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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.


Related in: MedlinePlus

Static yield stress as a function of electric field strength (15 wt%, T = 23°C) for PANI suspensions: nanofibers (square points), microparticles (triangle points), and nanoparticles (circle points) [98].
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Figure 8: Static yield stress as a function of electric field strength (15 wt%, T = 23°C) for PANI suspensions: nanofibers (square points), microparticles (triangle points), and nanoparticles (circle points) [98].

Mentions: By adjusting aniline/acid ratio or solution acidity, not only PANI nanofibers but also spherical micrometer-size and nano-size PANI particles were further prepared by a modified oxidative polymerization in low-cost citric acid solution and their electric, ER, sedimentation, and temperature properties were systematically compared recently [98]. It was found that the PANI nanofiber suspension exhibited the strongest ER effect under electric fields. Its yield stress was about 2.5 to 3.0 times as high as that of the PANI nanoparticle suspension and 1.3 to 1.5 times as high as that of the PANI microparticle suspension. The dependence of yield stress on electric field for the PANI nanofiber suspension was found to follow the power-law relation with a smaller exponent compared with the PANI nanoparticle suspension and microparticle suspension (see Figure 8). This was considered to be related to the anisotropic morphology of PANI nanofibers. The analogical result had also been obtained in the suspensions of spherical and whisker-like inorganic aluminum borate [67,68]. Especially, it was interesting that the PANI nanofiber suspension was found to show lower off-field viscosity compared to the suspension of PANI nanoparticles, which proposed a possible way to overcome the problem of large off-field viscosity of the present nanoparticle-based ER fluids [57-61]. Furthermore, it was found that the PANI nanofiber suspension could maintain a good ER effect in a wide temperature range like the PANI microparticle suspension, while the temperature stability of the PANI nanoparticle suspension was degraded. It was known that the Brown motion disturbed ER structures in nanoparticle suspension systems more easily compared to microparticle suspension systems, but the larger dipole moments and more robust dendrite-like network induced by electric fields in PANI nanofiber suspension were believed to contribute to good temperature stability of ER effect [98].


Electrorheology of nanofiber suspensions.

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

Static yield stress as a function of electric field strength (15 wt%, T = 23°C) for PANI suspensions: nanofibers (square points), microparticles (triangle points), and nanoparticles (circle points) [98].
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 8: Static yield stress as a function of electric field strength (15 wt%, T = 23°C) for PANI suspensions: nanofibers (square points), microparticles (triangle points), and nanoparticles (circle points) [98].
Mentions: By adjusting aniline/acid ratio or solution acidity, not only PANI nanofibers but also spherical micrometer-size and nano-size PANI particles were further prepared by a modified oxidative polymerization in low-cost citric acid solution and their electric, ER, sedimentation, and temperature properties were systematically compared recently [98]. It was found that the PANI nanofiber suspension exhibited the strongest ER effect under electric fields. Its yield stress was about 2.5 to 3.0 times as high as that of the PANI nanoparticle suspension and 1.3 to 1.5 times as high as that of the PANI microparticle suspension. The dependence of yield stress on electric field for the PANI nanofiber suspension was found to follow the power-law relation with a smaller exponent compared with the PANI nanoparticle suspension and microparticle suspension (see Figure 8). This was considered to be related to the anisotropic morphology of PANI nanofibers. The analogical result had also been obtained in the suspensions of spherical and whisker-like inorganic aluminum borate [67,68]. Especially, it was interesting that the PANI nanofiber suspension was found to show lower off-field viscosity compared to the suspension of PANI nanoparticles, which proposed a possible way to overcome the problem of large off-field viscosity of the present nanoparticle-based ER fluids [57-61]. Furthermore, it was found that the PANI nanofiber suspension could maintain a good ER effect in a wide temperature range like the PANI microparticle suspension, while the temperature stability of the PANI nanoparticle suspension was degraded. It was known that the Brown motion disturbed ER structures in nanoparticle suspension systems more easily compared to microparticle suspension systems, but the larger dipole moments and more robust dendrite-like network induced by electric fields in PANI nanofiber suspension were believed to contribute to good temperature stability of ER effect [98].

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