2D conjugated microporous polyacetylenes synthesized via halogen-bond-assisted radical solid-phase polymerization for high-performance metal-ion absorbents

• Main Authors: Le, Hong Tho, Wang, Chen-Gang, Goto, Atsushi
• Other Authors: School of Chemistry, Chemical Engineering and Biotechnology
• Format: Article
• Language: English
• Published: 2023
• Subjects: Science::Chemistry; Science::Chemistry::Organic chemistry::Polymers; Polymer; Polyacetylenes; Two-Dimensional Conjugated Microporous Polymers
• Online Access: https://hdl.handle.net/10356/165708
• Institution: Nanyang Technological University

The paper reports the first free-radical solid-phase polymerization (SPP) of acetylenes. Acetylene monomers were co-crystalized using halogen bonding, and the obtained cocrystals were polymerized. Notably, because of the alignment of acetylene monomers in the cocrystals, the adjacent C≡C groups were close enough to undergo radical polymerization effectively, enabling the radically low-reactive acetylene monomers to generate high-molecular-weight polyacetylenes that are unattainable in solution-phase radical polymerizations. Furthermore, the SPP of a crosslinkable diacetylene monomer yielded networked two-dimensional conjugated microporous polymers (2D CMPs), where 2D porous polyacetylene nanosheets were cumulated in layer-by-layer manners. Because of the porous structures, the obtained 2D CMPs worked as highly efficient and selective adsorbents of lithium (Li+) and boronium (B3+) ions, adsorbing up to 312 mg of Li+ (31.2 wt%) and 196 mg of B3+ (19.6 wt%) per 1 g of CMP. This Li+ adsorption capacity is the highest ever record in the area of Li+ adsorption.