Synthesis and evaluation of a new polysiloxane as SAW sensor coatings for DMMP detection

A new polysiloxane material, polymethyl[3-(2-hydroxy)phenyl] siloxane (PMPS), was synthesized. The PMPS is a linear polysiloxane polymer functionalized with o-allyl phenol group. The chemoselective polymer was spin-coated on a 434 MHz surface acoustic wave (SAW) device for detection of dimethyl methylphosphonate (DMMP) vapor ranging from 5 to 40 ppm. It was found that the frequency shifts were linear to the vapor concentrations with a high sensitivity of 3 kHz/ppm. Fast response of 30 s and good reproducibility were achieved as well. The influence of humidity on the sensor response was also examined. The results showed that the sensitivity decreased about 1/2 when tested in 70% RH wet air than in dry nitrogen.