Preparation and characterisation of graphene composite hydrogels

Stable dispersions containing graphene and gellan gum are used to form composite films. Incorporation of graphene into the gellan gum matrix results in mechanical reinforcement and electrical conductivity at low and high graphene loading fractions, respectively. Graphene-containing gellan gum hydrogel films are prepared by immersion of composite films in Ca2+ cross-linking solutions. The resulting hydrogels are electrically conducting and exhibit reinforcement compared to the corresponding gellan gum hydrogels.

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► Gellan–graphene drop-cast films can be prepared by combining gellan solutions with graphene dispersions.
► Percolation threshold of graphene–gellan gum significantly higher than carbon nanotubes–gellan gum.
► Incorporating graphene mechanically reinforces gellan gum films.
► Graphene containing hydrogel prepared by swelling in cross-linking solution.
► Graphene mechanically reinforces gellan gum hydrogel films.