Synthesis of 2-{5-[4-((4-nitrophenyl)diazenyl)phenyl]-1,3,4-oxadiazol-2-ylthio}ethyl acrylate monomer and its application in a dual pH and temperature responsive soluble polymeric sensor

Abstract

The monomer 2-{5-[4-((4-nitrophenyl)diazenyl)phenyl]-1,3,4-oxadiazol-2-ylthio}ethyl acrylate (NDPOE-acrylate) was synthesized in five steps and then copolymerized with N-isopropylacrylamide, leading to a dual pH and temperature responsive polymeric sensor. Obtained copolymer exhibited the lower critical solution temperature only in acidic medium (pH 2) as 32°C. The UV-vis and fluorescence of copolymer was investigated at different pH values in various temperatures. The UV-vis of copolymer are independent to temperature above pH 4. The copolymer exhibited sensitive fluorescence change towards pH between 2 and 10 at different temperatures.