Assembly of Regioregular Polythiophene onto Silicon Dioxide Dielectric Layer: Towards High Performance Polymer Thin Film Transistors

Polymer thin film transistors have potential to replace the conventional amorphous silicon transistors for certain applications. A high quality organic/inorganic hybrid junction can be created by assembling regioregular polythiophene derivatives on the surface of silicon dioxide dielectric layer. The polymer will be covalently bound to the silicon dioxide substrate (polymerization from surface or grafting onto silicon dioxide) or aligned to the surface by functional groups driven assembly. Correlation of the alignment of the polymer chains with the device performance will allow its optimization and a better understanding of the charge transport mechanism in polymer thin film transistors.

Supramolecular Organization in Electronic Polymers: Block-Copolymers Containing Regioregular Polythiophenes and Liquid Crystalline Polymers

Well-defined rod-rod block copolymers containing regioregular polythiophene and helical liquid crystalline segments will be generated by a combination of living polymerization techniques. Poly(N-hexylisocyanate), poly[(R)-2,6-dimethylheptyl isocyanate], poly(N,N-di-n-hexylguanidine) and poly(g-benzyl-L-glutamate) will be incorporated in block copolymers with regioregular poly(3-hexylthiophene). These novel materials are expected to generate well-ordered supramolecular assemblies with tunable optoelectronic properties. The proposed rod-rod copolymers will be used in organic electronics applications, such as thin film transistors and chemical sensors.

Novel Lanthanide Catalysts for the Synthesis of Biodegradable Materials Based on Aliphatic Polyesters for Localized and Controlled Drug Delivery

This proposal describes the synthesis and characterization of new b-diketiminate lanthanide complexes. Their catalytic activity in ring-opening polymerization of e-caprolactone and L-lactide can be tuned by changing the ligand environment and the lanthanide ion. The optimization of the proposed catalytic system is expected to generate a living ring-opening polymerization. Incorporation of e-caprolactone and L-lactide in well-defined block copolymer structures with variable compositions will generate tunable rates of degradation, which are required for their successful use in localized and controlled drug delivery.

Conjugated Polymer-quantum Dot Networks for Hybrid Solar Cell Applications

Extensive research is currently directed towards conjugated polymer-quantum dot bulk heterojunction solar cells, an alternative to crystalline silicon inorganic counterparts. To increase the performance of these solar cells, quantum dots must be efficiently blended into the conjugated polymer matrix. Additionally the charge transport through the conjugated polymer quantum dot interface must be improved. Here conjugated polymer-quantum dot networks will be generated using the interaction between quantum dots and poly[2-methoxy-5-(2’-ethylhexyloxy)-1,4-phenylenevinylene] derivatives containing 4-alkoxypyridine side chains or poly(4-vinylpyridine) grafts. The interaction of pyridine motifs with the quantum dots is expected to create both an increased interfacial contact and a more effective dispersion of the inorganic phase into the organic matrix.