Why does cornflower mixed with water turn solid when it's kept moving and go liquid when it's sitll?

because when it moves to fast the starch molecules all lock up, because of their jagged shape, but when nothing is forcing them they can keep their distance from one another and just slide across each other

Why does cornflower mixed with water turn solid when it's kept moving and go liquid when it's sitll?
The viscosity of a liquid (how thick or pourable it is) can depend on many things.





When you apply a force along the surface of a liquid (a shear force), the molecules move. How much they move depends on the type of liquid. Some liquid such as cornflour and water mixture.....or those trays of solid paint are referred to as 'shear thinning'. This means that as you increase the shear force e.g. by stirring, or applying it to a roller, the liquid 'thins' or becomes more viscous. Other liquids have different behaviour. Take water as an example the viscosity will not vart significantly with the shear stresses applied, this type of liquid is refferd to as 'Newtonian'. There is a 3rd group which exhibit a different behaviour called Bingham plastics I think (but I can not remember very much about these).
Reply:it's known as a non-newtonion liquid, which is a fluid in which the viscosity changes with the applied strain rate.





In the case of cornflower it is due to the large amount of starch and the interactions the occurs with the solution.