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Electrorheology of nanofiber suspensions.

Yin J, Zhao X - Nanoscale Res Lett (2011)

Bottom Line: Recent researches of using nanoparticles as the dispersal phase have led to new interest in the development of non-conventional ER fluids with improved performances.In this review, we especially focus on the recent researches on electrorheology of various nanofiber-based suspensions, including inorganic, organic, and inorganic/organic composite nanofibers.Our goal is to highlight the advantages of using anisotropic nanostructured materials as dispersal phases to improve ER performances.

View Article: PubMed Central - HTML - PubMed

Affiliation: Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710129, China. jbyin@nwpu.edu.cn.

ABSTRACT
Electrorheological (ER) fluid, which can be transformed rapidly from a fluid-like state to a solid-like state under an external electric field, is considered to be one of the most important smart fluids. However, conventional ER fluids based on microparticles are subjected to challenges in practical applications due to the lack of versatile performances. Recent researches of using nanoparticles as the dispersal phase have led to new interest in the development of non-conventional ER fluids with improved performances. In this review, we especially focus on the recent researches on electrorheology of various nanofiber-based suspensions, including inorganic, organic, and inorganic/organic composite nanofibers. Our goal is to highlight the advantages of using anisotropic nanostructured materials as dispersal phases to improve ER performances.

No MeSH data available.


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Viscosity at high shear rate as a function of the particle concentration for goethite and hematite suspensions. The lines correspond to the fit of the data to the Dougherty-Krieger equation [78].
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Figure 4: Viscosity at high shear rate as a function of the particle concentration for goethite and hematite suspensions. The lines correspond to the fit of the data to the Dougherty-Krieger equation [78].

Mentions: Ramos-Tejada et al. compared the ER response of the suspension containing goethite (β-FeOOH) nanorods with axial ratio around 8 with the suspension containing polyhedral hematite (α-Fe2O3) particles with a mean diameter of 105 nm [78]. Both types of particles were said to possess similar chemical compositions and electrical properties and their average particle sizes were very close too. Thus, goethite and hematite samples differed mainly in particle shape. The experiments showed that the goethite suspension changed its rheological behavior from Newtonian without electric field to shear thinning at electric fields. In particular, the suspension of elongated goethite particles produced a more efficient ER response to the electric field than that made of polyhedral hematite particles since the former gave rise to higher yield stress for the same field strength, and exhibited a lower viscosity (see Figure 4) in absence of electric fields. As the chemical compositions and electrical properties, as well as the average particle sizes of elongated goethite and polyhedral hematite were very close, they attributed the ER enhancement to the larger dipole moments induced in elongated particles by the electric field. This consideration also justified why the goethite sample showed the same ER response as hematite one at low electric field of approximately 0.7 kV/mm, while their yield stresses differed significantly at high electric field of 1.5 and 2.0 kV/mm.


Electrorheology of nanofiber suspensions.

Yin J, Zhao X - Nanoscale Res Lett (2011)

Viscosity at high shear rate as a function of the particle concentration for goethite and hematite suspensions. The lines correspond to the fit of the data to the Dougherty-Krieger equation [78].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211318&req=5

Figure 4: Viscosity at high shear rate as a function of the particle concentration for goethite and hematite suspensions. The lines correspond to the fit of the data to the Dougherty-Krieger equation [78].
Mentions: Ramos-Tejada et al. compared the ER response of the suspension containing goethite (β-FeOOH) nanorods with axial ratio around 8 with the suspension containing polyhedral hematite (α-Fe2O3) particles with a mean diameter of 105 nm [78]. Both types of particles were said to possess similar chemical compositions and electrical properties and their average particle sizes were very close too. Thus, goethite and hematite samples differed mainly in particle shape. The experiments showed that the goethite suspension changed its rheological behavior from Newtonian without electric field to shear thinning at electric fields. In particular, the suspension of elongated goethite particles produced a more efficient ER response to the electric field than that made of polyhedral hematite particles since the former gave rise to higher yield stress for the same field strength, and exhibited a lower viscosity (see Figure 4) in absence of electric fields. As the chemical compositions and electrical properties, as well as the average particle sizes of elongated goethite and polyhedral hematite were very close, they attributed the ER enhancement to the larger dipole moments induced in elongated particles by the electric field. This consideration also justified why the goethite sample showed the same ER response as hematite one at low electric field of approximately 0.7 kV/mm, while their yield stresses differed significantly at high electric field of 1.5 and 2.0 kV/mm.

Bottom Line: Recent researches of using nanoparticles as the dispersal phase have led to new interest in the development of non-conventional ER fluids with improved performances.In this review, we especially focus on the recent researches on electrorheology of various nanofiber-based suspensions, including inorganic, organic, and inorganic/organic composite nanofibers.Our goal is to highlight the advantages of using anisotropic nanostructured materials as dispersal phases to improve ER performances.

View Article: PubMed Central - HTML - PubMed

Affiliation: Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710129, China. jbyin@nwpu.edu.cn.

ABSTRACT
Electrorheological (ER) fluid, which can be transformed rapidly from a fluid-like state to a solid-like state under an external electric field, is considered to be one of the most important smart fluids. However, conventional ER fluids based on microparticles are subjected to challenges in practical applications due to the lack of versatile performances. Recent researches of using nanoparticles as the dispersal phase have led to new interest in the development of non-conventional ER fluids with improved performances. In this review, we especially focus on the recent researches on electrorheology of various nanofiber-based suspensions, including inorganic, organic, and inorganic/organic composite nanofibers. Our goal is to highlight the advantages of using anisotropic nanostructured materials as dispersal phases to improve ER performances.

No MeSH data available.


Related in: MedlinePlus