Study On Preparation And Performance Of SWCNT/PET Composite Films

Single-walled carbon nanotubes（SWCNTs）have excellent mechanical,electrical and thermal properties due to their unique one-dimensional hollow tubular structure,which are considered as ideal material s to enhance the properties of polymer matrix composites.T his advanced composite material can be used in fields such as electronic device,integrated circuit packaging,electr omagnetic shielding.At present,due to the poor dispersion of SWCNTs in the polymer matrix,the problems of the interpenetration and bonding between carbon nanotubes and the polymer matrix are still unresolved,which severely limits the enhancement of performance and wide commercial application of SWCNT/polymer composites.In this study,we directly composited the SWCNT films with high-quality,small-tube bundles,porous structure and the polyethylene terephthalate（PET）matrix by hot pressing to avoid the liquid phase dispersion process and explored the controllable preparation and performance of SWCNT/PET transparent conductive composite films.T he main experimental conclusions are as follows:Controlled preparation of SWCNT/PET composite films.Adopted th e floating catalyst chemical vapor deposition method and controllable preparation conditions of fabricating high quality,small bundles of SWCNT transparent conductive film of the research development to prepare and collect SWCNT films of different light transmittance（80%、70%、60%、50%、40%）,and then the SWCNT film was transferred onto the PET substrate by a dry method to form a pre-compressed body with a single-layer SWCNT film and a single-layer PET film superimposed structure.The SWCNT/PET composite ma terial was prepared by hot-pression method,and the influence of the hot-pression temperature,pressure,and time on the structure of the SWCNT/PET composite film specifically was specifically studied.T he optimized hot-pression conditions were obtained:the hot-pressing temperature,pressure and time were 240℃,15 MPa and 10 min,respectively.T he prepared SWCNT/PET composite film at the optimized conditions maintains the properties of PET and solves the problem of infiltration and bonding between PET and SWCNT simultaneously.At the same time,the small tube bundle and homogeneous porous network structure SWCNT film could avoid the dispersion process and maintain the intrinsic structure of SWC NT.The mechanical,electrical and thermal stability properties of SWCNT/PET composite films with different transmittance fabricated under optimized conditions were tested.With the addition of very low volume fraction of SWCNT films（0.20vol%-0.50vol%）,the properties of the SWCNT/PET composite film have been greatly improved.T he maximum Young’s modulus and tensile strength of SWCNT/PET composite films are increased by～61%and～70%,respectively,when the addition amount of SWCNT is 0.5vol%.Sheet resistance of the composite membrane surface is only～120Ω/□.Compared with the insulating PET film,the surface resistance is reduced by about 10^{1 4} times.Although the thermal stability of the SWCNT/PET composite film is not significantly improved,compared to the thermal decomposition temperature of the original PET film of～400.3°C,the addition of SWCNT increases the thermal decomposition temperat ure by～13.5°C,which is expected to be applied to the field of electronic device design.