Desenvolvimento e aplicação de sistemas nanoestruturados a partir da meso-porfirina derivada do LCC

Abstract

Porphyrins are very attractive system to study self-assembly due to its basic structure, chemical and thermal stability, synthetic versatility and important technological applications. This work presents the development of self-assembled systems meso-porphyrin derived from cardanol, the major constituent of the LCC. We were developed Langmuir and Langmuir-Blodgett (LB) thin films and superparamagnetic nanosystems coated with meso-porphyrin. The Langmuir films showed molecular area mean of the 177 Å 2 confirmed by compressibility modulus. The 700 nm band observed in the Langmuir films supports the coexistence of monomers and dimers similar to the spectra of the solution (CHCl3/CH3COOH). The Brewster angle microscopy measurements showed formation of bright block domains with different sizes and shapes for the monolayer that disappears after surface pressure starts to increase. The UV–vis spectra of the Langmuir films and FTIR reflection of the Langmuir–Blodgett films (LB) indicated that the molecules exhibit preferential orientation with the parallel planes to the water (Langmuir) and in the substrate (LB). The LB film of 5 layers showed better response as electrode and has been tested as a promethazine sensor. Magnetic Fe 3 O 4 nanoparticles with an average size of 11 nm were coated with oleic acid layer and a meso-porphyrin layer to producing a novel superparamagnetic fluorescent nanosystem. Also were obtained systems coated with meso-porphyrins metallated with Co2+, Ni2+, Cu2+ and Zn2+ ions. The systems were characterized by TEM, FT-IR, TGA, vibrating sample magnetometry, UV-Vis, fluorescence and confocal miscroscopy. The systems showed good thermal stability, excellent magnetization and nanosized dimensions.