Dispersion and Stabilization of Photocatalytic TiO₂Nanoparticles in Aqueous Suspension for Coatings Applications

Abstract

To produce titanium dioxide (TiO2) nanoparticle coatings, it is desirable that the nanoparticles are dispersed into a liquid solution and remain stable for a certain period of time. Controlling the dispersion and aggregation of the nanoparticles is crucial to exploit the advantages of the nanometer-sized TiO2particles. In this work, TiO2nanoparticles were dispersed and stabilized in aqueous suspensions using two common dispersants which were polyacrylic acid (PAA) and ammonium polymethacrylate (Darvan C). The effect of parameters such as ultrasonication amplitude and type and amount of dispersants on the dispersibility and stability of the TiO2aqueous suspensions were examined. Rupture followed by erosion was determined to be the main break up mechanisms when ultrasonication was employed. The addition of dispersant was found to produce more dispersed and more stabilized aqueous suspension. 3 wt.% of PAA with average molecular weight (Mw) of 2000 g/mol (PAA 2000) was determined to produce the best and most stable dispersion. The suspensions were then coated on quartz glass, whereby the photocatalytic activity of the coatings was studied via the degradation of formaldehyde gas under UV light. The coatings were demonstrated to be photocatalytically active.

The short-term toxic effects of TiO2 nanoparticles toward bacteria through viability, cellular respiration, and lipid peroxidation

“…At low NP concentrations, the suspension size was similar to primary particle size, and at higher concentrations, the NP size increased from one to two orders of magnitude (data not shown). This phenomenon has also been discussed and reported by others (Lee et al 2012;Othman et al 2012;Sohaebuddin et al 2010). The antibacterial activity of TiO 2 NPs was examined in E. coli and B. subtilis bacteria as a function of particle size (Fig.…”

One dimensional CdS nanowire@TiO2 nanoparticles core-shell as high performance photocatalyst for fast degradation of dye pollutants under visible and sunlight irradiation

“…2B. The absorption band observed at 623.0 cm -1 is due to the stretch vibrations [36], while intense broadband in the vicinity of 400 to 800 cm −1 attributed to the stretching vibration of Ti-O-Ti as expected for 1D CdS NWs@TiO 2 NPs sample [37,38].…”

Dispersion of Titanium Oxide Nanoparticles in Aqueous Solution with Anionic Stabilizer via Ultrasonic Wave

“…PAA coatings and thin films were prepared by electrosynthesis [14,15] from acrylic acid monomer solutions. Furthermore, Othman et al [16] used two common dispersants which were PAA and ammonium poly-methacrylate to find that the 3 wt% of PAA is the optimal dispersion. Vallar et al [17] found the optimal the dispersion parameters of the oxide slurries by zeta potential measurements.…”