@article{DodooBalzerHugeletal.2013,
  author    = {Dodoo, Samuel and Balzer, Bizan N. and Hugel, Thorsten and Laschewsky, Andr{\´e} and von Klitzing, Regine},
  title     = {Effect of ionic strength and layer number on swelling of polyelectrolyte multilayers in water vapour},
  series = {Soft materials},
  volume    = {11},
  journal   = {Soft materials},
  number    = {2},
  publisher = {Taylor \& Francis Group},
  address   = {Philadelphia},
  issn      = {1539-445X},
  doi       = {10.1080/1539445X.2011.607203},
  pages     = {157 -- 164},
  year      = {2013},
  abstract  = {The swelling behavior of polyelectrolyte multilayers (PEMs) of poly(sodium-4 styrene sulfonate) (PSS) and poly(diallyl dimethyl ammonium chloride) (PDADMAC) prepared from aqueous solution of 0.1 M and 0.5 M NaCl are investigated by ellipsometry and Atomic Force Microscopy (AFM). From 1 double-layer up to 4 double-layers of 0.1 M NaCl, the amount of swelling water in the PEMs decreases with increasing number of adsorbed double layers due to an increase in polyelectrolyte density as a result of the attraction between the positively charged outermost PDADMAC layer and the Si substrate. From 6 double layers to 30 double layers, the attraction is reduced due to a much larger distance between substrate and outermost layer leading to a much lower polyelectrolyte density and higher swelling water. In PEMs prepared from aqueous solution of 0.5 M NaCl, the amount of water constantly increases which is related to a monotonically decreasing polyelectrolyte density with increasing number of polyelectrolyte layers. Studies of the surface topology also indicate a transition from a more substrate affected interphase behavior to a continuum properties of the polyelectrolyte multilayers. The threshold for the transition from interphase to continuum behavior depends on the preparation conditions of the PEM.},
  language  = {en}
}