Nanostructured and Functionalized Materials and Devices
Another major area of research in the Department focuses on specially functionalized materials for biosensors, polymer electronics, and novel tunable membranes and for applications in life sciences. This Thrust also encompasses activities in synthesis of nanostructured materials for catalysis, separations technology and fuel cells. The research programmes span wide range of length scales, from molecular-level synthesis and manipulation of materials to the macroscopic fabrication of surfaces and bulk materials and nanocomposites. Excellent, in-house analytical and characterization facilities (e.g., a number of spectroscopic techniques, transmission and scanning electron microscopes, X-ray diffractometers, etc.) provide support for cutting-edge research in the Department.
Current research activities in functionalized and nanostructured materials & devices in the Department include, but are not limited to,
Materials for biomedical applications
Molecular functionalization techniques are used to tailor substrates for biomedical applications. Examples include microbicidal surfaces which inhibit biofilm formation; high strength bone cements with bactericidal biopolymers or antibiotic-conjugated monomers which achieved higher antibacterial efficacy longer than the present cements; and magnetic nanoparticles for bioimaging and tumor targeting. In a separate development, the adsorption disruption of oriented liquid crystal molecules on a patterned surface was developed into a new label-free optical method for the simultaneous detection of multiple glycine oilgomers using sample size as little as 2 μL.
Materials for energy applications
Research in energy is focused on the design and synthesis of new and alternative materials for energy supply, transformation, storage, delivery and end-use. There are strong coordinated efforts in developing catalysts for fuel production, and for the non-oil based route to chemicals production. Ceramic membranes are used to produce oxygen from air. Electrochemical energy conversion is another focused research area covering a number of technological areas: anode materials for lithium-ion batteries, catalysts and polymer electrolyte membranes for direct alcohols fuel cells, and materials for supercapacitors.
Materials for optoelectronic applications
Many optical devices based on 3D photonic crystals, such as optical switches, low-threshold lasers and light-emitting diodes, and waveguide, require the exact placement of artificial defects embedded in the interior of the photonic crystals. We have recently embedded artificial line-defects in a 3D photonic crystal using a combination of “bottom-up” self-assembly method and the conventional “top-down” technique. The new technique circumvents some of the problems in the self-assembly approach to fabricating functional photonic devices from photonic crystals.
Polymer and molecular electronics
Molecular memories based on polymers and organic materials have the advantages of simplicity in structure, drive-free read and write capability, good scalability, 3-D stacking ability, low-cost potential, and a large capacity for data storage. By combining molecular design with novel synthesis approaches, several polymer/molecular memories, including flash (rewritable) memory, write-once read-many-times (WORM) memory and dynamic random access memory (DRAM) have been realized. All these devices exhibit stable states with high ON/OFF current ratios (104-107), and perform up to 108 read cycles under ambient conditions.
Self-assembly of nanomaterials
A real-world functional material (e.g. solid catalyst) is a highly organized multi-component materials system. This modern view calls for the development of new strategies promoting the self-assembly of various functional components. For example, catalytic metals such as Au and Co can be introduced to the exterior surfaces or interior spaces of photosensitized metal oxide systems to enhance their functions as preparative nano-reactors. In another development colloidal and interfacial polymerizations are used to produce hydrophilic-lipophilic polymer composite membranes for separation; and micro-spheres and porous continuous media for catalyst immobilization and storage of energetic materials.