Polar-Molecule-Dominated Electrorheological Fluids Featuring High Yield Stresses

2009 ◽  
Vol 21 (45) ◽  
pp. 4631-4635 ◽  
Author(s):  
Rong Shen ◽  
Xuezhao Wang ◽  
Yang Lu ◽  
De Wang ◽  
Gang Sun ◽  
...  
2007 ◽  
Vol 21 (28n29) ◽  
pp. 4798-4805 ◽  
Author(s):  
KUNQUAN LU ◽  
RONG SHEN ◽  
XUEZHAO WANG ◽  
GANG SUN ◽  
WEIJIA WEN ◽  
...  

The static and dynamic shear stress of newly developed electrorheological (ER) fluids can reach more than 100 kPa and over 60 kPa at 3 kV/mm, respectively. The high yield stress of those ER fluids and its near linear dependence on the electric field are different from the conventional ER fluids and can not be explained with traditional dielectric theory. Experiment demonstrates that the polar molecules adsorbed on the particles play crucial role in those ER fluids, which can be named as polar molecule type electrorheological (PM-ER) fluids. To explain PM-ER effect a model is proposed based on the interaction of polar molecule-charge in between the particles, where the local electric field is much higher than the external one and can cause the polar molecules aligning. The main effective factors for achieving high-performance PM-ER fluids are discussed.


Author(s):  
KUNQUAN LU ◽  
RONG SHEN ◽  
XUEZHAO WANG ◽  
GONG SUN ◽  
WEIJIA WEN ◽  
...  

2009 ◽  
Vol 30 (10) ◽  
pp. 4521-4524 ◽  
Author(s):  
X.Z. Wang ◽  
R. Shen ◽  
D. Wang ◽  
Y. Lu ◽  
K.Q. Lu

2007 ◽  
Vol 102 (2) ◽  
pp. 024106 ◽  
Author(s):  
R. Shen ◽  
X. Z. Wang ◽  
Y. Lu ◽  
W. J. Wen ◽  
G. Sun ◽  
...  

2010 ◽  
Vol 49 (8) ◽  
pp. 837-843 ◽  
Author(s):  
Xuehui Liu ◽  
Jianjun Guo ◽  
Yuchuan Cheng ◽  
Gaojie Xu ◽  
Yong Li ◽  
...  

2011 ◽  
Vol 25 (07) ◽  
pp. 957-962 ◽  
Author(s):  
KUNQUAN LU ◽  
RONG SHEN ◽  
XUEZHAO WANG ◽  
DE WANG ◽  
GANG SUN

In recent years, a new type ER fluids named as polar-molecule-dominated electrorheological (PM-ER) fluids have been developed, of which the yield stress can reach more than 100 kPa and behaves a linear dependence on the electric field. A brief description on the composition and synthesizing method for the materials is given. The main merits of PM-ER fluid are as follows: high yield stress, the shear stress increasing with shear rate up to more than 103 s -1, low current density, rapid electric response and anti-sedimentation. Some perspectives on PM-ER fluid and its applications are presented.


Author(s):  
N. Tempel ◽  
M. C. Ledbetter

Carbon films have been a support of choice for high resolution electron microscopy since the introduction of vacuum evaporation of carbon. The desirable qualities of carbon films and methods of producing them has been extensively reviewed. It is difficult to get a high yield of grids by many of these methods, especially if virtually all of the windows must be covered with a tightly bonded, quality film of predictable thickness. We report here a method for producing carbon foils designed to maximize these attributes: 1) coverage of virtually all grid windows, 2) freedom from holes, wrinkles or folds, 3) good adhesion between film and grid, 4) uniformity of film and low noise structure, 5) predictability of film thickness, and 6) reproducibility.Our method utilizes vacuum evaporation of carbon from a fiber onto celloidin film and grid bars, adhesion of the film complex to the grid by carbon-carbon contact, and removal of the celloidin by acetone dissolution. Materials must be of high purity, and cleanliness must be rigorously maintained.


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