Predictive relation for the a-relaxation time of a coarse-grained polymer melt under steady shear

被引：63

作者：

Giuntoli, Andrea ^{[1
,2
,5
]}

Puosi, Francesco ^{[3
]}

Leporini, Dino ^{[3
,4
]}

Starr, Francis ^{[2
]}

Douglas, Jack F. ^{[1
]}

机构：

[1] NIST, Mat Sci & Engn Div, Gaithersbug, MD 20899 USA

[2] Wesleyan Univ, Dept Phys, Middletown, CT 06459 USA

[3] Univ Pisa, Dipartimento Fis Enrico Fermi, Largo B Pontecorvo 3, I-56127 Pisa, Italy

[4] CNR, UOS Pisa, IPCF, Pisa, Italy

[5] Northwestern Univ, Dept Civil & Environm Engn, 2145 Sheridan Rd, Evanston, IL 60208 USA

来源：

SCIENCE ADVANCES | 2020年 / 6卷 / 17期

关键词：

MOLECULAR MOBILITY; DYNAMICS; GLASS; TEMPERATURE; CREEP; FLOW; HETEROGENEITIES; DEFORMATION; SUSPENSIONS; ENERGY;

D O I：

10.1126/sciadv.aaz0777

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

We examine the influence of steady shear on structural relaxation in a simulated coarse-grained unentangled polymer melt over a wide range of temperature and shear rates. Shear is found to progressively suppress the a-relaxation process observed in the intermediate scattering function, leading ultimately to a purely inertially dominated beta-relaxation at high shear rates, a trend similar to increasing temperature. On the basis of a scaling argument emphasizing dynamic heterogeneity in cooled liquids and its alteration under material deformation, we deduce and validate a parameter-free scaling relation for both the structural relaxation time tau(alpha) from the intermediate scattering function and the "stretching exponent" beta quantifying the extent of dynamic heterogeneity over the entire range of temperatures and shear rates that we can simulate.

引用

页数：9

共 57 条

[11] Tracer Measurements of Atomic Diffusion inside Shear Bands of a Bulk Metallic Glass [J].