Synthesis and characterization of a nanostructured photoluminescent silsesquioxane containing urea and dodecyl groups that can be patterned on carbon films

Abstract

A silsesquioxane was synthesized by the hydrolysis and polycondensation of (EtO)3-Si(CH2)3NHCONH(CH2)11CH3 in tetrahydrofuran (THF) employing formic acid as catalyst. The silsesquioxane self-assembled into nanorods due to the strong H-bonds among urea groups and the tail-to-tail associations of organic chains. The nanostructuration was characterized by a variety of experimental techniques (FTIR, 29Si NMR, XRD, TEM, HRTEM, and SAED). A colloidal solution of the silsesquioxane in methanol was deposited on a carbon film generating coffee ring structures with nanoparticles located at the boundary of rings. The significance of these results is related to the intrinsic photoluminescence of silsesquioxanes containing urea groups. The possibility of patterning these hybrid polymers on a surface can give place to materials exhibiting periodically modulated optical properties with potential applications in optoelectronics and light-emitting devices.