A series of different methods have been used to fabricate the polyelectrolyte multilayer films through the layer-by-layered adsorption self-assembly method based on electrostatic attraction.In this presentation the multilayer building-up methods through dipping and spin-coating were used to study the influence of the multilayer buildingup methods on the multilayers’ structure and properties.Experimentally

azobenzenecontaining polyelectrolyte PNACN was fabricated into multilayers with counterpart polyelectrolyte PDAC using the layer-by-layer technique based on dipping and spin-coating

respectively.The differences in growth mechanism

structure and photo-sensitive properties of the multilayers fabricated with the two different methods were studied using UV-Vis

ellipsometer and AFM for characterization.Experimental results show that both of the dipping and spin-coating methods could fabricate uniformly layer-by-layered growth multilayer films while the multilayers fabricated by dipping grew faster than those fabricated by spin-coating.Both of the multilayers have relatively smooth surfaces with some spherical structure on them

which is believed to be due to the aggregation of hydrophobic azobenzene chromophores.Interestingly

these two kinds of multilayers have obviously different and complicated responses to the photo irradiation.Under irradiation with interference polarized laser beams

the multilayers by spin-coating could be written with surface relief gratings (SRGs) while not for those by dipping in case that both of the multilayers were less than 100 nm thick approximately.When the multilayers became thicker (for example more than 200 nm) both of the multilayers could be written with obvious SRGs

and the SRGs on the dipping multilayer surface were deeper for its thicker total multilayers.The difference of the multilayers in optical properties is believed to have close relationship with their difference in multilayer structures.Generally

the polymer chains in the multilayers fabricated through dipping are strongly interpenetrated among the ambient layers so that the combination of the interpenetration and electrostatic attraction between the opposite charged polyelectrolytes leads to a crosslinkagelike multilayer structure.On the other hand

the interpenetration of the polymer chains in the multilayers fabricated through spin-coating are much weak for the short time fabrication cycles

and consequently the polymer chains in the multilayers fabricated through spin-coating are more free and mobile.As a result

when the multilayer is relatively thin (less than about 100 nm) the SRGs structure can be formed on the spin-coating multilayer surface

but not on the dipping multilayer surface.