2 research outputs found
Influence of Morphology on the Mechanical Properties of Polymer Nanocomposites Filled with Uniform or Patchy Nanoparticles
In
this work we perform molecular-dynamics simulations, both on
the coarse-grained and the chemistry-specific levels, to study the
influence of morphology on the mechanical properties of polymer nanocomposites
(PNCs) filled with uniform spherical nanoparticles (which means without
chemical modification) and patchy spherical nanoparticles (with discrete,
attractive interaction sites at prescribed locations on the particle
surface). Through the coarse-grained model, the nonlinear decrease
of the elastic modulus (<i>G</i>′) and the maximum
of the viscous modulus (<i>G</i>″) around the shear
strain of 10% is clearly reproduced. By turning to the polybutadiene
model, we examine the effect of the shear amplitude and the interaction
strength among uniform NPs on the aggregation kinetics. Interestingly,
the change of the <i>G</i>′ as a function of the
aggregation time exhibited a maximum value at intermediate time attributed
to the formation of a polymer-bridged filler network in the case of
strong interaction between NPs. By imposing a dynamic periodic shear,
we probe the change of the <i>G</i>′ as a function
of the strain amplitude while varying the interaction strength between
uniform NPs and its weight fraction. A continuous filler network is
developed at a moderate shear amplitude, which is critically related
to the interaction strength between NPs and the weight fraction of
the fillers. In addition, we study the self-assembly of the patchy
NPs, which form the typical chain-like and sheet-like structures.
For the first time, the effect of these self-assembled structures
on the viscoelastic and stress–strain behavior of PNCs is compared.
In general, in the coarse-grained model we focus on the size effect
of the rough NPs on the Payne effect, while some other parameters
such as the dynamic shear flow, the interaction strength between NPs,
the weight fraction, and the chemically heterogeneous surface of the
NPs are explored for the chemistry-specific model
Influence of Morphology on the Mechanical Properties of Polymer Nanocomposites Filled with Uniform or Patchy Nanoparticles
In
this work we perform molecular-dynamics simulations, both on
the coarse-grained and the chemistry-specific levels, to study the
influence of morphology on the mechanical properties of polymer nanocomposites
(PNCs) filled with uniform spherical nanoparticles (which means without
chemical modification) and patchy spherical nanoparticles (with discrete,
attractive interaction sites at prescribed locations on the particle
surface). Through the coarse-grained model, the nonlinear decrease
of the elastic modulus (<i>G</i>′) and the maximum
of the viscous modulus (<i>G</i>″) around the shear
strain of 10% is clearly reproduced. By turning to the polybutadiene
model, we examine the effect of the shear amplitude and the interaction
strength among uniform NPs on the aggregation kinetics. Interestingly,
the change of the <i>G</i>′ as a function of the
aggregation time exhibited a maximum value at intermediate time attributed
to the formation of a polymer-bridged filler network in the case of
strong interaction between NPs. By imposing a dynamic periodic shear,
we probe the change of the <i>G</i>′ as a function
of the strain amplitude while varying the interaction strength between
uniform NPs and its weight fraction. A continuous filler network is
developed at a moderate shear amplitude, which is critically related
to the interaction strength between NPs and the weight fraction of
the fillers. In addition, we study the self-assembly of the patchy
NPs, which form the typical chain-like and sheet-like structures.
For the first time, the effect of these self-assembled structures
on the viscoelastic and stress–strain behavior of PNCs is compared.
In general, in the coarse-grained model we focus on the size effect
of the rough NPs on the Payne effect, while some other parameters
such as the dynamic shear flow, the interaction strength between NPs,
the weight fraction, and the chemically heterogeneous surface of the
NPs are explored for the chemistry-specific model