In-situ Graphical Metal Growth Technology Based On Polymer Films And Its Application

In recent years,the rapid development of new devices represented by wearable and flexible electronic devices has put forward new challenges to the corresponding preparation process.The traditional metal graphics technology based on lithographic graphics and evaporation technology is faced with such problems as large equipment scale,high production cost,harsh production environment,incompatibility of graphics technology,weak bond between metal and polymer substrate and so on.It has become a key problem for the development of flexible electronics industry to develop new metal graphic deposition technology with high efficiency and energy saving.On the in-situ graphical metal growth processes,the metals are growth from the interior of the substrate.As a result,the ion exchange based in-situ graphical metal growth method is one of the ways to fundamentally solve the adhesion problem between the conductive layer and the flexible substrate.In addition,in-situ graphical metal growth method is a low-cost,environmentally friendly,full-solution chemical method.However,up to now,literatures about practical applications of the ion exchange based in-situ graphical metal growth method in the area of wearable devices is still scarce.On the one hand,the basic principles of each link of the ion exchange based in-situ graphical metal growth method have not been explained in a unified way,and the core laws and characteristics of the metal deposition process are still need to be studied.On the other hand,metal nanoparticles prepared by chemical method on polyimide substrate have weak resistance to chemical corrosion.This makes it difficult for metal electrodes prepared by the in-situ graphical metal growth method to directly apply to the electronic devices in solution system.Especially in the area of flexible supercapacitor,which requires both high mechanical stability and high chemical stability.Based on this,this paper studied the mechanism of ion exchange based in-situ graphical metal growth method,explored the growth conditions of metal electrodes prepared by different ways,and optimized the existing environment-friendly in-situ metal preparation technology.In order to test the application capability of the prepared functional nanoparticle films in the area of flexible devices,strain gauge sensors,flexible temperature sensors,flexible heaters and flexible supercapacitors are prepared and studied in this paper,by combining the traditional lithographic graphics technology and new graphics technologies.The main results are as follows:1.The film forming mechanism of metal nanoparticle film guided by gas phase by-product is proposed.Then,based on the conductivity of the prepared metal nanoparticle films,the basic law of ion exchange based in-situ metal growth method is summarized.The results show that the conductivity of metal nanoparticle films prepared by ion exchange method is mainly affected by the thickness of PAA layer,the concentration of metal ion source,the ion exchange time,the concentration of reducing agent and the reduction time.The ion exchange process determines the amount of the prepared metal nanoparticles,and the conductance of the metal nanoparticle films can be controlled by regulating the related factors.The reduction process determines the surface morphology of the prepared metal nanoparticle films.Especially for the reduction process with gas phase by-products,a variety of functional nanoparticle films can be obtained by selecting the types of reducing agents,and then flexible devices with different functions can be prepared.2.A graphic electroless metal electrode with high thermal stability and high flexibility was prepared by using ICM printing mask method and environmentally friendly electroless nickel technology.This paper gives full play to the high catalytic activity of Ni seed layer and optimizes the existing environment-friendly electroless deposition technology by reducing the time of ion exchange.Then the metal heater with high thermal stability and the supercapacitor with high flexibility were prepared by ICM printing mask method which has the capacity of mass manufacturing.The electroless metal heater can reach the stable heating temperature of more than 230 ? at the working voltage of 7 V.And the supercapacitor based on the prepared electroless current collector can withstand tens of thousands of bending times without any attenuation of capacitance.3.By introducing graphene anti-corrosion technology,the chemical stability of electroless nickel electrode was greatly improved,and the rGO supercapacitor with high mechanical stability and high chemical stability was prepared.The results show that the rGO nanosheet used in this paper not only acts as the active material of the rGO supercapacitor,but also acts as the anti-corrosion protection layer of the electroless nickel current collector.The prepared rGO supercapacitor has ultrahigh chemical stability and can maintains 96.7 % of the capacitance value after 13 000 of CV cycling times.4.Based on the characteristics of electroless metal layer and the technology of hard mask embossing,a high performance flexible supercapacitor with bioinspired interfacial structuring was developed.Due to the high ductility of electroless metal,3D micro-nano structure can be prepared on the surface of electroless metal by hard mode embossing.By this method,a dual bioinspired structure is introduced between the electroless fluid/active material interface of the supercapacitor.Thus,the mechanical and electrochemical properties of the supercapacitor with bioinspired interface have been optimized.In particular,due to the interface regulation effect of the dual bioinspired structure,the potential window of the solution of system symmetrical supercapacitor is raised from 1.2 to 1.6 V,which greatly increases the energy density of the prepared supercapacitor.5.The technology of Ni seed layer preparation by adsorption deposition method based on cellulose substrate was developed.For the first time,the environmentally friendly graphical electroless metal deposition technology was transferred to the paper substrate.And paper based supercapacitor with high conductivity,high flexible metallized paper electrode and high chemical stability was prepared.The cellulose paper with porous and hydrophilic properties can be used as carrier of metal ions.Since,the core of ion exchange based in-situ metal growth method preparation on PI substrate is that the surface modified PI substrate is an ion carrier which can hold a large number of metal ions.Therefore,environmentally friendly electroless metal layer can be prepared on the cellulose paper substrate using the same treatment mode as the ion exchange method.In this paper,Ni seed layers with high electroless activity were prepared on a variety of cellulose paper substrates based on the principle of adsorption deposition.In addition,ICM printing mask method is used to solve the problem of fabricating large quantities of paper-based graphical metal electrodes.Then a paper-based supercapacitor with high chemical stability is prepared.