Highly moisture resistant super gas barrier polyelectrolyte complex thin film

Abstract

Polyelectrolyte complex (PEC) thin films have demonstrated remarkable oxygen barrier properties, but the moisture sensitivity from the hydrophilic nature of polyelectrolytes is a significant drawback. In this study, various molar ratios (1:1, 1:2, and 1:3) of branched polyethyleneimine (PEI) and poly(acrylic acid) (PAA) were prepared as one‐pot coating solutions, which can be deposited via a simple dip‐coating process and cured with a citric acid buffer solution, which increases the charge density of PEI and triggers complexation. As‐prepared conformal thin films impart excellent gas barrier, high modulus, and high moisture resistance. Undetectable oxygen transmission rate (OTR), at both 0% and 90% RH, can be achieved with a PEI:PAA molar ratio of 1:1 and buffer curing at pH 3. The strong complexation from ionic crosslinking creates an unusually dense thin film that is promising for various packaging applications (food, electronics, etc.). This thin film exhibits one of the best‐ever polymer‐based oxygen barriers at high humidity.

Hydrogen bonded polymer complex thin films for highly stretchable gas barriers

“…It is interesting to note that an inverse relationship between barrier and ductility of polymer complex films is expected based on previous work, 6 but the present study exhibits the opposite situation. Indeed, when low permeability is largely ascribed to high cohesive energy density, barrier properties are expected to correlate to film stiffness.…”

“…Gas barrier films are desirable for applications such as food and drug preservation, electronic device encapsulation, and fuel cell membranes. [1][2][3][4][5] While barrier tends to improve with increased stiffness, 6,7 highly stretchable gas barrier films are required for applications in next-generation stretchable electronics, such as deformable batteries and flexible OLEDs. 8,9 Gas barrier films are often constructed of polymeric materials due to their light weight, low cost, and easily processable nature.…”

Phosphate and nitrogen‐rich polyelectrolyte complex flame retardant treatment for cotton fleece

“…PECs are entropy‐driven associations of oppositely‐charged polyelectrolytes, whose complexation is determined by concentration, ionic strength, and solution pH. PECs can be deposited in a few steps, imparting flame retardancy, gas barrier, or antibacterial properties to a material 5,19,20 . When only one species is sufficiently charged, a stable, water‐soluble PEC exists.…”

“…PECs can be deposited in a few steps, imparting flame retardancy, gas barrier, or antibacterial properties to a material. 5,19,20 When only one species is sufficiently charged, a stable, water-soluble PEC exists. Under circumstances where both polyelectrolytes are highly charged (e.g., acidic pH), the complex is rendered insoluble.…”

Counter Anion Type Influences the Glass Transition Temperature of Polyelectrolyte Complexes

“…The phase behavior and the thermal and mechanical properties are affected by water, temperature, pH, salt, solvent, hydrophobicity, and chemistry of the PEs. − PECs are composed of two different types of ion pairs: extrinsic ion pairs formed between polyelectrolyte charge groups and counterions and intrinsic ion pairs formed between the oppositely charged PEs . Due to their tunability and versatility, PECs find applications in the field of drug delivery, underwater contact adhesives, separation membranes, electrochemistry, tissue engineering, and many more. − …”