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.

Alginic acid as a stabilizer of zirconia suspensions in the presence of cationic surfactants

The influence of hydrocarbon (CTAB), fluorocarbon (S-106-A) and silicone (C-Si) cationic surfactants: on stability, adsorption and electrokinetic properties of the alginic acid (AA)/zirconia (ZrO₂) suspensions was studied. The results obtained from the spectrophotometric measurements indicate on very high effectiveness of the surfactants in stabilization of the studied systems. This is due to the formation of multimolecular complexes between alginic acid and the surfactants. The existence of these complexes was confirmed by the surface tension and the zeta potential measurements. Presented studies also enabled the estimation of the conditions under which the complexes are effectively created and the determination of their character. These findings were also confirmed by the adsorption data. Moreover, the surface charge density measurements proved that the adsorption of AA or the AA/surfactant complexes changes the structure of the electrical double layer. The presented results may find applications in the fields of functionalized materials.