Conjugated microporous polymer membranes for light-gated ion transport

Abstract

Inspired by the light-gated ion channels in cell membranes that play important roles in many biological activities, herein, we developed an artificial light-gated ion channel membrane out of conjugated microporous polymers. Through bottom-up design of the monomer molecular structure and by the electropolymerization method, the membrane pore size and thickness were precisely controlled on the molecular level. The obtained membrane exhibited uniform pore size and highly sensitive light-switchable response. The photoisomerization of the polymer chain resulted in a reversible “on and off” light control over the pore size and subsequently led to light-gated ion transport across the membrane for a series of ions including hydrogen, potassium, sodium, lithium, calcium, magnesium, and aluminum ions.

Photoswitchable Nanoporous Metal–Organic Framework Monolayer Film for Light-Gated Ion Nanochannel

“…After 5 s of UV light irradiation, the photoisomerization reached a photostationary state with a final percentage of cis -form of approximately 53.5%, which exhibited a high photoisomerization efficiency (Figure a,b). The gradual decrease of the percentage of trans -isomer with increasing UV irradiation time led to the decrement in the UV absorption peak intensity at 352 nm. ,, By contrast, the cis -to- trans process was completely achieved after 16 s of white light exposure (Figure c, Figure S16). The photoswitching between the trans - and cis -isomers was demonstrated to be reversible by performing five irradiation cycles, with almost full recovery of the absorption signals (Figure d).…”

“…The gradual decrease of the percentage of trans-isomer with increasing UV irradiation time led to the decrement in the UV absorption peak intensity at 352 nm. 35,38,39 By contrast, the cis-to-trans process was completely achieved after 16 s of white light exposure (Figure 3c, Figure S16). The photoswitching between the trans-and cis-isomers was demonstrated to be reversible by performing five irradiation cycles, with almost full recovery of the absorption signals (Figure 3d).…”

“…In order to better realize the application of light-responsive nanochannels, more precise regulation is required. Considering the rapid photoisomerization reaction, azobenzene becomes one of the most widely studied light-responsive molecules. − Its reversible trans – cis photoisomerization process can directly convert light energy into mechanical motion, leading to a reversible change of its geometry between planar trans and nonplanar cis isomers. − …”

Recent Advances in Stimuli‐Responsive Smart Membranes for Nanofiltration

“…Azobenzene‐containing monomer molecules form a conjugated 3D network with uniform micropores through continuous redox reactions. [ 196 ] These numerous and interconnected micropores act as intelligent ion channels. This bottom‐up design strategy can accurately endow each module of each channel in the membrane with an optical switch regulation mechanism, thereby achieving photoisomerization response and controllable ion transport.…”

Novel quinoxaline core-conjugated microporous polymer coating for highly sensitive solid-phase microextraction of phthalate esters in liquid food samples

“…Therefore, the development of a highly e cient, inexpensive, and life-long SPME ber coating remains the goal of researchers. To date, a variety of different SPME ber coating materials for the enrichment and separation of PAEs, including polysulfone (Huang et (Zhou et al 2022). However, although CMPs exhibit promising potential for application in analytical chemistry, to the best of our knowledge, they have not yet been explored as an SPME ber coating for PAE separation and enrichment (Meng et al 2018).…”