Dispersion of aluminum‐doped zinc oxide nanopowder in non‐aqueous suspensions

Abstract

This study proposes appropriate dispersants for dispersing aluminum-doped zinc oxide (AZO) nanopowder in the commonly used organic solvent-dimethylacetamide (DMAC). The dispersion efficiencies and stabilization mechanisms of four DMAC-soluble dispersants, poly(acrylic acid) (PAA), polyethyleneimine (PEI), poly(vinyl alcohol) (PVA), and poly(vinyl pyrrolidone) (PVP), are compared. The non-polyelectrolyte-based PVA and PVP surprisingly exhibit greater efficiency than the polyelectrolyte-based PAA and PEI. This is because the nano AZO is soft-agglomerated in DMAC and easily de-agglomerated by the application of ultrasonic power; therefore, the increased viscosity contributed from additions of PVA and PVP efficiently prevent reagglomeration and sedimentation of the nanopowder. This stabilization mechanism is evidenced by an experimental analysis of zeta potentials and rheology and also by theoretical calculations based on Stokes' law.

A multifunctional integrated carbon nanotubes/polyphenylene sulfide composite: preparation, properties and applications

“…Thermal stability and corrosion resistance Fig. 7a displays the thermogravimetric (TGA) analyses of PVA, PPS/PVA and 33% CNTs-PPS/PVA aer annealing at 300 °C for 3 h. For pure PVA, annealing treatment improves heat resistance with an initial decomposition temperature of 350 °C compared with PVA powder, 24 and the mass of residuum reaches up to 66.9%. When PPS combines with PVA with a mass ratio of 5 : 8, the quality loss is only 20.3% at 500 °C.…”

“…22 Polyvinyl alcohol (PVA), which is a well known watersoluble polymer, is a good lm-forming agent with strong viscosity. 23,24 So far, it has been widely used in spinning, printing, papermaking, pharmaceutical manufacturing and so on. 25,26 Furthermore, related research studies manifest that PVA solution can prevent nano-particles from gathering together.…”

“…Besides, the crystal structure of CNTs reminds the same at 25.6° 35. In summary, the crystal structure changes of PPS and PVA are caused by deformation and dehydration, respectively, which are consistent with the previous results.Thermal stability and corrosion resistanceFigure7adisplays the thermogravimetric (TGA) analyses of PVA, PPS/PVA and 33% CNTs-PPS/PVA after annealed at 300 ℃ for 3 h. For pure PVA, annealing treatment improves heat resistance with initial decomposition temperature of 350 ℃ compared with PVA powder,24 and the mass of residuum reaches up to 66.9%. When PPS combines with PVA with mass ratio of 5:8, the quality loss is only 20.3% at 500 ℃.…”

Additive manufacturing of thin electrolyte layers via inkjet printing of highly-stable ceramic inks

“…The agglomerated particles are thus eroded and split by the collisions [32]. UD is considered beneficial to the reduction of ceramic slurry viscosity, sintered density, and properties of the resultant ceramics [33,34]. In this study, an ultrasonic disperser (Scientz-D, Xinzhi Tech., China) was used Ⅱ under a mode of 570 W and 20 Hz for 30 min.…”

Instant Postsynthesis Aqueous Dispersion of Sb-Doped SnO2 Nanocrystals: The Synergy between Small-Molecule Amine and Sb Dopant Ratio

“…In sharp contrast, in the postsynthesis dispersion, agglomeration of the oxide nanoparticles already occurs after they have been washed and dried, which causes a great difficulty in redispersion of the powder . In this case, a stronger steric effect from much larger organic molecules like polymers (e.g., poly­(vinyl alcohol) (PVA) and poly­(vinylpyrrolidone) (PVP)) is essential to form the colloidal solution. , However, these long-chain organic ligands or polymers usually exert a detrimental effect on the electrical conductivity and transparency of TCO films, because during film processing, their incomplete decomposition can leave carbon residues and lead to high porosity of the film. , Moreover, due to the highly hydrophobic tail, the ligand-protected TCO nanocrystals can only be dispersed in nonpolar solvents, such as hexane and toluene, which is not preferred for TCO film deposition, compared to the environmental friendliness of the aqueous dispersion. A postsynthesis aqueous TCO colloidal solution with good dispersity is thus highly desired.…”