Out of equilibrium dynamics of poly(vinyl methyl ether) segments in miscible poly(styrene)-poly(vinyl methyl ether) blends

Lorthioir, Cédric; Alegría, Ángel; Colmenero, Juan

doi:10.1103/physreve.68.031805

Cited by 90 publications

(152 citation statements)

References 25 publications

Supporting

Mentioning

131

Contrasting

Order By: Relevance

“…The fact that intermolecular constraints rule the dynamics is supported by results of systematic changes of dynamics with increase of intermolecular constraints and hence the presence of correlations between n, m, and the ratio τ α /τ β . These results from MD simulations are fully compatible with the experimental data of mixtures of small molecule glassformers [38][39][40][41], and polymer blends [42][43][44], which have been explained by the CM [37,38,[43][44][45] 4 .…”

Section: Dynamic Propertiessupporting

confidence: 86%

Guides to solving the glass transition problem

Ngai¹,

Prevosto²,

Capaccioli³

et al. 2008

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Relaxation in glass-forming substances is necessarily a many-body problem because of intermolecular interactions and constraints. Results from molecular dynamics simulations and experiments are used to reveal the critical elements and general effects originating from many-body relaxation, but not dealt with in conventional theories of the glass transition. Although many-body relaxation is still an unsolved problem in statistical mechanics, these critical elements and general effects will serve as guides to the construction of a satisfactory theory of the glass transition. This effort is aided by concepts drawn from the coupling model, whose predictions have been shown to be consistent with experimental facts.

show abstract

Section: Dynamic Propertiessupporting

confidence: 86%

Guides to solving the glass transition problem

Ngai¹,

Prevosto²,

Capaccioli³

et al. 2008

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…Decoupling of self-and collective motions was also found in sodium disilicate, a system displaying enhanced dynamic asymmetry [45]. Finally, Arrhenius-like temperature dependencies were observed in some confined glass-forming systems [41] and also in the low-T g -component of miscible polymer blends with strong dynamic asymmetry [42]. Thus, such exotic behavior could be attributed to the emergence of confinement effects associated to the presence and enhancement of dynamic asymmetry in the system.…”

Section: Structural Relaxation Of the Side Groupsmentioning

confidence: 74%

Nanophase Separation and Exotic Dynamic Behavior in Comb-Like Polymers

Arbe

2013

J. Phys. Soc. Jpn.

View full text Add to dashboard Cite

We show the potential of neutron scattering combined with isotopic labeling to unravel structural and dynamical properties of 'comb-like' polymers. Results on homopolymers with alkyl side groups of varying length, namely on the families of poly(n-alkyl methacrylates) (PnMAs) and poly(alkylene oxides) (PAOs) are summarized. Diffraction experiments and fully atomistic molecular dynamics simulations evidence the formation of self-assembled nanodomains of the side groups surrounded by the main chains, independently of the nature of the latter. Neutron spin echo, time of flight and backscattering techniques were employed to investigate the collective dynamics relating inter-and intra-nanodomain correlations as well as the incoherent scattering function of hydrogens. The results are combined with other experimental techniques -dielectric spectroscopy and differential scanning calorimetry-to put into a context the dynamical processes identified. Plasticization and confinement effects arise in PnMAs, but not in the PAOs counterparts. The results point to the dynamic asymmetry developed in systems with intrinsic dynamic heterogeneities between the constituent parts as the key ingredient leading to the main features observed in PnMAs. This scenario is supported by coarsegrained simulations on generic comb-like polymers.

show abstract

“…For instance, we note the emergence of subdiffusive-like behavior for the fast particles in simulated mixtures of dynamically asymmetric components. [98][99][100][101] In real systems like polymer blends, 102,103 this dynamic asymmetry has been invoked as responsible for deviations in the temperature dependence of the relaxation time of the fast component from VF toward Arrhenius-likein a similar way as observed for water from NMR and BDS studies. Such an interpretation was also proposed for water in PVP in the previous BDS work.…”

Section: Polymer Versus Water Dynamics: Dynamic Asymmetrymentioning

confidence: 87%

Component dynamics in polyvinylpyrrolidone concentrated aqueous solutions

Busselez

Arbe

Cerveny

et al. 2012

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

Intermolecular momentum transfer in poly(perfluorosulfonic acid) membrane hydrated by aqueous solution of methanol: A molecular dynamics simulation study J. Chem. Phys. 131, 224901 (2009) 2 H-nuclear magnetic resonance (NMR) and neutron scattering (NS) on isotopically labelled samples have been combined to investigate the structure and dynamics of polyvinylpyrrolidone (PVP) aqueous solutions (4 water molecules/monomeric unit). Neutron diffraction evidences the nanosegregation of polymer main-chains and water molecules leading to the presence of water clusters. NMR reveals the same characteristic times and spectral shape as those of the slower process observed by broadband dielectric spectroscopy in this system [S. Cerveny et al., J. Chem. Phys. 128, 044901 (2008)]. The temperature dependence of such relaxation time crosses over from a cooperative-like behavior at high temperatures to an Arrhenius behavior at lower temperatures. Below the crossover, NMR features the spectral shape as due to a symmetric distribution of relaxation times and the underlying motions as isotropic. NS results on the structural relaxation of both components-isolated via H/D labeling-show (i) anomalously stretched and non-Gaussian functional forms of the intermediate scattering functions and (ii) a strong dynamic asymmetry between the components that increases with decreasing temperature. Strong heterogeneities associated to the nanosegregated structure and the dynamic asymmetry are invoked to explain the observed anomalies. On the other hand, at short times the atomic displacements are strongly coupled for PVP and water, presumably due to H-bond formation and densification of the sample upon hydration.

show abstract

Out of equilibrium dynamics of poly(vinyl methyl ether) segments in miscible poly(styrene)-poly(vinyl methyl ether) blends

Cited by 90 publications

References 25 publications

Guides to solving the glass transition problem

Guides to solving the glass transition problem

Nanophase Separation and Exotic Dynamic Behavior in Comb-Like Polymers

Component dynamics in polyvinylpyrrolidone concentrated aqueous solutions

Contact Info

Product

Resources

About