Research Projects

Dipolar colloids are class of colloids for which interparticle interactions can be tuned using external energy. Paramagnetic colloids (NMPs) are subclass of such dipolar colloids for which external energy source is in the form of magnetic field. NMPs upon applying external magnetic field acquire induced dipole moment in the direction of the external field. In principle, the induced dipole is instantaneous, appearing when the field is applied and disappearing when it is removed. This phenomenon provides spatiotemporal control over particle interactions allowing fabricating different structures and dynamics. In the recent years, NMPs have proven quite useful in understanding versatile fundamental problems including phase transitions, crystal formation, crystal defects, etc. Typically, in the presence of rotational magnetic field (RMF) NMPs arrange into 2D crystal-like structures. Based on the strength of the external magnetic field, NMPs show phase transition from Brownian to 2D cluster to 2D crystalline arrangements. In the recent years, it has been shown that these 2D structures built using NMPs express typical bulk properties of materials such as surface tension, viscosity, shear modulus, etc. Since interparticle interactions mimic molecular Lennard-Jones type interactions, these 2D structures are making their impact in studying fundamentals of 2D crystalline materials. 2D materials, such as graphene, Mxenes, MoS2, phosphene, etc. are established advance materials and more 2D materials are being invented due to their impact on current technology. Dipolar colloids have significantly advanced our understanding of atomic-scale dynamics, particularly in grain boundary and grain defect. Another promising avenue of research is the deformation of 2D materials. Understanding deformations in 2D materials is critical because it directly influence their physical properties. However, visualizing deformation mechanisms at the nanoscale remains a considerable experimental challenge, limiting our knowledge of atomic-scale rearrangements. Dipolar colloids offer immense potential to bridge this gap and provide valuable insights into this area of research. This proposal focuses on investigating deformation mechanisms and dynamics in 2D colloidal crystals. By applying controlled strain and stress to the colloidal 2D lattice, we aim to study the material’s response and unravel the dynamics of particle rearrangements that accommodate these deformations. Additionally, the research seeks to establish a link between particle-level deformations and the bulk mechanical properties of colloidal crystals. By leveraging the concept of colloids as "Big Atoms," this work represents a cutting-edge approach in soft matter science. This study has the potential to open new avenues for exploring the fundamental behavior of 2D materials using colloidal particles as model systems.