Microscopic origin of the terminal relaxation time in polymer nanocomposites: an experimental precedent

Nusser, Klaus; Schneider, Gerald J.; Richter, D.

doi:10.1039/c1sm05555k

Cited by 48 publications

(45 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the polymer melts interacting with a confining surface, they found an anchored surface layer with internal high mobility, which was considered to be glassy in past works [370,376]. In addition, for poly(ethylene-alt-propylene) (PEP) matrices filled with hydrophobic (non-attractive) silica NPs, they reported several key findings [374,375]: (i) the Gaussian behavior of polymer chains was still preserved at a high volume fraction of NPs; (ii) NPs were found to have negligible influence on the basic Rouse relaxation rate of PEP chains; (iii) the effective lateral confining length of PEP chains increased with the NP volume fraction; (iv) a crossover from polymer chain entanglements to "NP entanglements" was observed with a critical NP volume fraction of about 35%; and (v) both the CLF and CR effects were suppressed by the appearance of NPs. All of these key findings, except (ii) and (v), were later observed by Li et al [329] in large-scale isobaric MD simulations with generic NPs.…”

Section: Polymer Dynamics At Interfaces and In Interphasesmentioning

confidence: 90%

“…For this reason, many computational and experimental works have been performed in recent years to understand the polymer dynamics at the interface and in the interphase [127,128,328,329,[370][371][372][373][374][375][376][377][378][379][380][381][382]. While extensive works have been done to explore the chain dynamics inside PNCs, widely different and often conflicting results are reported.…”

Section: Polymer Dynamics At Interfaces and In Interphasesmentioning

confidence: 99%

“…On the other hand, silica NPs have been found to have no influence on the local segmental dynamics of poly(vinyl acetate) chains adjacent to them, when compared with the chains in the bulk [383]. Very recently, Richter and his co-workers carried out extensive neutron spin echo experiments on the dynamics of entangled polymer chains in PNCs [374,375,384]. For the polymer melts interacting with a confining surface, they found an anchored surface layer with internal high mobility, which was considered to be glassy in past works [370,376].…”

Section: Polymer Dynamics At Interfaces and In Interphasesmentioning

confidence: 99%

See 2 more Smart Citations

Challenges in Multiscale Modeling of Polymer Dynamics

et al. 2013

View full text Add to dashboard Cite

The mechanical and physical properties of polymeric materials originate from the interplay of phenomena at different spatial and temporal scales. As such, it is necessary to adopt multiscale techniques when modeling polymeric materials in order to account for all important mechanisms. Over the past two decades, a number of different multiscale computational techniques have been developed that can be divided into three categories: (i) coarse-graining methods for generic polymers; (ii) systematic coarse-graining methods and (iii) multiple-scale-bridging methods. In this work, we discuss and compare eleven different multiscale computational techniques falling under these categories and assess them critically according to their ability to provide a rigorous link between polymer chemistry and rheological material properties. For each technique, the fundamental ideas and equations are introduced, and the most important results or predictions are shown and discussed. On the one hand, this review provides a comprehensive tutorial on multiscale computational techniques, which will be of interest to readers newly entering this field; on the other, it presents a critical discussion of the future opportunities and key challenges in the multiscale geometric mapping matrix between all-atomistic and coarse-grained models N number of monomers per chain N e entanglement length, which is the number of monomers between two entanglements n v number of polymer chains per unit volume n ij (n 0 (r ij )) entanglement number (at equilibrium) between particle pairs i and j p r , P R configurational probability distributions in all-atomistic and coarse-grained models, respectively R ee end-to-end distance of polymer chain R G radius of gyration of polymer chain s segment index/contour length variable along primitive chain S(q) single chain coherent dynamic scattering function Z number of entanglements per chain, defined as Z = N/N e α exponent in standard Mittag-Leffler function σ

show abstract

Section: Polymer Dynamics At Interfaces and In Interphasesmentioning

confidence: 90%

Section: Polymer Dynamics At Interfaces and In Interphasesmentioning

confidence: 99%

Section: Polymer Dynamics At Interfaces and In Interphasesmentioning

confidence: 99%

See 1 more Smart Citation

Challenges in Multiscale Modeling of Polymer Dynamics

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Nevertheless, a particular slowing down of long-wavelength Rouse modes cannot be excluded, since the signature of such Rouse modes would be overshadowed by confinement effects. In a following article 43 it is also shown that the extracted confinement length can be directly connected with rheological data from the same samples. In addition, qualitative evidences were also found from the rheological data that the contour length fluctuations and constraint release mechanisms are less effective in nanocomposites with high concentration of NPs.…”

Section: Nanocomposites Solid Polyelectrolytes and Blendsmentioning

confidence: 99%

“…Semicrystalline polymers, 37,38 solid polyelectrolytes, [39][40][41] nanocomposites 39,[42][43][44] and polymer blends 45 have been subject of QENS studies by several groups. In many of those works, confinement effects arise as a key ingredient.…”

Section: Recent Progress On Polymer Dynamics By Neutron Scatteringmentioning

confidence: 99%

Recent progress on polymer dynamics by neutron scattering: From simple polymers to complex materials

Colmenero

Arbe

2012

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

ABSTRACT:The recent (from 2010 onward) contributions of quasielastic neutron scattering techniques (time of flight, backscattering, and neutron spin echo) to the characterization and understanding of dynamical processes in soft materials based on polymers are analyzed. The selectivity provided by the combination of neutron scattering and isotopic-in particular, proton/deuterium-labeling allows the isolated study of chosen molecular groups and/or components in a system. This opportunity, together with the capability of neutrons to provide space/time resolution at the relevant length scales in soft matter, allows unraveling the nature of the large variety of molecular motions taking place in materials of increasing complexity. As a result, recent relevant works can be found dealing with dynamical process which associated characteristic lengths and nature are as diverse as, for example, phenyl motions in a glassy linear homopolymer like polystyrene and the chain dynamics of a polymer adsorbed on dispersed clay platelets. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 51: 2013 KEYWORDS: molecular dynamics; neutron scattering; relaxation POLYMER DYNAMICS AT DIFFERENT LENGTH AND TIME SCALES: FROM SIMPLE POLYMERS TO COMPLEX MATERIALSPolymers are composed of macromolecules which are built up by a large number N of monomer units linked together by covalent bonds. Because of this macromolecular nature, the structural and dynamic properties of polymeric systems strongly depend on a hierarchy of length and time scales. From a structural point of view, the random coil shape of linear polymer chains in the melt and glassy state-proposed by Flory in the 50s 1 -is nowadays well established by small angle neutron diffraction (SANS). At smaller length scales than those characteristic for the chain dimensions, the local arrangements of the atoms give rise to broad maxima in the static structure factor S(Q) also accessible by neutron diffraction. Usually, a first main peak centered at Q-values ≈ 1 . . . 1.5 Å −1 is present. The T-dependence of this maximum, following the expansion coefficient, indicates an interchain origin, that is, it mainly relates to correlations between atoms belonging to different chains (or to the same chain but well separated segments).2 A second peak located at ∼3 Å −1can also be usually found in S(Q). The small value of the associated characteristic length and its weak T-dependence indicate the intrachain nature of the correlations giving rise to this maximum. We also note that the broadening of the Bragg peaks found in polymers reveals a clear amorphous character. In fact, the features shown in S(Q) in polymeric systems are universal for amorphous materials, not only for polymers, and in particular for glass forming systems. Thus, a universal behavior common for all glass forming materials can also be expected in the dynamics, including the observation of the glass transition phenomenon. 3As anticipated, the complexity of amorphous polymers shows up not only in the structural propertie...

show abstract

Effect of Particle Size and Shape on the Reinforcing Efficiency of Nanoparticles in Polymer Nanocomposites

Hassanabadi

Rodrigue

2014

Macro Materials & Eng

View full text Add to dashboard Cite

The effect of particle characteristics such as size and shape on the reinforcing efficiency of nano‐particles is investigated. Nanocomposites based on ethylene vinyl acetate (EVA) copolymer containing five different nano‐particles including clay, multiwall carbon nanotube (CNT), CaCO3, talc, and nano‐crystalline cellulose (NCC) were produced. The analyses are performed in the melt and solid states. The highest property changes were obtained for clay and CNT, followed by talc, NCC, and CaCO3. By using morphological analyses, mechanical properties, and rheological data, the results were correlated to the amount of available surface area between the particles and polymer. Finally, the particles were compared using a material cost over mechanical performance ratio where the optimum was obtained for talc followed by clay, NCC, CNT and CaCO3.

show abstract

Microscopic origin of the terminal relaxation time in polymer nanocomposites: an experimental precedent

Cited by 48 publications

References 17 publications

Challenges in Multiscale Modeling of Polymer Dynamics

Challenges in Multiscale Modeling of Polymer Dynamics

Recent progress on polymer dynamics by neutron scattering: From simple polymers to complex materials

Effect of Particle Size and Shape on the Reinforcing Efficiency of Nanoparticles in Polymer Nanocomposites

Contact Info

Product

Resources

About