Chih Hao Yu

Engineering of a monodisperse core-shell magnetic Ti-O-Si oxidation nanocatalyst.

There has been limited development in catalyst carriers for magnetic separations where superparamagnetic nanoparticles of a high saturation magnetization with no coercivity are required to isolate expensive catalyst reagent that are subjected to repeated magnetic cycles. By using simple stepwise layer-by-layer nanochemistry techniques, we show that an fcc FePt nanomagnet can be created inside each silica particle with tailored dimensions to great precision. Subsequent engineering of the external surface with Ti-O-Si species in an optimum structure to create a unique interface gives high activity and excellent selectivity of the composite material for the trans-stilbene oxidation to the corresponding epoxide in the presence of tert-butyl hydroperoxide. Thus, a new magnetic separable epoxidation catalyst is described. This work clearly demonstrates the significance of nanoengineering of a single catalyst particle by a bottom-up construction approach in modern catalyst design, which could lead to new catalytic properties.

Functionalized Silica Coated Magnetic Nanoparticles With Biological Species for Magnetic Separation

Magnetic nanoparticle captured in a thin functional coating as magnetic separable nano-vehicle for carrying chemical species is a hot and challenging area. Here, we report a synthesis of silica encapsulated magnetic nanosize particles (4-11 nm) as a magnetic separable carrier based on a simple microemulsion technique. The silica coating surface is shown to isolate and protect the magnetic core from reactive environment where a range of conditions for magnetic separation can be made possible. Thus, it is demonstrated that the relatively smaller size coated magnetic nanoparticle can carry bulky protein, the bovine serum albumin (BSA) on the silica overlayer surface, which is confirmed by the FTIR study.

Chapter 5 Chemical Methods for Preparation of Nanoparticles in Solution

Abstract The technology for synthesis of nanomaterials with defined dimensions, structure and composition is one of the most important pre-requisite criteria before new applications such as bio-separation, drug delivery, imaging, catalysis, sensing and data storage can be systematically studied. Chemical synthesis represents a key approach for the production of materials, which generally involves a number of steps taking place in liquid or gas phase. The formation of atoms can be accomplished by using chemical reaction(s) under controlled but mild reaction conditions. Thus, freshly formed atoms can then undergo elementary nucleation followed by growth processes leading to the formation of defined nanoparticles. This chapter will highlight some common chemical methodologies for the synthesis of metal and metal core-shell nanoparticles with particular emphasis on the important roles of solvent, capping agent, additive and stabilizer for kinetic controls of tailored nanomaterials.

Chapter 10 Some Applications of Nanoparticles

Abstract Nanotechnology is science and engineering at the scale of atoms and molecules. It is the manipulation and use of materials and devices at this level, which is going to create significant impacts on our daily life ranging from fabrication of new construction materials to applications in biomedicine and pharmaceuticals. In this chapter, two areas of applications, namely biotechnology and industrial catalysis, are particularly highlighted. In the biotechnology area, magnetic nanoparticles for drug screening, contrast enhancement agents, magnetic resonance imaging, medicine and bio-separation are focused. Catalysis plays an important role in our society. Presently, over 90% of all industrial chemical productions involve the use of at least one catalytic step. Structure of catalyst used determines how atoms interact on surface. This chapter will demonstrate the use of tailored nanoparticles which offers exciting possibilities for engineering reaction selectivity of catalytic systems of interests at molecular level.

Fe3O4-in-silica super crystal of defined interstices for single protein molecules entrapment under magnetic flux

Confocal fluorescence demonstrates that single molecules of dye-labelled Cytochrome C or B5 containing paramagnetic Fe(III) can be magnetically placed into the interstices of super-crystal which is composed of three dimensional regular arrays of Fe(3)O(4) nanoparticles.