Controlling the growth behaviour of multilayered films via layer-by-layer assembly with multiple interactions

Layer-by-layer (LbL) assembly of chitosan-graft-phenyl (CHI-g-Ph) and poly(aspartic-graft-octadecyl) chain (PASP-g-OD) with multiple interactions, i. e. electrostatic interaction and hydrophobic interaction, was studied and the growth rate of multilayered films was found to be strongly dependent on the concentration of NaCl in the aqueous solution. LbL assembly of phenyl chitosan-graft-cyclodextrin (Ph-CHI-g-CD)/PASP-g-OD and chitosan-graft-cyclodextrin (CHI-g-CD)/PASP-g-OD with electrostatic interaction and host-guest interaction was further carried out. The growth of these multilayered films was also affected by the concentration of NaCl in the aqueous solution. For comparison, the LbL assembly of the chitosan (CHI)/polyaspartic acid (PASP) and CHI/PASP-g-OD multilayered films fabricated with electrostatic interaction only were also studied to identify the effect of the multiple interactions on the LbL assembly. H-1 MNR, transmission electron microscopy (TEM), fluorescence spectroscopy and dynamic light scattering (DLS) were used to characterize the polyelectrolytes. LbL assembly processes were monitored by UV-Vis spectroscopy, and the morphology of multilayered films was observed by atomic force microscopy (AFM). This research may provide a new strategy to control the growth behaviour of multilayered films via LbL assembly with multiple interactions.