Improved stability of a polyion-complexed monolayer of a maleic acid copolymer by using alkoxyethyldimethylamines as hydrophobic counterparts at the air-water interface

Amphiphilic tert-amines, 2-(dimethylamino)ethyl octadecyl ether(C18ODA), 2-(dimethylamino)ethyl octadecyl ethylene glycol diether(C18O2DA), and 1,3-dioctadecyl-2-(2-(N,N-dimethylamino)ethyl) glyceryl triether (2C18O3DA), were synthesized and employed as hydrophobic counterparts for spreading a water-soluble copoly(maleic acid-methyl vinyl ether) by polyion complexation at the air-water interface. The amines stabilized the monolayers with the order of 2C18O3DA > C18ODA > C18O2DA > N,N-dimethyloctadecylamine. The stabilized monolayer could be transferred on solid substrates.