Concurrent aggregation and deposition of TiO2 nanoparticles in a sandy porous media.
The possibility of simultaneous particle aggregation and deposition in a porous medium was examined for the case of TiO(2) nanoparticles (NPs). While potential for particle aggregation is typically assumed to be negligible in porous media due to favored interactions with porous media surfaces (collectors), we show that nanoscale particle dimensions may favor aggregation kinetics, thus altering the transport and retention of these materials in saturated porous media. When surface chemistry favors nanoparticle-nanoparticle attachment (alpha(pp)) over nanoparticle-collector attachment (alpha(pc)), the rate of particle aggregation within pores may be comparable to that of deposition at ratios of collector to nanoparticle surface areas as high as 40. Aggregation of NPs in the porous media enhances NP deposition, however aggregates that are not removed will sample a smaller portion of the available pore network within the column due to size exclusion.
Solovitch
Natalia
N
CEREGE, UMR 6635 CNRS/Aix Marseille University, Europole Mediterraneen de l'Arbois, 13545 Aix-en-Provence, Cedex 04, France. solovitch-vella@cerege.fr
Labille
Jérôme
J
Rose
Jérôme
J
Chaurand
Perrine
P
Borschneck
Daniel
D
Wiesner
Mark R
MR
Bottero
Jean-Yves
JY
D004784:Environmental Monitoring / Q000379:methods; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium