화학공학소재연구정보센터
Langmuir, Vol.23, No.19, 9606-9610, 2007
Fluorocarbon crowning: Langmuir-Blodgett deposition versus self-assembly at molecularly rough surfaces
Langmuir-Blodgett deposition of a single monolayer of 1,2,4,5-tetrakis[(N-(perfluoroundecanoamidoethyl)-N,N-dimethylammonium)m ethyl] benzene tetrabromide (1) onto a thin film made from alternating layers of poly-(diallydimethylammonium chloride) (PDADMA) and poly(4-styrenesulfonate) (PSS) ions affords a uniform fluorinated surface of low energy. An analogous surface that has been constructed by self-assembly shows the same critical surface tension of 16.5 dyn/cm. A comparison of Zisman plots for these two modified films, in combination with analysis by X-ray photoelectron spectroscopy, indicates that Langmuir-Blodgett deposition produces a higher quality and more densely packed fluorocarbon surface that is very hydrophobic. In sharp contrast, the use of a single-chain analog (i.e., N-(perfluoroundecanoamidoethyl)-N,N,N-trimethylammonium bromide) (2)) affords relatively high energy surfaces by Langmuir-Blodgett deposition and by self-assembly.