Fabrication Of Pi/Inorganic Hybrid Films And Microtuning Their Microstructures And Properties Based On Ion-Exchange Technique

Fabrication of functional inorganic components onto polymeric surfaces has been attracting great of interest due to several distinctive properties of inorganic nanoparticles and anomalous cooperative properties of systems. Among polymeric materials, polyimide (PI) is a promising candidate for the substrate due to its attractive properties including excellent tensile strength and modulus, low thermal expansivity, high thermal stability. Fabrication of metal nanolayers and/or metal sulfide onto flexible PI surfaces is still of great interest because of their various practical applications, such as in flexible piezoelectric, ferroelectric, solar cells, and ferromagnetic elements.In this thesis, functional polyimide/inorganic hybrid composite films which include PI/Ni, PI/Cu and PI/cobalt-sulfide (CoS) nanocomposite films are prepared respectively. The methods mainly rely on surface alkaline hydrolysis, subsequently ion exchange, and finally interfacial reaction. Firstly, nickel layers on the double surfaces of the flexible PI matrix have been prepared through nickel reducing technique using ethylene glycol or sodium borohydride aqueous solution as reductants respectively. To prepare PI/Cu nanocomposite thin films, we use of silver nano-crystal as seeds and electroless plating technologies via H2O2 aqueous solution as a reductant. While PI/CoS composite films were fabricated by "solid-liquid" interface reaction via immersion Co2+ doped film in Na2S aqueous solution. Composite films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), inductively coupled plasma (ICP), scanning electron microscopy (SEM), transmission electron microscope (TEM) and the universal testing machine. The experimental results show that the PI composite films have maintaining the excellent performance of the parent and good bonding properties.