Nanomaterials based on block copolymers

Research area: Polymer science, nanomaterials and nanocomposites
Degree: Honours
Supervisors: Prof Naba Dutta and Prof Namita Roy Choudhury

Summary: Block copolymers, with monomer sequences sufficiently incompatible, spontaneously self-assemble in order to minimize interactions between their incompatible components. Depending on the structure considered in the block copolymers, the incompatible segments might be of different contrast such as: compositional contrast; conformational contrast (rigid/flexible, oriented/unoriented, long/short); morphological contrast (amorphous/crystalline, glassy/rubbery, swollen/contracted) etc. Nevertheless, the chemical link between different blocks prevent phase separation in macroscopic length scale and the phase separation leads to regular structures with periodicity in the nanometre range, whereas dilution with solvent produces highly associated but disordered phases.

Depending on the composition of the amphiphilic polymers and the interaction between constituent segments different packing (sperical, cylindrical, bi-continuous, lamellar, etc.) and morphologies of typical domain size in nanometre range emerge. By controlling appropriately the segment nature and length of each constituent of the block in block copolymers, a wide variety of micro-domain structures of high degree of richness and complexity in bulk as well in solution phase are possible (1-4). The supramolecular assemblies of meso/nano-scale dimension are of great recent interest in the design of novel functional materials and template for nanocomposites.

A specific block copolymer may be optimum nanomaterial, either for their intrinsic properties as self-organised assemblies or for their ability to template other organic, inorganic, semi-conducting, metallic or biologically relevant materials. The clever manipulation of this architectural contrast and self-organisation provide us with the opportunity to use them as the optimum nonmaterial for nanotechnology, either for their intrinsic properties as self-organised assemblies or for their ability to template other organic, inorganic, semiconducting, metallic, magnetic or biological relevant materials (5-8). 

The aim of this project is to use the block as precise nanoreactors (diameter between 1 to 15 nm) for organization of self-assembled fillers or other inorganic nanoparticles followed by their immobilization/stabilization as guest material. The effect of selective solvent on the phase behaviour block copolymer will be carried out in details. The characterization of the morphological and thermodynamic behaviour will be carried out using differential scanning calorimetry, rheology and atomic force microscopy and transmission electron microscopy.

References
1.Amphiphilic Block Copolymers: Self-Assembly and Applications, Eds. P. Alexandridis; B. Lindman, Elsevier, Amsterdam, 2000.
2. F. S. Bates and G.H. Fredrickson, Physics Today, 52 (1999)32.
3. N.K. Dutta, N.; Roy Choudhury A.. Bhowmick, Hand book of Thermoplastics, ed. Olagoke Olabisi, Marcel Dekker, New York, 1997.
4. E. L.Thomas, D. M. Anderson, C. S. Henkee, D. Hoffman, Nature 334 (1988) 598.
5. M.U. Pralle, C. M. Whitaker, P. V.Braun and S.I Stupp, Macromolecules 33 (2000) 3550.
6. E. Jeoung, T. H. Galow, J. Schotter, M. Bal, A. Ursache, M. T. Tuominen, C. M. Stafford, T. P. 7. Russel and V. M. Rotello, Langmuir, 17(2001)6396.
8. T. Hashimoto, K. Tsutsumi and Y. Funaki, Laangmuir, 13 (1997) 6869.

Areas of study and research

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