Detection of Polymer Miscibility by 1H/13C/14N Triple Resonance Solid State Nuclear Magnetic Resonance

1H/13C/14N triple resonance has been used to verify the existence of a template complex formed by poly(methacrylic acid) and poly(N-vinylimidazole). The proximity of the imidazole ring and the carbonyl group of poly(methacrylic acid) leads to a significant loss of carbon-13 spin-echo intensity when 14N is irradiated. This means that the internuclear distances in this template complex between the carbons of poly(methacrylic acid) and the nitrogen of poly(N-vinylimidazole) are less than 5 Å, as confirmed by a numerical model. Such an intimate mixing of the two components can also be concluded from proton T 1 ρ measurements.