Unraveling the Mechanism of Nanoscale Mechanical Reinforcement in Glassy Polymer Nanocomposites

Cheng, Shiwang; Bocharova, Vera; Belianinov, Alex; Xiong, Shanxin; Kisliuk, A.; Somnath, Suhas; Holt, Adam P.; Ovchinnikova, Olga S.; Jesse, Stephen; Martin, Halie; Etampawala, Thusitha; Dadmun, Mark; Sokolov, Alexei P.

doi:10.1021/acs.nanolett.6b00766

Cited by 155 publications

(195 citation statements)

References 69 publications

Supporting

Mentioning

178

Contrasting

Order By: Relevance

“…Given that typical solution-processed graphene flakes are much larger4 than the largest flakes studied here, we expect a sustained improvement in the composite stiffness with increasing flake size, a typical flake size for optimal reinforcement being in the 1–10 μm range36. It is also worth noting that a very recent experimental study of poly(vinyl acetate)/silica in the glassy phase has provided direct confirmation of an interfacial layer at the filler–matrix interface that consists of stretched polymer chains with an intrinsically higher interfacial elastic modulus than the matrix37. That work also demonstrates that the experimentally observed composite stiffness enhancement is best captured by a continuum model that accounts explicitly for the mechanical properties of the interfacial region (i.e., a three-phase model consisting of filler, interface, and matrix) rather than conventional two-phase composite models, which adds further credence to our observation in this work that the details of the filler–matrix interface are important beyond considerations of load transfer alone.…”

Section: Discussionsupporting

confidence: 51%

A Comparison of the Elastic Properties of Graphene- and Fullerene-Reinforced Polymer Composites: The Role of Filler Morphology and Size

Weerasinghe

Maroudas

et al. 2016

Sci Rep

View full text Add to dashboard Cite

Nanoscale carbon-based fillers are known to significantly alter the mechanical and electrical properties of polymers even at relatively low loadings. We report results from extensive molecular-dynamics simulations of mechanical testing of model polymer (high-density polyethylene) nanocomposites reinforced by nanocarbon fillers consisting of graphene flakes and fullerenes. By systematically varying filler concentration, morphology, and size, we identify clear trends in composite stiffness with reinforcement. To within statistical error, spherical fullerenes provide a nearly size-independent level of reinforcement. In contrast, two-dimensional graphene flakes induce a strongly size-dependent response: we find that flakes with radii in the 2–4 nm range provide appreciable enhancement in stiffness, which scales linearly with flake radius. Thus, with flakes approaching typical experimental sizes (~0.1–1 μm), we expect graphene fillers to provide substantial reinforcement, which also is much greater than what could be achieved with fullerene fillers. We identify the atomic-scale features responsible for this size- and morphology-dependent response, notably, ordering and densification of polymer chains at the filler–matrix interface, thereby providing insights into avenues for further control and enhancement of the mechanical properties of polymer nanocomposites.

show abstract

Section: Discussionsupporting

confidence: 51%

A Comparison of the Elastic Properties of Graphene- and Fullerene-Reinforced Polymer Composites: The Role of Filler Morphology and Size

Weerasinghe

Maroudas

et al. 2016

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The mechanism of mechanical reinforcement due to filler/polymer interface has been a controversial topic in composite research . For example, some researchers claimed that filler network plays a dominating role in mechanical reinforcement .…”

Section: Introductionmentioning

confidence: 99%

Effect of interface on the mechanical behavior of polybutadiene–silica composites: An experimental and simulation study

Brisbin

et al. 2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

The effect of interface property on the mechanical behavior of silica-polybutadiene composites is systematically investigated via combined experimental and dynamics simulation. In experiment, the interface property is controlled by SiO 2 particle size, silane coupling agents, and silane grafting density. The effects of these control parameters on the vulcanization kinetics, tensile strength, and dynamic mechanic properties are investigated and discussed. Both the experimental and simulation studies reveal the pivot role of filler-polymer interface on the mechanical reinforcement. Simulation study reveals that the constrained polymer layer (12 nm) surrounding the silica particles shows increased stress from 30 to 230 MPa, which is identified as the major reason for the overall enhancement of 100% modulus from 0.8 to 1.6 MPa. The molecular mechanics of interface from simulation is well correlated to the experimental results in this study, which provides a molecular level understanding of the relationship between interfacial interaction and mechanical reinforcement.

show abstract

“…Confinement in polymer nanocomposites occurs when 1) polymer chains are constrained between layered silicates, 2) polymer chains are inside nanopores or nanocylinders, or 3) inorganic nanoparticles and hybrids (i.e., silica, alumina, POSS, and so on) dispersed in a polymer matrix where polymer fractions would have reduced mobility due to being tightly bound to the nanoparticles or in highly confined regions between closely packed nanoparticles …”

Section: Introductionmentioning

confidence: 99%

Viscoelasticity and Dynamics of Intercalated Polymer/Bentonite Nanocomposites

Romo-Uribe

2018

Macro Chemistry & Physics

View full text Add to dashboard Cite

Nanoclays are 2D silicate structures with spatial periodicity and relatively constant gallery separation d 001 of the order of 1 nm. Hence, these nanoparticles offer naturally confining environments to macromolecules, especially in an intercalated state. It is believed that the macromolecular nanoconfinement found in intercalated morphologies of polymer-clay nanocomposites, would be largely responsible for the changes of thermomechanical properties. [8] It is known that confinement can induce lowering or increasing of the glass transition temperature, T g , in small molecule glassy materials, [9] in glassy polymers, [10][11][12] and in polymer nanocomposites. [6][7][8]13,14] The influence of confinement has also been evidenced in rheological properties when analyzing ultrathin films of polydimethyl siloxane. [15] Confinement has also induced changes to crystallization and crystalline structure of hybrid nanocomposite networks. [16,17] Confinement in polymer nanocomposites occurs when 1) polymer chains are constrained between layered silicates, [1,7,8] 2) polymer chains are inside nanopores or nanocylinders, [18,19] or 3) inorganic nanoparticles and hybrids (i.e., silica, alumina, POSS, and so on) dispersed in a polymer matrix where polymer fractions would have reduced mobility due to being tightly bound to the nanoparticles or in highly confined regions between closely packed nanoparticles. [13,14,[20][21][22][23] Additional to the topological confinement condition the polymer dimensions also dictate the degree of confinement. Hence, 2R < d defines a weak confined system whereas 2R >> d defines a strongly confined system, where R is the polymer dimension (e.g., radius of gyration or hydrodynamic radius) and d is the pore diameter or gallery spacing, as depicted in Scheme 1. [24][25][26] Finally, polymer-solid interface (nanoparticle) interactions which can be attractive or repulsive play a prominent role defining the properties in a nanocomposite; [23,26] the picture is quite complex.Model polymeric systems mimicking confined environments based on ultrathin films have been investigated to explain the behavior of the glass transition temperature T g . [27][28][29][30][31][32] Nanostructured films obtained from grafted nanoparticles (gold or SiO 2 ) dispersed in a polymeric solution have also been studied to understand the influence of nanoparticle-matrix interactions on the thermal properties (tuning the length of the grafted chains promoted or not interactions with the polymer Nanocomposites This research investigates confinement-induced dynamics retardation behavior in intercalated acrylic/clay nanocomposites. Nanostructured waterborne latex contains up to 3 wt% nanoclay, and transmission electron microscopy shows well-dispersed intercalated morphology. Dynamics in the melt is analyzed using the time-temperature superposition principle. Confinement induces dynamics retardation, and the entanglement relaxation time τ e increases over an order of magnitude. The cooperative motion retardation also reduces viscous d...

show abstract

Unraveling the Mechanism of Nanoscale Mechanical Reinforcement in Glassy Polymer Nanocomposites

Cited by 155 publications

References 69 publications

A Comparison of the Elastic Properties of Graphene- and Fullerene-Reinforced Polymer Composites: The Role of Filler Morphology and Size

A Comparison of the Elastic Properties of Graphene- and Fullerene-Reinforced Polymer Composites: The Role of Filler Morphology and Size

Effect of interface on the mechanical behavior of polybutadiene–silica composites: An experimental and simulation study

Viscoelasticity and Dynamics of Intercalated Polymer/Bentonite Nanocomposites

Contact Info

Product

Resources

About