The synthesis, characterization and carbon dioxide adsorption of polyimide aerogels containing Tröger’s base units

Microporous polymers with uniform pores and large specific surface areas have been extensively studied in the field of CO2 adsorption and separation. However, the synthesis of these microporous materials is quite complex and difficult to achieve large-scale production and application. In this study, we have successfully synthesized a novel mesoporous polyimide aerogel containing Tröger’s base using a facile and mild method at room temperature. Thermal decomposition temperature of the obtained polyimide aerogels was above 420°C, which exhibited outstanding thermal stability. The maximum adsorption capacity of CO2 is 24.08 cm3/g. The high CO2 adsorptions are attributed to the abundance of nitrogen-rich heteroatoms in the polyimide networks. The mild and convenient preparation method and high CO2 adsorptive capacity indicate that the mesoporous polyimide aerogels with Tröger’s base can also be suitable as an adsorbent for CO2 capture in industrial applications.

Silica-Supported Nitrogen-Enriched Porous Benzimidazole-Linked and Triazine-Based Polymers for the Adsorption of CO2

Two crystalline and five amorphous benzimidazole polymers (BINP) were synthesized and conjugated to porous silica via amine and aldehyde-based materials by a simple reflux procedure. The resulting polymers were subject to thermal analysis for monitoring and quantification of the adsorption and desorption of CO₂. All the polymers were capable of adsorbing CO₂ from a flowing stream of only 80 mL/min at 25 °C. The adsorbed CO₂ onto the polymers were effectively desorbed at room temperature, illustrating the potential application of such polymers for repeated adsorption/desorption of CO₂. The CO₂ adsorption capacities of these polymers were dependent upon their nitrogen content, specific surface area, and pore size. The available nitrogen atoms for binding to the carbon of CO₂ via tetrel bonds also plays an important role in the capture of this gas. Minimal and much lower CO₂ adsorption was also noted with two crystalline polymers, compared to the five amorphous counterparts. Intermolecular hydrogen bonding and π-π interaction effectively prevented the polymer N sites of the crystalline polymers from interacting with polarized CO₂ molecules.

Selective enrichment of sialylated glycopeptides with mesoporous poly-melamine-formaldehyde (mPMF) material

Analysis of glycoprotein sialylation is challenging due to the relatively low abundance of sialylated glycopeptides (SGPs) in complex biosamples and low signals of SGPs in mass spectrometry. In this study, a mesoporous poly-melamine-formaldehyde (mPMF) polymer was prepared and utilized as the high-efficiency sorbent for SGPs. The mPMF polymer featured high surface area (755.4 m² g^-1) and high density of amine and triazine functional groups. This polymer demonstrated high enrichment selectivity (resistant to 100 molar fold interference of BSA) and superior adsorption capacity (560 mg g^-1) for SGPs. The high performance of mPMF toward SGPs ascribes to the unique physicochemical properties of mPMF and high density of accessible binding sites for glycopeptides. Further application of mPMF to HeLa S3 cell lysate resulted in 576 characterized glycopeptides with 218 unique glycosylation sites. This finding provides a new choice of promising extraction approach for characterization of protein glycosylation. Graphical abstract A mesoporous poly-melamine-formaldehyde (mPMF) polymer was prepared and utilized as the high-efficiency enrichment sorbent for sialylated glycopeptides (SGPs).

Nitrogen-doped mesoporous carbon-armored cobalt nanoparticles as efficient hydrogen evolving electrocatalysts

A series of Co nanoparticles embedded, N-doped mesoporous carbons have been synthesized through chelate-assisted co-assembly strategy followed by thermal treatment. The preparation is based on an assembly process, with evaporation of an ethanol-water solution containing melamine formaldehyde resin (MF resin) as carbon source, nitrogen source, and chelating agent. Moreover, F127 and Co(NO₃)₂ are used as template and metallic precursor, respectively. The Co nanoparticles embedded, N-doped mesoporous carbon annealed at 800 °C (denoted as MFCo800) shows high electrocatalytic activity for hydrogen evolution reaction (HER) with high current density and low overpotential, which has the ability to operate in both acidic and alkaline electrolytes.

Reactive molecular dynamics study of the decomposition mechanism of the environmentally friendly insulating medium C3F7CN

The decomposition mechanism of an environmentally friendly insulating medium C₃F₇CN was explored.