Macromol. Rapid Commun. 10/2017

Abstract

Front Cover: A polyelectrolyte‐based nanocoating exhibits super oxygen barrier and humidity‐responsive self‐healing behavior. An 8‐bilayer polyethylenimine/poly(acrylic acid) thin film improves the oxygen barrier of a thick poly(ethylene terephthalate) substrate by more than 1000×. High humidity (symbolized by the thread in this schematic) completely restores the super oxygen barrier of the damaged/cracked coating in just 10 minutes. This fast and high‐efficiency self‐healing is repeatable for at least 10 damaging–healing cycles. Further details can be found in article number https://doi.org/10.1002/marc.201700064 by Y. Song, K. P. Meyers, J. Gerringer, R. K. Ramakrishnan, M. Humood, S. Qin, A. A. Polycarpou, S. Nazarenko* and J. C. Grunlan*.

Highly selective multilayer polymer thin films for CO2/N2 separation

“…However, the robustness of the LbL assembly technique means that these high selectivity coatings could be readily combined with high flux materials. In addition to their ease of application to nearly any type of substrate, these nanocoatings have a high modulus and glass transition temperature, which should help them to survive in high temperature and/or pressure environments.…”

Self-healing polymer–clay hybrids by facile complexation of a waterborne polymer with a clay

“…Layer-by-layer (LbL) assembly technique 54 has been used to prepare water-induced selfhealing materials. 24,31,[55][56][57][58][59][60][61] Uniform stacking of oppositely charged materials has been obtained by sequential deposition, while it is difficult and time-consuming to produce the thick film by the LbL technique. In the present study, simple casting was employed because the method is simple, ecofriendly and environmentally friendly to obtain uniform polymer-clay films.…”

High Moisture Barrier with Synergistic Combination of SiOx and Polyelectrolyte Nanolayers

“…These PEM coatings have been widely exploited for applications such as gas barrier and gas separation, [21][22][23] energy storage and conversion, [24,25] bio-sensors, [26][27][28] antimicrobial coatings, [29] actuators, [30][31][32] and anti-corrosion. [33,34] Despite exhibiting outstanding oxygen barrier, [35] PEM coatings alone exhibit very limited moisture barrier as a result of loosened chain packing and higher chain mobility in humid conditions. [36,37] No more than a 78% water vapor transmission rate (WVTR) reduction has ever been achieved despite numerous attempts.…”

“…An 8-bilayer (BL) polyethylenimine (PEI)/ poly acrylic acid (PAA) coating is used here as the PEM layer due to its high oxygen barrier and relatively high modulus. [35] The influence of each layer is investigated by comparing the barrier performance of single-or two-layer films based on SiO x and PEM. When applying a single PEM layer above or below the SiO x layer (i.e., a two-layer system), the moisture barrier is small.…”

“…After being exposed to humid conditions, the underlying PEI/PAA layer experiences increased polymer chain mobility that creates a smooth surface, with a roughness around 1.2 nm (Figure S1). [35,44] Additionally, PEI has been widely used as an adhesive due to its reactive amine groups. [45] More importantly, the high modulus of PEI/PAA reduces the stiffness mismatch between the substrate and the SiO x layer.…”