Adsorbed Triblock Copolymers Deliver Reactive Iron Nanoparticles to the Oil/Water Interface

Abstract

Reactive zero valent iron nanoparticles can degrade toxic nonaqueous phase liquids (NAPL) rapidly in contaminated groundwater to nontoxic products in situ, provided they can be delivered preferentially to the NAPL/water (oil/water) interface. This study demonstrates the ability of novel triblock copolymers to modify the nanoiron surface chemistry in a way that both promotes their colloidal stability in aqueous suspension and drives their adsorption to the oil/water interface. The ability of the copolymers to drive adsorption is demonstrated by the ability of copolymer-modified iron nanoparticles, but not the unmodified iron nanoparticles, to stabilize oil-in-water emulsions.

“Green” Atom Transfer Radical Polymerization: From Process Design to Preparation of Well-Defined Environmentally Friendly Polymeric Materials

“…The particles should also be stable toward oxidation. A triblock copolymer, MAA 42 -b-MMA 26 -b-NaSS 462 , was shown 455 to be a very efficient surfactant for Fe 3 O 4 -coated iron nanoparticles. The polyMAA block served to anchor the polymer to the magnetite shell, the hydrophobic polyMMA segment provided affinity of the particles toward DNAPL and protected the particles from oxidation, and, finally, the charged (sulfonate) block served to prevent particle aggregation and to increase the particles' affinity for water.…”

Deposition of Silver Nanoparticles in Geochemically Heterogeneous Porous Media: Predicting Affinity from Surface Composition Analysis

“…A typical example would be the recent advancement of using nanoparticles such as nano Zero Valent Iron (nZVI) for ground water remediation (Feitz, Joo et al 2005;Liu, Majetich et al 2005;Tratnyek and Johnson 2006;Liu, Phenrat et al 2007). In this case our knowledge on particle deposition could help us modify the surface the nZVI particles and make them more mobile so that they can be delivered to target contaminated zone (Saleh, Phenrat et al 2005;Kanel, Choi et al 2007;Phenrat, Saleh et al 2008). Beyond the engineering scope, the deposition process is also strongly relevant to environment and human health because it determines the transport and fate of colloids in ground water and other aquatic systems.…”

“…Among these particles some are by themselves environmental contaminants (Kessler and Hunt ;Buddemeier and Hunt 1988) while some serve as vehicles to facilitate the transport of a variety of other contaminants that otherwise would be relatively immobile without the presence of the colloids (McCarthy and Zachara 1989;Corapcioglu and Jiang 1993;Grolimund, Borkovec et al 1996;Ryan and Elimelech 1996). Different types of environmentally relevant particles have been studied, including various minerals, Rajagopalan and Chu 1982;Puls and Powell 1992;Ryde, Kihira et al 1992) bacteria and viruses, (Logan, Hilbert et al 1993;Pieper, Ryan et al 1997;Ryan, Elimelech et al 1999;Redman, Walker et al 2004;Walker, Hill et al 2005) and engineered nanoparticles (Lecoanet, Bottero et al 2004;Brant, Lecoanet et al 2005;Saleh, Phenrat et al 2005;Chen and Elimelech 2006;Espinasse, Hotze et al 2007;Jaisi, Saleh et al 2008). The transport and mobility of engineered nanoparticles have been of particular interest over the past few years due to concerns over possible environmental and health impact of these materials (Hoet, Nemmar et al 1999;Colvin 2003;Borm, Robbins et al 2006;Renn and Roco 2006;Wiesner, Lowry et al 2006).…”

A critical review of nanohybrids: synthesis, applications and environmental implications

“…are typically adsorbed onto the NMs to enhance dispersion in a desired solvent and have been studied for environmental implications. [134][135][136][137] However, the recent surface modification of NMs are performed with rather complex supramolecules or heterocyclic structures (e.g. porphyrins), which are covalently bound to the NM surfaces.…”