Nonconventional Macromolecular Luminogens: Rational Design, Photophysical Properties, and Applications

Saha, Biswajit (2020) Nonconventional Macromolecular Luminogens: Rational Design, Photophysical Properties, and Applications. PhD thesis, Indian Institute of Science Education and Research Kolkata.

PDF (PhD thesis of Biswajit Saha (14RS005)) 14RS005.pdf - Submitted Version Restricted to Repository staff only Download (8MB)

Abstract

Conventional organic luminogens comprised of π-π conjugated structures have attracted a great deal of attention owing to their exclusive Photophysical property and multitudinous applications including organic lasers, solar cells, organic light-emitting diodes, sensors, etc. However, the high cytotoxicity and low biocompatibility of these conjugated luminogens limits their practical biomedical applications. Therefore, besides these organic luminogens, an astonishing evolution of nonconventional macromolecular luminogens (NMLs) has been witnessed over the past few years due to their unique intrinsic emission features. NMLs represent a new class of luminescent polymeric material without carrying any conjugated fluorophore unit. These are generally composed of non-traditional chromophores/electron-rich heteroatoms such as nitrogen (N), oxygen (O), sulphur (S), phosphorus (P), C=O, C≡N, tertiary amine, etc. which certainly eliminate the toxicity and introduce good biocompatibility into the systems. Moreover, NMLs follow certain principles that are quite distinct from the traditional luminescence paradigm viz. they do not require any excitation of delocalized π-electrons and do not act as an independent or single molecular unit to exhibit emission properties, contrary to traditional luminogens. The most fascinating aspect of this systems is relies on their ability to retain the emission characteristics in concentrated solution and even in aggregated/solid state. In this regard, a tremendous effort have been devoted for the design and development of these kind of unique luminescent polymeric material and to get an insight into the emission sources/mechanisms. Noteworthy, the emission mechanism is still under dark. To have a detailed knowledge of such unusual luminescence phenomenon, this thesis research mostly focus on the development of NMLs in such a way that they could possess certain interesting features: multiple stimuli-responsiveness, self-assembly and so forth, along with inexplicable luminescence characteristics by employing controlled radical and conventional free radical polymerization techniques. Indeed, the aforesaid facets allowed us to implement this diverse NMLs in various field of science such as chemical sensing, drug delivery, intracellular temperature imaging, etc.

Actions (login required)

View Item