Coulombin

Coulombin is a fictional ionic polymer used in educational and speculative contexts to illustrate the role of long-range electrostatic interactions in polymeric materials. The name derives from Coulomb's law, reflecting the central influence of charge–charge forces on the material's behavior.

In the idealized model, Coulombin comprises alternating cationic and anionic monomer units linked into a chain or network. Counterions balance the overall charge, and the material is imagined to form microphase-separated domains where electrostatic attractions between opposite charges stabilize the structure. The model predicts high stiffness, elevated dielectric strength, and strong dependency on moisture and counterion identity.

Synthesis in real life is not documented; discussions of Coulombin in teaching materials describe a hypothetical condensation or step-growth polymerization between difunctional cationic and anionic precursors, with deliberate choice of counterions to maintain charge neutrality during growth. The concept is used to explore how strong electrostatic interactions influence processing and structure in polyelectrolyte-like systems.

In educational contexts, Coulombin serves to discuss how salt-like polymers can conduct ions, how charge screening and ion pairing affect phase behavior, and why real polyelectrolytes are challenging to process.

Potential applications in fiction or thought experiments include ion-conducting membranes or dielectrics; in practice the concept highlights limits due to moisture sensitivity and phase separation.

See also: Coulomb's law; polyelectrolyte; ionic polymer.