Transparent, Stretchable, and Self‐Healable Gas Barrier Films with 2D Nanoplatelets for Flexible Electronic Device Packaging Applications

Abstract

AbstractSelf‐healable elastomeric materials (PUAxPU10–x‐PDMS, x = 4, 6, or 8) have been synthesized and utilized as substrates or encapsulation films on the top of barrier films (deposited on polyethylene terephthalate (PET) substrates) to improve their gas barrier properties for packaging applications. Hexa‐layer (HL) assembly consisting of two inorganic 2D nanoplatelets, including Mg‐Al layered double hydroxide (LDH) and hexagonal boron nitride (hBN), and two oppositely charged polyelectrolytes, that is, polyethyleneimine (PEI) and poly(sodium styrene‐4‐sulfonate) (PSS), have been developed by alternative depositions of HL (i.e., PSS/LDH/PSS/PEI/hBN/PEI) sequentially. Then, a layer‐by‐layer technique is applied to produce multiple assemblies of hexa‐layer (HL)n and reduce water vapor transmission rate (WVTR) values of elastomeric PUA8PU2‐PDMS and PET substrates. The optimum WVTR values of 7.1 × 10−3 and 8.0 × 10−3 g m−2 day−1 are achieved using barrier PET/(HL)8/PUA8PU2‐PDMS (125/3/1 µm) and PUA8PU2‐PDMS/(HL)8 (125/3 µm) films, respectively. The self‐healable barrier PUA8PU2‐PDMS and PUA8PU2‐PDMS/(HL)8 films recover their initial WVTR values after self‐healing of mechanically damaged films. Organic light‐emitting diodes (OLEDs) encapsulated with PET/(HL)8/PUA8PU2‐PDMS and PUA8PU2‐PDMS/(HL)8 have 9–10 times longer half‐lifetime values than bare OLEDs. Accordingly, this report develops transparent, stretchable, and self‐healable gas barrier films for next‐generation flexible electronic device packaging applications.