title: Self-healing guar gum and guar gum-multiwalled carbon nanotubes nanocomposite gels prepared in an ionic liquid.
abstract: Guar gum is a galactomannan extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba. It was found to form a soft viscoelastic gel in 1-butyl-3-methylimidazolium chloride, an ionic liquid at an optimized concentration of 10%w/v. A nanocomposite gel of the gum with enhanced strength could be prepared with 0.2%w/v of multiwalled carbon nanotubes (MWCNTs) in the ionic liquid. When the gels thus prepared were subjected to surface fractures or bisected completely, they found to self-heal at room temperature without any external interventions. The self-healing process could be repeated several times. These viscoelastic gel systems showed thixotropic nature and recovery of the storage modulus with time for several cycles was observed upon rheological investigations. The interaction took place between ionic liquid, guar gum and MWCNT was studied by SEM, TEM, FT-IR, powder XRD and rheometry. The results suggested that, upon standing at room temperature development of electrostatic interactions and the van der Waals interactions among the ionic liquid molecules facilitated the formation of reversible noncovalent bonds and eventually activated the self-healing in the gel systems through appropriate chain entanglements.
authors.affiliation: AcSIR-Central Salt & Marine Chemicals Research Institute, G.B. Marg, Bhavnagar, 364002 Gujarat, India.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Sharma
authors.forename: Dibyendu
authors.initials: D
authors.lastname: Mondal
authors.forename: Chandrakant
authors.initials: C
authors.lastname: Mukesh
authors.forename: Kamalesh
authors.initials: K
authors.lastname: Prasad
mesh_terms: D005685:Galactans / Q000737:chemistry*; D005782:Gels; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D008351:Mannans / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D053149:Plant Gums / Q000737:chemistry*
chemical_list: D005685:Galactans; D005782:Gels; D007093:Imidazoles; D052578:Ionic Liquids; D008351:Mannans; D037742:Nanotubes, Carbon; D053149:Plant Gums; C502841:1-butyl-3-methylimidazolium chloride; C007894:guar gum
keywords: Bio-adhesive; Bio-inspired; Carbon nanotube; Ion-gel; Ionic liquid; Self-healing