Difference Between Lipophilic and Hydrophilic Emulsifier

The key difference between lipophilic and hydrophilic emulsifier is that lipophilic emulsifiers work with oil-based emulsions whereas hydrophilic emulsifiers work with water-based emulsions.

An emulsifier is a chemical agent that allows us to stabilize an emulsion. That means; it prevents the separation of liquids that usually do not mix with each other. It does so by increasing the kinetic stability of the mixture. One good example of an emulsifier is surfactants. There are two types of emulsifiers as lipophilic emulsifiers and hydrophilic emulsifiers.

1. Overview and Key Difference
2. What is Lipophilic Emulsifier
3. What is Hydrophilic Emulsifier
4. Side by Side Comparison – Lipophilic vs Hydrophilic Emulsifier in Tabular Form
5. Summary

What is Lipophilic Emulsifier?

Lipophilic emulsifiers are emulsifying agents that work with oil-based emulsions. These chemical reagents are important in removing a penetrant when a defect due to over-washing of the emulsion is a concern. Here, lipophilic emulsifiers can make the excess penetrant more removable with washing using water. Usually, lipophilic emulsifiers are oil-based materials and these reagents are produced as ready-to-use agents by the manufacturer.

Difference Between Lipophilic and Hydrophilic Emulsifier

Figure 01: Emulsifying Action

Lipophilic emulsifiers were developed during the 1950s. These agents can work efficiently with both chemical and mechanical action. Therefore, after the lipophilic emulsifier has coated the surface of the object (emulsion), we can use mechanical action to remove excess penetrant.

What is Hydrophilic Emulsifier?

Hydrophilic emulsifiers are emulsifying agents that work with water-based emulsions. Similar to lipophilic emulsifiers, these chemical reagents also are important in removing a penetrant from a defect when over-washing of the emulsion is a concern. Here, lipophilic emulsifiers can make the excess penetrant more removable with washing using water. Usually, hydrophilic emulsifiers are water-based materials and are produced as a concentrate by the manufacturer. Therefore, we need to dilute the concentration of the hydrophilic emulsifier using water to a preferable concentration before using it.

The action of a hydrophilic emulsifier is different from that of lipophilic emulsifiers because no diffusion takes place during the emulsifying process. Basically, these are detergents that contain a solvent and surfactants. The hydrophilic emulsifier breaks up the penetrant into small quantities and prevents the recombining of pieces in the emulsion. This method was introduced in the late 1970s. The major advantage of using hydrophilic emulsifier is that it is less sensitive to the variation in contact and removal time. However, if we use a lipophilic emulsifier, then a variation as little as 15 seconds can make a significant effect on the final outcome.

What is the Difference Between Lipophilic and Hydrophilic Emulsifier?

An emulsifier is a chemical agent that can stabilize an emulsion by preventing it from separating into its components. There are two major types of emulsifiers as lipophilic emulsifiers and hydrophilic emulsifiers. The key difference between lipophilic and hydrophilic emulsifier is that lipophilic emulsifiers work with oil-based emulsions whereas hydrophilic emulsifiers work with water-based emulsions.

Moreover, lipophilic emulsifiers come in ready-to-use form while hydrophilic emulsifiers come in concentrated form so we have to dilute with water before using it. Apart from that, using hydrophilic emulsifier is more useful when variations in time should not affect the outcome because lipophilic emulsifiers can be sensitive to little time variations such as 15 seconds.

Below tabulation summarizes the difference between lipophilic and hydrophilic emulsifier.

Summary – Lipophilic vs Hydrophilic Emulsifier

Reference:

1. Helmenstine, Anne Marie. “Emulsifier Definition: Emulsifying Agent.” ThoughtCo, Jan. 29, 2020, thoughtco.com/definition-of-emulsifier-or-emulsifying-agent-605085.
2. “Emulsifiers .” Understanding Emulsifiers and Knowing When to Use Them, Available here.
3. “Emulsifiers.” NDT Resource Center, Available here.