Gas Separation/Barrier Membranes from Graphene Oxide
Physical Sciences : Materials and Compounds
Available for licensing
- Christopher Ellison, Ph.D.
- Heonjoo Ha, M.S. , Chemical Engineering
In recent years, flexible polymers have become increasingly important for many flexible or membrane applications that impact daily life, such as economical gas barriers and wearable devices. These high-end applications typically require the use of an elastomer or rubber to impart flexibility and mechanical robustness for optimum interfacing. While there exist commercial choices for elastomer precursors, they are generally high in viscosity, limited in available grades, and complex in final elastomer preparations. Therefore, the development of new methods for forming elastomers with only a few simple components which exhibit unique combinations of properties can improve any industry that manufactures flexible products, ranging from industrial separation membranes to personal devices.
Researchers at The University of Texas at Austin are exploring the use of an elastomeric composite material comprising of functional polymers and graphene derivatives as a novel high gas barrier and separation membrane. The graphene derivatives are a key component to gas barriers in that they reduce the permeability of various gases. Previous studies have focused on the development of gas barrier membranes in which flexible substrates are simply coated with a thin layer of graphene oxide. The synthesis of a graphene-coated elastomer is a complex process that requires excessive material, time, and costs.
In contrast, the proposed material is a homogeneous barrier membrane composed of the flexible component and gas impermeable graphene component. Synthesis of the proposed elastomer requires only two low-cost materials: graphene derivatives and functional polymers. Only a small amount of graphene is needed in order to create the impermeable membrane, and a large range of polymers can be used as the flexible component. The composite is not only easily made from readily-obtained materials, but also possesses excellent flexibility and conveniently tunable mechanical properties that can accommodate the material to a specific function. For example, the chemical structure of the elastomer can be modified to allow for conduction of electricity or mechanical robustness required for wearable products. As such, this material is a cost-effective, high performance gas barrier membrane that can be easily produced for varied applications.
- Customizable physical properties allows for a wide variety of applications
- Can be manufactured by simple and scalable methods
- Simplified elastomer recipe
- Increases mechanical properties without decrementing other physical properties
- Made from any graphite derivative or polymer possessing excellent flexibility
- Requires small amounts of readily available materials
- Minimizes manufacturing procedure by a tremendous amount of steps
- Mass-producible in any sample size
- Stable maleated polymer/graphene oxide composite
- Excellent mechanical properties, such as well-maintained elasticity
- Homogeneous material that is both flexible and gas impermeable
- Simple universal synthesis reaction from two commercially available, low-cost materials
- Only 5 wt% of graphene oxide insertion can result in a >70% increase in tensile strength and >2600% increase in modulus while retaining elasticity
- Customizable physical properties (mechanical strength, elongation at break, conductivity, separation performance, thermal properties, chemical resistance, etc.)
- Can function as a highly selective gas barrier
- High performance in several implementations
The proposed elastomer material is mainly applicable to industrial processes that require gas separation barriers. However, flexible polymers have also become increasingly important for many applications that impact daily life, including wearable devices, flexible displays, and devices for monitoring physiological signals. Therefore there are several industries that would find the implementation of the invented elastomer useful in various applications. BCC Research reports the combined U.S. market for membranes used in gas and liquid separating applications was worth approximately $2.2 billion in 2013. The market is expected to increase to about $3.5 billion by 2019.