Process for producing monolithic film of integrated highly oriented halogenated graphene sheets or molecules

1. A process for producing an integrated layer of highly oriented halogenated graphene sheets or molecules, said process comprising:

(a) preparing either a graphene oxide dispersion having graphene oxide sheets dispersed in a fluid medium or a graphene oxide gel having graphene oxide molecules dissolved in a fluid medium, wherein said graphene oxide sheets or graphene oxide molecules contain an oxygen amount 5% by weight to 46% by weight;

(b) introducing a halogenating agent into said graphene oxide dispersion or gel and effecting a chemical reaction between said halogenating agent and said graphene oxide sheets or molecules to form a dispersion of halogenated graphene sheets or a gel of halogenated graphene molecules, wherein said halogenated graphene sheets or molecules have a chemical formula of C 6 Z x O y , wherein Z is a halogen element selected from F, Cl, Br, I, or a combination thereof, x=0.01 to 6.0, y=0 to 5.0, and x+y<6.0;

(c) dispensing and depositing a layer of said halogenated graphene dispersion or gel onto a surface of a supporting substrate under a shear stress condition, wherein said dispensing and depositing procedure includes shear-induced thinning of said halogenated graphene dispersion or gel and shear-induced orientation of halogenated graphene sheets or molecules, to form a wet layer of halogenated graphene on said supporting substrate; and

(d) removing said fluid medium from the wet layer of halogenated graphene to form said integrated layer of halogenated graphene having an inter-planar spacing d 002 of 0.35 nm to 1.2 nm as determined by X-ray diffraction.

2. The process of claim 1 , wherein the graphene oxide sheets contain single-layer graphene oxide or few-layer graphene oxide sheets each having 2-10 oxidized graphene planes.

3. The process of claim 1 , wherein the dispensing and depositing step includes a reverse roll transfer coating procedure.

4. The process of claim 1 , wherein the dispensing and depositing step includes a slot die coating or comma coating procedure.

5. The process of claim 1 , further comprising a step (e) of heat treating the integrated layer of oriented halogenated graphene at a first heat treatment temperature higher than 100° C. but no greater than 3,200° C. for a desired length of time to produce a graphitic film having an inter-planar spacing d 002 less than 0.4 nm and a combined oxygen/halogen content less than 1% by weight.

6. The process of claim 1 , wherein the fluid medium consists of water, an alcohol, a mixture of water and alcohol, or an organic solvent.

7. The process of claim 1 , further comprising a compression step, during or after removing the fluid medium, to reduce a thickness of said integrated layer.

8. The process of claim 1 , wherein the graphene oxide dispersion or gel has a graphene oxide content of 1% to 50% by weight prior to introducing the halogenating agent.

9. The process of claim 1 , wherein the graphene oxide dispersion or gel has a graphene oxide content of 3% to 50% by weight prior to introduction the halogenating agent, and the graphene oxide dispersion or gel possesses a liquid crystal phase.

10. The process of claim 1 , wherein the step of removing the fluid medium from the wet layer of halogenated graphene is carried out by heat treatment, vacuum, or a combination thereof.

11. The process of claim 1 , wherein the step of forming a dispersion of halogenated graphene sheets or a gel of halogenated graphene molecules comprises irradiation with UV light in a liquid medium containing chlorine or bromine.

12. The process of claim 1 , wherein the integrated layer of halogenated graphene has a thickness from 10 nm to 500 μm.