Proton Conduction Properties of Intrinsically Sulfonated Covalent Organic Framework Composites

Abstract

The long–term stability of proton conductors is one of the most important factors in evaluating materials. Guest molecules can act as “bridges” for proton conduction channels and reside in the channels of covalent organic frameworks, but they are prone to leakage. Therefore, it is important to develop proton conductors with intrinsic proton conductivity. In this paper, we synthesized an intrinsically sulfonated covalent organic framework, TpPa–SO3H, which has a more stable proton conducting performance than that of TpPa@H2SO4 by loading guest molecules. Meanwhile, the proton conductivity of TpPa–SO3H was further improved by coating a superabsorbent polymer through an in situ reaction to obtain PANa@TpPa–SO3H (PANa: sodium polyacrylate). As a result, the modified composite exhibits an ultrahigh proton conductivity of 2.33 × 10−1 S cm−1 at 80 °C under 95% relative humidity (RH). The stability of PANa@TpPa–SO3H makes it an efficient proton transport platform with excellent proton conductivity and long–term durability.

Keywords

• covalent organic framework
• PANa
• proton conduction
• composite