Min-Kyeong Yeo

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We investigated the environmental fate and bioaccumulation of TiO2 nanomaterials in a simplified paddy microcosm over a period of 17 days. Two types of TiO2 nanomaterials, nanoparticles (TiO2-NP) and nanotubes (TiO2-NT), were synthesized to have a negative surface charge. Ti concentrations in the environmental media (water, soil), crops (quillworts, water(More)
Metal-based nanoparticles (NPs) such as silver (Ag) and titanium dioxide (TiO2) are widely used in industrial and household applications. Because of the increasing use of such manufactured NPs and their release into the natural environment, NPs are likely to have a widespread geographic distribution. Concerns over discharge of considerable amounts of these(More)
Triclosan, bisphenol A (BPA) and bisphenol A diglycidyl ether (BADGE) are widely used in cosmetics, cleaners and plastic bowls. However, triclosan has been detected in sewage samples after treatment. Moreover, BPA and BADGE are thought to be endocrine disruptors, and these chemicals bio-accumulate in aquatic living organisms. Human skin and oral tissues are(More)
We investigated the comparative effects of Cu 15 mol % doped TiO2 (anatase crystal phase, 20 ppt) nanoparticles and pure TiO2 (anatase crystal phase, 20 ppt) nanoparticles on cellular toxicity, penetration, and gene expression in zebrafish embryogenesis. HRTEM analysis observed that pure TiO2 particles were in the form of small balls (<10 nm), while(More)
In this study, we investigated the effects of TiO2 nanoparticles, potential biological toxins, on zebrafish (Danio rerio) embryogenesis. We exposed zebrafish embryos to TiO2 particles of three different diameters (12–14 nm, 80–100 nm, 150–200 nm) and compared the acute responses of the embryos during embryogenesis. Scanning electron microscope (SEM) images(More)
We investigated the relationship between the TiO2 photocatalytic decomposition of bisphenol A and biological toxicity to zebrafish (Danio rerio). TiO2 particles, which prepared using a solvothermal method, were applied to produce a nanometer-sized TiO2 thin film. An alcoholic solution containing the TiO2 particles and an inorganic binder was directly coated(More)
In this study, we investigated the biological toxicities of two crystalline phases and differential sizes of TiO2 nanoparticles (anatase; 7–8 nm, 12–14 nm, and 17–23 nm, rutile; 80–100 nm, 150–200 nm, and 500 nm) using the zebrafish in an aquatic ecosystem. The zebrafish morphants that survived exposure to the TiO2 nanoparticles exhibited incomplete(More)
Zn-doped nano-scale TiO2 is a useful material in the production of both hydrogen energy and LEDs. However, scientists have raised concerns regarding the toxicity of nano-scale materials. In this study, we investigated the biological toxicity of nano-scale Zn (0.1, 0.5, and 1 mol%)-doped TiO2 and pure TiO2 nanoparticles using the freshwater cnidarian Hydra(More)
Nanomaterials composed of silver (Ag), copper-doped titanium dioxide (Cu-TiO2), and pure titanium dioxide (TiO2) have wide applications in consumer products such as cosmetics, electronic appliances, clothes, and industry materials such as solar cell. However, there are problems associated with the exposure of aquatic organisms in the ecosystem to such(More)
In this study, we manufactured metal-doped TiO2 nanoparticles using several transition metals (Mn, Fe, Ni, and Cu). Their physicochemical properties were evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis, and UV-visible spectra. The energy efficiency of the metals increased in the order of Ni-<Cu-<Mn-<Fe-TiO2. For(More)