Fabrication And Property Study Of The Sensing And Motion Device Based On Stimuli-responsive Polymer Materials

In recent years,polymer materials have attracted more and more attention because of their superior performance.Compared with traditional metal and inorganic non-metal materials,polymers may have light weight and strong corrosion resistance.In addition,with the development of polymer materials,some functional polymeric materials have been exploited in daily life.Among those,the representative stimuli-responsive polymer materials are widely used in biomedical,environmental monitoring and many other fields because of their response to environmental stimulus.In this thesis we have carried out the fabrication and property study of the sensing and motion device based on stimuli-responsive polymer materials and the main content covers the following three aspects:1.We have studied the fabrication of microstructures of stimuli-responsive polyaniline and its application in sensing device.In this work,we report a unique hierarchical core-shell polycaprolactone-polyaniline(PCL-PANI)fiber with spinous surface structures,which is fabricated by direct in-situ oxidative polymerization of aniline on the surface of porous electrospun PCL fibers,then we utilize the sensitivity of PANI to ammonia gas to produce gas sensor.Due to the high surface area to volume ratio caused by the hierarchical structure,when utilized for ammonia gas sensing,the resulting core-shell fibers exhibit high sensitivity,which is far superior to that of the film or the smooth fiber counterparts.In addition,the fabrication process of the sensor based on the current structure is very simple with low cost.Furthermore the sensing device exhibit the fast response to ammonia and the low detection limit.Moreover,the sensor not only shows good repeatability when repetitively exposing it to the ammonia gas but also exhibits good selectivity toward ammonia over other common volatile organic compounds.We thus believe the structure reported in the current study may have potential applications in the field of ammonia gas sensor.2.We construct a hydrogel consist of stimul i-re spo ns ive po ly(N-isopropylarylamide)and polyacrylic acid and study its application in motor device.Owing to the fast responsibility and controllable self-propelling movement of motors,they had been applied in biomedical and environmental monitoring fields in the past few years.However,it is difficult to actuate the self-propelled motors with multi-stimuli.To overcome this problem,we have synthesized poly(N-isopropylarylamide)and polyacrylic acid hydrogel by a free radical polymerization process,which is responsive to temperature and pH.By combining Pt nanoparticles(which can catalyze the deconposition of hydrogen peroxide to generate O2),a stimuli-responsive motor can be constructed.Temperature and pH will change the volume of hydrogel,which alter the exposed area of Pt.This process can influence the decomposition rate of hydrogen peroxide and control the moving speed of the motor.This stimuli-responsive self-propelled motor may have potential applications in drug delivery and release,environmental remediation and other fields.3.We construct a microstructure of polypyrrole(PPy)and study its application in motion-based sensor.Here,we construct a PPy microtube by the template synthesis method,and deposit Pt nanoparticles on the inner wall of the tube.Compared with the common electrochemical deposition method to synthesize the microtube structure,this template synthesis method is easy and low cost.However,it still can form a stable micro structure.Under different pH,the PPy micromotors show different moving speeds in the hydrogen peroxide and exhibit a superior response to pH,which provide a new method for pH detection.