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Association of Nano-C60 with Clay Minerals.

Abstract:

Rapid industrial scale production, coupled with unique material properties, under-pin rising concerns of nano-scale materials inadvertently impacting the health and func-tion of natural systems. Carbon based, nano-scale materials such as fullerenes and nanotubes in particular, have been widely proposed for a variety of applications. Fun-damentally understanding the behavior of these materials in natural matrixes is critical for accurate risk assessments and effective waste disposal management. Of particular interests are interactions with high-surface area, charged sub-surface fractions such as clay minerals and natural organic matter as they relate to the fate and transport proc-esses of said materials. To date, information regarding interactions between fullerenes and fullerene derivatives with clay minerals has been limited and focused on underivat-ized fullerenes in organic solvent and/or specific water soluble fullerene derivatives in-teracting with defined clay minerals. Research presented herein details specific interactions between C60 as an aggre-gate suspension (20-150 nm crystalline aggregates of underivatized fullerenes in water - termed nano-C60 [1]) and clay minerals; specifically, with a smectite (Ca-bentonite Cal-cigel, Bavaria Germany; Sudchemie AG), a kaolinite (KGa-1, Georgia; CMS source clay), and a synthetic layered double hydroxide (LDH Syntal HSA 696; Sudchemie AG). Batch and simple 1-D flow-through column interactions were analyzed via trans-mission electron microscopy, X-ray diffraction analyses and UV/Vis spectroscopy. Re-sults indicate that nano-C60 suspended in water does interact with clay minerals. The synthetic LDH, with a positive surface charge, had the greatest capacity to associate with the negatively charged nano-C60. Findings suggest that specific material interac-tions are primarily dominated by: - Available surface area; the more surface area available will result in higher associa-tion capacities. - Positively charged points on the mineral surface and/or edge in relation to the net negative surface charge of nano-C60 (as an electrostatic interaction). - Probable incorporation into mineral interlayers (smectite and LDH). [1] Fortner JD, Lyon DY, Sayes CM, Boyd AM, Falkner JC, Hotze EM, Alemany LB, Tao Yj, Guo W, Ausman KD, Colvin VL, Hughes JB. C-60 in water: Nanocrystal for-mation and microbial response. Environmental Science and Technology, 39 (2005) 4307

Authors:

Fortner, John and Plötze, Michael and Solenthaler, Christian

Index Terms:

ClayGroup; clay; c60; ldh; Fortner, John; Plotze, Michael; Solenthaler, Christian

Further Information:

Date published: 2006