**1. Introduction of foam**

Foam is the gas dispersion in liquid. The liquid phase is called exterior stage and the stage of gas is spread in interior stage. We can see the foam formation in **Figure 1**. We called thin fluid film lamella. In Foam we can separate a lamella into internal gas bubbles. The Point where the lamella contact with each other is called 'Plateau border. It is shown in **Figure 1**. There is a density difference between the medium and gas bubbles due to which the system rapidly split in to two layers and the gas bubbles moved to the top [1]. Pure liquid could not foam. They only foam when they have a surface-active material [1, 2]. We find that whenever a bubble of gas is injected under the surface of liquid, its outburst instantly. If we use diluted surfactant solution then a restoring force is created that effort to launch the equilibrium,

## *Analytical Chemistry - Advancement, Perspectives and Applications*

**Figure 1.**

*A schematic of three bubbles meeting at a plateau border.*

#### **Figure 2.**

*Foam stabilisation and formation of polyhedral structure foam.*

as the air/liquid interface enlarge the surface equilibrium changes, this leads to form polyhedral structure as shown in **Figure 2**.
