Constructing metalated three-dimensional (3D) covalent organic frameworks is a challenging synthetic task. Herein, we report the synthesis and characterization of a highly porous (SA = 5083 m g) 3D COF with a record low density (0.13 g cm) containing π-electron conjugated dehydrobenzoannulene (DBA) units. Metalation of DBA-3D-COF 1 with Ni to produce Ni-DBA-3D-COF results in a minimal reduction in the surface area (SA = 4763 m g) of the material due to the incorporation of the metal within the cavity of the DBA units, and retention of crystallinity. Both 3D DBA-COFs also display great uptake capacities for ethane and ethylene gas.

Finding new ways to construct crystalline multiple-component covalent organic frameworks (COFs) has become an important focus. Herein we report the synthesis of three novel COFs containing a homogeneous and heterogeneous distribution of π-conjugated dehydrobenzoannulene (DBA) vertex units. The COFs were synthesized by reacting different ratios of C3-symmetric DBA catechol monomers with C2-symmetric pyrene-2,7-diboronic acid (PDBA) to yield three COFs, Py-DBA-COF 1, Py-DBA-COF 2, and Py-MV-DBA-COF. All three materials are highly crystalline and display unique luminescent properties in the solid state.

Developing novel synthetic strategies to construct crystalline polymeric materials with excellent chemical stability and high carbon capture capacity has become a challenging process. Herein, we report the synthesis of two novel 2D benzobisoxazole-linked covalent organic frameworks (BBO−COFs) utilizing C 3 -symmetric formyl-and C 2symmetric o-aminophenol-substituted molecular building blocks. The BBO−COFs exhibit excellent water stability, high surface areas, and great CO 2 uptake capacities. This general synthetic method affords the opportunity to prepare ordered BBO-based polymeric materials for carbon capture, chemical sensing, and organic electronic applications.

Advances in materials, designs, and controls are propelling the field of soft robotics at an incredible rate; however, current methods for prototyping soft robots remain cumbersome and struggle to incorporate desirable geometric complexity. Herein, a vat photopolymerizable self-healing elastomer system capable of extreme elongations up to 1000% is presented. The material is formed from a combination of thiol/acrylate mixed chain/step-growth polymerizations and uses a combination of physical processes and dynamic-bond exchange via thioethers to achieve full self-healing capacity over multiple damage/healing cycles. These elastomers can be three dimensional (3D) printed with modular designs capable of healing together to form highly complex and large functional soft robots. Additionally, these materials show reprogrammable resting shapes and compatibility with self-healing liquid metal electronics. Using these capabilities, subcomponents with multiple internal channel systems were printed, healed together, and combined with functional liquid metals to form a high-wattage pneumatic switch and a humanoid-scale soft robotic gripper. The combination of 3D printing and self-healing elastomeric materials allows for facile production of support-free parts with extreme complexity, resulting in a paradigm shift for the construction of modular soft robotics.

Covalent organic frameworks (COFs) are an attractive class of crystalline, porous materials because their reticular chemistry allows frameworks to be synthesized in a predictable manner. As a result of this defining characteristic, the past decades have witnessed considerable efforts to demonstrate unique pore shapes and sizes; however, less attention is often given to atomistic level structural changes. To further understand the relationship of a COF’s structure and its unique properties, this work provides a foundational study exploring the relationship of structural isomer linkages in two COFs, TAPA–PDA COF and IISERP-COF2. These imine-based COFs were extensively studied and compared with respect to their synthetic conditions, framework properties, phase reversibility, optical properties, and surface energy. Our results suggest that compared to IISERP-COF2, the TAPA–PDA COF has stronger phase change reversibility and significant red shifting of the UV–vis absorption and fluorescence and exhibits hydrophilicity. These findings provide evidence that careful consideration of monomer pairs is necessary when designing materials because these minor structural changes can lead to vastly diverging properties.