title: Photo-responsive polyethyleneimine microcapsules cross-linked by ortho-nitrobenzyl derivatives.
abstract: Intelligent capsules are widely used as carriers for loading small molecules and particles for their capacity to respond to environmental stimuli. In this study, photo-responsive polyethyleneimine (PEI) microcapsules were fabricated using 4-bromomethyl-3-nitrobenzoic acid (BNBA) bearing a photodegradable ortho-nitrobenzyl group as a cross-linker. PEI-doped CaCO3 particles were used as the sacrificial templates, in which the PEI molecules were cross-linked by BNBA molecules under the activation of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) and N,N-diisopropylethylamine (DIEA). After the removal of CaCO3 particles by hydrochloric acid, the PEI-BNBA capsules were obtained. Since the C-N bond that formed via reaction of benzyl bromide and amine is photo-cleavable, the capsules could be decomposed under UV irradiation at 365nm. The loaded macromolecules could be released upon UV irradiation, exhibiting the microcapsules' potential applications in the field of controlled release.
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University in Hangzhou, 310027, China.
authors.forename: Huiying
authors.initials: H
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University in Hangzhou, 310027, China. Electronic address: tongwj@zju.edu.cn.
authors.forename: Weijun
authors.initials: W
authors.lastname: Tong
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University in Hangzhou, 310027, China.
authors.forename: Changyou
authors.initials: C
authors.lastname: Gao
mesh_terms: D002214:Capsules; D003432:Cross-Linking Reagents / Q000737:chemistry*; D015394:Molecular Structure; D009579:Nitrobenzoates / Q000737:chemistry*; D010316:Particle Size; D055668:Photochemical Processes; D011094:Polyethyleneimine / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D002214:Capsules; D003432:Cross-Linking Reagents; D009579:Nitrobenzoates; C075153:4-bromomethyl-3-nitrobenzoic acid; D011094:Polyethyleneimine
keywords: Microcapsules; Photo-responsive; Polyethyleneimine; ortho-Nitrobenzyl