A Superacid-Catalyzed Synthesis of Porous Membranes Based on Triazine Frameworks for CO₂ Separation

Abstract

A general strategy for the synthesis of porous, fluorescent, triazine-framework-based membranes with intrinsic porosity through an aromatic nitrile trimerization reaction is presented. The essence of this strategy lies in the use of a superacid to catalyze the cross-linking reaction efficiently at a low temperature, allowing porous polymer membrane architectures to be facilely derived. With functionalized triazine units, the membrane exhibits an increased selectivity for membrane separation of CO(2) over N(2). The good ideal CO(2)/N(2) selectivity of 29 ± 2 was achieved with a CO(2) permeability of 518 ± 25 barrer. Through this general synthesis protocol, a new class of porous polymer membranes with tunable functionalities and porosities can be derived, significantly expanding the currently limited library of polymers with intrinsic microporosity for synthesizing functional membranes in separation, catalysis, and energy storage/conversion.

Covalent Triazine Frameworks via a Low‐Temperature Polycondensation Approach

“…CTF‐HUST‐2 exhibited two features at approximately 6° and 25° (Figure S7a, blue curve); CTF‐HUST‐3 contained two features at approximately 8° and 22° (Figure S7d, blue curve), and CTF‐HUST‐4 showed two features at around 6° and 21° (Figure S7g, blue curve). These features are very broad, even with respect to the relatively broad peaks observed for CTFs produced by ionothermal routes,7b and it is not possible to match these to a specific structural model. These features do suggest, however, the possibility of at least partially layered structures.…”

Mercury nano-trap for effective and efficient removal of mercury(II) from aqueous solution

“…1) that features high surface area with densely populated yet highly accessible Hg(II) binding sites thereby affording high Hg(II) adsorption capacity; strong Hg(II) chelating groups that are well dispersed throughout the single-walled pore surface thus rendering high affinity for Hg(II) and efficient utilization of Hg(II) binding sites; large yet tunable pore size to enable fast yet controllable kinetics of Hg(II) adsorption; Hg(II) chelating groups that are covalently anchored to the backbone thus avoiding the leaching of binding sites; exceptional water/chemical stability facilitating regeneration/recyclability. Such mercury 'nano-trap' can be targeted by grafting desired Hg(II) chelating groups to the highly robust porous organic polymers (POPs) [35][36][37][38][39][40][41][42][43][44] that exhibit high surface areas, tunable pore sizes and high water/ chemical stabilities, via stepwise post-synthetic modification 45 of the phenyl rings of their structural components using various established organic reactions. Herein we demonstrate such a POP-based mercury 'nano-trap' that exhibits an exceptional mercury saturation uptake capacity of over 1,000 mg g À 1 and can effectively reduce Hg(II) concentration from 10 p.p.m.…”

Triazine containing N-rich microporous organic polymers for CO 2 capture and unprecedented CO 2 /N 2 selectivity

“…Further, it is very challenging to control the organic building block in the porous structure to enhance the adsorption capacity and the selectivity of CO2. Covalent triazine functionalized conjugated framework is also another important class of materials for selective CO2 adsorption [24]. Zhou et al have highlighted a highly porous host PPN and subsequent introduction of polar group in order to enhance the CO2 uptake capacity [25].…”