This review article comprehensively summarizes the recent progress in the development of covalent organic framework materials for separation applications.

Green synthesis of crystalline porous materials for energy-related applications is of great significance but very challenging. Here, we create a green strategy to fabricate a highly crystalline olefin-linked pyrazine-based covalent organic framework (COF) with high robustness and porosity under solvent-free conditions. The abundant nitrogen sites, high hydrophilicity, and well-defined one-dimensional nanochannels make the resulting COF an ideal platform to confine and stabilize the H3PO4 network in the pores through hydrogen-bonding interactions. The resulting material exhibits low activation energy (Ea) of 0.06 eV, and ultrahigh proton conductivity across a wide relative humidity (10–90 %) and temperature range (25–80 °C). A realistic proton exchange membrane fuel cell using the olefin-linked COF as the solid electrolyte achieve a maximum power of 135 mW cm−2 and a current density of 676 mA cm−2, which exceeds all reported COF materials.

Traditional covalent organic frameworks (COFs) are prepared via polymerization based on small molecular monomers. However, the employment of polymers as building blocks to construct COFs has not been reported yet. Herein, we create a new concept of polymer covalent organic frameworks (polyCOFs) formed by linear polymers as structural building blocks, which inherit the merits from both COFs and linear polymers. PolyCOFs represent a new category of porous COF materials that demonstrate good crystallinity and high stability. More importantly, benefiting from the flexibility and processability of a linear polymer, polyCOFs can spontaneously form defect-free, flexible, and freestanding membranes that exhibit excellent mechanical properties and undergo reversible mechanical transformation upon exposure to various organic vapors. For the first time, we demonstrated that polyCOF membranes can be used as artificial muscles to perform various complicated motions (e.g., lifting objects, doing “sit-ups”) triggered by vapors. This study bridges the gap between one-dimensional amorphous linear polymers and crystalline polymer frameworks and paves a new avenue to prepare stimuli-responsive actuators using porous COF materials.

D rug-eluting stent (DES) use during percutaneous coronary intervention (PCI) has resulted in improved clinical outcomes compared with bare metal stents.1,2 However, late stent thrombosis after DES remains a concern.3,4 Although current guidelines recommend prolonged dual antiplatelet therapy (DAPT) for all patients undergoing implantation ofBackground-There are no reports on a large-scale randomized trial exploring optimal dual antiplatelet therapy (DAPT) duration after biodegradable polymer sirolimus-eluting stent implantation. We sought to report the outcomes of a randomized substudy of the prospective Evaluate Safety and Effectiveness of the Tivoli DES and the Firebird DES for Treatment of Coronary Revascularization (I-LOVE-IT 2) trial. Methods and Results-In the prospective noninferiority randomized I-LOVE-IT 2 trial, 1829 patients allocated to the biodegradable polymer sirolimus-eluting stent group were also randomized to receive either 6-month (n=909) or 12-month DAPT (n=920). The primary end points of this noninferiority substudy were 12-month target lesion failure (composite of cardiac death, target vessel myocardial infarction or clinically indicated target lesion revascularization), and the major secondary end points were 12-month net adverse clinical and cerebral events (composite of all-cause death, all myocardial infarction, stroke, or major bleeding [Bleeding Academic Research Consortium type ≥3]). The 12-month target lesion failure in 6-month DAPT group was comparable with the 12-month DAPT group (6.8% versus 5.9%; difference and 95% confidence interval, 0.87% [−1.37% to 3.11%], P for noninferiority=0.0065). Further followup at 18 months showed that incidence of target lesion failure and net adverse clinical and cerebral events were similar between the 2 groups (7.5% versus 6.3%, log-rank P=0.32; 7.8% versus 7.3%, log-rank P=0.60; respectively), as well as their individual end point components. Conclusions-This study indicated noninferiority in safety and efficacy of 6-month versus 12-month DAPT after implantation of a novel biodegradable polymer sirolimus-eluting stent. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01681381.(Circ Cardiovasc Interv. 2016;9:e003145.