Self-Patterning Polyelectrolyte Multilayer Films: Influence of Deposition Steps and Drying in a Vacuum

Abstract

Typically, laterally patterned films are fabricated by lithographic techniques, external fields, or di-block copolymer self-assembly. We investigate the self-patterning of polyelectrolyte multilayers, poly(diallyldimethylammonium) (PDADMA)/poly(styrenesulfonate) (PSS) short . The low PSS molecular weight (M w (PSS short ) = 10.7 kDa) is necessary because PSS short is somewhat mobile within a PDADMA/PSS short film, as demonstrated by the exponential growth regime at the beginning of the PDADMA/PSS short multilayer build-up. No self-patterning was observed when the PDADMA/PSS film consisted of only immobile polyelectrolytes. Atomic force microscopy images show that self-patterning begins when the film consists of seven deposited PDADMA/PSS short bilayers. When more bilayers are added, the surface ribbing evolved into bands, and circular domains were finally observed. The mean distance between the surface structures increased monotonously with the film thickness, from 70 to 250 nm. Scanning electron microscopy images showed that exposure to vacuum resulted in thinning of the film and an increase in the mean distance between domains. The effect is weaker for PSS short -terminated films than for PDADMA-terminated films. The mechanism leading to domain formation during film build-up and the effect of post-preparation treatment are discussed.

Modification of Polydiallyldimethylammonium Chloride with Sodium Polystyrenesulfonate Dramatically Changes the Resistance of Polymer-Based Coatings towards Wash-Off from Both Hydrophilic and Hydrophobic Surfaces

“…One of the advantages of PDADMAC is that it has good solubility in water, as well as in the presence of a pH-independent quaternized amino group. This allows one to use various methods of forming coatings from solutions by dip-coating, solution deposition on the surface with further drying, spraying, and so on [ 18 , 19 , 20 ]. On the other hand, good solubility in water can lead to effective rinsing of coatings upon contact of the treated surface with water.…”

Molecular Organization in Exponentially Growing Multilayer Thin Films Assembled with Polyelectrolytes and Clay

“…The film thickness of PDDA-PAA-PDDA-Laponite multilayer for the same number of layers is an order of magnitude greater ( Figure 1 c). We note here that removal of multilayer films from water and exposure to air can cause some thinning, and exposure to vacuum during SEM can cause even more shrinking [ 35 , 36 , 37 ]. However, as discussed in the “Multilayer Composition” section of this work, the water content of PDDA-Laponite multilayers and PDDA-PSS-PDDA-Laponite multilayers is negligible based on TGA evaluation ( Table 1 ).…”

Fast‐Dip Layer‐by‐Layer Self‐Assembly of Polyelectrolytes as a Low‐Cost Biosensing Platform

“…[57,58] Porous or rougher surfaces can be attained by assembly or postassembly modifications. [59][60][61][62][63] We have also compared FDip-LbL devices with intermediate fabrication technology, that is, spin-LbL for biosensing applications. [64,65] Spin-LbL PEM devices were fabricated at a spin speed of 2000 RPM and a spinning time of 40 s for each layer deposition, followed by a mandatory DI water rinse of 40 s between every deposit, as detailed in our earlier work.…”