Amphiphilic gels of solvatochromic fluorescent poly(2-oxazoline)s containing D–π–A pyrenes. Issue 49 (3rd May 2016)

• Record Type: Journal Article
• Authors: Chen, Chia-Hsiu; Niko, Yosuke; Konishi, Gen-ichi
• Is Part Of: RSC advances. Volume 6:Issue 49(2016)
• Page Start: 42962
• Page End: 42970
• Publication Date: 2016-05-03
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra06251b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : We report amphiphilic, fluorescent, solvatochromic poly(2-methyl-2-oxazoline) (POZO-py ) and poly(2-ethyl-2-oxazoline) (PEtOZO-py ), which contain D–π–A pyrene dye units in their side chains. Abstract : Herein, we report amphiphilic, fluorescent, solvatochromic poly(2-methyl-2-oxazoline) (POZO-py ) and poly(2-ethyl-2-oxazoline) (PEtOZO-py ), which contain D–π–A pyrene dye units in their side chains. These new fluorescent polymers display solvatochromism and bright fluorescence in a variety of solvents, ranging from toluene (475 nm) to methanol (515 nm) and water (535 nm). Furthermore, amphiphilic gels (amphigels) ofPOZO-py andPEtOZO-py were synthesized by cross-linking the amine sites of partially hydrolyzedPOZO-py andPEtOZO-py . Amphigels were formed rapidly when bridging ethyleneimine moieties were used forPOZO-py andPEtOZO-py . These amphigels swell in various solvents, resulting in a solvatochromic shifts of the fluorescence emission. We furthermore determined the relationship between the swelling process, the solvatochromic properties, and the polymer structure of thePOZO-py andPEtOZO-py gels. The different swelling properties led to different amphigel structures in water and hence, to different maximum fluorescence wavelengths. For example, aPOZO-py amphigel with 10% ethyleneimine bridging exhibited the same solvatochromic behavior asPOZO-py in solution. These results are significant in order to evaluate the solvatochromic properties of pyrene chromophores in polymers and to investigate gel structures and functional group interactions in gels.