Basic knowledge--What is water emulsification

Water in oil, oil in water, oil enclosing dirt, dirt enclosing oil, water enclosing dirt, dirt enclosing water – when oil, water, and dirt form a suspension, this is the emulsification of water. Just drain the emulsified water.

This post was last edited by Desert Fish on 2015-11-8 08:42. An organic compound that enables immiscible liquids to form stable emulsions. They are all substances with surface activity that can reduce the interfacial tension between liquids, thereby facilitating the emulsification of immiscible liquids. During emulsification, the dispersed phase is uniformly distributed in the continuous phase in the form of very small liquid droplets (with diameters ranging from 0.1 micrometers to several dozen micrometers). Emulsifiers form a film or double layer on the surface of these droplets, preventing them from coalescing and thus maintaining the stability of the emulsion. An emulsion is a heterogeneous system. The most common type is an oil-in-water emulsion, with water as the continuous phase and a water-insoluble organic liquid as the dispersed phase. There are also water-in-oil emulsions in which water serves as the dispersed phase, while an water-insoluble organic liquid acts as the continuous phase. To prepare a stable emulsion, an emulsifier of a single component can be added, or several emulsifiers can be added simultaneously. Emulsifier molecules have both hydrophilic and lipophilic parts. Based on the properties of their hydrophilic parts, they can be classified into the following categories: ① Anionic emulsifiers. They are emulsifiers that ionize in water to produce hydrophilic groups with alkyl or aryl groups, such as carboxylates, sulfates, and sulfonates. These types of emulsifiers are the most commonly used, and common commercial examples include soap (C15–17H31–37COONa), sodium stearate (C17H35COONa), sodium dodecyl sulfate (C12H25OSO3Na), and calcium dodecylbenzenesulfonate, among others. Anionic emulsifiers require to be used under alkaline or neutral conditions. When preparing emulsions using various emulsifiers, anionic emulsifiers can be used together with each other, as well as in combination with non-ionic emulsifiers. Anionic and cationic emulsifiers cannot be used together in the same emulsion; mixing them will destroy the stability of the emulsion. ②Cationic emulsifiers. It ionizes in water to produce hydrophilic groups that are cations carrying alkyl or aryl groups. There are few types of such emulsifiers; they are all derivatives of amines, such as N-dodecyldimethylamine, which can be used in polymerization reactions. Non-ionic emulsifier. Its characteristic is that it does not ionize in water. Its hydrophilic portion consists of various polar groups, with polyoxyethylene ethers and polyoxypropylene ethers being common examples. Its lipophilic portion (alkyl or aryl) is directly bonded to the oxyethylene ether linkage. Typical products include octylphenol polyoxyethylene ether: the oxygen atoms in the polyether chain of this non-ionic emulsifier can form hydrogen bonds with water, allowing it to dissolve in water. It can be used in both acidic and alkaline conditions, and it provides excellent emulsification effects; it is widely used in the production of chemicals, textiles, pesticides, petroleum, and latex.

It’s the issue of poor separation between oil, water, and dirt; what is supposed to be discharged is water, but the water that comes out contains oil and dirt. ——If the separation is effective, there should be layers; from top to bottom, these are oil, water, and dirt, each being discharged through its own outlet. ——If separated properly, the effluent from each stage should be clear. After emulsification, the water discharged is cloudy and opaque, like milk.

Emulsification creates a third phase between oil and water, known as an emulsion (where a suspension consists of small solid particles suspended in water); this results in an oil-in-water or water-in-oil structure, which reduces the effectiveness of separation

I have a question: after emulsification, what methods can be used to separate the oil from water again...

Demulsifier: It can separate oil from water.