On the gas storage properties of 3D porous carbons derived from hyper-crosslinked polymers

The preparation of porous carbons by post-synthesis treatment of hypercrosslinked polymers is described, with a careful physico-chemical characterization, to obtain new materials for gas storage and separation. Different procedures, based on chemical and thermal activations, are considered; they include thermal treatment at 380 degrees C, and chemical activation with KOH followed by thermal treatment at 750 or 800 degrees C; the resulting materials are carefully characterized in their structural and textural properties. The thermal treatment at temperature below decomposition (380 degrees C) maintains the polymer structure, removing the side-products of the polymerization entrapped in the pores and improving the textural properties. On the other hand, the carbonization leads to a different material, enhancing both surface area and total pore volumethe textural properties of the final porous carbons are affected by the activation procedure and by the starting polymer. Different chemical activation methods and temperatures lead to different carbons with BET surface area ranging between 2318 and 2975 m(2)/g and pore volume up to 1.30 cc/g. The wise choice of the carbonization treatment allows the final textural properties to be finely tuned by increasing either the narrow pore fraction or the micro- and mesoporous volume. High pressure gas adsorption measurements of methane, hydrogen, and carbon dioxide of the most promising material are investigated, and the storage capacity for methane is measured and discussed

Functionalization of 3D Polylactic Acid Sponge Using Atmospheric Pressure Cold Plasma

The deposition of organic functionalities on biomaterials to immobilize biomolecules is a research area of great interest in the medical field. The surface functionalization of a 3D porous scaffolds of PDLLA with carboxyl (-COOH) and amino (-NH2) groups by cold plasma treatment at atmospheric pressure is described in this paper. Two methods of continuous and pulsed plasma deposition were compared to assess the degree of functionalization of the internal porous 3D scaffold. In particular, the pulsed plasma treatment was found to functionalize uniformly not only the sample surface but also inside the open cavities thanks to its permeability and diffusion in the porous 3D scaffold. The species developed in the plasma were studied by optical emission spectroscopy (OES) technique, while the functionalization of the sponges was evaluated by the Diffuse Reflectance Fourier-Transform Infrared Spectroscopy (DR-FTIR) technique using also the adsorption of ammonia (NH3) and deuterated water (D2O) probe molecules. The functional groups were deposited only on the front of the sponge, then the structural characterization of both front and back of the sponge has demonstrated the uniform functionalization of the entire scaffold

A Porous Carbon with Excellent Gas Storage Properties from Recycled Polystyrene

In this paper, we describe the synthesis and gas adsorption properties of a porous carbonaceous material, obtained from commercial expanded polystyrene. The first step consists of the Friedel-Craft reaction of the dissolved polystyrene chains with a bridging agent to form a highly-crosslinked polymer, with permanent porosity of 0.7 cm 3 /g; then, this polymer is treated with potassium hydroxide at a high temperature to produce a carbon material with a porous volume larger than 1.4 cm 3 / g and a distribution of ultramicro-, micro-, and mesopores. After characterization of the porous carbon and determination of the bulk density, the methane uptake was measured using a volumetric apparatus to pressures up to 30 bar. The equilibrium adsorption isotherm obtained is among the highest ever reported for this kind of material. The interest of this product lies both in its excellent performance and in the virtually costless starting material

On the Gas Storage Properties of 3D Porous Carbons Derived from Hyper-Crosslinked Polymers

The preparation of porous carbons by post-synthesis treatment of hypercrosslinked polymers is described, with a careful physico-chemical characterization, to obtain new materials for gas storage and separation. Different procedures, based on chemical and thermal activations, are considered; they include thermal treatment at 380 °C, and chemical activation with KOH followed by thermal treatment at 750 or 800 °C; the resulting materials are carefully characterized in their structural and textural properties. The thermal treatment at temperature below decomposition (380 °C) maintains the polymer structure, removing the side-products of the polymerization entrapped in the pores and improving the textural properties. On the other hand, the carbonization leads to a different material, enhancing both surface area and total pore volume—the textural properties of the final porous carbons are affected by the activation procedure and by the starting polymer. Different chemical activation methods and temperatures lead to different carbons with BET surface area ranging between 2318 and 2975 m2/g and pore volume up to 1.30 cc/g. The wise choice of the carbonization treatment allows the final textural properties to be finely tuned by increasing either the narrow pore fraction or the micro- and mesoporous volume. High pressure gas adsorption measurements of methane, hydrogen, and carbon dioxide of the most promising material are investigated, and the storage capacity for methane is measured and discussed

A method of preparing a microporous carbon and the microporous carbon thereby obtained

A process is described for the preparation of a microporous carbon from a hyper-cross- linked polymer of formula (II), in which A is selected from a C atom, a Si atom, a Ge atom, a Sn atom, an adamantane group, an ethane group and an ethene group, in which each of B, C, D and E are ring structures selected from radicals of the compounds benzene, naphthalene, anthracene, phenanthrene, pyrene, optionally having one or more substituents selected from nitro, amine, hydroxyl, sulfonyl, halogen, phenyl, alkyl, haloalkyl, hydroxyalkyl, aminoalkyl, aryl, alkenyl and alkynyl groups, and in which n is an integer between 200 and 6000

A gas-adsorbing porous aromatic hyper-cross-linked polymer and a method of preparing thereof

The invention relates to a method of preparing a gas-adsorbing porous aromatic hyper- cross-linked polymer provided with an improved amount of ultramicropores and therefore particularly suitable to adsorb and store gases such as carbon dioxide, methane and hydrogen, and to the gas-adsorbing porous aromatic hyper-cross-linked polymer thereby obtainable

An atomistic model of a disordered nanoporous solid: Interplay between Monte Carlo simulations and gas adsorption experiments

A combination of physisorption measurements and theoretical simulations was used to derive a plausible model for an amorphous nanoporous material, prepared by Friedel-Crafts alkylation of tetraphenylethene (TPM), leading to a crosslinked polymer of TPM connected by methylene bridges. The model was refined with a trial-and-error procedure, by comparing the experimental and simulated gas adsorption isotherms, which were analysed by QSDFT approach to obtain the details of the porous structure. The adsorption of both nitrogen at 77 K and CO2 at 273 K was considered, the latter to describe the narrowest pores with greater accuracy. The best model was selected in order to reproduce the pore size distribution of the real material over a wide range of pore diameters, from 5 to 80 \uc5. The model was then verified by simulating the adsorption of methane and carbon dioxide, obtaining a satisfactory agreement with the experimental uptakes. The resulting model can be fruitfully used to predict the adsorption isotherms of various gases, and the effect of chemical functionalizations or other post-synthesis treatments. \ua9 2017 Author(s)

Theoretical prediction of high pressure methane adsorption in porous aromatic frameworks (PAFs)

The adsorption isotherms of methane in four micro- and mesoporous materials, based on the diamond structure with (poly)phenyl chains inserted in all the C-C bonds, have been simulated with Grand Canonical Monte Carlo technique. The pressure range was extended above 250 bar and the isotherms were computed at 298, 313, and 353 K, to explore the potentiality of these materials for automotive applications, increasing the capacity of high-pressure tanks or storing a comparable amount of gas at much lower pressure. The force field employed in the simulations was optimized to fit the correct behavior of the free gas in all the pressure range and to reproduce the methane-phenyl interactions computed at high quantum mechanical level (post Hartree-Fock). All the examined materials showed a high affinity for methane, ensuring a larger storage of gas than simple compression in all the conditions: two samples exceeded the target proposed by U.S. Department of Energy for methane storage in low-pressure fuel tanks (180 cm(3) (STP)/cm(3) at 35 bar and room temperature)

CO2 capture and reduction to liquid fuels in a novel electrochemical setup by using metal-doped conjugated microporous polymers

An electrochemical device for the reduction of CO2 back to liquid fuels is here presented. The key of this novel electrocatalytic approach is the design and development of the gas diffusion membrane (GDM), which is obtained by assembling (i) a proton selective membrane (Nafion), (ii) a nanocomposite electrocatalyst based on metal-doped conjugated microporous polymer (CMP) and (iii) a C-based support working as the gas diffusion layer. CMP is a very attractive material able to adsorb CO2 selectively with respect to other gases (such as H2, O2, N2, etc.), also in mild conditions (r.t. and atmospheric pressure). Particularly, tetrakis-phenylethene conjugated microporous polymer (TPE-CMP) was synthesized through Yamamoto homo-coupling reaction. TPE-CMP was modified by depositing noble (Pt) and non-noble (Fe) metal nanoparticles to create the active catalytic sites for the process of CO2 reduction directly on the polymer surface where CO2 is adsorbed. The metal-doped TPE-CMP electrocatalysts were fully characterized by infrared spectroscopy (IR), thermo-gravimetric analysis (TGA) and transmission electron microscopy (TEM). Then, the as-assembled GDM was tested in our homemade semi-continuous three-electrode electrochemical cell working in gas phase at 60 \ub0C, coupled with a cold trap for the accumulation of the liquid products. Results showed the better performances of the metal-doped TPE-CMP in terms of total productivity (C1\u2013C8 oxygenates) with respect to other kinds of materials that do not show high CO2 adsorption capacity