Preparation of nano-structured macro-porous materials

Abstract

This research reveals a catalyst development towards achieving catalysts with hierarchical porous structures with enhanced mechanical properties by using nano-structured macro-porous PolyHIPE polymer. This work can be divided into two parts: the fabrication and its characterisation of hierarchical metal structure using PHP and other fibre materials; and the fabrication and characterisation of PHP with silica particles and glass wool, further coated with silane material as templates. A catalyst system was successfully fabricated forming a 3D-interconnecting network of pore size, ranging from tens of micrometers and gradually reducing finally to nanometer scale. An electroless deposition flow through method using Ni-B bath solution was performed on the templates and was subsequently heat treated to obtain porous metallic structures, thus providing accessibility for reactants to the surface and for products away from the surface. Meanwhile, silanated templates were produced by surface treatment. This was performed by submerging templates directly into the silanes solution at room temperature (24°C) using a water-ethanol based solution of the silanes. The polymer-metal/alloy or silica functionalized based composite demonstrated a high impact strength. The results showed that not only hierarchical pore structure was formed, but it was also demonstrated that silica particles were totally and uniformly covered/coated by metal deposit and had good adhesion. When used on glass wool, silanation had greatly improved the bond strengths of metal deposits to the templates. SEM micrographs revealed that the formation of cracks were tremendously reduced and exhibited higher bond strengths due to silanated glass surface. It is expected to be more efficient and robust in the case of an enhanced surface area, and most desirable in catalyst applications.