Abstract
The preparation of water vapor barrier coatings composed of polyelectrolyte/clay multilayers using the layer-by-layer technique is reported. The suitability of different synthetic and renewable polyelectrolytes for the preparation of barrier coatings in combination with montmorillonite (MMT) platelets as well as the influence of the ionic strength and the number of bilayers on the coating performance was investigated. Highly hydrophilic and permeable cellulose films were used as substrate for determining the influence of the coatings on the water vapor transmission rate (WVTR). Improved barrier properties were realized by the use of polyethylene imine (PEI) or 2-hydroxy-3-trimethylammonium propyl chloride starch (HPMA starch) in combination with MMT. After the application of only 5 bilayers of PEI and MMT (thickness ∼40 nm) on each side of the cellulose film, the WVTR was significantly reduced. By the deposition of 40 PEI/MMT bilayers, the WVTR transmission rate was reduced by 68%. However, HPMA starch containing coatings led to vapor transmission reduction of up to 32% at the same number of coating steps. A strong correlation between the barrier properties of the coatings and the layer thickness was observed. The barrier properties of the coatings could be increased using higher ionic strengths. These results represent unprecedented water vapor barrier properties for coatings prepared from hydrophilic materials.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
