Hetero-aggregation of 10 nm gold nanospheres (AuNSs) in presence of nonionic polymer modified single-walled carbon nanotubes (NIP-SWNTs) are systematically studied with dynamic light scattering (DLS). A wide range of mono- and di-valent electrolyte conditions (i.e., NaCl and CaCl2) spanning the entire range of reaction limited (RLCA) and diffusion limited (DLCA) aggregation regimes is used. NIP-SWNTs are found to be uninfluenced by the electrolyte chemistry; whereas, AuNS aggregation rates showed regime dependent responses. At RLCA regime, AuNS aggregation was hindered by NIP-SWNTs; whereas DLCA regime showed enhanced aggregation when compared to its homo-aggregation behavior. Presence of Suwannee River humic acid (SRHA) also showed aggregation enhancement for both homo- and hetero-systems, in presence of divalent Ca2+ ions. This first-of-its-kind study allows for mechanistic evaluation of AuNS hetero-aggregation in a wide range of electrolyte conditions and can have future expansion to formulate a robust hetero-aggregation strategy for other environmentally relevant colloids.

Mechanistic hetero-aggregation of gold nanoparticles in presence of nonionic polymer modified single-walled carbon nanotubes

245th National Meeting (2013)

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