Temperature-Driven Oxygenation Rate Control by Polymeric Photosensitizer

Abstract

A polymeric photosensitizer, poly(NIPAM-co-BP), consisting of N-isopropylacrylamide (NIPAM) and benzophenone (BP) units, demonstrates a temperature-controlled oxygenation activity in water. The system promotes a heat-induced oxygenation enhancement at <17 degrees C and suppression at >22 degrees C. This unprecedented photo-oxygenation activity is triggered by a heat-induced phase transition of the polymer from coil to micelle, and then to globule state, cleverly controlling the stability and diffusion of singlet oxygen and the location of substrate.

A Fluorescent Molecular Switch Driven by the Input Sequence of Metal Cations: An Azamacrocyclic Ligand Containing Bipolar Anthracene Fragments

“…[25] Absorption spectra were measured on a UV/Vis photodiode-array spectrophotometer (Shimadzu; Multispec-1500). [26] Time-resolved fluorescence decay measurements were performed by time-correlated single photon counting on a PTI-3000 apparatus (Photon Technology International) by using a Xe nanoflash lamp filled with N 2 as excitation source. All of the measurements were carried out in the presence of NaClO 4 to maintain the ionic strength of the solution (I = 0.15 m) and at 298 AE 1 K by using a quartz cell with 10 mm path length.…”

Covalently immobilized porphyrins as photooxidation catalysts

“…Other recent and interesting proposals have appeared, such as immobilization of porphyrins in polymer microchannels, 12 linking fullerenes to amino functionalized silica gel, 13 benzophenone copolymer, 14 polymer spheresupported seco-porphyrazines, 15 porphyrins loaded in polystyrene beads, 16 porphyrin dendrimer structures, 17 and polystyrene nanocontainers doped with porphyrins. 18 …”

Photoregulated optical switching of poly(N-isopropylacrylamide) hydrogel in aqueous solution with covalently attached spironaphthoxazine and D-π-A type pyran-based fluorescent dye

“…Within the large polymer particles, the fluorophore units scarcely absorb the excitation beam, thus resulting in emission quenching which is accordance with the formation of the huge hydrophobic domain [19]. Fig.…”