Preparation Of High-performance Gels Using Nanosilica As Crosslinking Point And Its Application In Flexible Electronic Devices

With its unique stretchability,high efficiency and low cost in manufacturing,the stretchable and flexible electronic devices have a widespread application in the fields of information,energy,medical treatment,national defense and so on.Flexible electronic devices are usually composed of a flexible conductive medium sandwiched between two flexible electrodes.However,low conductivity,poor tensile properties and low environmental stability are the disadvantages of the present flexible electrolytes,resisting the application of the flexible devices.In view of the above problems,inorganic nano particles as crosslinking points,multifunctional coupled gels with high mechanical strength and flexibility were prepared by physical crosslinking method.Baesd on this,the corresponding electronic devices were also preapred.The experimental results show that the tensile strength of the hydrogel prepared by using Si O₂as the crosslinking point is 3 KPa-90 KPa and the elongation at break is 350%-3120%,which has reached the utmost as far as reported.Considering the self-healing property,it only takes 15 min to recover from the fracture.Nevertheless,due to the great deal of water in the hydrogels,its mechanical and electrochemical properties are sensitive to temperature,leading to the failure of electronic devices made by them.Comparatively,ionic gels are much more stablefor the applications in dramatically tunable environment.The acrylic/Si O₂composite ionic gel prepared by the subject can be stretched 40 times longer than its original length without any cracks.The self-healing efficiency is beyond 50%at room temperature for 180 min,revealing fine self-healing property.The repaired samples show the similar ionic properties to that of former one and exhibit excellent tensile properties.The elongation at break reached 2500%after self healing,which has been in the forefront of ionic gels.In addition,we have prepared a novel ionic liquid gel with high enviromental stability by using the hydrophobic monomer and ionic liqiud with Si O₂as the crosslinking point,the failure temperature of which is as high as 573K.Finally,the supercapacitors and sensors were assembled by the prepared flexible electrolyte.The modified hydrogel and ionic gel successfully improved the electrochemical performance of the flexible supercapacitor,performing high envirometnal stability and fatigue resistance.In this thesis,through the modification of flexible electrolyte,the performances of flexible electronic devices are greatly improved,which provides a new train of thought for the development of flexible electronic industry.