US 2014/0154464 A1 · GRAPHENE MEMBRANE WITH SIZE-TUNABLE NANOSCALE PORES

Abstract

Technologies are generally described for a graphene membrane with uniformly-sized nanoscale pores that may be prepared at a desired size using colloidal lithography. A graphene monolayer may be coated with colloidal nanoparticles using self-assembly, followed by off-axis metal layer deposition, for example. The metal layer may form on the colloidal nanoparticles and on portions of the graphene not shadowed by the nanoparticles. The nanoparticles may be removed to leave a negative metal mask that exposes the underlying graphene through holes left by the removed nanospheres. The bare graphene may be etched to create pores using an oxygen plasma or similar material, while leaving metal-masked regions intact. Pore size may be controlled according to size of colloidal nanoparticles and angle of metal deposition relative to the substrate. The process may result in a dense, hexagonally packed array of uniform holes in graphene for use as a membrane, especially in liquid separations.

Claims28

Dependent claims

A porous membrane, comprising:

a graphene monolayer;
an array of colloid particles on a surface of the graphene monolayer, wherein the colloid particles are formed sufficient to define a shadow-masked fraction and an unmasked fraction of the surface of the graphene monolayer;
a metal film coated on at least a portion of the unmasked fraction of the surface of the graphene monolayer;
and
an array of nanoscale pores perforating the graphene monolayer characterized by a substantially uniform pore diameter in a substantially hexagonal arrangement, wherein the array of nanoscales pores are formed when the shadow-masked fraction of the surface of the graphene monolayer is etched upon removal of the array of colloid particles.

2 more elements

A method of preparing a porous membrane, comprising:

positioning a graphene monolayer on a support substrate in a deposition chamber with a sample manipulator;
forming an array of colloid particles on a surface of the graphene monolayer employing a colloid deposition source and the sample manipulator, wherein the colloid particles are formed sufficient to define a shadow-masked fraction and an unmasked fraction of the surface of the graphene monolayer;
coating a metal film on at least a portion of the unmasked fraction of the surface of the graphene monolayer, wherein a metal deposition source and the sample manipulator are cooperatively configured to provide off-axis deposition of the metal film to the surface of the graphene monolayer held at the sample manipulator;
removing the colloid particles from the shadow-masked fraction of the surface of the graphene monolayer employing a colloid removal apparatus;
etching the shadow-masked fraction of the surface of the graphene monolayer to form an array of nanoscale pores in the graphene monolayer employing an etchant source;
and
releasing the graphene monolayer from the support substrate to form the porous membrane employing the sample manipulator.

4 more elements

A system for manufacturing a porous membrane, the system comprising:

a deposition chamber;
a sample manipulator configured to position a graphene monolayer at a support substrate in the deposition chamber;
a colloid deposition source;
a metal deposition source, wherein the metal deposition source and the sample manipulator are cooperatively configured to provide off-axis deposition of a metal film to a surface of the graphene monolayer held at the sample manipulator;
a colloid removal apparatus;
an etchant source;
and
a microprocessor coupled to the deposition chamber, the sample manipulator, the colloid deposition source, the metal deposition source, the colloid removal apparatus, and the etchant source, wherein the microprocessor is configured via machine executable instructions to:
control the colloid deposition source and the sample manipulator effective to deposit an array of colloid particles on the surface of the graphene monolayer such that the colloid particles define a shadow-masked fraction and an unmasked fraction of the surface of the graphene monolayer;
control the metal deposition source and the sample manipulator effective to coat a metal film on at least a portion of the unmasked fraction of the surface of the graphene monolayer;
control the colloid removal apparatus effective to remove the colloid particles from the shadow-masked fraction of the surface of the graphene monolayer;
control the etchant source to etch the shadow-masked fraction of the surface of the graphene monolayer effective to form an array of nanoscale pores in the graphene monolayer;
and
control the sample manipulator effective to release the graphene monolayer from the support substrate to form the porous membrane.

11 more elements

A computer-readable storage medium having machine executable instructions stored thereon for manufacturing a porous membrane, comprising instructions to:

control a colloid deposition source and a sample manipulator effective to deposit an array of colloid particles on a surface of a graphene monolayer such that the colloid particles define a shadow-masked fraction and an unmasked fraction of the surface of the graphene monolayer;
control a metal deposition source and a sample manipulator effective to coat a metal film on at least a portion of the unmasked fraction of the surface of the graphene monolayer;
control a colloid removal apparatus effective to remove the colloid particles from the shadow-masked fraction of the surface of the graphene monolayer;
control an etchant source to etch the shadow-masked fraction of the surface of the graphene monolayer effective to form an array of nanoscale pores in the graphene monolayer;
and
control the sample manipulator effective to release the graphene monolayer from a support substrate to form the porous membrane.

3 more elements

Dependencies are inferred from the claim text.

Graphene membrane with size-tunable nanoscale pores

Life of this patent

Graphene membrane with size-tunable nanoscale pores

Life of this patent

Abstract

Claims28