Written by Norman Lowe, April 2026
In surfactant chemistry, we discuss four broad types based on their ionic charge. The first three are: “anionics,” which provide a negative charge in solution; “cationics,” which provide a positive charge in solution; and “non-ionics,” which do not ionize in solution and thus carry no charge. The fourth type is the “amphoterics,” which possess both a negative and positive charge, for example:
R.N⁺(R²)2.COO־
This example features a quaternary nitrogen group (N⁺R₄) with a positive charge and an acyl group (COO־) with a negative charge within the same molecule. This is balanced at neutral pH and is known as the “zwitterionic form.”Continue reading
