Studies On The Shear-thickening Behavior Of Solution Composed Of PEO And Nano-SiO₂

Shear thickening fluid (STF) is one of the Non-Newtonian Fluid, also called the expansion of fluid, and is a new type of smart material. Generally speaking, the shear thickening fluid material performance as a Newtonian fluid when there is no external force. Once it come across extrusion or just high speed impact of other exterior stress effect, the material will become very hard because of reflecting the Non-Newtonian Fluid performance. In other words, the shear viscosity of fluid material increases with the increase of shear rate. For most common scattered systems such as emulsion, suspension and polymer/packing system also display the shear thickening behavior. With the development of research in recent years, hydrophobic associating polymer and polyelectrolyte both display shear thickening phenomenon in the appropriate concentration conditions. Taking advantage of this kind of unique performance, we find widespread use in seismic minus rushed, daily chemical industry, military project and enhanced oil recovery. The most significant effects have achieved. So there is a wide range of application significance and scientific research value in the research of shear thickening fluid.Based on the background of a large number of literature investigation and above the research, we began this paper. The rheological method, laser particle size analyzer and viscosity analyzer techniques are used to investigate the experiment. According to relevant literature research, the composite system solution of Poly ethylene oxide and nanosize silica (PEO/SiO2) display shear thickening behavior. And on this basis discovery, the different alcohol, and the temperature influence on PEO/SiO2composite system are studied. The different molecular weight of PEO solution is also discussed. The main results are summarized in this paper as follows:1. Along with the development of modern technology and polymer industrial progress, formed "macromolecular theory" on the polymer structure, and it is a theoretical foundation for polymer solution. At the same time, polymer solution displays the different special performance because of the large molecular weight and complex internal structure. For the particular interaction polymer, it often shows shear thickening behavior. That is to say the shear viscosity increase with the increase of shear rate in the appropriate concentration conditions (commonly in semi-dilute solution state). This paper introduces the polymer solution of shear thickening behavior from the shear thickening mechanism and influential factors and so on.2. Shear thickening behavior of PEO/SiO2solution was measured, and the effect of alcohol upon the shear thickening behavior of PEO and nano-SiO2solution was studied. It has been found that the critical shear rate corresponding to the increase of the shear viscosity of solution, γc of PEO and nano-SiO2solution increase in the presence of monobasic alcohol (methyl alcohol, ethanol and isopropanol),and the γc of composite system of dibasic alcohol (glycol) is invariably. On the other hand, in the presence of trihydric alcohol (propanetriol), the critical shear rate γc decreases. The difference of alcohol upon the shear thickening behavior of PEO/SiO2solution is greatly associated with the adsorption of alcohol on the nano-SiO2which changes the surface property of nano-SiO2significantly.3. Researches Show that more high molecular weight alone PEO (6×106g/mol) solution also have shear thickening phenomenon. And this paper studies PEO solution of rheological behavior with the different molecular weight.5×105of PEO in a certain concentration performance as a Newton fluid, in other words the solution viscosity is invariant with the increase of shear rate;4million PEO solution performance Non-Newtonian fluid (pseudoplastic fluid), and solution viscosity decrease with the increase of shear rate; and last6million or higher PEO solution performance Non-Newtonian fluid, and solution viscosity increase with the increase of shear rate, it maybe that macromolecular chain is induced reunion (Self-aggregation) under the action of shear stress. The different temperature condition and the different anionic/cationic surfactant to shear thickening are studied.