PhD Thesis Defence

Defence took place on 28/10/2022

Transcript

1. Thermo-mechanical Response of Glassy Systems VINAY VAIBHAV PHYS10201505002, 2015-IPhD The Institute of Mathematical Sciences, Chennai Homi Bhabha National Institute, Mumbai Ph.D. Thesis Defence October 28, 2022 Doctoral Advisor: Prof. Pinaki Chaudhuri
2. Glass: brief introduction # Supercooled liquids: Liquids cooled to temperatures below melting point # Time scales for molecular rearrangements become surprisingly long Glass is an amorphous solid that has been quenched from the liquid state Liquid: Observation timescale >> Internal timescale Glass: Observation timescale << Internal timescale Glass: An out-of-equilibrium system Most glass-formers are mixtures Nature 410, 259-267 (2001)
3. Widespread glassy materials REVIEWS OF MODERN PHYSICS, VOLUME 90, 2018
4. Motivation: response of glasses to thermal and mechanical disturbances J. J. Lewandowski, and A. L. Greer; Nature materials 5 (2005) Radioactive waste trapped in glass https://physics.aps.org/articles/v5/18 Breakdown of glasses Volcanic melt Glass manufacturing 3D printing using glass Temperature rise at shear bands in metallic glasses
5. Outline # Part-I: Thermal response of glassy system Temperature gradient and compositional inhomogeneity # Part-II: Mechanical response of thermally processed glass Shear response of inhomogeneous states # Part-III: Poiseuille fl ow of soft glass: role of thermalization protocol Rheology in the presence or absence of thermal gradient # Part-IV: Glassy binary mixture with large size bidispersity: interdiffusion and rheology Microscopic understanding of the origin of rigidity in asymmetric mixtures
6. Vinay Vaibhav, Juergen Horbach, and Pinaki Chaudhuri Part-I Thermal response of glassy system Temperature gradient and compositional inhomogeneity
7. In the presence of gradient THot TCold At constant temperature Thermophoresis : Soret Effect Uniform composition Compositional inhomogeneity Heat fl ow Binary mixture ST = D0 D = 1 c1c2 rc1 rT Goal
8. Imposing thermal gradient : steady state response of supercooled glassy liquid Supercooled liquid: Tm> TMCT THot = Tm + 0.025 TCold = Tm - 0.025 Molecular dynamics simulation: 80-20 binary Lennard-Jones mixture ST = 1 c1c2 rc1 rT <latexit sha1_base64="11dTX0xJQ2wArXVlUBk5JayK8lw=">AAACIXicdZDLSgMxFIYzXmu9VV26CbaCG4eZAbEboeDGZcXeoC1DJs20oZnMkGSEMuRV3Pgqblwo0p34MmZ6Aa8/BP585xyS8wcJo1I5zru1srq2vrFZ2Cpu7+zu7ZcODlsyTgUmTRyzWHQCJAmjnDQVVYx0EkFQFDDSDsbXeb19T4SkMW+oSUL6ERpyGlKMlEF+qVq58xvwCvZCgXB27uoM+y7EvqcXqMdRwFBOtV5eGlpX/FLZsb0Lxwj+Nq7tzFQGC9X90rQ3iHEaEa4wQ1J2XSdR/QwJRTEjuthLJUkQHqMh6RrLUURkP5ttqOGpIQMYxsIcruCMfp3IUCTlJApMZ4TUSP6s5fCvWjdVYbWfUZ6kinA8fyhMGVQxzOOCAyoIVmxiDMKCmr9CPEImGGVCLZoQlpvC/03Ls13Hdm+9cq22iKMAjsEJOAMuuAQ1cAPqoAkweABP4AW8Wo/Ws/VmTeetK9Zi5gh8k/XxCSosovc=</latexit> <latexit sha1_base64="11dTX0xJQ2wArXVlUBk5JayK8lw=">AAACIXicdZDLSgMxFIYzXmu9VV26CbaCG4eZAbEboeDGZcXeoC1DJs20oZnMkGSEMuRV3Pgqblwo0p34MmZ6Aa8/BP585xyS8wcJo1I5zru1srq2vrFZ2Cpu7+zu7ZcODlsyTgUmTRyzWHQCJAmjnDQVVYx0EkFQFDDSDsbXeb19T4SkMW+oSUL6ERpyGlKMlEF+qVq58xvwCvZCgXB27uoM+y7EvqcXqMdRwFBOtV5eGlpX/FLZsb0Lxwj+Nq7tzFQGC9X90rQ3iHEaEa4wQ1J2XSdR/QwJRTEjuthLJUkQHqMh6RrLUURkP5ttqOGpIQMYxsIcruCMfp3IUCTlJApMZ4TUSP6s5fCvWjdVYbWfUZ6kinA8fyhMGVQxzOOCAyoIVmxiDMKCmr9CPEImGGVCLZoQlpvC/03Ls13Hdm+9cq22iKMAjsEJOAMuuAQ1cAPqoAkweABP4AW8Wo/Ws/VmTeetK9Zi5gh8k/XxCSosovc=</latexit> <latexit sha1_base64="GMapPsaH7ui60C7Y6GuzWN/Dh4U=">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</latexit> <latexit sha1_base64="GMapPsaH7ui60C7Y6GuzWN/Dh4U=">AAACNHicdVBLSwMxGMz6tr6qHr0Eq6CHls2C6EUoeBH1UKEvaOuSTbM1mM2uSVYoy/4oL/4QLyJ4UMSrv8Fsu4LPgYRhZj6Sb7yIM6Vt+9GamJyanpmdmy8sLC4trxRX15oqjCWhDRLyULY9rChngjY005y2I0lx4HHa8q6OMr91Q6VioajrYUR7AR4I5jOCtZHc4unWiYvgISyfuQm6Tru+xCTpCuxxDOtpUr9wUliGmYlSmOs7eSqIXVTObscE090tt1iyK86ebQB/E1SxRyiBHDW3eN/thyQOqNCEY6U6yI50L8FSM8JpWujGikaYXOEB7RgqcEBVLxktncJto/ShH0pzhIYj9etEggOlhoFnkgHWl+qnl4l/eZ1Y+we9hIko1lSQ8UN+zKEOYdYg7DNJieZDQzCRzPwVkktsGtGm54Ip4XNT+D9pOhVkV9C5U6pW8zrmwAbYBDsAgX1QBcegBhqAgFvwAJ7Bi3VnPVmv1ts4OmHlM+vgG6z3DxBFqLg=</latexit> <latexit sha1_base64="GMapPsaH7ui60C7Y6GuzWN/Dh4U=">AAACNHicdVBLSwMxGMz6tr6qHr0Eq6CHls2C6EUoeBH1UKEvaOuSTbM1mM2uSVYoy/4oL/4QLyJ4UMSrv8Fsu4LPgYRhZj6Sb7yIM6Vt+9GamJyanpmdmy8sLC4trxRX15oqjCWhDRLyULY9rChngjY005y2I0lx4HHa8q6OMr91Q6VioajrYUR7AR4I5jOCtZHc4unWiYvgISyfuQm6Tru+xCTpCuxxDOtpUr9wUliGmYlSmOs7eSqIXVTObscE090tt1iyK86ebQB/E1SxRyiBHDW3eN/thyQOqNCEY6U6yI50L8FSM8JpWujGikaYXOEB7RgqcEBVLxktncJto/ShH0pzhIYj9etEggOlhoFnkgHWl+qnl4l/eZ1Y+we9hIko1lSQ8UN+zKEOYdYg7DNJieZDQzCRzPwVkktsGtGm54Ip4XNT+D9pOhVkV9C5U6pW8zrmwAbYBDsAgX1QBcegBhqAgFvwAJ7Bi3VnPVmv1ts4OmHlM+vgG6z3DxBFqLg=</latexit> Response in glassy- regime: Finite heat transport; no large-scale mass transport => No Soret effect Heat Current Pro fi le Temperature Pro fi le Concentration Pro fi le Soret Coef fi cient TMCT ~ 0.435 Tg ~ 0.3 Tm = 0.5, 0.55, 0.6, 0.7, 0.8,0.9,1.0
9. T > Tg BG tage DG AG <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> texp <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> t2 T < Tg T < Tg After removal of gradient, glassy states develop spatial inhomogeneity 0.95 1.00 1.05 ˜ r(z) 0.95 1.00 1.05 ˜ xA (z) 10 30 50 70 90 z °6.7 °6.5 °6.3 U(z) No gradient TH = 0.30 TH = 0.40 TH = 0.45 TH = 0.50 TC = 0.2 Order of heterogeneity depends on the size and exposure time of the gradient Density Concentration Potential energy TMCT ~ 0.435; Tg ~ 0.3 Response of glassy state to a thermal gradient pulse https://www.trumpf.com/en_US/applications/laser-welding/ Laser welding Lz History dependent concentration inhomogeneity
10. Part-I: summary Response of glassy liquids to thermal gradients V. Vaibhav, J. Horbach and P. Chaudhuri; Phys. Rev. E 101, 022605 (2020) # Thermal response of glass-forming material in supercooled and glassy regime; thermal transport and mass transport coupled # Glassy regime: Mass transport suppressed # Heating-cooling experiments: Designing material with speci fi ed compositional inhomogeneity THot TCold
11. Vinay Vaibhav, Juergen Horbach, and Pinaki Chaudhuri Part-II Mechanical response of thermally processed glass Shear response of inhomogeneous states Manuscript under preparation
12. Thermal protocol and response T > Tg BG tage DG AG <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> texp <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> t2 T < Tg T < Tg Glassy state is exposed to a thermal gradient pulse After removal of gradient, glassy states develop spatial inhomogeneity 0.95 1.00 1.05 ˜ r(z) 0.95 1.00 1.05 ˜ xA (z) 10 30 50 70 90 z °6.7 °6.5 °6.3 U(z) No gradient TH = 0.30 TH = 0.40 TH = 0.45 TH = 0.50 TC = 0.2 TH = 0.30, 0.40, 0.45, 0.50 Order of heterogeneity depends on the size and exposure time of the gradient Density Concentration Potential energy TMCT ~ 0.435 Tg ~ 0.3
13. Shear response of thermally processed states 0.0 0.5 1.0 1.5 0.2 0.6 1.0 sxz 0 6 12 18 g °6.54 °6.50 °6.46 U(z) No gradient TH = 0.30 TH = 0.40 TH = 0.45 TH = 0.50 Timescale for emergence of non-equilibrium steady-state depends on thermal processing Deforming the heterogeneous samples at fi xed shear-rates Shear-rate = 1e-3 Stress vs strain Potential energy vs strain TC = 0.2 TH = 0.30, 0.40, 0.45, 0.50
14. Shear bands in heterogenous samples # Shear band: region of high mobility # Control over the formation of shear- bands? Tc = 0.2, Th = 0.50 Tc = 0.2, Th = 0.40 No gradient 0.1 0.5 1.0 2.0 5.0 Strain 1.0 0.0 Mobility 0.0 0.1 0.2 0.3 Mobility °0.2 °0.1 0.0 0.1 0.2 DU 0.0 0.1 0.2 0.3 Mobility °0.2 °0.1 0.0 0.1 0.2 DU Local mobility (strain = 0.1) vs local shifted potential energy (strain = 0) No gradient TC = 0.2 TH = 0.3 TC = 0.2 TH = 0.4 TC = 0.2 TH = 0.5 Deforming the heterogeneous samples at fi xed shear-rates
15. Shear bands in heterogenous samples Unprocessed sample T = 0.2 Processed sample Tc = 0.2 and TH = 0.5
16. Part-II: summary Mechanical response of thermally processed glass V. Vaibhav, J. Horbach and P. Chaudhuri; Manuscript under preparation # Thermal gradient pulse to generate inhomogeneous states # Dependence of timescale for emergence of non-equilibrium steady state on thermal processing # Impact on shear-bands T > Tg BG tage DG AG <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> texp <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> <latexit sha1_base64="zz21L9RixGJZE6S/Smx6MJRMarw=">AAAB8HicbVA9TwJBEJ3DL8Qv1NJmI5hYkTsaLUmksMREQAMXsrfMwYa9vcvungm58CtsLDTG1p9j579xgSsUfMkkL+/NZGZekAiujet+O4WNza3tneJuaW//4PCofHzS0XGqGLZZLGL1EFCNgktsG24EPiQKaRQI7AaTm7nffUKleSzvzTRBP6IjyUPOqLHSY7XfRGEoqQ7KFbfmLkDWiZeTCuRoDcpf/WHM0gilYYJq3fPcxPgZVYYzgbNSP9WYUDahI+xZKmmE2s8WB8/IhVWGJIyVLWnIQv09kdFI62kU2M6ImrFe9ebif14vNeG1n3GZpAYlWy4KU0FMTObfkyFXyIyYWkKZ4vZWwsZUUWZsRiUbgrf68jrp1GueW/Pu6pVGM4+jCGdwDpfgwRU04BZa0AYGETzDK7w5ynlx3p2PZWvByWdO4Q+czx9y0Y+C</latexit> t2 T < Tg T < Tg
17. Vinay Vaibhav, and Pinaki Chaudhuri Part-III Poiseuille fl ow of soft glass: role of thermalization protocol Rheology in the presence or absence of thermal gradient
18. Poiseuille fl ow of yield stress materials Glass: yield-stress material; fl ows if imposed stress is above a threshold Whipped cream Thick syrup REVIEWS OF MODERN PHYSICS, VOLUME 89, 2017 YouTube: MIT Made A 3D Printer That Uses Glass
19. Poiseuille fl ow of glassy binary mixture °40 °20 0 20 40 z 0.40 0.42 0.44 0.46 0.48 T(z) °40 °20 0 20 40 z 0.0 0.1 0.2 0.3 0.4 0.006 0.007 0.008 0.009 0.010 0.011 Applied different forcing strengths to cause the fl ow Temperature of the fl owing material is controlled using two different methods a) Wall thermostat: atoms making the walls are vibrating; thermal wall control fl uid temperature; close to experiments and applications b) DPD thermostat: walls are rigid and fl uid temperature is controlled via direct thermostatting Wall thermostat DPD thermostat forcing strength w = 100 Imposed Stress Field Expected Velocity X Z Flow Direction Confinement Goal fl
20. Steady state response of the system 10°5 10°4 10°3 10°2 ˙ g 10°2 10°1 100 sxz 10°5 10°4 10°3 10°2 ˙ g 0.006 0.007 0.008 0.009 0.010 0.011 # Wall thermostat: Presence of stress-gradient with temperature gradient # Difference in fl ow curves # Possible to tune fl ow properties Wall thermostat DPD thermostat forcing strength Flow curves
21. Part-III: summary In fl uence of thermalisation protocol on Poiseuille fl ow of con fi ned soft glass V. Vaibhav, and P. Chaudhuri; Physics of Fluids 33, 053103 (2021) # Thermalization via wall and direct thermalisation of fl uid # Steady and transient response # Impact on rheology: presence of temperature gradient in wall thermostat case (b) (c) Imposed Stress Field Expected Velocity X Z Flow Direction Confinement w = 25 w = 100
22. Part-IV Glassy binary mixture with large size bidispersity: interdiffusion and rheology Microscopic understanding of the origin of rigidity in asymmetric mixtures
23. Binary mixture with large bidispersity Goal
24. Model System details Purely repulsive WCA interaction 50-50 mixture; A: large and B: small Size: A = [0.85, 1.15] B = 0.35 Mean diameter ratio ~2.85 Bigger species mostly occupy the volume Temperature of the system is fi xed Equilibrated using hybrid Swap MC- MD protocol LAMMPS: Molecular dynamics simulation ! Density of the system is varied !
25. diameter of A-species Stress-strain Snapshot 0.0 0.2 0.4 0.6 0.8 1.0 g 0.0 0.4 0.8 1.2 sXY ˙ g = 4e ° 6 ˙ g = 1e ° 5 ˙ g = 1e ° 4 ˙ g = 1e ° 3 # Shear XY plane along X with different shear-rates # Nonequilibrium steady state: system yields and shear-stress becomes steady; measurements are done in y directions # Interplay of different time-scales: timescale introduced by shear competes with the relaxation timescales associated with two species Control parameter: shear-rate and density Apply shear: imposing fi xed shear rates 10°4 10°2 100 102 hdr2 A (t)i 1.050 1.087 1.095 1.103 1.113 1.125 1.148 1.250 1.500 1.750 10°1 101 103 105 t 10°4 10°2 100 102 104 hdr2 B (t)i Quiescent MSD Bigger species Smaller species Timescale separation rhoA
26. Viscosity Stress Macro-micro connection 10°6 10°5 10°4 10°3 DA 1.050 1.087 1.113 1.148 1.250 1.500 1.750 10°6 10°5 10°4 10°3 ˙ g 10°4 10°3 10°2 10°1 DB 10°3 10°1 101 sxy( ˙ g) 10°6 10°5 10°4 10°3 ˙ g 102 104 106 h( ˙ g) 1.050 1.079 1.087 1.095 1.103 1.113 1.125 1.148 1.250 1.500 1.750 rhoA rhoA Bigger species Smaller species Micro: Diffusion coef fi cient vs shear-rate Macro: stress and viscosity vs shear-rate # Very small densities: Newtonian liquid <=> shear independent diffusivity of both species # Intermediate densities: Non-Newtonian regime <=> shear dependent diffusivity of only bigger species # High densities: Emergence of fi nite yield stress at vanishing shear-rates <=> shear dependent diffusivity of both species Emergence of rigidity
27. Part-IV: summary # Unperturbed and perturbed system of glassy mixture with large size disparity # Interdiffusion: Finite interdiffusion even when very small diffusion of bigger species ==> modi fi ed de fi nition of dynamical quantities for better picture # Shear response: timescale separation between species => macro-micro measurements =>density dependent response to the shear Finite-size effects in the diffusion dynamics of a glassforming binary mixture with large size ratio V. Vaibhav, J. Horbach, and P. Chaudhuri; JCP (2022) Rheological response of a glass-forming liquid having large bidispersity V. Vaibhav, J. Horbach, and P. Chaudhuri; Soft matter (2022) 10°6 10°5 10°4 10°3 ˙ g 10°3 10°1 101 sxy( ˙ g)
28. Published: # Problem I- Response of glassy liquids to thermal gradients V. Vaibhav, J. Horbach and P. Chaudhuri; Phys. Rev. E 101, 022605 (2020) # Problem II- In fl uence of thermalization protocol on Poiseuille fl ow of con fi ned soft glass V. Vaibhav, and P. Chaudhuri; Physics of Fluids 33, 053103 (2021) # Problem III- Finite-size effects in the diffusion dynamics of a glass-forming binary mixture with large size ratio V. Vaibhav, J. Horbach and P. Chaudhuri; JCP (2022) # Problem IV- Rheological response of a glass-forming liquid having large bidispersity V. Vaibhav, J. Horbach and P. Chaudhuri; Soft matter (2022) Under preparation: @ Problem V- Mechanical response of thermally processed glass V. Vaibhav, J. Horbach and P. Chaudhuri
29. Thank you Acknowledgements # Pinaki and Jürgen — supervision and collaboration # DC members — suggestions # Group members — Discussions and interactions # IMSc technical — Smooth and user-friendly infrastructure # IMSc admin — Supportive and friendly environment # Colleagues/Friends — Academic interaction, discussions, …. # Teachers during +12 and Bachelors — Motivation and encouragement # Family members — Love, patience, support, care, …