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Washburn's equation is also used commonly to determine the contact angle of a liquid to a powder using a force tensiometer. [ 5 ] In the case of porous materials, many issues have been raised both about the physical meaning of the calculated pore radius r {\displaystyle r} [ 6 ] and the real possibility to use this equation for the calculation ...
The contact angle (symbol θ C) is the ... Washburn's equation capillary rise method. In case of a porous materials many issues have been raised both about the ...
A force balance equation known as Washburn's equation for the above material having cylindrical ... The contact angle of mercury with most solids is between 135 ...
For contact angle measurements on powders, they are typically compressed or adhered to a substrate which can effectively change the surface characteristics of the powder. Alternatively, the Washburn method can be used, but this has been shown to be affected by column packing, particle size, and pore geometry. [ 4 ]
Contact angle method is the standard surface energy measurement method due to its simplicity, applicability to a wide range of surfaces and quickness. The measurement can be fully automated and is standardized. [4] In general, as surface energy increases, the contact angle decreases because more of the liquid is being "grabbed" by the surface.
An ideal solid surface is flat, rigid, perfectly smooth, and chemically homogeneous, and has zero contact angle hysteresis. Zero hysteresis implies the advancing and receding contact angles are equal. Figure 1: Contact angle for a liquid droplet on a solid surface. In other words, only one thermodynamically stable contact angle exists. When a ...
The last image we have of Patrick Cagey is of his first moments as a free man. He has just walked out of a 30-day drug treatment center in Georgetown, Kentucky, dressed in gym clothes and carrying a Nike duffel bag.
An alternative method for measuring the contact angle is the Wilhelmy method, which employs a sensitive force meter of some sort to measure a force that can be translated into a value of the contact angle. In this method, a small plate-shaped sample of the solid in question, attached to the arm of a force meter, is vertically dipped into a pool ...