Electrostatic and electrosteric stabilization of aqueous suspensions of barite nanoparticles

Effects of operating parameters on the production of barium sulfate nanoparticles in stirred media mill

“…The reason for this behavior may be due to the fact that low amount of dispersant is not effective in providing sufficient surface coverage and not effective to prevent aggregation during wet grinding, and on the other hand higher amount of dispersant addition may result into increased viscosity and thereby may not be able to provide effective stabilization. Thus, the optimum amount of dispersant for selected experimental conditions is found to be 2 wt%, which is consistent with the reported results [20]. The effectiveness of optimum amount of dispersant can further be substantiated by observing dispersant concentration effects on the produced surface area and energy efficiency (Fig.…”

“…13, that the pH change is very high during the initial period of grinding and then it is gradually decreased indicating higher rate of size reduction during initial period of grinding and then decreased with grinding time. The reason for the decrease in pH can be attributed to the rapid adsorption of OH À ions from water onto the positively charged barite nanoparticles surface in order to provide electro-neutrality as explained in the literature [20]. The pH of barite suspension has decreased with time when pH was maintained at 11 [24].…”

“…First two experiments were carried out in absence of sodium salt of polyacrylic acid (PAA-Na) to check the effectiveness of pH control to provide electrostatic stabilization. First, the experiment was conducted at native pH of 9.6 without control of pH in absence of PAA-Na, second at pH = 10.5 which is far away from isoelectric point of pH = 7.8 as reported in the literature [20] with the control of pH and in absence of PAA-Na and final experiment with pH control and in the presence of dispersant PAA-Na. The results are presented in the Fig.…”

High catalytic efficiency of palladium nanoparticles immobilized in a polymer membrane containing poly(ionic liquid) in Suzuki–Miyaura cross-coupling reaction

“…The presence of appropriate stabilizers is necessary to prevent their aggregation, which usually results in loss of activity. The stabilization of MNPs can be accomplished by a steric effect [12], an electrostatic effect [13], a combination of both (electrosteric effect) [14], or a ligand [15].…”

Influence of PAA on the Microstructure and Corrosion Resistance of Electrophoretically Deposited SiO2 and Ni/SiO2 Coatings on X2CrNiMo17-12-2 Steel

“…Steric stabilization requires the use of surfactant, which adsorbs on the surface of nanoparticles and forms a thin layer which prevents agglomeration [10][11][12]. In general, combination of both types of stabilization is called electrosteric stabilization [13]. It can be achieved for example by using polyelectrolyte.…”