title: Role of Surface Area, Primary Particle Size, and Crystal Phase on Titanium Dioxide Nanoparticle Dispersion Properties.
abstract: Characterizing nanoparticle dispersions and understanding the effect of parameters that alter dispersion properties are important for both environmental applications and toxicity investigations. The role of particle surface area, primary particle size, and crystal phase on TiO2 nanoparticle dispersion properties is reported. Hydrodynamic size, zeta potential, and isoelectric point (IEP) of ten laboratory synthesized TiO2 samples, and one commercial Degussa TiO2 sample (P25) dispersed in different solutions were characterized. Solution ionic strength and pH affect titania dispersion properties. The effect of monovalent (NaCl) and divalent (MgCl2) inert electrolytes on dispersion properties was quantified through their contribution to ionic strength. Increasing titania particle surface area resulted in a decrease in solution pH. At fixed pH, increasing the particle surface area enhanced the collision frequency between particles and led to a higher degree of agglomeration. In addition to the synthesis method, TiO2 isoelectric point was found to be dependent on particle size. As anatase TiO2 primary particle size increased from 6 nm to 104 nm, its IEP decreased from 6.0 to 3.8 that also results in changes in dispersion zeta potential and hydrodynamic size. In contrast to particle size, TiO2 nanoparticle IEP was found to be insensitive to particle crystal structure.
authors: Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.|Department of Chemical Engineering, Kasetsart University, 50 Paholyothin Road, Jatujak, Bangkok, 10900, Thailand.
authors: Komkrit
authors: K
authors: Suttiponparnit
authors: Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
authors: Jingkun
authors: J
authors: Jiang
authors: Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
authors: Manoranjan
authors: M
authors: Sahu
authors: Department of Chemical Engineering, Kasetsart University, 50 Paholyothin Road, Jatujak, Bangkok, 10900, Thailand.
authors: Sirikalaya
authors: S
authors: Suvachittanont
authors: Center of Excellence in Particle Technology, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Patumwan, Bangkok, 10330, Thailand.
authors: Tawatchai
authors: T
authors: Charinpanitkul
authors: Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA. pratim.biswas@wustl.edu.
authors: Pratim
authors: P
authors: Biswas
keywords: Ionic strength; Isoelectric point; Nanoparticle dispersion; Nanotoxicology; Titania