Effect of freeze/thaw on aggregation and transport of nano-TiO₂ in saturated porous media

Abstract

Research has focused on nanoparticle (NP) aggregation and transport behavior in saturated granular porous media, but few studies have looked at the effect that temperature variability associated with winter conditions will have on engineered NPs.

Experimental methods in chemical engineering: Zeta potential

“…• Wastewater treatment with innovative materials (eg, graphene sheet or bio-composite [101][102][103] ); • Engineered Nano systems for oil recovery and environmental remediation [104,105] ; • Next generation 2D and 3D NP characterization, such as nanotube or nano-flowers [106,107] ; • Design of innovative drug delivery systems based on the fluid-carrier interaction [108,109] ; • Investigation of the transport properties, and the fate of NP in groundwaters [84,110] ; • Synthesis of green based antibacterial, antioxidant, materials [111][112][113] ; and • Complex colloidal systems characterization, for example, emulsion gels or pickering emulsions. [114,115] Due to the relatively simplicity of the ZP technique, and the increasing interest in colloids and NPs, ZP will play an even bigger role among the conventional characterization methods.…”

“…[ 80 ] When the particles are suspended in a natural environment, their actual diameter is greater than the declared nominal size. [ 81 ] While pH is the main parameter in body fluids, in a natural environment we consider ionic strength ( I S ), [ 82 ] natural organic matter (NOM), [ 83 ] temperature, freezing point, [ 84 ] and type of electrolyte, [ 85 ] all of which affect the surface charge and therefore the aggregation/stability of the NPs. In particular, increasing the I S reduces the thickness of the electrostatic double layer and the repulsive forces.…”

Single- and Multi-Element Quantification and Characterization of TiO2 Nanoparticles Released From Outdoor Stains and Paints

“…For instance, for scenarios where the panels were in extended contact with sitting water or snow (e.g., on a deck), stronger NP release was observed as compared to the weathering of surfaces where precipitation was not allowed to accumulate (e.g., outdoor facades). While the weathering experiments were performed under realistic environmental scenarios, losses of the NP due to agglomeration (Azimzada et al, 2020;Farner et al, 2020) and a potential underestimation of the measured NP concentrations (Azimzada et al, 2017;Hadioui et al, 2019) implies that the actual release rates could be higher in environmental systems. On the other hand, the recovered (measured) NP concentrations are likely to represent the most mobile and bioavailable fraction that is likely to be of highest environmental relevance.…”

Photodegradation of Methylene Blue and Evans Blue by Iron and Sulphur Doped TiO2 Nanophotocatalyst under Ultraviolet and Visible Light Irradiation

“…Where ℎ , and are the total integral breadth of Bragg peak, the x-ray wavelength and the lattice strain, respectively. Relation (9) introduces the uniform deformation model (UDM), where lattice strain and deformation are assumed to be uniform in all crystallographic directions. This model assumes that the isotropic nature of the crystallite and the material properties are independent of the measured directions.…”

“…TiO2 reveals three common crystalline phases including anatase, rutile, and brookite, whilst the photocatalytic activity is practicable in anatase crystalline phase. Many researchers investigated and characterized the heterogeneous and doped TiO2 Nps due to the large bandgap of anatase [7][8][9][10]. Dopants and composites could modify and make active Nps upon the maximum absorption wavelength λ_max≤387 nm in UV irradiation for the pure anatase phase.…”