pH- and near-infrared light-responsive,biomimetic hydrogels from aqueous dispersions of carbon nanotubes

Owing to their low flexibility,poor processability and a lack of responsiveness,inorganic materials are usually non-ideal for constructing a living organism.Hence,to date,lifelike materials with structural hierarchies and adaptive properties usually rely on light and soft organic molecules,although few exceptions have been acquired using two-dimensional(2D)inorganic nanosheets.Herein,with a systematic study on the gelation behavior of carbon-based 0D quantum dots,1D nanotubes,and 3D fullerenes,we find that acidified 1D carbon nanotubes(CNTs)can serve as an alternative building block for fabricating purely inorganic biomimetic soft materials.The as-prepared CNT gels exhibit not only a pH-or photothermal-triggered mechanical and tribological adaptivity,which allows them to simulate the behavior of sea cucumbers,peacock mantis shrimps,and mammalian muscles or cortical bones,but also a unique damping property that is similar to spider’s cuticular pad.Their high elasticity,effective lubrication,excellent biocompatibility,and controllable friction and wear also allow them to function as a new type of smart lubricants,whose tribological properties can be regulated either by its internal pH changes or spatiotemporally by near-infrared(NIR)light irradiations,free of any toxic and flammable base oils or additives.

Melamine-imprinted electrochemical sensor of graphene/ionic liquid composites and its use for the detection of melamine in dairy products

By exchanging the conventional role of functional monomer and template molecules,we develop a new molecu-larly imprinted nanospheres with grape grain structures based on multi-hydrogen bonding interactions between melamine and 6-aminouracil.Molecular imprinting-electrochemical sensor was established with the assistance of graphene and ionic liquids.The content of melamine in dairy products was detected by the molecular imprinting-electrochemical sensor.The detection limit was determined to be as low as 1.57×10^(−3) mg kg^(-1).

Hydrogels totally from inorganic nanosheets and water with mechanical robustness,self-healing,controlled lubrication and anticorrosion

Synthetic hydrogels with attractive mechanical strength and self-healing are particular appealing,in light of their significance and prospects in industrial,engineering and biomimetic fields.Fabricating various mechanically robust and self-healable hydrogels have achieved some successes in using strong covalently bonded organic polymers as building blocks.However,creation of such soft materials entirely building on rigid inorganic components remains greatly challenging,because inorganic materials are usually poorly flexible and processable.In this study,mechanical robustness and self-recovery are successfully integrated into a single-component colloidal hydrogel system of aluminium hydroxide nanosheets(AHNSs).The inorganic colloidal hydrogel gains an excellent elasticity and stiffness,as indicated by its elastic modulus>10 MPa,due to the use of tough AHNS gelator and the formation of long-range ordered lamellar architectures consisting of self-assembled side-to-side or interlaced-stacking NS superstructures.The metastability in internal gel network endows the hydrogel a self-healing efficiency of larger than 100%.The AHNS hydrogel has been demonstrated to be effectively lubricative and anti-corrosive.Its mechanical,tribological and anticorrosion properties can be optimized by tuning its internal NS configuration and salt content.Our study may be a potent replenishment to the scope of materials science and may provide new insights into nanotechnology,colloidal chemistry,green tribology and mechanical engineering.