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In this paper, we describe stimuli-responsive hydrogels prepared from a rigid rod-like polyelectrolyte 'imogolite' and a dicarboxylic acid. The hydrogel exhibited thixotropy in response to mechanical shock within the order of seconds or sub-seconds. Here, using the latest structural/rheological characterisation techniques, the relationship between the structural transition processes and the shear thinning was estimated. The evidence obtained by the experiments revealed for the first time the direct relationship between the microscopic structural change and the macroscopic thixotropic behavior that have been extensively discussed. The thixotropic hydrogel has the hierarchical architecture in the combination of imogolite and dicarboxylic acid, i.e., sheathed nanotubes/hydroclusters of cross-bridged nanotubes/frameworks. The formation and disintegration of the network structure upon resting and agitating, respectively, were the origin of gel/sol transition (thixotropy), although the hydroclusters of cross-bridged nanotubes were maintained throughout the transition.

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We report a quasi-solid electrolyte comprising a transparent thixotropic gel swelled by an ionic liquid that is formed by a framework of single-walled aluminosilicate cylindrical inorganic "imogolite" nanotubes. The quasi-solid electrolyte shows moldability, thermal stability, and high ionic conductivity, and has potential applications in free-moldable conductive and anti-icing coatings, or electrolytes for batteries.

Preparation and graft-copolymerization of hydrogenated natural rubber are performed in latex stage after removal of proteins from the rubber with urea and surfactant. Hydrogenation of deproteinized natural rubber (DPNR) latex is carried out with palladium catalyst under hydrogen atmosphere. The hydrogenated DPNR (HDPNR) is crosslinked with a peroxide followed by graftcopolymerization of styrene (Sty) and acrylonitrile (AN) in latex stage in order to prepare a graft-copolymer of crosslinked HDPNR with poly(Sty-co-AN) (HDPNR-graft-PSAN). Characterization of the products is performed by nuclear magnetic resonance spectroscopy. The conversion of hydrogenation is investigated with respect to the catalyst feed, acidity (pH), and dry rubber content. In the resulting HDPNR-graft-PSAN, mole fraction of AN and Sty is 1.4 and 5.8 mol %, respectively. The graft-copolymer is used to improve properties of PSAN as an impact modifier. The Charpy impact strength of crosslinked HDPNR-graft-PSAN/PSAN is about eight times as high as that of PSAN.