Nacre-like MXene/Polyacrylic Acid Layer-by-Layer Multilayers as Hydrogen Gas Barriers
Yang Hyun Auh1, Natalie N Neal2, Kailash Arole1
1Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States.
ACS Applied Materials & Interfaces
|May 13, 2025
Summary
We developed novel MXene/PAA coatings using hydrogen bonds for superior gas barriers. These pH-responsive, nacre-like films offer excellent hydrogen blocking and conductivity, enabling new applications in coatings and films.
Area of Science:
- Materials Science
- Nanotechnology
- Surface Chemistry
Background:
- MXenes are 2D nanomaterials with potential for gas barrier applications.
- Negative surface charges on MXenes hinder assembly with negatively charged polymers like PAA.
- Overcoming electrostatic repulsion is key for developing advanced MXene-based coatings.
Purpose of the Study:
- To develop a method for assembling MXene and PAA into gas barrier coatings.
- To leverage hydrogen bonding to overcome electrostatic repulsion between MXene and PAA.
- To investigate the properties and pH responsiveness of the resulting multilayers.
Main Methods:
- Layer-by-layer (LbL) assembly of MXene and PAA under acidic conditions.
- Utilizing hydrogen bonding interactions to facilitate multilayer formation.
- Characterization of multilayer structure, gas barrier properties, and electrical conductivity.
Main Results:
- Formation of conformal, pinhole-free, nacre-like MXene/PAA LbL multilayers.
- Achieved exceptionally low hydrogen gas permeability (0.14 ± 0.01 cc·mm·m-2·day-1·MPa-1).
- Demonstrated high electrical conductivity (up to 370 ± 30 S cm-1) and reversible pH-dependent deconstruction.
Conclusions:
- Hydrogen bonding is an effective strategy for creating MXene/PAA LbL multilayers.
- These multilayers function as excellent gas barriers and conductive coatings.
- The pH-tunable nature allows for deconstructable thin film applications.
