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Linking the Physicochemical Properities of Titania with Its Biocidal Properities
Citation:
Veronesi, B., C. Han, L. Putvin, M. Pelaez, H. Zamankhan, H. Choi, D. Betancourt, AND D. Dionysiou. Linking the Physicochemical Properities of Titania with Its Biocidal Properities. Presented at SOCIETY OF TOXICOLOGY MEETING, Phoenix, AZ, March 23 - 27, 2014.
Impact/Purpose:
This is a novel attempt to use cost effective, HTP screening models(bioluminescent bacteria) to link physicochemial properties of nanoparticles with their biocidal toxicity.
Description:
LINKING THE PHYSICOCHEMICAL PROPERTIES OF TITANIA WITH ITS BIOCIDAL PROPERTIES. C. Han1, L. Putvin2, M. Pelaez1, H. Zamankhan3, H. Choi3, D. Betancourt4a, D. Dionysiou1. B. Veronesi4b, 1 Department of Biomedical, Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, 2 Department of Biomedical Engineering, North Carolina State University, Raleigh, NC, 3Department of Civil Engineering, The University of Texas at Arlington, Arlington, TX and 4a National Risk Management Research Laboratory and 4bNational Health and Environmental Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC, Modification of parent TiO2 nanoparticles is done to optimize photo-efficacy under either solar light or visible light illumination. However, cost effective and relevant, high throughput assays (HTP) are needed to test the modified materials for effectiveness and environmental risk. TiO2 nanoparticles are well known for their biocidal properties. A series of TiO2 materials with different crystal phase, size, porosity, and surface area were synthesized by sol-gel methods followed by calcination at temperatures ranging from 100-900 °C. Each material was characterized by conventional microscopy and physicochemical techniques. The materials exhibited pore volumes in the range 0.2-0.659 cm3/g, BET surface areas from 0.95 to 482 m2/g and crystalline size from 4.5 to 42.5 nm. To understand if the biocidal effectiveness of these materials related to physicochemical characteristics, a HTP assay was used that featured a gram negative, bioluminescent bacteria (vibrio fischeri). Viability measures of these organisms were collected after a 30 and 60 min exposure to each material (500-2000 g ml-1). The anatase crystal phase was consistently more toxic than rutile phase. Linear regression analyses indicated that across all concentrations, the highest correlation between toxicity and the individual physical characteristic occurred in the following rank order (highest to lowest): porosity>surface area>>particle size. Such data sets may be helpful in the future design of metal oxides with controlled biocidal properties. This abstract does not reflect the views and policies of the USEPA.