Surfactant means a substance which is added in a small amount to cause a significant change in the interface state of the solution system. It has a fixed hydrophilic lipophilic group and can be aligned on the surface of the solution. The molecular structure of the surfactant is amphiphilic: one end is a hydrophilic group and the other end is a hydrophobic group; the hydrophilic group is often a polar group such as a carboxylic acid, a sulfonic acid, a sulfuric acid, an amino group or an amine group. The salt, hydroxyl group, amide group, ether bond and the like may also serve as a polar hydrophilic group; and the hydrophobic group is often a non-polar hydrocarbon chain, such as a hydrocarbon chain of 8 or more carbon atoms. Surfactants are classified into ionic surfactants (including cationic surfactants and anionic surfactants), nonionic surfactants, amphoteric surfactants, complex surfactants, other surfactants, and the like. And the N-Ethylacetamide NEA CAS 625-50-3 is the main materail of Surfactant.