Synthesis of hyper-cross-linked microporous poly(phenylacetylene)s having aldehyde and other groups and their chemisorption and physisorption ability

Combining Polymerization and Templating toward Hyper-Cross-Linked Poly(propargyl aldehyde)s and Poly(propargyl alcohol)s for Reversible H2O and CO2 Capture and Construction of Porous Chiral Networks

Two series of hyper-cross-linked microporous polyacetylene networks containing either -[CH=C(CH=O)]- or -[CH=C(CH₂OH)]- monomeric units are reported. Networks are prepared by chain-growth copolymerization of acetal-protected propargyl aldehyde and acetal-protected propargyl alcohol with a 1,3,5-triethynylbenzene cross-linker followed by hydrolytic deprotection/detemplating. Deprotection not only liberates reactive CH=O and CH₂OH groups in the networks but also modifies the texture of the networks towards higher microporosity and higher specific surface area. The final networks with CH=O and CH₂OH groups attached directly to the polyene main chains of the networks have a specific surface area from 400 to 800 m²/g and contain functional groups in a high amount, up to 9.6 mmol/g. The CH=O and CH₂OH groups in the networks serve as active centres for the reversible capture of CO₂ and water vapour. The water vapour capture capacities of the networks (up to 445 mg/g at 297 K) are among the highest values reported for porous polymers, making these materials promising for cyclic water harvesting from the air. Covalent modification of the networks with (R)-(+)-3-aminopyrrolidine and (S)-(+)-2-methylbutyric acid enables the preparation of porous chiral networks and shows networks with CH=O and CH₂OH groups as reactive supports suitable for the anchoring of various functional molecules.

Microporous Hyper-Cross-Linked Polymers with High and Tuneable Content of Pyridine Units: Synthesis and Application for Reversible Sorption of Water and Carbon Dioxide

New hyper-cross-linked porous organic polymers (POPs) with a high content of pyridine segments (7.86 mmol pyridine g^-1 ), and a micro/mesoporous texture are reported. The networks are achieved by the chain-growth homopolymerization of 2,6- and 3,5-diethynylpyridines. The pyridine segments form links interconnecting the polyacetylene main chains in these networks. The content of pyridine segments in the networks can be tuned by copolymerizing diethynylpyridines with 1,3-diethynylbenzene. The pyridine rings in the networks serve as base and hydrophilic centers for the sorption of CO₂ and water. The homopolymer pyridine networks are highly efficient in the low-pressure adsorption/desorption of CO₂ . This sorption mode is promising for the postcombustion removal of CO₂ from the fuel gas. The poly(3,5-diethynylpyridine) network exhibits high efficiency in capturing and releasing water vapor (determined capacity 376 mg g^-1 at 298 K and relative humidity (RH) = 90% is one of the highest values reported for POPs) and is a promising material for the cyclic water harvesting from air. The reported networks are characterized by ¹³ C cross-polarization magic angle spinning NMR, thermogravimetric analysis, and N₂ adsorption/desorption and their efficiency in CO₂ and H₂ O capturing is discussed in relation to the content and type of incorporated pyridine segments.

Preparation of metal-organic framework based carbon materials and its application to adsorptive removal of cefepime from aqueous solution

Metal-organic framework based carbon material UC-X was prepared by template method, and adopted to remove cephalosporins from aqueous solution. The effect of templates including cetyltrimethyl ammonium bromide and sodium laurate was discussed. The UC-0.1 with the pore size of 5.38 nm has the best adsorption. According to FTIR spectrum, with the gradual increase of sodium laurate, the functional groups like CO increased, which promoted the adsorption capacity of cefepime in UC-X materials from 42.52 to 84.23 mg⋅g^-1. The optimal conditions for the adsorption of cefepime were determined by the response surface method: the adsorption temperature was 25.8 °C, the initial pH value was 6.11, and the ionic strength was 1.13 g·L^-1. Under the best adsorption condition, the adsorption-desorption experiments showed that the adsorption capacity of UC-0.1 material decreased by less than 10 % after five times usage, which indicated that its recycling property was competitive. The adsorption process conformed to the mixed-order kinetic model, and the error of equilibrium adsorption capacity between model fitting and actual experiments is not more than 1 %. The overall results of adsorption isotherm model and thermodynamic analysis demonstrated that Redlich-Peterson isothermal model could describe the adsorption process better.