[DPS Seminar] Prof. Rajarshi Chakrabarti (Indian Institute of Technology Bombay)

Description:	[DPS Seminar] Prof. Rajarshi Chakrabarti (Indian Institute of Technology Bombay) -- Statistical Mechanics of active polymers: from dilute to dense phase
Date:	Friday, Jun 07, 2024
Time:	2:30 p.m. - 4 p.m.
Venue:	Asima Chatterjee Lecture Theatre
Details:	Colloidal chains driven by local chemical reactions [1] or in a bath of bacteria [2] show unusual scaling behavior, not observed in equilibrium. In the first part of the talk, I will briefly discuss some analytically solvable models for a single active polymer chain or a passive polymer chain in active baths [3-5]. These models can actually predict experimentally observed superdiffusive motion of the tagged monomer of a colloidal chain in an active bacteria bath. These models also predict swelling of active chains in passive baths and passive chains in active baths, long-time enhanced diffusion as seen in experiments [1-2]. To understand the motion of active shape- deforming agents,a collection of rings made of active Brownian particles (ABPs) [3, 4] for differentpackingfractionsandactivitiesisinvestigatedusingcomputersimulations.This will be the topic for the second part of my talk. Our computer simulationsreveal thatactiveringsdisplayanoveldynamicclustering[5]insteadoftheconventionalmotility- induced phase separation (MIPS) [6] as observed in case of collection of ABPs. Surprisingly, increasing packing fraction of rings exhibits a non-monotonicity in the dynamics due to the formationofalargenumberofsmallclusters.Theconformationalfluctuationsofthepolymers suppress MIPS exhibited by ABPs. This demonstrates a complex interplay between activity, topology, and connectivity. References: 1. B. Biswas, R. K. Manna, A. Laskar, P. B. S. Kumar, R. Adhikari, and G. Kumaraswamy, ACS Nano, 11, 10025 (2017). 2. M. S. Aporvari, M. Utkur, E. U. Saritas, G. Volpe and J. Stenhammar, Soft Matter, 16, 5609 (2020). 3. N. Samanta and R. Chakrabarti, J. Phys. A: Math & Theo. 49, 195601 (2016). 4. S. Chaki and R. Chakrabarti, J. Chem. Phys, 16, 7103 (2020). 5. K. Goswami, S. Chaki and R. Chakrabarti, J. Phys. A: Math & Theo. 55, 423002 (2022). 6. L. Theeyancheri,S. Chaki,T. Bhattacharjee,R. Chakrabarti,Phys.Rev.E106,014504 (2022). 7. L. Theeyancheri,S. Chaki,T. Bhattacharjee,R. Chakrabarti,J.Chem.Phys.159,014902 (2023). 8. L. Theeyancheri,S. Chaki,T. Bhattacharjee,R. Chakrabarti,Phys. Rev. Res.6, L01238 (2024). 9. G. S. Redner,M. E. Hagan, A.Baskaran,Phys.Rev.Lett.110,055701 (2013).
Calendar:	Seminar Calendar (entered by rajni)