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Current Research
My research interest is in the design and synthesis of inorganic/bio-organic nanoscaled components that can self-assemble into 3-dimensional hierarchical structures with novel physical and chemical properties. Our strategy is to abstract the efficient designs from nature to guide the synthesis of self-assembled components of materials systems.
Our research goal is to advance the understanding of the self-assembly process in the bio-inorganic systems by determining the physical and chemical mechanisms by which important inhibitors or promoters control the nucleation, growth, aggregation, and phase transformations of materials assembled from asymmetric and/or symmetric components. The types of systems we are currently studying are nanospheres, nanowires, and icosahedral viruses.
For the icosahedral virus system, we are investigating the properties and assembly mechanism of these particles from small protein fragments into virus crystals. Specifically, we examine the effects of different solution compositions on the assembly of virus structures in solutions. We are also mapping the inter-viral potential energy surfaces in different solution compositions that lead to different virus assembled structures with force microscopy techniques. Comparison between the hierarchical structures made with different solution compositions and Monte Carlos simulation results of the model systems with the thermodynamic data from the energy landscape measurements are used to provide further insight of the assembly mechanisms.
Since device physics and properties of materials are known to change when the dimension of the device is reduced down to the nanometer scale, we are also applying the knowledge learnt from the self-assembly mechanism to engineer and characterize functional nanostructures for prototyping various kinds of analytical devices. The aims of these projects are to bridge the "gap" in the assembly of materials between the nanoscale (1-10nm), mesoscale (10nm - 1µm) and the micron scale systems for the fabrication of functional devices and systems.
In my research group, students gain experience in synthesizing low-dimensional materials such as semiconducting nanotubes and nanowires using liquid phase and chemical vapor deposition methods. They also learn diverse materials characterization skills such as atomic force microscopy, transmission electron microscopy and scanning electron microscopy. They do research in areas ranging from biomimetics through physical chemistry to materials science and analytical device fabrication.
Recent Publications
Wang, G.; Brewer, J.R.; Chan, J.Y.; Diercks, D.R. and Cheung, C.L., "Morphological evolution of neodymium boride nanostructure growth by chemical vapor deposition", Journal of Physical Chemistry C, 2009. in Press
Nikolic, RJ (Nikolic, R. J.); Conway, AM (Conway, A. M.); Reinhardt, CE (Reinhardt, C. E.); Graff, RT (Graff, R. T.); Wang, TF (Wang, T. F.); Deo, N (Deo, N.); Cheung, CL (Cheung, C. L.), "6 : 1 aspect ratio silicon pillar based thermal neutron detector filled with B-10", Applied Physics Letters, 93 (13): Art. No. 133502 Sep 29 2008
Deo, N (Deo, N.); Brewer, JR (Brewer, J. R.); Reinhardt, CE (Reinhardt, C. E.); Nikolic, RJ (Nikolic, R. J.); Cheung, CL (Cheung, C. L.), "Conformal filling of silicon micropillar platform with 10boron", Journal of Vacuum Science & Technology B, 26 (4): 1309-1314 Jul 2008.
Wang, G (Wang, Gonghua); Brewer, JR (Brewer, Joseph R.); Namavar, F (Namavar, Fereydoon); Sabirianov, RF (Sabirianov, Renat F.); Haider, H (Haider, Hani); Garvin, KL (Garvin, Kevin L.); Cheung, CL (Cheung, Chin Li), "Structural study of titanium oxide films synthesized by ion beam-assisted deposition", Scanning, 30 (2): 59-64 Mar-Apr 2008.
Namavar, F (Namavar, Fereydoon); Cheung, CL (Cheung, Chin Li); Sabirianov, RF (Sabirianov, Renat F.); Mei, WN (Mei, Wai-Ning); Zeng, XC (Zeng, Xiao Cheng); Wang, GH (Wang, Gonghua); Haider, H (Haider, Hani); Garvin, KL (Garvin, Kevin L.), "Lotus effect in engineered zirconia", Nano Letters, 8 (4): 988-996 Apr 2008.
Brewer, JR (Brewer, Joseph Reese); Deo, N (Deo, Nirmalendu); Wang, YM (Wang, Y. Morris); Cheung, CL (Cheung, Chin Li), "Lanthanum hexaboride nanoobelisks", Chemistry of Materials, 19 (26): 6379-6381 Dec 25 2007
