title: Rheology and morphology of pristine graphene/polyacrylamide gels.
abstract: Enhancement of toughness in nanomaterial-based hydrogels is a critical metric for many of their engineering applications. Pristine graphene-polyacrylamide (PAM) hydrogels are synthesized via in situ polymerization of acrylamide monomer in PAM-stabilized graphene dispersion. In-situ polymerization leads to the uniform dispersion of the graphene sheets in the hydrogel. The graphene sheets interact with the elastic chains of the hydrogel through physisorption and permit gelation in the absence of any chemical cross-linker. This study represents the first report of pristine graphene as a physical cross-linker in a hydrogel. The properties of the graphene-polymer hydrogel are characterized by rheological measurements and compressive tests, revealing an increase in the storage modulus and toughness of the hydrogels compared to the chemically cross-linked PAM analogues. The physically cross-linked graphene hydrogels also exhibit self-healing properties. These hydrogels prove to be efficient precursors for graphene-PAM aerogels with enhanced electrical conductivity and thermal stability.
authors.affiliation: Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409, United States.
authors.forename: Sriya
authors.initials: S
authors.lastname: Das
authors.forename: Fahmida
authors.initials: F
authors.lastname: Irin
authors.forename: Lan
authors.initials: L
authors.lastname: Ma
authors.forename: Sanjoy K
authors.initials: SK
authors.lastname: Bhattacharia
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Hedden
authors.forename: Micah J
authors.initials: MJ
authors.lastname: Green
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D055119:Elastic Modulus; D037741:Fullerenes / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D058105:Polymerization; D012212:Rheology
chemical_list: D000180:Acrylic Resins; D037741:Fullerenes; C016680:polyacrylamide gels; C530172:pristine (C60); D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006108:Graphite