Study On Nanostructural Polyaniline Composite Fibers And Their Gas-response Behavior

As a member of conjugated conducting polymers,polyaniline(PANI) exhibits unique properties,i.e.high electrical conductivity,reversible nonredox doping/dedoping process,excellent environmental stability and low cost.In recent years,PANI and its nanocomposites with micro/nano-structures has attracted much research interest in the field of potential applications including highly sensitive sensors,radar absorbing materials,electrorheological fluid and information storage material.In this paper,sensitive chemical active polyaniline(PANI) nanorods were successfully prepared.The blend solution of PANI nanorods and poly(vinyl pyrrolidone)(PVP) was used to produce stable and ordered nanofibers by electrospinning technology.The composite nanofibers were used to prepare the chemical sensors,and the gas sensitive property of the sensors was investigated.The main results were presented as follows:(1) Nanostructural polyaniline were successfully prepared by both interfacial polymerization and a sonochemical way with hydrogen peroxide as the oxidant.The uniformity and the length of PANI nanorods were greatly improved by ultrasonic polymerization,in comparison with the interfacial polymerization.PANI prepared through two ways of polymerization exhibited similar FTIR spectra,UV-vis spectra and XRD patterns,indicating the similar chemical and electronic structures and crystalline properties.For the electrical property,the nanostructural polyaniline fitted with the Ohm law according to the linear relationship of I-V curves.(2) Polyaniline solution was prepared to produce nanofibers by electrospinning technology,in which polyaniline nanorods prepared via ultrasonic method was used as a sensible material,and poly(vinyl pyrrolidone)(PVP) and poly(vinyl alcohol)(PVA) were used as the matrices.Moreover,nanofibers with uniaxially aligned array were obtained using a parallel electrode collection in the electrospinning.The gas sensitive properties of the composite nanofibers were investigated in a specific chemical environment of CH₃Cl₃,NH₃ or alcohol gases.As a result,there was a good response relationship between the electrical behavior of the nanomaterials and the gas concentration,and the responding mechanism to the gas was preliminary discussed.