title: High-water-content mouldable hydrogels by mixing clay and a dendritic molecular binder.
abstract: With the world's focus on reducing our dependency on fossil-fuel energy, the scientific community can investigate new plastic materials that are much less dependent on petroleum than are conventional plastics. Given increasing environmental issues, the idea of replacing plastics with water-based gels, so-called hydrogels, seems reasonable. Here we report that water and clay (2-3 per cent by mass), when mixed with a very small proportion (<0.4 per cent by mass) of organic components, quickly form a transparent hydrogel. This material can be moulded into shape-persistent, free-standing objects owing to its exceptionally great mechanical strength, and rapidly and completely self-heals when damaged. Furthermore, it preserves biologically active proteins for catalysis. So far no other hydrogels, including conventional ones formed by mixing polymeric cations and anions or polysaccharides and borax, have been reported to possess all these features. Notably, this material is formed only by non-covalent forces resulting from the specific design of a telechelic dendritic macromolecule with multiple adhesive termini for binding to clay.
authors.affiliation: Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Qigang
authors.initials: Q
authors.lastname: Wang
authors.forename: Justin L
authors.initials: JL
authors.lastname: Mynar
authors.forename: Masaru
authors.initials: M
authors.lastname: Yoshida
authors.forename: Eunji
authors.initials: E
authors.lastname: Lee
authors.forename: Myongsoo
authors.initials: M
authors.lastname: Lee
authors.forename: Kou
authors.initials: K
authors.lastname: Okuro
authors.forename: Kazushi
authors.initials: K
authors.lastname: Kinbara
authors.forename: Takuzo
authors.initials: T
authors.lastname: Aida
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D055162:Biocatalysis; D000077215:Clay; D020100:Hydrogels / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D014867:Water / Q000032:analysis*
chemical_list: D000538:Aluminum Silicates; D020100:Hydrogels; D011108:Polymers; D014867:Water; D000077215:Clay