A systematic evaluation of agglomeration of Ag and TiO 2 nanoparticles under freshwater relevant conditions

Agglomeration of Ag and TiO2 nanoparticles in surface and wastewater: Role of calcium ions and of organic carbon fractions

“…The critical parameters for the agglomeration of ENPs (Ca 2þ , Mg 2þ , DOC and alkalinity), at their respective concentrations (Topuz et al, 2014) were employed to make a preliminary classification for the sample site selection, based on the rivers in the NADUF (National long-term surveillance of Swiss rivers) project database (http://www.bafu.admin.ch/). Concentration ranges were assigned for each parameter (Table S1 in Supporting Information (SI)) and 8 classes were developed not to miss out a critical concentration level.…”

“…According to our previous study in synthetic media (Topuz et al, 2014), the agglomeration behavior of citrate coated Ag nanoparticles (AgNP-Cit) and TiO 2 depends on the concentration of Ca 2þ and the presence of NOM, which can provide steric stabilization of particle size over 1 week. In contrast, polyvinylpyrrolidone AgNP (AgNP-PVP) were stable over 1 week in the presence of various ions except Mg 2þ at high concentrations.…”

“…In contrast, polyvinylpyrrolidone AgNP (AgNP-PVP) were stable over 1 week in the presence of various ions except Mg 2þ at high concentrations. Complexation of Ca 2þ with citrate (El Badawy et al, 2010) and Mg 2þ with PVP coating (Topuz et al, 2014) can lead to agglomeration of AgNP-Cit and AgNP-PVP, respectively. Therefore, a surface water simulated medium was proposed for the agglomeration studies.…”

Toxic effects of silver nanoparticles in mammals – does a risk of neurotoxicity exist?

“…The type of capping agent may also play a crucial role in stabilization of AgNPs. Polyvinylpyrrolidone (PVP)-coated AgNPs were found to be stable over a 1-week period in water, whereas citrate-coated AgNPs are unstable [136].…”

Influence of Ag/TiO2 nanoparticle on the surface hydrophilicity and visible-light response activity of polyvinylidene fluoride membrane

“…Under visible light illumination, Ag nanoparticles on the surface of PVDF membrane can absorb photons owing to LSPR effect and produced photo-electron and hole pairs. The photoexcited electrons can be transferred to the conduction band of TiO 2 [16,18], because the Fermi level of Ag was higher than that of TiO 2 under visible light irradiation [17]. The electrons can be captured by the oxygen molecule (O 2 ) on the TiO 2 surface to produce O 2 − , HO 2 − , H 2 O 2 and •OH [17].…”