Xl 30 fe sem

Abraded particles were collected on the bottom of the abrasion chamber on transparent drafting paper. Abrasion products were suspended in water to facilitate aquatic toxicity testing in a future study not reported here. Particles were characterized to determine their size, morphology, chemistry, and speciation of MWCNT. The size distribution of particles was measured by laser diffractometry using a Mastersizer 3000 (Malvern, UK) in batch experiments (1 g/L). Because of the high propensity for aggregation of particles in water, the particles were suspended in pure ethanol. For this same reason, we filtered ethanol suspended particles onto 50 nm cutoff polycarbonate filters (Isopore^™ Millipore) for SEM imaging. The filters were dried, gold-coated using a vacuum sputter coater (Denton Desk IV) and imaged using a FEI XL30 FE-SEM. Particle chemistry was assessed using FTIR (Thermo Scientific Nicolet 8700).