2021-09-28 Pageview:601
How to use dispersant for coating? Dissolve the dispersant in solvent in advance, then add the pigment.
Application range: Gravure ink, UV offset ink, automotive paint, industrial paint, plastic paint.
According to the “life course” of the bubble, we can observe the phenomenon that its structure changes over time. Containing ample liquid without significant deformation of the bubbles, it is called “wet bubbles” or “spherical bubbles”. When the liquid flows out of the aggregated foam film, the film becomes thinner and the bubbles gather tighter to form a multi-faceted structure called “wet dry bubble” or “polyhedral bubble”. The foam is produced and stabilized by external forces. When foam is generated, the free energy of the system also increases rapidly due to the rapid increase of the contact surface of the liquid and gas, which increases the fiberglass wax additive free energy of the foam system. According to the principle of thermodynamics, the infinitely small change dG of the free energy of a certain system can be expressed by the Gibbs adsorption equation.
After the bubble bursts, the surface area of the formed droplets is reduced, which is equivalent to a reduction in surface energy. Biker man provides a good example of this. A bubble with a radius of 1cm and a bubble film thickness of 10-3cm has a surface area of about 25cm². If it only forms a droplet, its surface area is only 0.2cm². The energy difference at this time is so large that the reduction in free energy of bubbles is also very significant. At this time, there is a strong tendency for droplets to form droplets. Obviously, the Gibbs equation needs to be modified to achieve the stabilization of the bubble.
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