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Aggregate of nanoparticles: rheological and mechanical properties.

Wang Y, Wu X, Yang W, Zhai Y, Xie B, Yang M - Nanoscale Res Lett (2011)

Bottom Line: By this modified elastic model, the size of the network mesh can be estimated by the elastic modulus of the network which can be easily obtained by rheology.The stress to destroy the aggregates, i.e., the yield stress (σy), and the elastic modulus (G') of the network are found to be depended on the concentration of nano-silica (ϕ, wt.%) with the power of 4.02 and 3.83, respectively.Via this concentration dependent behavior, we can extrapolate two important mechanical parameters for the agglomerates in a dense packing state (ϕ = 1): the shear modulus and the yield stress.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China. ysjsanjin@163.com.

ABSTRACT
The understanding of the rheological and mechanical properties of nanoparticle aggregates is important for the application of nanofillers in nanocompoistes. In this work, we report a rheological study on the rheological and mechanical properties of nano-silica agglomerates in the form of gel network mainly constructed by hydrogen bonds. The elastic model for rubber is modified to analyze the elastic behavior of the agglomerates. By this modified elastic model, the size of the network mesh can be estimated by the elastic modulus of the network which can be easily obtained by rheology. The stress to destroy the aggregates, i.e., the yield stress (σy), and the elastic modulus (G') of the network are found to be depended on the concentration of nano-silica (ϕ, wt.%) with the power of 4.02 and 3.83, respectively. Via this concentration dependent behavior, we can extrapolate two important mechanical parameters for the agglomerates in a dense packing state (ϕ = 1): the shear modulus and the yield stress. Under large deformation (continuous shear flow), the network structure of the aggregates will experience destruction and reconstruction, which gives rise to fluctuations in the viscosity and a shear-thinning behavior.

No MeSH data available.


Related in: MedlinePlus

Schematic configuration/structure changings of the gel network. Aggregates in the form of NCA can exhibit a polymer-like elastic behavior under small deformation. While under large deformation, aggregates will experience destruction, reconstruction, and agglomeration and cannot recover the initial structure.
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Figure 7: Schematic configuration/structure changings of the gel network. Aggregates in the form of NCA can exhibit a polymer-like elastic behavior under small deformation. While under large deformation, aggregates will experience destruction, reconstruction, and agglomeration and cannot recover the initial structure.

Mentions: To help in understanding the rheological and mechanical properties of the gel network or agglomerates, the configuration/structure changings on the nanoscale, such as a NCA, under different deformation conditions are illustrated in Figure 7.


Aggregate of nanoparticles: rheological and mechanical properties.

Wang Y, Wu X, Yang W, Zhai Y, Xie B, Yang M - Nanoscale Res Lett (2011)

Schematic configuration/structure changings of the gel network. Aggregates in the form of NCA can exhibit a polymer-like elastic behavior under small deformation. While under large deformation, aggregates will experience destruction, reconstruction, and agglomeration and cannot recover the initial structure.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211159&req=5

Figure 7: Schematic configuration/structure changings of the gel network. Aggregates in the form of NCA can exhibit a polymer-like elastic behavior under small deformation. While under large deformation, aggregates will experience destruction, reconstruction, and agglomeration and cannot recover the initial structure.
Mentions: To help in understanding the rheological and mechanical properties of the gel network or agglomerates, the configuration/structure changings on the nanoscale, such as a NCA, under different deformation conditions are illustrated in Figure 7.

Bottom Line: By this modified elastic model, the size of the network mesh can be estimated by the elastic modulus of the network which can be easily obtained by rheology.The stress to destroy the aggregates, i.e., the yield stress (σy), and the elastic modulus (G') of the network are found to be depended on the concentration of nano-silica (ϕ, wt.%) with the power of 4.02 and 3.83, respectively.Via this concentration dependent behavior, we can extrapolate two important mechanical parameters for the agglomerates in a dense packing state (ϕ = 1): the shear modulus and the yield stress.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China. ysjsanjin@163.com.

ABSTRACT
The understanding of the rheological and mechanical properties of nanoparticle aggregates is important for the application of nanofillers in nanocompoistes. In this work, we report a rheological study on the rheological and mechanical properties of nano-silica agglomerates in the form of gel network mainly constructed by hydrogen bonds. The elastic model for rubber is modified to analyze the elastic behavior of the agglomerates. By this modified elastic model, the size of the network mesh can be estimated by the elastic modulus of the network which can be easily obtained by rheology. The stress to destroy the aggregates, i.e., the yield stress (σy), and the elastic modulus (G') of the network are found to be depended on the concentration of nano-silica (ϕ, wt.%) with the power of 4.02 and 3.83, respectively. Via this concentration dependent behavior, we can extrapolate two important mechanical parameters for the agglomerates in a dense packing state (ϕ = 1): the shear modulus and the yield stress. Under large deformation (continuous shear flow), the network structure of the aggregates will experience destruction and reconstruction, which gives rise to fluctuations in the viscosity and a shear-thinning behavior.

No MeSH data available.


Related in: MedlinePlus