Postgraduate research opportunities Designing surfaces to control nucleation in pharmaceutical crystallisation

Crystallisation is widely used for purification of chemicals and pharmaceuticals and for making advanced materials for catalysis, separations and sensing applications. One of the main challenges in developing robust and efficient crystallisation processes is to control the process of crystal formation (i.e., nucleation). In addition, many substances tend to crystallise in multiple structural forms of the same composition called polymorphs, and controlling polymorphism is extremely important in the development of pharmaceutical products as polymorphs have different properties, such as solubility, dissolution rate and thus bioavailability in resulting dosage forms.

Nucleation mainly occurs via heterogeneous mechanisms, with the nucleus forming on a surface or interface, rather than in bulk solution. In large-scale industrial processes, heterogeneous nucleation is often undesirable in industry as it leads to fouling of vessels and a lower product yield, however, nucleants are often added to induce nucleation and/or produce a particular polymorph via heterogeneous nucleation. Numerous strategies have been proposed for the design of nucleant surfaces.

This project will use a combination of simulations and experiments to understand and predict how surfaces and interfaces affect nucleation. Experiments will be used to systematically investigate the effect of tunable functionalised surfaces on heterogeneous nucleation of representative organic compounds relevant to the pharmaceutical industry in order to explore the design space of novel heterogeneous nucleants.

Characterisation of functionalised surfaces and crystals grown on them will be performed with a suite of advanced characterisation techniques available in the CMAC National Facility (cmac.ac.uk) housed in the Technology and Innovation Centre at University of Strathclyde, including AFM, SEM, Raman microscopy and GI-SAXS. In the simulation part, we will gain a molecular level insight using a combination of quantum mechanical calculations and classical molecular dynamics simulations, which will enable calculation of relative energetics of competing polymorphs on various interfaces corresponding to systems investigated experimentally.

The project will be based in the Department of Chemical & Process Engineering in the University of Strathclyde, under the supervision of Dr Karen Johnston and Prof Jan Sefcik.

In addition to undertaking cutting-edge research, students are also registered for the Postgraduate Certificate in Researcher Development (PGCert), which is a supplementary qualification that develops a student’s skills, networks and career prospects.