Date of Award


Degree Name

Master of Science


Biomedical Engineering

First Advisor

Kohli, Punit

Second Advisor

Mohanty, Manoj


Polydiacetylenes (PDAs) exhibit a chromatic response to solvents, temperature, strain and other environmental perturbations. When formed in a solid-state polymerization, the backbone of the polymer is planar which provides extended conjugation polymer backbone. However, when an external force is exerted on the backbone, the extended conjugation is interrupted and an optical shift from blue to red is observed. A system using conjugated PDA Nano structures has been developed as a model to study the reversibility in the fluorescence resonance energy transfer (FRET) and electronic absorption of the PDA liposome particles. In the first study, a reversible system composed of PDA and Sulforrhodamine-101 was utilized where PDA and SR -101 act as acceptor and donor respectively. Colorimetric transition from blue to red in PDA liposomes was achieved through heating the conjugated liposomes. In this work, the FRET mechanism was evaluated without violating the role of nature that energy flows "down" hill and that the role of donor and acceptor in FRET are fixed. Reversible interchanging roles of donor and acceptor over many thermo-chromatic cycles in a modified-PDA-SR101 liposomal system were also evaluated. The nanotubes synthesized are thus unique and robust. The characterization studies showed that the nanotubes are both in Nano and micro scale. Thus the self-assembled chemistry using this material would find wide applications in such areas such as sensors, actuators, and computational devices at both micro and nano scale and further studies might offer them as an encapsulation drug delivery vehicle. Both these studies offer a new insight to the unique properties of polymerized PDA liposomes.




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