APPLICATIONS OF TECHNOLOGY:
- Protective coatings
- Barriers against liquid and gaseous contaminants or pathogens
- Filtration systems
- Controlled release device for small molecules
- Scaffolds for sensing devices
- Gas separation
- Simple assembly; can be prepared on any substrate
- Applicable over macroscopic length scales
- Solution processible
Berkeley Laboratory researchers have developed porous, flexible thin films by directing the co-assembly of molecular building blocks with block copolymers. The Berkeley Lab porous thin films may lead to a new family of nanomaterials with precise structural control as they show size-selective solution transport and accelerated gas molecule transport comparable to those seen in natural proteins.
The Berkeley Lab invention has nano- or subnanometer pores (measuring from 3 nm down to 0.7 nm in diameter) oriented perpendicularly to the surface over macroscopic distances. The simple assembly approach begins with the formation of a solution including a solvent, cyclic peptide-polymer conjugate and a block copolymer. The solution is applied to any substrate to form a thin film, and then the thin film is annealed. The result is a thin film containing highly oriented, hexagonally packed nanometer or subnanometer tubes spanning across the film. Specialized steps in the production process offer precise control over the pore shape and surface chemistry.
This new approach overcomes previous obstacles to producing subnanometer porous media such as the dimensions of individual polymer chains, the thermodynamics governing the microphase separation of block copolymers, the surface energy required to stabilize very small pores, and the relaxation behavior of synthetic polymers. The Berkeley Lab porous thin films offer a significant improvement over hypercrosslinked polymer networks that yield random pore size and spacing as well as nanoimprinting that achieves pores no smaller than 10 nm with varied pore size and shape.
DEVELOPMENT STAGE: Proven principle.
STATUS: Issued U. S. Patent #9180395. Available for licensing or collaborative research.
FOR MORE INFORMATION:
T. Xu, N. Zhao, F. Ren, R. Hourani, M. Tsang Lee, J.Y. Shu, S. Mao, and B.A. Helms, “Subnanometer Porous Thin Films by the Co-assembly of Nanotube Subunits and Block Copolymers,” ACS Nano, Vol. 5, No. 2, pp. 1376–1384, 2011.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
Precise Control of Nanoparticle Self-Assembly over Multiple Length Scales, JIB-2662
Water Retaining Polymer Membranes for Fuel Cell Applications, IB-2416
REFERENCE NUMBER: IB-2803