A strong hydrogen-bond acidic(HBA)polymer linear fluoroalcoholic polysiloxane(PLF),synthesized by one-step hydrosilylation,was introduced for 2,4-dinitrotoluene(2,4-DNT)detection using surface acoustic wave(SAW)devices.FT-IR spectra and1H NMR spectra characterizations confirmed its molecular structure.Then,PLF was dissolved in chloroform,and spray coated onto a434 MHz SAW device.And subsequently,the sensitivity and selectivity of the fabricated sensor were studied based on a SAW test platform.To 2,4-DNT of 1 ppm and 100 ppb(for DNT,1 ppm=8.1 mg/m3;1 ppb=8.1 lg/m3),the responses of the sensor rose 7.7 and 1.5 kHz,respectively.Furthermore,compared with some common interference vapors at 10 mg/m3,the response of the sensor to 2,4-DNT at1 ppm was 5 times stronger.The sensitive property was attributed to the hydrogen bond interaction between the hexafluoroisopropanol(HFIP)group in PLF and the basic lone electron pairs of nitro-groups in 2,4-DNT.Comparison between the PLF sensor and hydroxyl group functionalized polymer(carbowax and MOBCD)-coated sensors was investigated,and the results showed that the PLF sensor exhibited better sensitivity.In a word,the PLF sensor exhibited fast response,negligible baseline drifts and excellent reversibility,indicating good candidates of HFIP group functionalized HBA polymers for practical nitroaromatic explosives detection.
Yang WangXiaosong DuYin LongHuiling TaiYadong Jiang
