Synthesis of inorganic-organic hybrid membranes consisting of triazole linkages formed by the azide-alkyne click reaction

Inorganic-organic hybrid membranes consisting of aliphatic main chains and triazole rings were synthesized via copolymerization of a methacryloxysiloxane derivative with phosphonic acrylate, followed by hydrolysis. Hydroxyethyl methacrylate acid phosphate (HEMAP) was copolymerized with 3-methacryloxypropylmethyl-dimethoxysilane (MPMDMS), and then reacted with diethyl (4-(1-(3-(trimethoxysilyl)propyl)-1,2,3-triazol-4-yl)phenyl)phosphonate (TMSTAzPP), yielding inorganic-organic hybrid composites. The triazole ring of TMSTAzPP was constructed via the azide-alkyne click reaction using nanoporous Cu. IR, ¹³C, and ²⁹Si NMR spectroscopy supported the formation of the inorganic-organic hybrid structure including a triazole ring. The membranes showed good thermal stability up to 180 °C. The conductivity of the HEMAP/MPMDMS/TMSTAzPP membrane with a composition of 7:1:3 was higher than that of the HEMAP/MPMDMS membrane with a composition of 10:1. The conductivities of the 12:1:3 membranes at 130 °C were 1.05×10⁻¹ S cm⁻¹ and 1.68×10⁻⁴ S cm⁻¹ at 100% and 19.3% relative humidities (RHs), respectively. The power density of the 12:1:3 membrane was 3.9 mW cm⁻² at 140 °C and 30% RH.