Nanomaterials Synthesis and Applications

Our multi-disciplinary research group is exploring new ways of synthesizing size and shape-controlled metal, metal oxide and semiconductor nanoparticles/quantum dots based on chemical and biological principles. We are also very keen to develop the synthesis of specialized ligands for the surface engineering of these nanomaterials that would enable us to functionalize nanoparticle surfaces with various biomolecules and trigger their self-assembly into organized nanostructured materials with potential applications in biotechnology, catalysis, nanoelectronics and optics.

In particular, we are interested to explore the applications of nanomaterials in drug/gene delivery and to improve sensitivity and specificity of PCR-based diagnostic assays for the detection of infectious diseases. Ultrasensitive nanoprobes are being developed based on peptide/DNA/siRNA - nanoparticle bioconjugates to study nanoparticles-cell interaction, uptake and their toxicity, in collaboration with our national/international counterparts. We are also working on the use of nanoparticles as building blocks to design/fabricate new nano-structured materials such as nano/microwires, nanochains, porous composites and thin films etc. based on solution-based and/or template-based self-assembly strategies, for applications in catalysis, nano-electronics, optics and environmental remediation etc.

Faculty: Dr. Irshad Hussain

Recent research highlights of our group:



"Controlled step growth of molecularly linked gold nanoparticles: From metallic monomers to dimers to polymeric nanoparticle chains". I. Hussain, M. Brust, J. Barauskas and A.I. Cooper Langmuir, 2009, In press.



"Freeze-align and heat-fuse: Producing microwires from nanoparticle suspensions". H. Zhang, J-Y. Lee, A. Ahmed, I. Hussain and A.I. Cooper Angew. Chem., Int. Ed., 2008, 47, 4573-4576.

Synthesis and Properties of Magnetic and Electronic Perovskite Metal Oxides

We are interested in synthesis, characterization and properties of multifunctional transition metal perovskite oxides. Materials exhibiting colossal magnetoresistance (CMR), such as Sr2FeMoO6, LaxSr1–xMnO3 and related materials, undergo a large change in electrical resistance in response to an external magnetic field. These materials have potential applications in magnetic data storage devices, spin valves, sensors etc. We synthesize perovskite metal oxides by conventional solid state methods and sol gel methods and characterize them by powder X-ray diffraction technique. Their magnetic and electronic properties are investigated for their potential applications.
  

Another area of interest is synthesis of thermoelectric oxide materials (bulk), thin film deposition and their characterization. Thermoelectric oxide materials have potential applications in direct conversion of heat into electric power at higher temperatures where conventional thermoelectric materials do not work efficiently. In order to realize an efficient thermoelectric energy conversion, the following three physical properties are required in thermoelectric materials: (1) low thermal conductivity (?), which is necessary to introduce a large temperature difference into two ends of the material, (2) high electrical conductivity (?), which is required to reduce the internal resistance of the material, and (3) large thermoelectromotive force (Seebeck coefficient, S), which is needed to obtain a high voltage. Generally, the performance of a thermoelectric material is evaluated in terms of the dimensionless figure of merit, ZT = S2?T??1, where Z and T are the figure of merit and the absolute temperature, respectively. For practical thermoelectric applications, thermoelectric materials with ZT > 1 are required. We are investigating various perovskite oxide materials for their thermoelectric properties.

Faculty: Dr. Falak Sher

Catalysis and Green Chemistry

Our research interests lies at the interface of inorganic and organic chemistry. On the inorganic side, we are interested in designing new ligands. Once synthesized, these new ligands will be tested for improved efficiencies in various catalytic reactions. On the organic side, we are interested in developing new synthetic methodologies based on transition metal catalysts that will stream line the synthesis of small organic molecules by avoiding large number of steps required in the current procedures. Besides these we are also interested in designing new thiophene based conducting polymeric materials.

Faculty: Ghayoor Abbas Chotana

Irshad Hussain, Mathias Brust, Justas Barauskas and Andrew I. Cooper. Controlled step growth of molecularly linked gold nanoparticles – from metallic monomers to dimers to polymeric nanoparticle chains. Langmuir, 25, 1934, 2009.