Molecular Weight Dependence of Polymer Chain Mobility
within Multilayer Films
Li Xu
Victor Selin
Aliaksandr Zhuk
John F. Ankner
Svetlana A. Sukhishvili
10.1021/mz400413v.s001
https://acs.figshare.com/articles/journal_contribution/Molecular_Weight_Dependence_of_Polymer_Chain_Mobility_within_Multilayer_Films/2366758
Fluorescence
recovery after photobleaching has been applied to
determine, to our knowledge for the first time, the molecular weight
(<i>M</i><sub>w</sub>) dependence of lateral diffusion of
polymer chains within layer-by-layer (LbL) films. As shown by neutron
reflectometry, polyelectrolyte multilayers containing polymethacrylic
acid (PMAA, <i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.05) of various molecular weights assembled from solutions
of low ionic strengths at pH 4.5, where film growth was linear, showed
similar diffusion of PMAA in the direction perpendicular to the film
surface. At a salt concentration sufficient for unfreezing electrostatically
bonded chains, layer intermixing remained almost unaffected (changes
<1.0 nm), while the lateral diffusion coefficient (<i>D</i>) scaled with the PMAA molecular weight as <i>D ∼ M</i><sub>w</sub><sup>–1±0.05</sup>.
2013-10-15 00:00:00
layer intermixing
Polymer Chain Mobility
unfreezing electrostatically
film growth
polymethacrylic acid
Multilayer FilmsFluorescence recovery
neutron reflectometry
film surface
Molecular Weight Dependence
diffusion coefficient
salt concentration
Mw
polyelectrolyte multilayers
PMAA
polymer chains