Non Newtonian Fluid

[LobnaAbouHussein]

Hello, 

I am working on non-Newtonian fluid project. I have experimented with cornstarch and water and achieved the consistency desired with 55% cornstarch and 45% water.

Now I want to create similar outcome using Silica Nano particles and Polyethylene glycol (PEG 400). However I am not able to reach a proper result. I used the following ratio:  60:40 (polyethylene and silica) But I got a paste-like material instead of a shear thickening fluid.
And ideas on how to find an accurate ratio for desired result? Is the problem regarding the ratio or the mixing steps? Do I need specific equipment for the process?
Thank you. 

[meliskavak]

Hello,

I'm having the same problem with a silica (Aerosil 200) and PEG400 mixture. The mixture didn't become dilatant like Oobleck. How can I obtain a dilatant fluid like Oobleck using SiO2 and PEG400? It should behave like a solid under pressure. Thank you.

[hashirr0099]

To achieve a shear-thickening fluid with silica nanoparticles and PEG 400, start by adjusting your material ratios; try using closer to 50:50 or 40:60 (PEG) instead of the 60:40 ratio you used. Ensure thorough mixing with a high-shear mixer or homogenizer for uniform dispersion of nanoparticles, as simple stirring may not suffice. Test the fluid's shear-thickening behavior and refine based on your observations. Consider using a higher concentration of silica and lower PEG concentrations, and add surfactants if needed. Additionally, ensure the silica particle size is suitable for achieving the desired properties. streameastguide.com