PDADMAC/PSS Oligoelectrolyte Multilayers: Internal Structure and Hydration Properties at Early Growth Stages from
Pedro A Sánchez1,2, Martin Vögele3, Jens Smiatek4
1Laboratory of Mathematical Modeling of Physical and Chemical Processes in Multiphase Media, Institute of Natural Sciences and Mathematics, Ural Federal University, 620000 Ekaterinburg, Russia.
Molecules (Basel, Switzerland)
|April 23, 2020
Summary
We studied the structure of polymer multilayers during growth. Substrate proximity affects water and ion accumulation, influencing charge compensation, but the outer layers are position-independent.
Area of Science:
- Polymer Science
- Materials Science
- Physical Chemistry
Background:
- Layer-by-layer assembly is a key technique for creating functional thin films.
- Understanding early-stage growth is crucial for controlling multilayer properties.
- Previous studies lacked detailed analysis of substrate influence on internal structure.
Purpose of the Study:
- To investigate the internal structure and hydration of poly(diallyl dimethyl ammonium chloride)/poly(styrene sulfonate sodium salt) multilayers during initial growth.
- To analyze the impact of substrate proximity on charge compensation and water/ion accumulation.
- To establish the range of substrate influence on multilayer properties.
Main Methods:
- Large-scale molecular dynamics simulations with atomistic resolution.
- Analysis of the first four deposition cycles of polymer multilayers on a silica substrate.
- Local structural analysis to determine property dependence on distance from the substrate.
Main Results:
- Water and ion accumulation near the substrate reduces intrinsic charge compensation.
- Charge compensation remains the dominant mechanism in the interface region.
- Substrate influence extends approximately 3 nm; outer regions exhibit position-independent structure.
Conclusions:
- The substrate significantly impacts early-stage multilayer formation within a 3 nm range.
- Detailed structural characterization is vital for developing accurate mesoscale models.
- Findings provide insights for designing and controlling polymer multilayer architectures for technological applications.
