Talk:Rheopecty

The reference to high-income countries sounds inappropriate, rings of social commentary... —Preceding unsigned comment added by 129.215.5.120 (talk) 11:49, 14 January 2009 (UTC)

I agree with the parent. I was going to edit that line out of this page, but carefully reading the whole article reveals it was poorly written. As I am not an expert in Rheopecty, I can only kibitz. Johnm1019 (talk) 15:01, 31 August 2009 (UTC)

Additional Examples
Is egg-white rheopectic?

How about butter/cream? 121.72.240.101 06:17, 17 September 2007 (UTC)


 * 14 years late reply: No, the stiffening of rheopectic fluids are in general reversible - at rest they will become thin again (for some it might take a while). It is not due to an permanent physical change like when cream is whipped to butter or egg-white+sugar is whipped to meringue. Tøpholm (talk) 13:02, 19 June 2024 (UTC)

Bad entry title
This should be at Rheopexy. "Rheopecty" seems to be an error formed from "rheopectic"; search in Google Books to see how rare this form is. 81.152.72.174 (talk) 23:01, 1 July 2010 (UTC)

Could caster oil be an example? occasional user pharmacist anonym. 03-01-2011; 20:29 —Preceding unsigned comment added by 99.241.146.92 (talk) 01:29, 4 January 2011 (UTC)

I disagree, cornstarch in water really is rheopectic
"An incorrect example often used to demonstrate rheopecty is cornstarch mixed with water ... cornstarch in water is actually a dilatant fluid" I disagree, that example is not incorrect, cornstarch in water really is rheopectic. Whether or not cornstarch in water is dilatant or not has nothing to do with whether it is rheopectic. Sand in water is dilatant because it expands under shear, but it is not rheopectic. Like all rheopectic fluids, cornstarch in water exhibits an increase in viscosity with shear - there's absolutely no need for the viscosity to build up slowly with time for the fluid to be rheopectic, an instantaneous change suffices.Mollwollfumble (talk) 01:52, 6 June 2011 (UTC)

Supposed interest in rheopectic materials
I don't follow the logic of rheopexy being useful for shock absorption/impact-stress lowering materials. Why would the time-dependent increase of viscosity make such a material suitable for that purpose? It is my understanding that dilatant materials are in fact the materials of choice for this sort of application. There are also no citations for any of the claims in the paragraph about applications. Bonks1 (talk) 13:34, 27 March 2017 (UTC)

Need more examples
It is indeed a rare phenomena! So rare that few examples are given in the article.

The 1989 Honda Civic Wagovan was available with automatic-engaging four wheel drive, where the clutch in the four wheel drive transfer case was engaged by a rheopectic fluid. When a difference in surface velocity between the clutch discs that connect the front wheel drive and the rear wheels of the vehicle caused shear, the rheopectic fluid "stiffened up" and transferred torque between the clutch discs to the rear wheels. I sure would like to know what the fluid is they used. Perhaps they used cornstarch? I doubt it, that stuff would cook when it got hot!

Oh, the article forgot to mention whether the cornstarch was the uncooked raw powdered stuff straight out of the box from the grocery store mixed with water, or if you have to mix it with water and make stovetop gravy out of it for it to be rheopectic. I never noticed any rheopectic gravy on my mashed potatoes. However, I've had plenty of rheopectic mashed potatoes. How come mashed potatoes wasn't mentioned? Linstrum (talk) 21:28, 29 November 2019 (UTC)