• Journal of Surface Science and Engineering
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• v.57 no.5
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• pp.406-415
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• 2024

Using DC magnetron sputtering, we deposited a bilayer composed of a seed layer consisting of Ti, Cr, Co, and Zr, and an overlayer of Ag on MgO(001) single crystal substrates, creating self-assembled nanostructures. When Ti was used as the seed layer, it was observed that the formed nano-dots inherently aggregated into dot shapes. Additionally, Cr, Co, and Zr were chosen to investigate their influence on SLAA(Seed layer Assisted Agglomeration) depending on the seed layer material, revealing different shapes of the formed nano-dots. Moreover, it was observed that aggregation was inhibited as the thickness of the seed layer exceeded a critical point. X-ray diffraction analysis of the Ti seed layer revealed epitaxial growth of Ag along the (001) direction of the MgO substrate. In contrast, no epitaxial growth was observed when Cr, Co, and Zr were used as seed layer materials. Ultimately, Ti was identified as the most suitable seed layer material for the fabrication of self-assembled nanostructures utilizing the aggregation phenomenon of the bilayer. This research is deemed sufficiently valuable in addressing the limitations associated with the low productivity and high cost of current nano thin film processes.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.611-618
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• 2007

We demonstrate the sol-gel coating technique of colloidal clusters for producing hollow micro-particles with complex morphologies. Cross-linked amidine polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion copolymerization of styrene and divinylbenzene. The amidine PS particles were self-organized inside toluene-in-water emulsion droplets to produce large quantities of colloidally stable clusters. These clusters were coated with thin silica shell by sol-gel reaction of tetraethylorthosilicate (TEOS) and ammonia, and the organic polystyrene cores were removed by calcination at high temperature to generate nonspherical hollow micro-particles with complex morphologies. This process can be used to prepare hollow particles with shapes such as doublets, tetrahedra, icosahedra, and others.