Layer-by-layer assembled multilayers of charged polyurethane and graphene oxide platelets for flexible and stretchable gas barrier films

Abstract

With the advent of the era of consumer-oriented displays and mobile devices, the importance of barrier film coatings for securing devices from oxygen or moisture penetration has become more salient. Recently developed approaches to generate gas barrier films in a combination of polyelectrolyte multilayer matrices and incorporated inorganic nanosheets have shown great potential in outperforming conventional gas barrier films. However, these films have the intrinsic drawback of vulnerability to brittleness and inability to stretch for flexible device applications. To overcome this issue, we present a method in which we prepare multilayered films of complementarily charged polyurethane and graphene oxide platelets using spin-assisted, layer-by-layer self-assembly to obtain well-stacked film structures. As a result, the multilayered, thin films deposited on a poly(ethylene terephthalate) (PET) substrate can exhibit significantly reduced oxygen penetration properties (∼30 cc m-2 day-1 for the oxygen transmission rate) while still demonstrating large bending or stretching deformations. Therefore, the proposed approach in this study is anticipated to be extensively utilized for surface coating and protection of flexible and stretchable devices under various operating conditions.

Cephalopods-Inspired Rapid Self-Healing Nanoclay Composite Coatings with Oxygen Barrier and Super-Bubble-Phobic Properties

“…Hence, compared to the case without coating, the restorative nanoclay coating was evaluated to have demonstrated oxygen barrier performance, suggesting that it was effective in reducing the OTR to 1/100. The reduction effect was equal to or better than that of previous studies. ,,,, It also showed sufficient gas barrier properties for food packaging. , Considering the quick self-healing properties, the ability to maintain the gas barrier properties was a major advantage of this study. It was also found that by increasing the concentration of MMT, the shielding effect of nanoplatelets of MMT was more dominant than the highway function of increasing oxygen permeability due to the expansion of polymer multilayer under high humidity.…”

“…The reduction effect was equal to or better than that of previous studies. 11,17,20,31,40 It also showed sufficient gas barrier properties for food packaging. 4,5 Considering the quick selfhealing properties, the ability to maintain the gas barrier properties was a major advantage of this study.…”

“…Therefore, the LbL method is an effective construction method for both sides due to the advantage that the nanoplatelets can be oriented perpendicular to the oxygen diffusion direction and the amount of additives can be easily controlled by the initial concentration of the polymer solution. [19][20][21][22] Another advantage of using LbL self-assembly is its selfhealing function. 23,24 Polymer multilayers composed of weakly electrolyte polycations and polyanions can self-repair by watermediated membrane expansion and subsequent reformation of bonds between polymers.…”

“…The composite of the nanoclay and polymer exhibits remarkable gas barrier performance because of the tortuous pathway of gas molecules moving around the nanoplatelets, called the maze effect when oxygen permeates. − Therefore, it has been shown that increasing the amount and orientation of the nanoplatelets can produce a low oxygen transmission rate (OTR) comparable to that of conventional inorganic thin films. Therefore, the LbL method is an effective construction method for both sides due to the advantage that the nanoplatelets can be oriented perpendicular to the oxygen diffusion direction and the amount of additives can be easily controlled by the initial concentration of the polymer solution. − …”

Tailored growth of graphene oxide liquid crystals with controlled polymer crystallization in GO-polymer composites

“…[1][2][3] GO has been employed in fibers, membranes, water treatment, and polymer-based applications. [4][5][6][7][8] GO can be easily dispersed in polar solvents, including water, and is known to exhibit liquid crystallinity. [9][10][11][12] Good dispersity and the ability to form LC has enabled GO to be a good candidate as an effective nanofiller compared to other carbon materials.…”