT). The surface composition and chemical binding in NaCMC and GT changes are determined by means of FTIR and XPS (both methods detected the incorporation of oxygen-related functional groups). Moreover, the additional information about both the textural properties and morphological changes on the surfaces before and after CPT are studied using the BET, CHN, SEM HRTEM and STEM-EDS methods. The elemental mapping and scanning electron microscope imaging confirmed the NaCMC adsorption on GT (carbon mapping) and proved the GT surface lost its "house of card structure" after the CPT. As follows the CPT causes the protonation of NaCMC and the polymer cross-linking whereas the GT sample is more oxidized. Moreover, it was found that a significant improvement in the GT/NaCMC system stability and the NaCMC adsorption on the GT surface were a result of the CPT. The obtained data could be used for the colloidal stability of polymer/solid suspensions, thus providing new opportunities for the chemical industry; particularly for preparation of new functionalized materials.

Comparison of the influence of cationic polysaccharides on the stability properties of montmorillonite suspensions in the presence of sodium dodecyl sulphate.

The mixtures of cationic cellulose (CC) or cationic guar gum (CGG) with the anionic sodium dodecyl sulfate surfactant (SDS) were used as stabilizers for the aqueous suspensions of montmorillonite (Mt). The stabilization processes and the stabilization mechanism were investigated using the UV-VIS. The obtained results show that both polysaccharides can be used as stabilizers of the water suspensions of montmorillonite due to the effective adsorption of CC and CGG with or without SDS on the Mt. surface. To obtain complete information on the studied systems, the additional measurements of the surface tension, zeta potential, FT-IR, XRD and SEM were made. The results prove that the intermolecular complexes formed between the polysaccharides and SDS can adsorb on the Mt. surface, change the structure of the electrical double layer and the stability properties of the studied suspensions.