Method of manufacturing a graphene/graphehe oxide layer and a graphene/graphehe oxide-coated support

1. A method of manufacturing a graphene and graphene oxide layer comprising the steps of:

a) preparing a suspension of a mixture of graphene and graphene oxide comprising a mixture of flake shaped graphene and -graphene oxide particles in a suspension liquid,

wherein the suspension liquid is water wherein the suspension is free of nano-fibrillated cellulose,

b) coating the suspension on a paper support,

c) heating the suspension and the support to evaporate at least a part of the suspension liquid for forming a layer of graphene and graphene oxide on the support, and

d) pressing the layer of graphene and graphene oxide and the support between two objects.

2. The method according to claim 1 , comprising, before step b), the step b1) of applying a graphene bonding liquid on the support, and, in step c) allowing at least a part of the graphene bonding liquid evaporate wherein the bonding liquid facilitates ordering of the particles on the surface and binding of the particles together.

3. The method according to claim 1 , comprising, in step c), subjecting the graphene/graphene oxide layer to a non-contact or contact heat source to perform the drying process by evaporating at least a part of the suspension liquid.

4. The method according to claim 2 , wherein the graphene bonding liquid and the suspension liquid is the same and steps b1) and b) are carried out simultaneously.

5. The method according to claim 1 , wherein the support for step b1) or b) is fed from a roll.

6. The method according to claim 1 , wherein, in step d), the graphene/graphene oxide layer and the support is subjected to pressure and/or heat in a calender.

7. The method according to claim 1 , wherein, in step d), the graphene/graphene oxide layer and the support is subjected to at least one of super calendering, soft nip calendering, thermosoft calendering, hard nip calendering, shoe calendering, metal belt calendering, and multi-nip calendering.

8. The method according to claim 1 , wherein the graphene/graphene oxide layer and the support is subjected to pressure in multiple steps, where the pressure increases for each step.

9. The method according to claim 1 , wherein, after step d), in step e), the graphene/graphene oxide layer is subjected to annealing to heat the graphene/graphene oxide layer.

10. The method according to claim 9 , wherein step e) is carried out in a cooled atmosphere.

11. The method according to claim 9 , wherein step e) is carried out in oxygen free environment.

12. The method according to claim 9 , wherein step e) is carried out in a vacuum.

13. The method according to claim 9 , wherein step e) is carried out in an inert gas.

14. The method according to claim 9 , wherein, in step b) graphene/graphene oxide is applied on one side of the support and wherein, in step e), the support is cooled from the side on which graphene/graphene oxide is not applied.

15. The method according to claim 9 , wherein, in step b) graphene/graphene oxide is applied on both sides of the support.

16. The method according to claim 15 , wherein step e) is divided into two stages, in a first stage a first side of the coated support is cooled and the graphene/graphene oxide layer on the opposite, second side is subjected to annealing, and in a second stage where the second side of the support is subjected to cooling and the graphene/graphene oxide layer on the first side to annealing.