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(373u) Novel Methods for Characterizing Surface Charge, Area and Wettability of Nanoparticles and Their Correlation with Toxicity to Bacterial Cells

Fang, X., Langmuir Center for Colloids and Interfaces
Somasundaran, P., Columbia University

Nanoparticles (NPs) have been widely applied in many applications due to their specific physical or chemical properties that differ from their bulk counterparts. Hence, quantitative analytical methods are required to characterize their physico-chemical properties, since the existing routine methods developed for coarse particles are not always applicable to NPs. Among such properties is surface energy. We designed a novel technique to quantitatively evaluate this important characteristic for metal oxide NPs. For the first time, surface energy of a series of metal oxide NPs under ambient conditions was evaluated. The value obtained for 0.1mm aluminum particles matches the literature data well. Our results also allow assessment of size effects for anatase. The surface energy of nanoparticles is related to their wettability. Therefore, the ranking of solids on a various size scales according to the surface energy gives a new insight into their interactions with their environmental neighbors, e.g. proteins, and cells.