2022-11-06T05:22:43+03:00[Europe/Moscow] en true <p>Rheology</p>, <p>viscosity, elasticity</p>, <p>viscosity</p>, <p>high</p>, <p>low</p>, <p>Rate of shear</p>, <p>G</p>, <p>Shear stress</p>, <p>viscosity (n) * rate of shear</p>, <p>newtonian</p>, <p>newtonian systems</p>, <p>viscosity; fluidity </p>, <p>colloidal dispersions, emulsions, suspensions, ointments </p>, <p>non-newtonian systems</p>, <p>Newtonian</p>, <p>Simple Plastic flow</p>, <p>Simple pseudoplastic flow</p>, <p>Dilatant flow</p>, <p>dilatant </p>, <p>no yield value; viscosity decreasing with increased stress (shear thinning)</p>, <p>Pseudoplastic flow</p>, <p>Dilatant</p>, <p>Pseudoplastic </p>, <p>non-newtonian shear thinning systems</p>, <p>dilatant</p>, <p>Dilatant</p>, <p>Dilatant materials</p>, <p>Dilatant flow</p>, <p>particles are no longer wetting</p>, <p>dilatant flow</p>, <p>high-speed mixing, blending, milling</p>, <p>thixotropy </p>, <p>shearing</p> flashcards
Rheology

Rheology

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  • Rheology

    -term used to describe the flow of liquids and deformation of solids.

  • viscosity, elasticity

    Rheology has 2 principle components; what are they?

  • viscosity

    -shearing force required to produce a velocity of 1 cm/sec between two parallel planes of a liquid separated by 1 cm and each having an area of 1cm2.

  • high

    A suspension exhibiting low viscosity should exhibit what kind of shear?

  • low

    A suspension exhibiting high shear should exhibit what kind of viscosity?

  • Rate of shear

    -the difference in velocity between two planes of a liquid separated by an extremely small distance.

  • G

    Symbol for rate of shear?

  • Shear stress

    -the force per unit area required to bring about flow.

  • viscosity (n) * rate of shear

    Formula for shearing stress?

  • newtonian

    Which Rheological system has a shearing stress directly proportional to the rate of shear?

  • newtonian systems

    In _________, viscosity does not change with shear stress.

  • viscosity; fluidity

    In Newtonian systems, the ______ decreases and the _________ as the temperature increases.

  • colloidal dispersions, emulsions, suspensions, ointments

    What are some examples of Non-Newtonian systems?

  • non-newtonian systems

    Which Rheological system exhibits a nonlinear plot of Rate of shear (F) vs. Shear stress (G)?

  • Newtonian

    What type of flow does this graph represent?

    What type of flow does this graph represent?

  • Simple Plastic flow

    What type of flow does this graph represent?

    What type of flow does this graph represent?

  • Simple pseudoplastic flow

    What type of flow does this graph represent?

    What type of flow does this graph represent?

  • Dilatant flow

    What type of flow does this graph represent?

    What type of flow does this graph represent?

  • dilatant

    These systems increase in volume or dilate when sheared.

    Dilatant

    Pseudo plastic

    Simple plastic

    Newtonian

  • no yield value; viscosity decreasing with increased stress (shear thinning)

    What are special characteristics of Pseudoplastic Flow?

  • Pseudoplastic flow

    When stress is applied, long polymers align themselves in the direction of flow, facilitating motion. This applies to what kind of flow?

    -Dilatant

    -Pseudo plastic

    -Simple Plastic

    -Newtonian

  • Dilatant

    Which type of flow is observed in highly concentrated suspensions?

    -Dilatant

    -Pseudo plastic

    -Simple Plastic

    -Newtonian

  • Pseudoplastic

    Which type of Flow is found in polymers that are in solutions?

    -Dilatant

    -Pseudo plastic

    -Simple Plastic

    -Newtonian

  • non-newtonian shear thinning systems

    Thixotropy is only applicable to _________

  • dilatant

    Which newtonian system is a "shear thickening system"?

  • Dilatant

    -increased resistance to flow with increased rates of shear

  • Dilatant materials

    _______ can be poured at low stress.

  • Dilatant flow

    increase in stress= bulk of system expands and particles take on an open form of packing

  • particles are no longer wetting

    Why are dilatant materials resistant to flow?

  • dilatant flow

    Which suspension can become a paste when stress is increased enough?

  • high-speed mixing, blending, milling

    What appropriate precautions are needed when processing dilatant materials?

  • thixotropy

    -comparatively slow recovery of the material structure that lost through shearing.

  • shearing

    -the change of shape, without change of volume, of a layer of the substance, produced by a pair of equal forces acting in opposite directions along the two faces of the layer.