Publications

R&D Areas/Projects

• Nanoparticle synthesis:Nanoparticles are building blocks of nanotechnology and the advances crucially depend upon the ability to synthesize these particles, on an industrial scale, in a controlled and reproducible manner. Although the formation of spherical particles is fairly well researched, the synthesis of non-spherical or complex nanoparticles is poorly understood. We aim to undertake several studies to clearly identify factors affecting size, shape and distribution for nanoparticles and identify parameters crucial in large scale synthesis. (Positions available: 3 Phd positions)
• Colloidal Physics:Charged drops and vesicles are ubiquitous in nature. Ensembles of charged fluid drops dispersed in an electrolyte solution occur commonly in colloidal processing and in many microfluidic and nanotechnological applications. Similarly, charged vesicles and biological cells embedded in high salt concentration solutions are found in in-vivo conditions. We investigate the deformation of drops and vesicles in electrolyte solutions, by linear and nonlinear stability analysis supported by numerical calculations. (1 Phd, 1 RA position)
• Polymer Physics and Nanomachines:Polymer Physics and Nanomachines: We are presently pursuing two kinds of problems in polymer physics. The force extension relation for a single molecule semiflexible polymer like DNA is given by the now popular worm like chain model. However in situations where the configuration of the polymer is non-straight at $T=0$, the naive use of a straight configuration may lead to wrong calculation of the persistence length. In the second kind of problem, we try to construct self propelled configurations of DNA using the asymmetric hamiltonian of a semiflexible polymer and driven by the ratchet effect. This can be a potential nanomachine which can selectively deliver drugs, genes and other cargo inside a cell in advanced medical therapy.
• Hydrodynamic and Electrohydrodynamic stability:Flow over soft materials is qualitatively different from that over rigid surfaces because the time scale (\eta/E), the ratio of viscosity and shear modulus, can be of the same order as the shear rates in the system. This leads to a dynamical coupling between the solid and the fluid giving rise to new instabilities. We consider the effect of oscillatory shear, which represents most biological flows, on these instabilities. Electrohydrodynamics and electrokinetics find extensive use in Lithography and in colloidal systems respectively. The study of stability of thin films under applied electric field has recently gained importance because of possible applications in Nanotechnology and microfluidics. Better understanding of these systems can lead to tighter control of the product quality.

PhD TA Topics