화학공학소재연구정보센터
Langmuir, Vol.10, No.12, 4651-4656, 1994
Chain-Length Discrimination of Water-Soluble Polymers by a Poly(Methacrylic Acid) or Poly(Oxyethylene) Segment-Carrying Assemblies at the Air-Water-Interface
A poly(methacrylic acid) (1(n)) or poly(oxyethylene) (2(n))-functionalized, double-chain amphiphile, incorporated in organized monolayer assemblies, forms an interpolymer complex with the corresponding guest polymer (poly(ethylene glycol) (PEG) or poly(methacrylic acid) (PMAA)) present in an adjacent aqueous phase. Surface pressure-area isotherm and FTIR spectroscopy have been used for the characterization and investigation of the 1(n) or 2(n) host monolayer-guest polymer complexation. In both monolayers (1(n) and 2(n)) complexation occurs on acidic subphases. Surface pressure-area isotherms change sensitively to the chain length (m) of the guest polymers added into the subphase : in the combination of 1(n) monolayer-PEG the area per molecule decreases with increasing m up to m = n (n is the chain length of polymer segment of 1(n)), and in contrast in the combination of 2(n) monolayer-PMAA the area increases with increasing m up to m = n. Consequently, these polymer monolayers of 1(n) and 2(n) have been found to have an ability to discriminate against the chain length of the guest polymers. The driving force of such a complexation can be assigned to multiple hydrogen bonding between the carboxylic acid and the ether oxygen, which have led to either a shift or the appearance of a new band of C=O stretching in the FTIR spectra.