Light-switchable nanoparticles based on amphiphilic diblock, triblock and heterograft polyoxazoline

Abstract

Photo-active nanoparticles (NPD, NPT, NPH) were elaborated in water from amphiphilic diblock (D), triblock (T) and heterograft (H) copolymers based on a chromatic unit, coumarin, linked to an alkyl chain and a hydrophilic polyoxazoline chain.

Stimuli-Responsive Luminescent Solar Concentrators Based on Photoreversible Polymeric Systems

“…As the double bonds of coumarin groups reacted to form the cyclobutane rings by [2+2] cycloaddition (Scheme B), the conjugation is progressively lost, leading to a decrease in the absorbance. , The extent of the conversion of pendant coumarin groups into photodimers (dimerization degree, DD%) was calculated according to the following equation where A 0 and A t are the absorption intensities at 320 nm before and after a time t of UV exposure, respectively. As shown in Figure B, the dimerization degree increases over time and reaches a plateau after 120 min of exposure, corresponding to conversion of 93.2%, in line with previously reported systems. , As reported in Figure C, the UVA treatment for 120 min (corresponding to the maximum conversion of coumarin groups) strongly reduced the fluorescence intensity at 394 nm, owing to the decrease in the concentration of luminophores in dimerized PU-Cou . Nevertheless, the decrease was only 68.8%, significantly lower than the one calculated from the absorbance spectra (93.2%).…”

“…37,53 As reported in Figure 2C, the UVA treatment for 120 min (corresponding to the maximum conversion of coumarin groups) strongly reduced the fluorescence intensity at 394 nm, owing to the decrease in the concentration of luminophores in dimerized PU-Cou. 54 Nevertheless, the decrease was only 68.8%, significantly lower than the one calculated from the absorbance spectra (93.2%).…”

Amphiphilic polymers based on polyoxazoline as relevant nanovectors for photodynamic therapy

“…In the literature, only a few cases of polymeric self-assemblies crosslinked through coumarin dimerization have been described. One example was from our team using different polyoxazoline polymers 31,35,45 . This was focused on the physical chemistry aspect, in order to better understand how the microstructure of the polymer could interfere with the stability of the self-assemblies.…”

Polyoxazoline associated with cardanol for bio‐based linear alkyl benzene surfactants

“…who designed copolymers containing both hydrophilic and lipophilic POx blocks . More recently, POx blocks have been linked to bio‐based blocks such as glycopolymers and fatty derivatives or to petro‐based blocks including polysiloxanes, aliphatic polyesters and fluorinated chains, giving various amphiphilic copolymers with surfactant or self‐assembling properties . Their use as a surfactant for instance for emulsion polymerization or solubilization of dyes has recently been reported …”

“…39 More recently, POx blocks have been linked to bio-based blocks such as glycopolymers and fatty derivatives or to petro-based blocks including polysiloxanes, aliphatic polyesters and fluorinated chains, giving various amphiphilic copolymers with surfactant or self-assembling properties. [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] Their use as a surfactant for instance for emulsion polymerization or solubilization of dyes has recently been reported. 57,58 Here, in order to replace the toxic NPE surfactant, a peculiar phenolic lipid, cardanol, was associated with a hydrophilic poly(2-methyl-2-oxazoline) chain ( Fig.…”