Inspired by animal muscles, we developed a kind of tough elastomers combining high strength and high stretchability with autonomous self-healing capability. A key structural feature is the construction of a double network (DN) connected by the hydrogen bond and host−guest interactions. The first network is the classic elastomer polyacrylate matrix cross-linked by strong hydrogen bonding. The second network is formed through the host−guest interactions between polycyclodextrin and the adamantane (Ad) groups on the side of the polyacrylate chain. Supramolecular interactions between two networks make them miscible and interpenetrate in the molecular level and then can share the load as the sample was stretched. The host−guest interactions act not only as sacrificial bonds for energy dissipation but also as self-healing driving forces. The tensile strength of the DN elastomer reaches about 6.7 MPa and the strain is as high as about 950%. The DN elastomer can be easy to repair by touching the damaged surface together at ambient conditions when broken or cut. The recovered tensile strength can reach over 4.5 MPa, which is better than the most pristine strength of existing spontaneous self-healing elastomers.
The adsorption of CO 2 by conventional liquid alkanolamine adsorbents does not meet the requirements for green-friendly development in industrial applications. In this work, we constructed NH 2 -β-CD-MOF for the first time through the amino-functionalization of the lowest-priced, readily available, and biocompatible β-CD. Subsequently, the samples were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, elemental analysis, and N 2 adsorption/ desorption. The CO 2 adsorption capacity of NH 2 -β-CD-MOF was found to be 12.3 cm 3 /g, which is 10 times that of β-CD-MOF. In addition, NH 2 -β-CD-MOF has outstanding selective adsorption of CO 2 /N 2 (947.52) compared with the reported materials. The adsorption mechanism of CO 2 was analyzed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Furthermore, we have found that NH 2 -β-CD-MOF has better water stability relative to β-CD-MOF and γ-CD-MOF, and it can be recycled by an ultrasonic method.
The moisture stable γ-CD-K-MOF was obtained by simply treating MOF with H2S gas. H2S acting as new water adsorption sites protected the metal–ligand bonds from water attack and thus enhanced the moisture resistance of γ-CD-K-MOF.
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