Computation and Theory of Soft Materials

Colloidal Self-assembly

Self-assembly of nanoparticles and colloidal building blocks has enormous potential as a means of structure fabrication because of the scope for tuning the interparticle interactions. Anisotropy in interactions, now increasingly being achieved by either shape anisotropy or heterogeneous (patchy) surface chemistry at the nano- or micro-scale, has greatly enhanced the prospect of building complex three-dimensional architectures in a bottom-up fabrication. However, design rules for engineering their assembly into target structures are yet rather limited. We seek to devise strategies for programmed assembly of nanoparticles and colloidal building blocks in silico and to elucidate the kinetics of assembly in close connection with contemporary experimental research. Our current focus is on programming hierarchical self-assembly, which poses a multiscale design problem.

Active Colloids

Active colloids are microscale particles, which self-propel through viscous fluids by transducing energy into mechanical work and thus mimic the self-propulsion of living organisms. Active colloids, and more generally active matter, are at the forefront of current soft matter research with rich non-equilibrium phenomena. We are studying structural and dynamic properties of active colloidal suspensions, especially in the context of emergent collective behaviour, in order to programme self-organisation of active colloids.

Rheology of Soft Matter

Colloid-polymer systems, which offer the scope for tuning inter-particle interactions, are of interest for both fundamental science and formulation engineering. Understanding the fundamentals of colloid-polymer systems holds the key to informed formulation of many consumer products. The questions pertinent to the stability and mechanical properties of these systems are of particular relevance. We are currently developing a computational framework to investigate the structural, dynamical, and rheological properties of these complex multi-component systems.

Self-assembly of Liquid Crystals

Self-assembly of liquid crystals is a remarkably rich phenomenon with emergence of partial long-range order to a variable degree. Of our particular interest are a spectacular variety of columnar phases, exhibited by discotic molecules. We seek to understand the organisation of disc-shaped mesogens, in particular, in columnar phases and elucidate the phase behaviour for discotic liquid crystals focusing on potential opto-electronic applications.

Topological Soft Matter

Soft matter exhibits a variety of ordered phases, showcasing the interplay between topology and broken symmetry. In particular, topological defects in liquid crystals and more recently liquid crystal colloids have drawn much attention. Our interest lies in exploiting the interplay between topologies of the ordering field of a liquid crystalline medium and the surface of the colloidal particles to design self-assembled liquid crystal colloids for attractive photonic properties. We are also interested in studying topological properties of open colloidal crystals, which are sparsely populated periodic structures.