Humidity sensor based on a cross-linked porous polymer with unexpectedly good properties

Abstract

A humidity sensitive polymer was synthesized based on the derivative of triphenylphosphine by Friedel–Crafts alkylation. The polymer was formed of a hydrophobic skeleton with hydrophilic ions modified on phosphorous atoms evenly. The resultant polymer shows nanoporous characteristics. A humidity sensor based on the amphiphilic porous polymer shows unexpectedly good sensing properties, including high sensitivity, small humidity hysteresis, rapid response and recovery, and good stability. The good stability of the sensor is attributed to the cross-linked skeleton structure of the polymer, even though the content of ions in the polymer is high. These results demonstrate that porous polymers modified with certain hydrophilic groups are promising materials for high performance humidity sensors.