| 摘 要： | 1 Results Investigations on the sensing mechanism is important for understanding the electrical responses of humidity sensors to humidity change,and could provide guidelines for the design and synthesis of humidity sensitive materials with desirable properties.In this work,the sensing mechanism of humidity sensors based on quaternized poly(4-vinylpyridine) (PVP)/carbon black (CB) composite1] was studied by measuring their AC impedance spectra at various humidities at room temperature.Under low humidity,the AC impedance spectra of the composite was composed of a semicircle,while a semicircle at high frequency and a straight line at low frequency was observed in the spectra of quaternized PVP alone.The value of R which represented the resistance of film was estimated by the diameter of the semicircle.
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