Challenges in Groundwater Remediation with Iron Nanoparticles: Enabling Colloidal Stability - Nanotechnologies for Water Environment Applications - page 199

8.3.2 Rationale
In addition to possessing the ideal characteristics for an nZVI delivery system,
this class of polymers can be easily synthesized from a wide variety of commercially
available starting materials. For example, Gelest Inc. (Morrisville, PA, USA) sells a
variety of poly(dimethylsiloxane-co-methylhydrosiloxanes) copolymers with varying
methylhydrosiloxane contents and molecular weights as well as
poly(methylhydrosiloxane) homopolymers of varying molecular weights. With regard
to precursors for the generation of hydrophilic polymer grafts, Clariant (Charlotte, NC,
USA) sells an array of monovinyl-terminated PEGs of varying molecular weights.
Thus, with this class of graft copolymers, extensive structure-property relationships can
be developed by varying the polysiloxane backbone molecular weight, hydrophilic
polymer graft content and molecular weight, as well as the anchoring group content.
Figure 8.2 A schematic representation of the modified nZVI in water and at the
water/contaminant interface.
8.3.3 Experimental Methods
Synthesis and Characterization of nZVI. nZVI were synthesized using a
borohydride reduction method (Liu et al., 2005) with a slight modification (Bezbaruah et
al., 2008; Thompson, 2008). NaBH 4 (Alfa Aesar, Ward Hill, MA, USA) solution was