Nanoporous polymers offer great promise in chemical capture and separations because of their versatility, scalability, and robust nature. Here, we report a general methodology for one-pot, metal-free, and room-temperature synthesis of nanoporous polymers by highly stable carbon–carbon bond formation. Three new polymers, namely, COP-177, COP-178, and COP-179, are derived from widely available perfluoroarenes and found to be superhydrophobic, microporous, and highly stable against heat, acid, base, and organic solvents. Nitrile, amine, and ether functionalities were successfully installed by SNAr-type postfunctionalization and were shown to increase CO2 uptake twice and CO2/N2 selectivity 4-fold. Due to its inherent superhydrophobicity, COP-177 showed high organic solvent uptake both in liquid and vapor form. Furthermore, in a first of its kind, by combining microporosity and hydrophobicity, COP-177 separated two small molecules with the same boiling point in a continuous column setting.

Making metal–organic frameworks (MOFs) that are stabilized in nonpolar media is not as straightforward as making their inorganic nanoparticle counterparts, since surfactants penetrate through the porous structures or dissolve the secondary building units (SBUs) through ligand-exchange linker modulator mechanisms. Herein, we report that calixarenes stabilize UIO-66 nanoparticles effectively by remaining outside the grains through size exclusion, without pores becoming blocked, all the while providing amphiphilicity that permits the formation of stable colloidal dispersions with much narrower size distributions. Using the UIO-66 dispersed solutions, we show that smooth films from an otherwise immiscible polystyrene can be made feasibly.

Polypyrrole grafted polystyrene-b-poly(ethylene-ran-butylene)-b-polystyrene (SEBS-g-PPy)/multiwall carbon nanotubes (MWCNTs) conductive nanocomposites were fabricated using two different approaches. The approach of system-I involved primarily the grafting of PPy on SEBS and its subsequent composites with nanotubes. In system-II in situ polymerization/grafting of PPy on SEBS was carried out along with MWCNTs yielding nanomaterials. Presynthesized SEBS-g-PPy and nanocomposites were characterized by Fourier transform infrared spectroscopy, NMR, field emission scanning electron microscopy, transmission electron microscopy, and electrical, mechanical, and thermal properties. The π–π stacking interactions between PPy of SEBS-g-PPy and MWCNTs rendered ample dispersion of the nanotubes in system-II relative to system-I. The electrical conductivity and tensile data showed improvement in these properties of nanocomposites and that system-II nanocomposites can sustain higher stresses, is stiffer, and can absorb more energy before breaking. Thermal stability of both the systems was improved relative to the matrices, and decomposition temperatures were found to increase from 437 to 568 °C. Relative improvement in electrical, thermal and tensile properties were observed for system-II nanocomposites rather than for system-I nanocomposites.

Metal recovery from electronic waste and industrial wastewater has attracted increasing attention to recycle precious metals and inhibit the emission of hazardous heavy metals. However, the selective recovery of precious metals with a large quantity is still very challenging because wastewater contains a variety of different cations while precious metal ions are relatively scarce. Here, we introduce a simple method to selectively increase the adsorption of gold ions using tannin-coated porous polymer microspheres through photochemical reduction. Mesoporous poly(ethylene glycol dimethacrylate-co-acrylonitrile) microspheres with an average pore diameter of 13.8 nm were synthesized and used as an adsorbent matrix. Tannic acid (TA) was deposited onto the internal pores of the polymer matrix by simple immersion in an aqueous milieu. TA coatings increased the maximum number of adsorbed gold ions by 1.3 times because of the well-known metal ion chelation of TA. Under light illumination, the maximum number of adsorbed gold ions dramatically increased by 6.1 times. We examined two distinct mechanisms presumably involved in the enhanced adsorption: the photooxidation of TA and plasmon-induced hot electrons. Moreover, TA-coated microspheres exhibited remarkable selectivity for gold ions among competing metal ions commonly found in waste resources. This work suggests that the photochemically activated TA can serve as an excellent adsorbent for the selective and efficient recovery of gold ions from wastewater.

A new, high surface area, nanoporous polymer (COP-220) was synthesized using sustainable building blocks, namely, a food coloring dye (erythrosine B) and a commercial alkyne. During the Sonogashira coupling, it is observed that Pd and Cu ions and triphenylphosphine ligands of the catalyst get trapped inside the pores. The remnant synthesis catalyst components were characterized in detail and were tested as a new catalyst for Suzuki–Miyaura coupling reactions. COP-220 showed conversion yields comparable to the commercial homogeneous catalyst Pd(PPh3)2Cl2 with an additional advantage of size-dependent catalytic activity when bulkier substrates were used. COP-220 was highly stable under thermal and chemical treatments and recyclable with no loss of activity. These findings show a clear need for extensive characterization of nanoporous polymers made through cross-coupling reactions and the potential of the trapped catalysts for new catalytic activity without additional loading.