RESEARCH TOPICS

Polymers containing porphyrin units and their use as sensors

In the last years the research activity has concerned the synthesis, characterization and sensing response of copolyacrylates and copolyformals containing porphyrin units. The copolyacrylates were synthesized by radical polymerization between methyl methacrylate and 5,10,15-Tri[p-(9-methoxy-triethylenoxy)-phenyl]-20-(p-acryloxyphenyl)-porphyrin and characterized by MALDI-TOF, NMR spectroscopy and gel permeation chromatography. To test the sensing response, very thin layers of copolymer deposited on PMMA plates were exposed to acid vapors and NO₂ gas.The examination of the UV-Vis spectra after exposition showed the reduction of Soret band(at 424 nm) and the presence of a new band at 455 nm.The reversibility of interaction was verified by a simple exposure to ammonia or hot air. We have synthesized several copolyformals containing two new porphyrin monomers in the main chain: 5,15-di(pentafluorophenyl)-10,20-di(p-hydroxyphenyl)-porphyrin and 5,15-di(pentabutoxyphenyl)-10,20-di(p-hydroxyphenyl)-porphyrin. The copolyformls were obtained by reaction between dibromomethane, 1, 20-di(bisphenoxy-A)-eicosane , and different molar amount of porphyrin units. The sensing properties of the copolymers, toward a controlled exposition to NO₂/N₂ gaseous mixtures or acid vapors, were compared by examination of the corresponding UV-Vis spectra.The results obtained indicate that the copolymers containing decabuthoxy porphyrin units has a greater affinity than the others with both acids and NO₂. This different behavior must be ascribed to the major basicity of the porphyrin containing electron-rich substituents.

People to contact: Daniele Vitalini - Emanuela Spina

List of selected publication:

S.Dattilo, P.Mineo, E.Scamporrino, E.Spina, D.Vitalini
Synthesis and characterization of new copolyacrylates containing porphyrin units as pendant groups and their use as sensors
Journal of Polymer Science part A: Polymer Chemistry 49, 796-802 (2011)

P.Mineo, E.Scamporrino, E.Spina, D.Vitalini
Synthesis and characterization of copolyformals containing electron-rich or electron-poor porphyrin units in the main chain and their use as sensors
Sensors and Actuators B: Chemical 188, 1284-1292 (2013)