Polyacrylamide modified mesoporous SBA-16 hybrids encapsulated with a lanthanide (Eu3+/Tb3+) complex

Abstract

Novel luminescent polymer-functionalized mesoporous SBA-16 type hybrid materials with encapsulated lanthanide (Eu³⁺ and Tb³⁺) complexes for luminescence have been synthesized in situ. The organic molecule acrylamide (AM) was first modified by a silane coupling agent 3-(triethoxysilyl)propylisocyanate (TEPIC) to form an alkene precursor, which was then covalently bonded to a mesoporous SBA-16 backbone through co-hydrolysis and co-condensation reactions. Then, the flexible polymer chain polyacrylamide (PAM) within the pores of SBA-16 could be formed by initiating the monomer. Through introducing the lanthanide ions and the typical ligand 1,10-phenanthroline (phen), the luminescent mesoporous hybrids (denoted as Ln(S16-PAM-Si)₃ and Ln(S16-PAM-Si)₃phen, respectively) with the organic polymer acting as a flexible linker between the mesoporous framework and the lanthanide complex were finally attained. The results reveal that these materials exhibit high surface area, uniform mesostructure and efficient intramolecular energy transfer. Moreover, the ternary hybrids present higher red/orange ratio, stronger luminescent intensity, longer lifetime and higher ⁵D₀ luminescence quantum efficiency than the binary one, suggesting that the luminescent properties have been significantly improved with the introduction of the organic ligand phen.