Functionalising surfaces with unique properties via chemical and physical treatments at the nano-scale.

This research mainly covers three areas:

Superhydrophobic Thin Films

Fabrication of hydrophobic/superhydrophobic thin films and their application in a wide range of fields including self-cleaning, stain resistance and anti-fouling.

Surfaces on which the contact angle with water is greater than 150 degress are commonly referred to as superhydrophobic. Surfaces with this particular property presents self-cleaning properties, e.g., non-adhesive towards ice, snow, biological foulants and other unwanted contaminants.

Our research focus is on the fabrication of superhydrophobic surfaces combining novel elements of synthetic organic/inorganic nano-hybrids and advanced physical characterisation. Thin films prepared by packing hydrophobic modified nanoparticles provide the surface with extreme roughness. The resulting surface exhibits hydrophobicity with a contact angle reaching 175o and hysteresis less than 10o. The process demonstrates the power of nanotechnology in making unique products in an easier and less expensive way.

Thin Films Incorporating TiO2 Nanocrystalline Particles

Low temperature fabrication and incorporation of photocatalytic TiO2 nanocrystalline particles into polymers and textiles.

The ability of titanium dioxide (TiO2) nanocrystalline particles to oxidize a wide range of organic compounds under UV irradiation and eventually lead to complete decomposition into H2O and CO2 is environmentally friendly and renewable. Our research emphasizes the photocatalytic efficiency of TiO2 at a solid-solid interface as well as the study of its mechanistic pathways. Potential applications include self-cleaning coatings for textiles.

Tunable Hierarchical Roughness

Investigate the effect of controlling nanoparticle aggregation on hierarchical roughness of nanoparticle thin films.

The ideal non-stick surface is one that exhibits hierarchical roughness and hydrophobic surface chemistry. The surface of a lotus leaf exhibits co-existence of macro, micro and nanoscale topography. This combination results in a perpetually clean leaf surface. To harness this self-cleaning ability, biomimetic surfaces were fabricated synthetically using techniques such as lithography, plasma etching and most commonly, silica nanoparticle aggregation. The next step in non-stick surface fabrication is to control the hierarchical roughness at multiple length scales. The seemingly innocuous act of controlling roughness at the micron scale can cause a dramatic change in properties. Recent work has revealed that through simple micro-roughness control, a superhydrophobic surface exhibited both optical transparency and antifouling capabilities.