Abstract
The dew sensors were prepared by dispersing carbon powders to the hygroscopic polymers which were copolymerized previously with hydrophilic monomer (DMAA, HEM) and hydrophobic monomer (MMA, TFEM).
The properties and durability of the sensors were investigated. The results obtained were as follows : The humid sensitivity of the sensors was remarkably affected by the hygroscopicity of the copolymers and carbon powder concentration and its size. The hysteresis became small according to the degree of hydrophobic property of the hydrophobic part of the copolymers and carbon powder size. Response time became short according to the degree of hygroscopicity of the hydrophilic part of the copolymers and their flexibility. The molecular weight of the copolymers influenced the mechanical properties and the adhesive strength of sensing film to determine the durability of the sensors.
