Deakin Research

Institute for Frontier Materials

Nanoparticles

Porous TiO2 with a controllable bimodal pore size distribution from natural ilmenite

Tao Tao, Alexey M. Glushenkov, Qiyuan Chen, Huiping Hu, Dan Zhou, Hongzhou Zhang, Markus Boese, Sanly Liu, Rose Amal and Ying Chen

CrystEngComm 13 (2011) 1322-1327

Abstract: A new combination method of ball-milling, carbothermal reduction, dilute hydrochloric acid leaching and final calcining in air is used for the synthesis of porous titanium dioxide from ilmenite (FeTiO3). The resulting TiO2 is a porous material with a bimodal pore structure that consists of small mesopores (2-30 nm) and large meso- and macropores (centered at around 50-80 nm), respectively. The obtained porous rutile TiO2 shows a better photocatalytic activity than that of a commercial rutile TiO2 powder. Furthermore, a red shift in the band gap transition can be seen for the porous TiO2, which implies the possibility of photocatalytic activity under visible light irradiation.

TEM images of the porous TiO2 particles




Controlled amine functionalization and hydrophilicity of a poly(lactic acid) fabric

X. J. Dai, J. du Plessis, I. L. Kyratzis, G. Maurdev, M. G. Huson, C. Coombs

Plasma Process. Polym. 2009 accepted.
X. J. Dai, J. S. Church, M. G. Huson, Plasma Process. Polym. 2009, 6, 139

Plasma is a fourth state of matter after solid, liquid and gas. Various "cold" plasmas can now be generated in the laboratory and used to change surfaces or add entirely new layers to surfaces. This opens up enormous opportunities to tailor surfaces for particular applications. A novel plasma polymerization technology has been developed that can produce fluorescent organic nanoparticles (particles of 20 to 50 nm that give off visible light when stimulated with ultra-violet light). These are an alternative to quantum dots for potential application in drug delivery and early disease diagnosis. Another pulsed plasma functionalization system has been developed that can give nanostructured coatings or introduce various chemical functional groups (-NH2, -COOH, -SH, etc.) onto metals, semiconductors, ceramics, polymers, fibres, CNTs, and nanoparticles. The functional groups can be well controlled to match the requirements of the new surface, especially for improved biocompatibility of implants.

(a)&(b) AFM & SEM images of the fluorescent nanoparticles; (c) fluorescent spectra
(d)&(f) the density of -NH2 functional groups can be controlled by selection of pulsed plasma conditions




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Commercial scale production of inorganic nanoparticles

Takuya Tsuzuki

International Journal of Nanotechnology, 6 (2009) 567

Abstract: This review focuses on the current trend in the commercial scale production methods of inorganic nanoparticles. The limiting factors for the scalability of synthesis methods are explained and the relationship between commercial nanoparticle materials and production methods is discussed. Particular emphasis is placed on the fact that different synthesis techniques lead to different properties of nanoparticles even when the qualities such as particle size and crystal phase appear quite similar. The production techniques of nanoparticles need to be carefully selected based not only on the scalability and production costs, but also on the properties of nanoparticles required for specific applications.

Applications of Nanoparticles




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Mechanochemical synthesis of nanocrystalline SnO2-ZnO photocatalysts

Aaron Dodd, Allan McKinley, Martin Saunders and Takuya Tsuzuki

Nanotechnology 17 (2006) 692

Abstract: Mechanochemical processing of anhydrous chloride precursors with Na2CO3 has been investigated as a means of manufacturing nanocrystalline SnO2 doped ZnO photocatalysts. High-energy milling and heat-treatment followed by washing resulted in the formation of a SnO2 / ZnO hybrid nanopowder. The nanopowder was found to exhibit significantly higher photocatalytic activity than either single-phase SnO2 or ZnO powders that were synthesized using similar processing conditions. The heightened photocatalytic activity of the SnO2 doped ZnO was attributed to its higher specific surface area and the enhanced charge separation arising from the coupling of ZnO with SnO2

Bright-field TEM images  Bright-field TEM images

Bright-field TEM images of washed (SnO2)0.1(ZnO)0.9 powders DMPO-OH concentration as a function of exposure time for aqueous slurries of ZnO, SnO2, and (SnO2)0.1(ZnO)0.9 suspensions that were synthesized using a heat-treatment temperature of 700 °C




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Highly Transparent Refractive-Index Modified ZnO - Organic Hybrid Films

Takuya Tsuzuki

Macromolecular Materials and Engineering, 293 (2008) 109

The refractive index of ZnO/organic nanocomposite films was modified in the range from 1.44 to 1.55, while maintaining high visible transparency. The transparency of the nanocomposite films showed an abnormal behaviour as a function of the loading level of inorganic particles, because it did not decrease according to the Beer-Lambert law, but rather saturated to a near-constant value at high particle loading levels above 8 vol%. On the other hand, the refractive index of the film showed good agreement with the Bruggemann model, linearly increased as particle concentration increased. This result indicates the possibility of fabricating highly transparent nanocomposite films with controlled refractive indices.

image at 100 nm  refractive index

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21st February 2012