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Adhesion to many kinds of surfaces, including biological tissues, is important in many fields but has been proved to be extremely challenging. Furthermore, peeling from strong adhesion is needed in many conditions, but is sometimes painful. Herein, a mussel inspired hydrogel is developed to achieve both strong adhesion and trigger-detachment. The former is actualized by electrostatic interactions, covalent bonds, and physical interpenetration, while the latter is triggered, on-demand, through combining a thixotropic supramolecular network and polymer double network. The results of the experiments show that the hydrogel can adhere to various material surfaces and tissues. Moreover, triggered by shear force, non-covalent interactions of the supramolecular network are destroyed. This adhesion can be peeled easily. The possible mechanism involved is discussed and proved. This work will bring new insight into electronic engineering and tissue repair like skin care for premature infants and burn victims.

Au nanoparticles (AuNPs) (10−15 nm in size) were prepared and deposited on the surfaces of silica particles functionalized using 3-aminopropyltriethoxysilane as the seeds under mild conditions. Then, Au seeds grew further and formed nanosheets by the method of gold chloride hydrate reduction. 3, 5-dimethylphenyl isocyanate derivative of cellulose as chiral selector was coated on the surfaces of SiO2/Au. The obtained spheres possessed a sandwich structure in which silica bead, the packed Au NPs monolayer and cellulose derivative were the core, the interlayer and the shell, respectively. The resultant packing material was evaluated by high-performance liquid chromatography (HPLC) as chiral stationary phase (CSP). The separations of nine pairs of enantiomers were achieved in the normal-phase liquid chromatography mode. The results showed that the new CSP has sufficient interaction with the analytes due to the existence of AuNPs on silica surfaces compared with coated cellulose-silica column.

Functionalized melamine sponge based on β-cyclodextrin (β-CD) and graphene oxide (GO) as a new solid phase extraction (SPE) adsorbent, was developed for determination of malachite green (MG) in seafood, coupled with high-performance liquid chromatography (HPLC). The obtained sponge prepared by an easy method and simple step, is placed into a syringe to enrich quickly MG. The extraction procedure was further improved by investigating the effects of the experimental parameters on pre-enrichment of MG. The present method had been successfully applied to determination of MG from crayfish and squid sample and obtained satisfied recovery value (88.6–100.8%) with coefficient of variance below 2.6–9.2% (n = 3), which indicated that the method was suitable for the analysis of MG in complex samples. The method displayed good linear relationship in the concentration range of 0.5–20 μg mL−1 (R2 > 0.99), the low limit of detection of 0.21 mg L−1 and 1.0 mg kg−1 for food samples. Therefore, the β-CD-GO/MeS material has great application potential in the area of pre-concentration of complex matrix.