Photo‐Modulating CO₂Uptake of Hypercross‐linked Polymers Upcycled from Polystyrene Waste

Abstract

Supporting information for this article is given via a link at the end of the document.

Delivering low-energy carbon capture with photo-responsive hypercrosslinked polymers derived from polystyrene waste

“…Like other HCPs, 37,64,65 CO 2 desorption from pristine HCPs in this work could only be enabled by thermal methods where a high temperature of 110 °C and a vacuum environment was required. Meanwhile, visible light (450 nm) was used here to trigger CO 2 desorption from trans -HCPs@Azo and cis -HCPs@Azo.…”

“…Without dipole–quadrupole interactions between CO 2 and azobenzene molecules, a 20 mL min −1 N 2 sweep gas could then easily remove these CO 2 molecules from the adsorbent surface. Additionally, cis–trans isomerisation of azobenzene also reduced the accessible pore volume, 37 where the physical dimensions of azobenzene increased from 5.5 Å to 9 Å could force out CO 2 molecules from the pores. Here, it is important to highlight that although vis-modulated desorption efficiency could only reach 14%, this could be potentially improved by ensuring that all cis -HCPs@Azo that were packed into the quartz container were exposed to the light source.…”

“…HCPs@Azo were fabricated using our previously reported protocol. 37 Briefly, 500 mg azobenzene was dissolved in 20 mL of ethanol. 200 mg of HCPs were steeped into the azobenzene ethanolic solution for 12 hours to reach equilibrium.…”

“…Herein we deployed photo-responsive HCPs loaded with 8.9 wt% azobenzene (HCPs@Azo) that were developed in our previous work 37 in simulated post-combustion flue gas mixtures (CO 2 4–20 v/v% in N 2 ) to address this knowledge gap. Upon UV-irradiation, the azobenzene molecules incorporated within HCP pores undergo a photo-reversible trans – cis isomerization caused by n–π* and π–π* excitations, 38 leading to changes in physical dimensions and dipole moment, from 9 Å ( trans ) to 5.5 Å ( cis ), 39 and 0 D ( trans ) to 3.0 D ( cis ), 40 respectively.…”

Mesoscale artificial synthesis of conjugated microporous polymers

“…Microporous materials, such as zeolites, 1 metal–organic frameworks (MOFs), 2,3 covalent organic frameworks (COFs), 4–6 and microporous organic polymers (MOPs) 5,7–10 have been explored for a variety of applications, such as energy storage, 11,12 gas uptake, 13 heterogeneous catalysis 14 and molecular separations. 2,5,15 However, despite the ultra-high surface areas of the crystalline MOFs and COFs due to their defined pore structures, 3 some suffer from a lack of stability on exposure to ‘real-world’ conditions that would be used, for example, in a rechargeable battery.…”