Covalently bonded assembly and photoluminescent properties of rare earth/silica/poly(methyl methacrylate-co-maleic anhydride) hybrid materials

Copolymer (MMA-co-MAL) of methyl methacrylate (MMA) and maleic anhydride (MAL) was prepared and grafted by 3-aminopropyltriethoxysilane (APES), which behaves as the structural precursor for functional bridge to assemble the covalently bonded systems through the coordination to rare earth ions (Eu3+, Tb3+) with carboxylic groups of maleic anhydride. On the other hand, 1,10-phenanthroline (phen) is engaged in a second functional ligand to sensitize the luminescence of RE3+ (rare earth ions) by intramolecular energy transfer process. Meanwhile, the cohydrolysis and copolycondensation processes happened between triethoxysilyl of modified copolymer (MMA-co-MAL-APES) and tetraethoxysilane (TEOS) with Si–O covalent bonds, resulting in the polymer-inorganic hybrids (phen-RE-MMA MMA-co-MAL-Si) exhibiting characteristic red or green emissions of Eu or Tb ions. Especially the luminescent quantum efficiencies of europium hybrid systems are estimated and discussed in detail.