首页   按字顺浏览 期刊浏览 卷期浏览 Yield Stresses in Concentrated Dispersions of Closely Packed, Deformable Gel Particles
Yield Stresses in Concentrated Dispersions of Closely Packed, Deformable Gel Particles

 

作者: L. L. Navickis,   E. B. Bagley,  

 

期刊: Journal of Rheology  (AIP Available online 1983)
卷期: Volume 27, issue 6  

页码: 519-536

 

ISSN:0148-6055

 

年代: 1983

 

DOI:10.1122/1.549717

 

出版商: The Society of Rheology

 

数据来源: AIP

 

摘要:

Wheat starch granules dispersed in water and heated to 70°C swell extensively to form dispersions of irregularly shaped, deformable particles. Because the granules are deformable under shear, the rheological properties of the dispersions can be examined at volume fractions up to unity, which corresponds to a starch concentration of 14%. At concentrations of 10–13%, yield stresses are observed in couette flow at 23°. At concentrations of 14% and above, the dispersions show essentially solidlike behavior in shear. Shear stress‐shear strain diagrams for these gels were obtained in a parallel plate rheometer. The major experimental problem in this testing mode is slip between the gel and the parallel plates. This problem was resolved by using cyanoacrylate ester adhesive to attach the gel to the parallel plates. With slip eliminated, the shear stress‐shear strain diagrams show an initial linear region from which a small deformation modulus is obtained. As shear strain increases, a yield point is observed where the stress‐strain curve shows an inflection point. At higher strains, the curve rises again, and forces normal to the direction of shear are generated. Failure finally occurs at strains of 25–50%.

 

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