Research

Related papers

• The conformational phase diagram of neutral polymers in the presence of attractive crowders, H Garg, R Rajesh, S Veparala (2023) https://doi.org/10.1063/5.0140721

• Rationalizing polymer swelling and collapse under attractive cosolvent conditions, J Heyda et al (2013) https://doi.org/10.1021/ma302320y 

• Chain conformations and phase separation in polymer solutions with varying solvent quality, Y Huang et al (2021) https://doi.org/10.1002/pol.20210526 

A charged polymer (polyelectrolyte) transitions from coil to globule in presence of counter ions given sufficient backbone charge density

When the electrostatic attraction overcomes the counter-ion thermal energy, the ions condense on the chain and make it collapse

We're looking at the effects of both counter-ions and crowders on conformation due to long-range (electrostatic) and short-range (L-J) forces 

Related papers

• The conformational phase diagram of charged polymers in the presence of attractive crowders, K Tripathi, H Garg, R Rajesh, S Veparala (2023) https://doi.org/10.1063/5.0172696

aggregation dynamics of polymer chains in presence of attractive crowders and formation of polymer networks and gels

Understanding the aggregation dynamics is important to understand various biological and mechanical processes.  Aggregation plays role in DNA packaging, cytoskeleton organisation, contributes to human disease state such as Alzheimer and Parkinson disease.  Similarly, the organisation of actin filaments into bundles is required for cellular processes such as motility, morphogenesis and cell division.  We are studying the aggregation of neutral polymers (rigid as well as flexible) in the presence of attractive crowders and investigating the effect of crowder sizes and flexibility on it.    We are also looking at power law the fraction of aggregates follows with time.  

 When mixture of two good solvents give rise to effective poor solvent condition, this phenomena is known as cononsolvency. For eg PNIPAM polymer in aqueous methanol is immiscible whereas PNIPAM is miscible individually in water and methanol.  Many experiments, simulations and theory try to explain it through specific interactions and chemical composition, but universal explanation of such phenomena is still lacking. We are trying to explain cosolvency and cononsolvency in terms of solvent-cosolvent interaction which could be good enough to explain such behaviour.  

Depletion effect (or excluded volume effect) is attractive force occur between two bodies when particles around it cannot enter the excluded volumes of the bodies and creates osmotic pressure and make them close closer . 

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