emulsifier vs wetting agent

emulsifier and wetting agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
emulsifier	Yes	No	No	No
wetting agent	Yes	No	No	No

As nouns, wetting agent is a hypernym of emulsifier; that is, wetting agent is a word with a broader meaning than emulsifier:

emulsifier: a surface-active agent that promotes the formation of an emulsion
wetting agent: a chemical agent capable of reducing the surface tension of a liquid in which it is dissolved

Other hypernyms of emulsifier include surface-active agent, surfactant, wetter.

emulsifier (noun)	wetting agent (noun)
a surface-active agent that promotes the formation of an emulsion	a chemical agent capable of reducing the surface tension of a liquid in which it is dissolved