Time-dependent NMR-velocimetry of a colloidal glass

被引：9

作者：

Rogers, S. A. ^{[1
]}

Callaghan, P. T. ^{[1
]}

机构：

[1] Victoria Univ Wellington, MacDiarmid Inst Adv Mat & Nanotechnol, Wellington, New Zealand

来源：

RHEOLOGICA ACTA | 2009年 / 48卷 / 07期

关键词：

Flow visualisation; Flow-sensitive viscosity; Shear-induced structure formation; Soft solids; Start-up experiment; Steady shear; SHEAR;

D O I：

10.1007/s00397-009-0368-6

中图分类号：

O3 [力学];

学科分类号：

08 ; 0801 ;

摘要：

The time-dependent velocity profiles in a Couette geometry of a soft glass made of colloidal star polymers suspended in squalene is presented. A shear-banded structure, hinted at by conventional rheological methods, is unequivocally confirmed with the local shear-rate of the low shear-rate branch below the measurable threshold. The evolution of the extent of the 'zero-shear-band' band is tracked and found to follow a Gompertz-like growth. The effects of altering shear rate, waiting time and temperature on the Gompertz fit parameters are investigated and show, among other relations, that the growth rate of the zero-shear band is proportional to the inverse of the applied shear rate, the time taken to reach unit strain.

引用

页码：735 / 745

页数：11

共 12 条

[1] A thermodynamically consistent model for the thixotropic behavior of concentrated star polymer suspensions [J].

Beris, A. N. ;

Stiakakis, E. ;

Vlassopoulos, D. .

JOURNAL OF NON-NEWTONIAN FLUID MECHANICS, 2008, 152 (1-3) :76-85

[2] Rheo-NMR: nuclear magnetic resonance and the rheology of complex fluids [J].

Callaghan, PT .

REPORTS ON PROGRESS IN PHYSICS, 1999, 62 (04) :599-670

[3] 1H NMR spectroscopy of polymers under shear and extensional flow [J].

Callaghan, PT ;

Gil, AM .

RHEOLOGICA ACTA, 1999, 38 (06) :528-536

[4]

Gompertz B., 1825, PHILOS T ROY SOC LON, V115, P513, DOI [10.1098/rstl.1825.0026, DOI 10.1098/RSTL.1825.0026]

[5] Viscoelasticity and shear melting of colloidal star polymer glasses [J].

Helgeson, Matthew E. ;

Wagner, Norman J. ;

Vlassopoulos, Dimitris .

JOURNAL OF RHEOLOGY, 2007, 51 (02) :297-316

[6] Shear banding phenomena in ultrasoft colloidal glasses [J].

Holmes, WM ;

Callaghan, PT ;

Vlassopoulos, D ;

Roovers, J .

JOURNAL OF RHEOLOGY, 2004, 48 (05) :1085-1102

[7] Generic rugged landscapes under strain and the possibility of rejuvenation in glasses [J].

Isner, BA ;

Lacks, DJ .

PHYSICAL REVIEW LETTERS, 2006, 96 (02)

[8] Gels and glasses in a single system: Evidence for an intricate free-energy landscape of glassy materials [J].

Jabbari-Farouji, Sara ;

Wegdam, Gerard H. ;

Bonn, Daniel .

PHYSICAL REVIEW LETTERS, 2007, 99 (06)

[9] Reversible thermal gelation in soft spheres [J].

Kapnistos, M ;

Vlassopoulos, D ;

Fytas, G ;

Mortensen, K ;

Fleischer, G ;

Roovers, J .

PHYSICAL REVIEW LETTERS, 2000, 85 (19) :4072-4075

[10] Measurement of multilamellar onion dimensions under shear using frequency domain pulsed gradient NMR [J].

Lutti, Antoine ;

Callaghan, Paul T. .

JOURNAL OF MAGNETIC RESONANCE, 2007, 187 (02) :251-257

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