Carbon Aerogels with Excellent CO₂ Adsorption Capacity Synthesized from Clay-Reinforced Biobased Chitosan-Polybenzoxazine Nanocomposites

Abstract

The present study reports for the first time the use of biobased chitosan-polybenzoxazine (CTS-PBZ) as a precursor for high CO 2 adsorbing carbon aerogels (CAs). Montmorillonite (MMT) is used to reinforce the CTS-PBZ aerogel. MMT-CTS-PBZ nanocomposite aerogels are synthesized using the freeze-drying technique and then cross-linked via ring-opening polymerization of benzoxazine followed by carbonization at 800 °C. Polybenzoxazine improves the structural stability for removing CO 2 from the environment even at a high pressure. The properties of polymeric and nanocomposite aerogels have been evaluated using X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The microstructure of the CAs is characterized by N 2 adsorption−desorption measurements. The CAs exhibit mesoporous materials with pore sizes in the range of 2−7 nm and high BET surface area. The total pore volume of CAs is as large as 0.296 cm 3 g −1 , and the maximum BET surface area is 710 m 2 g −1 . Breakthrough curves of CO 2 adsorption show high CO 2 adsorption capacity at ambient conditions and excellent CO 2 adsorption−desorption reversible performance with a maximum of 5.72 mmol g −1 . Adsorption isotherms and thermodynamic properties of CO 2 adsorption are described.

Carbon Aerogels Synthesizd with Cetyltrimethyl Ammonium Bromide (CTAB) as a Catalyst and its Application for CO2 Capture

“…They further explored new material of nitrogen enriched porous carbon sphere, and its adsorption capacity was up to 22.5cm 3 · g –1 . Alhwaige et al synthesized carbon aerogels from clay‐reinforced chitosan‐polybenzoxazine, which exhibited about 19.8 cm 3 · g –1 CO 2 uptake at 25 °C and 0.15 bar.…”

The Meeting Point of Carbonaceous Materials and Clays: Toward a New Generation of Functional Composites

“…Together with these commonly employed mono‐ or disaccharides, carbonaceous materials can be produced from other available biomass sources, with a particular interest in those biopolymers obtained from waste materials, such as chitosan, which is mainly extracted from the exoskeleton of crustaceans. Thus, a macroporous chitosan nanocomposite material prepared by freeze‐drying and containing polybenzoxazine as crosslinker was transformed into a carbon aerogel by carbonization at 800 °C . Similarly, lipids can be used as carbon precursors.…”

“…Carbon materials processed as foams are also useful in environmental remediation. For instance, chitosan–montmorillonite nanocomposites crosslinked with polybenzoxazine gave rise to carbon aerogels after freeze‐drying and carbonization at 800 °C . These materials showed high BET surface area, around 700 m 2 g −1 , and mesopores in the range of 2–7 nm.…”

Carbon Dioxide‐Switchable Chitosan/Polymer Composite Nanogels

“…For example, chitosan‐based carbon spheres with the high CO 2 ‐adsorption capacity were synthesized by thermal treatment under an inert atmosphere . Polyvinyl amine/chitosan/graphene oxide matrix membrane and chitosan‐polybenzoxazine nanocomposite aerogels were fabricated respectively and was used as CO 2 capture …”

“…[42] Polyvinyl amine/chitosan/graphene oxide matrix membrane and chitosan-polybenzoxazine nanocomposite aerogels were fabricated respectively and was used as CO 2 capture. [43,44] N-(3-(dimethylamino) propyl) methacrylamide (DMAPMA) is a water-soluble methacrylamide monomer which contains tertiary amine providing cationic polymers after polymerization. DMAPMA was initiated to form polymers or copolymers to fabricate ion-exchange resins [45] and gene delivery.…”