Fragility of an Isochorically Confined Polymer Glass

被引：40

作者：

Zhang, Chuan ^{[1
]}

Guo, Yunlong ^{[1
]}

Shepard, Kimberly B. ^{[1
]}

Priestley, Rodney D. ^{[1
,2
]}

机构：

[1] Princeton Univ, Dept Chem & Biol Engn, Princeton, NJ 08544 USA

[2] Princeton Univ, Princeton Inst Sci & Technol Mat, Princeton, NJ 08544 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY LETTERS | 2013年 / 4卷 / 03期

关键词：

TRANSITION TEMPERATURE; STRUCTURAL RELAXATION; DYNAMIC FRAGILITY; POLYSTYRENE FILMS; FREE SURFACES; THIN-FILMS; DEPRESSION; MOBILITY; LIQUIDS; SPHERES;

D O I：

10.1021/jz302002v

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We report the effect of isochoric confinement on the dynamic fragility of a polymeric glass-former, that is, polystyrene (PS). Utilizing silica-capped PS nanospheres as a model system, the fictive temperature (T-f) and the isochoric heat capacity (C-v) are measured as a function of diameter via differential scanning calorimetry. By examining T-f as a function of cooling rate for each sample, the isochoric fragility (m(v)) is obtained, which decreases significantly as the diameter of the nanospheres is reduced from 260 to 129 nm. Hence, the temperature dependence of structural relaxation near the glass transition is weakened with isochoric confinement.

引用

页码：431 / 436

页数：6

共 42 条

[1] Reduced Glass Transition Temperatures in Thin Polymer Films: Surface Effect or Artifact? [J].

Baeumchen, O. ;

McGraw, J. D. ;

Forrest, J. A. ;

Dalnoki-Veress, K. .

PHYSICAL REVIEW LETTERS, 2012, 109 (05)

[2] NONEXPONENTIAL RELAXATIONS IN STRONG AND FRAGILE GLASS FORMERS [J].

BOHMER, R ;

NGAI, KL ;

ANGELL, CA ;

PLAZEK, DJ .

JOURNAL OF CHEMICAL PHYSICS, 1993, 99 (05) :4201-4209

[3] Tg depression and invariant segmental dynamics in polystyrene thin films [J].

Boucher, Virginie M. ;

Cangialosi, Daniele ;

Yin, Huajie ;

Schoenhals, Andreas ;

Alegria, Angel ;

Colmenero, Juan .

SOFT MATTER, 2012, 8 (19) :5119-5122

[4] Physical aging of polystyrene/gold nanocomposites and its relation to the calorimetric Tg depression [J].

Boucher, Virginie M. ;

Cangialosi, Daniele ;

Alegria, Angel ;

Colmenero, Juan ;

Pastoriza-Santos, Isabel ;

Liz-Marzan, Luis M. .

SOFT MATTER, 2011, 7 (07) :3607-3620

[5] Isobaric and isochoric properties of decahydroisoquinoline, an extremely fragile glass-former [J].

Casalini, R. ;

McGrath, K. J. ;

Roland, C. M. .

JOURNAL OF NON-CRYSTALLINE SOLIDS, 2006, 352 (42-49) :4905-4909

[6] Why liquids are fragile [J].

Casalini, R ;

Roland, CM .

PHYSICAL REVIEW E, 2005, 72 (03)

[7] The distribution of glass-transition temperatures in nanoscopically confined glass formers [J].

Ellison, CJ ;

Torkelson, JM .

NATURE MATERIALS, 2003, 2 (10) :695-700

[8]

Floudas G, 2011, ADV DIELECTR, P1, DOI 10.1007/978-3-642-04902-6

[9] Effect of free surfaces on the glass transition temperature of thin polymer films [J].

Forrest, JA ;

DalnokiVeress, K ;

Stevens, JR ;

Dutcher, JR .

PHYSICAL REVIEW LETTERS, 1996, 77 (10) :2002-2005

[10] Interface and chain confinement effects on the glass transition temperature of thin polymer films [J].

Forrest, JA ;

DalnokiVeress, K ;

Dutcher, JR .

PHYSICAL REVIEW E, 1997, 56 (05) :5705-5716

← 1 2 3 4 5 →