Probe Into the Influence of Crosslinking on CO2 Permeation of Membranes

A Rapid and Dual Optical CO2 -responsive Polydimethylsiloxane Elastomer with a Fluorinated Cyanine Dye

We found that our optically CO2 -responsive polydimethylsiloxane (PDMS) elastomer rapidly and reversibly underwent both visible and fluorescent color changes in the presence of CO2 gas. Unlike conventional optically CO2 -responsive polymeric materials, it functions in totally dry gaseous conditions. The visible color and fluorescence of the elastomer sheet change after only 1 min of exposure to CO2 , and the sheet exhibits excellent repeatability in terms of color switching that persists for at least 20 times.

Multi-cycle reversible control of gas permeability in thin film composite membranes via efficient UV-induced reactions

This communication presents a new, UV-induced mechanism to reversibly control the permeability of ultra-thin polymer coatings. Photoreversible [2+2] cycloaddition reactions were utilised to adjust the crosslinking degree and glass transition temperature of a coating. Consequently, a 300%, reversible change in the coating's oxygen permeability was achieved without loss of performance. Ultimately, the findings demonstrate the capability of using low UV doses to reversibly and efficiently regulate mass transport through ultra-thin coatings fabricated in a facile manner.

Synergy of CO2 Response and Aggregation-Induced Emission in a Block Copolymer: A Facile Way To "See" Cancer Cells

Carbon dioxide (CO₂), an important gas molecule metabolite produced by the tricarboxylic acid cycle, is a direct signal for identifying cancers in cells and tissues. Herein, design and synthesis of a novel "breathable" block polymer supramolecular assembly probe consisting of a hydrophilic block, an amidine-containing CO₂-responsive block, and an aggregation-induced emission (AIE) luminescence block to detect CO₂ metabolized by cancer cells is reported. The triblock copolymer poly-(4-undecoxy tetraphenyl ethylene methacrylate)-b-poly-((N-amidino)-(2,3-dihydro-1H-1, 4-methyl-1, 2,3-triazole)-(ethenylbenzene))-b-poly(ethylene oxide) (PTPE-b-PAD-b-PEO) was successfully synthesized and characterized. This triblock copolymer could be self-assembled into "breathable" aqueous solution vesicles. In the presence of CO₂, the amidine-containing CO₂-responsive block (PAD block) of the vesicle "inhales" an amount of CO₂, which causes the volume of the vesicle to expand. The expansion of the vesicle induces the aggregation of the AIE luminescence block (PTPE block), which resulted in the fluorescence intensity enhancement. The supramolecular vesicles "exhale" CO₂, and the volume and AIE phenomenon of the vesicles decrease when N₂ is passed into the solution. On the basis of this reversible change of fluorescence intensity, HeLa cervical cancer cells, CNE1 nasopharynx cancer cells, 5-8F nasopharynx cancer cells, 16HBE human bronchial epithelial cells, and GES-1 human gastric mucosa epithelial cells have all been successfully detected and identified.