What is Cassie-Baxter equation?
Cassie-Baxter proposed that the apparent contact angle is related to the fraction of the surface that is in contact with the liquid as shown in the following equation. cos θ CB = f 1 + cos θ − 1.
Why does the Cassie-Baxter equation apply?
Application of the Cassie–Baxter equation to the calculation of apparent contact angles is discussed. It is demonstrated that taking into account the precursor film surrounding the drop justifies the application of the Cassie–Baxter equation.
What is the Cassie-Baxter State?
Cassie-Baxter state The notion of roughness effecting the contact angle was extended by Cassie and Baxter in 1944 when they focused on porous mediums, where liquid does not penetrate the grooves on rough surface and leaves air gaps. They devised the Cassie-Baxter equation; , sometimes written as where the has become .
How do you derive Young’s equation?
3.2. Derivation of Young’s equation
- G(h, h’, r)= a∫0[2πrγ⋅√1+(dhdr)2 +U(r,h)+[2πr(γSL− γSO)]]dr E25.
- V0=a∫02πr⋅[h(r)]dr E26.
- ˜G(h,h′,r)=2πγr√1+h′2 +U(r,h)+2πr(γSL− γSO)+ 2πβrh E28.
What are wetting and non wetting liquids?
A wetting liquid is a liquid that forms a contact angle with the solid which is smaller then 90º. A non-wetting liquid creates a contact angle between 90º and 180º with the solid.
What is contact angle hysteresis?
Contact angle hysteresis is a reflection of the activation energy required for movement of a droplet from one metastable state to another on a surface. This can be expressed quantitatively in terms of changes in the interfacial area and thus interfacial free energy.
What is M in Young’s equation?
We call m the order of the interference. For example, m = 4 is fourth-order interference. The equations for double slit interference imply that a series of bright and dark lines are formed.
Is water wet or dry?
Water is wet, in the sense of being a liquid which flows easily, because its viscosity is low, which is because its molecules are rather loosely joined together.
Is water wet Wikipedia?
Answer 1: Liquid water is not itself wet, but can make other solid materials wet. Wetness is the ability of a liquid to adhere to the surface of a solid, so when we say that something is wet, we mean that the liquid is sticking to the surface of a material.
What is the Cassie-Baxter equation?
The more commonly encountered equation is that of Cassie-Baxter [2]. It describes the contact angle on a porous surface. Instead of having two different surface chemistries as in Cassie law, the surface is now composed of solid surfaces and areas where the drop is in contact with air. The equation can be written as
What is Cassie’s Law in chemistry?
Cassie’s law, or the Cassie equation, describes the effective contact angle θ c for a liquid on a chemically heterogeneous surface, i.e. the surface of a composite material consisting of different chemistries, that is non uniform throughout.
Did Rene Caisse pass on the Essiac formula?
Rene Caisse did pass on different versions of the Essiac formula to at least four people before she died in 1978. CLICK HERE to read ” Who Owns Essiac? ” for more information about the history of Essiac and Essiac timeline. Every herbal formula has its own synergy and therefore creates a specific effect.
What is Cassie’s angle?
It describes the contact angle on a porous surface. Instead of having two different surface chemistries as in Cassie law, the surface is now composed of solid surfaces and areas where the drop is in contact with air. The equation can be written as