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An anionic mechanism is used to create polymers and copolymers as confined to, or anchored to, high-surface-area porous nanoparticles. Linear polymers with soft and glassy chains, such as polyisoprene and polymethylmethacrylate, were produced by confined anionic polymerization in 3D networks of porous aromatic frameworks. Alternatively, multiple anions were generated on the designed frameworks which bear removal protons at selected positions, and initiate chain propagation, resulting in chains covalently connected to the 3D network. Such growth can continue outside the pores to produce polymer-matrix nanoparticles coated with anchored chains. Sequential reactions were promoted by the living character of this anionic propagation, yielding nanoparticles that were covered by a second polymer anchored by anionic block copolymerization. The intimacy of the matrix and the grown-in polymers was demonstrated by magnetization transfer across the interfaces in 2D 1 H-13 C-HETCOR NMR spectra.

It has been over half a century since polyacrylonitrile (PAN)-based carbon fibers were first developed. However, the mechanism of the carbonization reaction remains largely unknown. Structural evolution of PAN during the preoxidation reaction, a stabilization reaction, is one of the most complicated stages because many chemical reactions, including cyclization, dehydration, and cross-linking reactions, simultaneously take place. Here, we report the stabilization reaction of single PAN chains within the one-dimensional nanochannels of metal–organic frameworks (MOFs) to study an effect of interchain interactions on the stabilization process as well as the structure of the resulting ladder polymer (LP). The stabilization reaction of PAN within the MOFs could suppress the rapid generation of heat that initiates the self-catalyzed reaction and inevitably provokes many side-reactions and scission of PAN chains in the bulk state. Consequently, LP prepared within the MOFs had a more extended conjugated backbone than the bulk condition., Accommodation of polyacrylonitrile in MOFs facilitated and regulated the transformation to ladder polymer in the carbonization process.

The synthesis of porous organic 3D frameworks, wherein amine, hydroxyl and Li-alkoxide functions were built directly on the monomer-unit carbon core, realizes improved interactions with target gases. CO2 was retained by the amine group with a remarkable energy of 54 kJ mol-1, while 2D MAS NMR provided rare evidence of amine-to-gas short-distance interactions. Frameworks containing hydroxyl and Li-alkoxide functions show optimal interaction energies with CH4 of up to 25 kJ mol-1. The light network of 3-branch building units ensures the expandability of the nano-sponges.

High surface area 3D polymers represent one of the most promising classes of porous materials because of their high gas uptake and stability to thermal and chemical degradation. A series of porous organic polymers with aromatic building units have been synthesized and compared to explore their high-pressure performance as adsorbents of gases of relevant importance for energy and the environment. Particular attention was paid to methane storage up to pressures as high as 180 bar at ambient temperature. Porous polymers were prepared starting from a wide choice of spatially expanded aromatic monomers: a systematic change in the number of rings, variable size and shape was taken under consideration. The high number of rings (up to 6), which act as multiple reactive sites and form a number of connections between the multi-dentate nodes, result in an extensive cross-linked framework. Condensation was obtained by two alternative synthetic routes, viz., Yamamoto cross-coupling and Friedel–Crafts alkylation reactions. The structural characteristics and high stability of the porous polymers, even to mechanical compression, were carefully determined by several methods, including 1D and 2D solid state NMR, FT IR and thermal analyses. The CH4 uptake in the porous polymers allowed an understanding of the incremental response to pressure, up to extremely high values, and the exploitation of the extensive pressure range to customize the gas adsorption/desorption cycles for storage and transportation. Owing to the notable presence of large mesopores and network flexibility, combined with high surface area, a remarkable gain at high pressure was achieved, ensuring a highly competitive uptake/delivery efficiency. At 180 bar, adsorption values up to 445 cm3 STP g−1 were measured for porous organic polymers such as carbazolyl- and triptycene-based materials. The benchmark of these materials PAF1 reaches the value of 916 cm3 STP g−1 of adsorbed CH4, exceeding the performance of most of the best performing MOFs, COFs and activated carbons. CO2 and N2 adsorption isotherms collected at room temperature enabled the assessment of the suitability of such polymer networks for CO2 selective separation and capture. In summary, the in-depth and extensive comparative screening within this class of materials up to high pressures provides the necessary parameters for further synthetic and applicative work.