Ravi Prakash Jagadeeshan

Ravi Prakash Jagadeeshan

Monash University

Chemical Engineer
Fellow, Elected 2019

Professor Ravi Prakash Jagadeeshan received his PhD in Chemical Engineering from the Indian Institute of Science in 1989 under the supervision of K. R. Kaza, working on the compressible flow of granular materials. After his first postdoc with R. A. Mashelkar at NCL, Pune, he began a second postdoc in 1991 with Sam Edwards at Cambridge, where he developed the widely cited Bouchaud, Cates, Ravi Prakash, Edwards (BCRE) model for sand pile physics. His third postdoc was with Hans Christian Oettinger at ETH, Zürich in 1993, where he learnt the technique of Brownian dynamics simulations. In 1994, he returned to India as an Assistant Professor at IIT, Madras. In 1999, he was awarded a Humboldt fellowship in the Technical University at Kaiserslautern, Germany, where he worked on the problem of treating excluded volume effects in flowing polymer solutions. In 2001, Ravi Prakash took up a Senior Lectureship at Monash University in the Department of Chemical Engineering, where he currently leads the Molecular Rheology group.

An overarching theme in Ravi Prakash’s research is his endeavour to take advantage of the existence of universal behaviour in polymer solutions, independent of the chemistry of the monomer. His fundamental contribution to solution rheology has been to show how universality can be exploited to make quantitative predictions with Brownian dynamics simulations, based on simple coarse-grained models for the polymer, and to interpret experimental observations with the help of scaling theories to produce master plots that collapse rheological data for a variety of systems. The central elements that underpin these contributions are his introduction of a methodology to treat the quality of a solvent, and the technique for obtaining parameter free predictions, both at equilibrium and in shear and extensional flows. By introducing the successive fine-graining technique, he has shown that excellent agreement with a number of different experimentally measured properties can be obtained, independent of the choice of model parameters, such as the conformational evolution of single DNA molecules undergoing planar extensional flow in a cross-slot device, and theextensional viscosities of dilute polystyrene, and DNA solutions subjected to uniaxial extensional flow.

He has determined the theta temperature and the solvent quality of DNA solutions with the help of light scattering experiments, and has established that the behaviour of DNA solutions is universal – thereby validating the widespread use of DNA as a model polymer in rheology.

His recent experimental observations and computer simulations have revealed universal aspects of semidilute polymer solution behaviour that were previously unknown. The scaling arguments that he has formulated, which have identified the proper scaling variables that lead to data collapse for equilibrium and non-equilibrium properties, have transformed our understanding of semidilute polymer solution rheology.

Based on the documents submitted by Tam Sridhar.