Suitable concentration of surfactants can make the foam have impact resistance.

2020-04-17 09:47:48

Surfactants are also widely used in the pharmaceutical industry. In the pharmaceutical, some volatile oil soluble cellulose, steroids and many other insoluble drugs can form transparent solution and increase the concentration by the solubilization of surfactants; in the pharmaceutical preparation process, it is an indispensable emulsifier, wetting agent, suspending agent, foaming agent and defoamer. A bubble is a film of liquid surrounding a gas. Some surfactants and water can form a certain strength film, which surrounds the air and forms foam. It is used for flotation flotation, foam extinguishing and washing decontamination. This active agent is called foaming agent. Sometimes it is necessary to use defoamer. There are too many bubbles in the process of making sugar and making Chinese medicine. It is necessary to add proper surfactants to reduce the strength of the film, eliminate bubbles and prevent accidents. A kind of

In the pesticide industry, a certain amount of surfactants are needed for wettable powder, emulsifiable oil and concentrated emulsion. For example, most of the raw materials of wettable powder are organic compounds, which are hydrophobic. Only in the presence of surfactants, reducing the surface tension of water, can the particles be wetted by water and form water suspension.

Surfactant is used in flotation of ore, that is to use floatation. By stirring and bubbling gas from the bottom of the pool, bubbles with effective mineral powder gather on the surface, collect and defoamer to concentrate, so as to achieve the purpose of enrichment. The mud, sand and rock without ore shall be left at the bottom of the pool and removed regularly. When 5% of the mineral sand surface is covered by collector, the surface will be hydrophobic, which will be attached to the bubble and rise to the liquid surface together, so as to facilitate collection. Select a suitable collector, so that its hydrophilic group is only adsorbed on the surface of mineral sand, and the hydrophobic group is toward water.

Suitable concentration of surfactants can make the foam have impact resistance and ensure the stability of foam. When the local liquid film of the foam is thinned by impact, the surface area of the liquid film increases, and the density of the surfactant molecules adsorbed on it changes drastically, and the density of the surface thinning decreases. A large number of molecules in the surface of the surfactant will move to a small density and take part of the liquid, which will eventually restore the molecular density of the adsorbed surfactant, restore the thickness of the liquid film, and restore the strength of the liquid film, so the foam shows good stability.

When the concentration of surfactant solution is appropriate (below the critical micelle concentration), the stability of the foam is high. When the surfactant solution concentration is too high (exceeding the critical micelle concentration), the surface adsorption rate of surfactant molecules is faster, and it reaches the new equilibrium state quickly. Therefore, the stability of the foam is often low. Generally, the foam stability of the low alcohol aqueous solution is not high, which is related to the rate of adsorption of alcohol molecules on the surface.