Effect of triblock copolymer non-ionic surfactants on the rheology of 3mol% yttria stabilised zirconia nanosuspensions

Abstract

The effect of three different molecular weights of a triblock copolymer nonionic surfactant composed of poly(ethylene oxide) and poly(propylene oxide) have been investigated on the zeta potential, stability and rheology of a commercial nanosuspension of 3 mol% yttria stabilised zirconia (3YSZ). Whilst the surfactants showed some evidence of being adsorbed onto the nanoparticle surfaces, it was in insufficient quantities to achieve complete coverage and measurement of the total organic carbon content suggested that the bulk of the surfactants remained in the liquid medium. As a result, there was only a small effect on the zeta potential. Nevertheless, the stability of the suspension was not affected up to solids contents as high as 54 wt%. Whilst the viscosity of the nanosuspension increased slightly with increasing surfactant concentration due to the presence of the polymer molecules, for the lowest molecular weight surfactant the effect was relatively small. Finally, it was observed that if the ionic strength of the suspension was reduced via the removal of free electrolytes in the suspension by dialysis, the viscosity decreased significantly. The reverse behaviour was also observed when extra NH 4 Cl electrolyte was added to the nanosuspension.

Formulation and characterization of biocompatible and stable I.V. itraconazole nanosuspensions stabilized by a new stabilizer polyethylene glycol-poly(β-Benzyl- l -aspartate) (PEG-PBLA)

“…Zeta potential is essential to the stability of colloidal dispersions, and it has been reported that a zeta potential of approximately -20 mV is sufficient to stabilize a nanosuspension system (Liang and Binner, 2008;Pu et al, 2009b). The lyophilized ITZ-PBLA-Nanos only showed a small increase in size (about 10 nm, data not shown) after stored at 4℃ for 30 days, confirming that lyophilzation is a feasible means to improve long term stability of ITZ-PBLA-Nanos.…”

Preparation, characterization and antifungal activity of pyraclostrobin solid nanodispersion by self‐emulsifying technique

“…Zeta potential around ±30 mV means that the nanodispersion is stable. Owing to the combined electrostatic and steric stabilizer, a zeta potential of ±20 mV would be acceptable . The absolute zeta potential of the solid nanodispersion diluted to 0.05% with deionized water was −29.3 (Fig.…”

“…To clarify the fungicidal mechanism of pyraclostrobin with different concentrations on F. oxysporum, total protein, manganesecontaining SOD (Mn-SOD), SOD and CAT in pyraclostrobin-treated mycelia were measured to test the antioxidant defenses. 36 As shown in Figure 13, the total protein content decreased significantly after treatment with three different concentrations (5,20 and 50 μg mL −1 ) of pyraclostrobin for 24 h. This was mainly because oxidative damage affects the expression of proteins in fungi. Compared with the WDG group, the total proteins of the PSND group decreased more obviously.…”

“…Owing to the combined electrostatic and steric stabilizer, a zeta potential of ±20 mV would be acceptable. 20 The absolute zeta potential of the solid nanodispersion diluted to 0.05% with deionized water was −29.3 (Fig. 3), indicating that the Pest Manag Sci 2019; 75: 2785-2793 electrostatic repulsion between the particles was large and that the physical stability was good.…”

Preparation of metal nano-fluid via electrical discharge machining

“…The zeta-potential represents the Coulomb repulsion force which prevents the particles from aggregating or precipitating out of solution. However, many factors like the particle size, particle/ion concentration, pH could affect zetapotential magnitude or maintenance [16,17]. In this research, the EDM system was equipped bulk silver rod (99.9%), after a minute process in water; the resultant silver nano-fluid contains both silver nanoparticles and ionic silver.…”