Challenges in Groundwater Remediation with Iron Nanoparticles: Enabling Colloidal Stability - Nanotechnologies for Water Environment Applications - page 206

8.4 Conclusions

A series of APGCs were successfully synthesized using a process that consisted
of hydrosilylation of tert -butylacrylate and monoallyl-functional PEG to a polysiloxane
copolymer containing hydride groups and subsequent hydrolysis of the tert -butylester
groups. The APGCs were composed of polydimethylsiloxane (PDMS), polyethylene
glycol (PEG) and acrylic acid (AA). The PEG hydrophilic groups promoted colloidal
stability of nZVI in aqueous media. The APGC with the highest concentration of
carboxylic acid anchoring groups provided the highest colloidal stability. The modified
nZVI were significantly more stable than bare nZVI. The polysiloxane polymer
backbone is expected to protect nZVI from oxidation by non-target compounds and
create an affinity of the modified nZVI for the water/organic (specifically, non-aqueous
phase liquids) interface. The polymer coating will make more nZVI reactive surface
available for contaminant degradation.

8.5 Acknowledgements

Grants from USGS/NDWRRI (ID: 2007ND150B) and the North Dakota State
University Development Foundation are thankfully acknowledged. Help from Eric
Jarabek and David Christianson of the Center for Nanoscale Science and Engineering is
highly appreciated.

8.6 References

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