Synthesis and Self-Aggregation of Poly(2-ethyl-2-oxazoline)-Based Photocleavable Block Copolymer: Micelle, Compound Micelle, Reverse Micelle, and Dye Encapsulation/Release.

摘要: We report on the synthesis of photocleavable poly(2-ethyl-2-oxazoline)-block-poly(2-nitrobenzyl acrylate) (PEtOx-b-PNBA) block copolymers (BCPs) with varying compositions via combination microwave-assisted cationic ring-opening polymerization (CROP) and atom transfer radical (ATRP) using α-bromoisobutyryl bromide as an orthogonal initiator. The amphiphilic nature this BCP causes them to self-assemble into primary micelles in THF/H2O, which further undergo secondary aggregation nanostructured compound established through DLS, FESEM, TEM. Upon UV irradiation (λ = 350 nm), photocleavage PNBA PEtOx-b-PNBA takes place, that leads formation doubly hydrophilic poly(2-ethyl-2-oxazoline)-b-poly(acrylic acid) (PEtOx-b-PAA) causing rupture confirmed by spectroscopic microscopic techniques. Encapsulation a model hydrophobic guest molecule, nile red (NR), micellar core aqueous solution its UV-induced release is also investigated fluorescence emission measurements. amphiphiles are shown spherical nanostructures (∼90 nm) dichloromethane DLS TEM analysis. These referred reverse able encapsulate anionic dye, Eosin B, facilitate solubilization organic media.