Research Fellows Directory
Dr Santanu Panja
University of Glasgow
Optoelectronic materials are hugely important for devices such as solar cells. Most examples are based on inorganic materials, where it is difficult to fine-tune the properties, or organic polymeric materials. For polymeric materials, synthesis is often difficult to reproduce exactly, leading to variable properties. An alternative route is the exploitation of the self-assemble features of small organic molecules into the larger structures through the implication of various non-covalent forces (hydrogen bond, p-stacking, electrostatic and van der Waals interactions etc.) involving gelation. Such gels are easy to make and if structural designs are appropriate, it is then possible to induce these molecules to self-assemble into the larger structures that will make up the optoelectronic device.
However, a key issue is that most self-assembled gels are prepared under kinetic control, meaning that reproducibility and scalability are difficult. In general, self-assembled gels are prepared at a high rate, where errors are maintained during self-assembly leading to non-optimal structures. If such gels are to be used effectively for high value applications like optoelectronics, we need to be able to overcome this kinetic control.
One method to get around this kinetic trapping that has not been investigated for supramolecular gels is annealing. In this proposal, we intend to develop methods to ‘anneal’ gels by using photobases, after they are formed. Photobases are the molecules that reversibly direct the pH of the medium upon irradiation. Hence, we will be able to control the local self-assembly by subtle control over the pH of the medium. This will allow us to drive the assembly closer towards equilibrium, preparing gels with more controlled properties. We also anticipate that these methods will allow us to prepare materials with properties that cannot be achieved by simple kinetic control.
Interests and expertise (Subject groups)