In this paper, we present a computational framework that integrates coarse-grained (CG) molecular dynamics (MD) simulations and a data-driven machine-learning (ML) method to gain insights into the conformations of polymers in solutions. We employ this framework to study conformational transition of a model thermosensitive polymer, poly(N-isopropylacrylamide) (PNIPAM). Here, we have developed the first of its kind, a temperature-independent CG model of PNIPAM that can accurately predict its experimental lower critical solution temperature (LCST) while retaining the tacticity in the presence of an explicit water model. The CG model was extensively validated by performing CG MD simulations with different initial conformations, varying the radius of gyration of chain, the chain length, and the angle between the adjacent monomers of the initial configuration of PNIPAM (total simulation time = 90 μs). Moreover, for the first time, we utilize the nonmetric multidimensional scaling (NMDS) method, a data-driven ML approach, to gain further insights into the mechanisms and pathways of this coil-to-globule transition by analyzing CG MD simulation trajectories. In conclusion, NMDS analysis provides entirely new insights and shows multiple metastable states of PNIPAM during its coil-to-globule transition above the LCST.
Bejagam, Karteek K., et al. "Machine-Learning Enabled New Insights into the Coil-to-Globule Transition of Thermosensitive Polymers Using a Coarse-Grained Model." Journal of Physical Chemistry Letters, vol. 9, no. 22, Oct. 2018. https://doi.org/10.1021/acs.jpclett.8b02956
Bejagam, Karteek K., An, Yaxin, Singh, Samrendra, & Deshmukh, Sanket A. (2018). Machine-Learning Enabled New Insights into the Coil-to-Globule Transition of Thermosensitive Polymers Using a Coarse-Grained Model. Journal of Physical Chemistry Letters, 9(22). https://doi.org/10.1021/acs.jpclett.8b02956
Bejagam, Karteek K., An, Yaxin, Singh, Samrendra, et al., "Machine-Learning Enabled New Insights into the Coil-to-Globule Transition of Thermosensitive Polymers Using a Coarse-Grained Model," Journal of Physical Chemistry Letters 9, no. 22 (2018), https://doi.org/10.1021/acs.jpclett.8b02956
@article{osti_1543673,
author = {Bejagam, Karteek K. and An, Yaxin and Singh, Samrendra and Deshmukh, Sanket A.},
title = {Machine-Learning Enabled New Insights into the Coil-to-Globule Transition of Thermosensitive Polymers Using a Coarse-Grained Model},
annote = {In this paper, we present a computational framework that integrates coarse-grained (CG) molecular dynamics (MD) simulations and a data-driven machine-learning (ML) method to gain insights into the conformations of polymers in solutions. We employ this framework to study conformational transition of a model thermosensitive polymer, poly(N-isopropylacrylamide) (PNIPAM). Here, we have developed the first of its kind, a temperature-independent CG model of PNIPAM that can accurately predict its experimental lower critical solution temperature (LCST) while retaining the tacticity in the presence of an explicit water model. The CG model was extensively validated by performing CG MD simulations with different initial conformations, varying the radius of gyration of chain, the chain length, and the angle between the adjacent monomers of the initial configuration of PNIPAM (total simulation time = 90 μs). Moreover, for the first time, we utilize the nonmetric multidimensional scaling (NMDS) method, a data-driven ML approach, to gain further insights into the mechanisms and pathways of this coil-to-globule transition by analyzing CG MD simulation trajectories. In conclusion, NMDS analysis provides entirely new insights and shows multiple metastable states of PNIPAM during its coil-to-globule transition above the LCST.},
doi = {10.1021/acs.jpclett.8b02956},
url = {https://www.osti.gov/biblio/1543673},
journal = {Journal of Physical Chemistry Letters},
issn = {ISSN 1948-7185},
number = {22},
volume = {9},
place = {United States},
publisher = {American Chemical Society},
year = {2018},
month = {10}}
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific
Computing
Center (NERSC); Univ. of California, Oakland, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1543673
Journal Information:
Journal of Physical Chemistry Letters, Journal Name: Journal of Physical Chemistry Letters Journal Issue: 22 Vol. 9; ISSN 1948-7185