Induced electrical polarization and conductivity homogenization via internal architectural regulation in PC/PVDF/MWCNTs/PEDOT:PSS transparent conductive films

With polycarbonate (PC)/polyvinylidene fluoride (PVDF) co-continuous matrix as the substrate, composite transparent conductive films with excellent conductive properties were prepared by melt blending and rod coating method. After a surface sulfonation, the conductivity of PVDF films embedded with multi-walled carbon nanotubes (MWCNTs) decreased by three quarters. An ethylene glycol (EG) activated poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) layer was coated on PC/PVDF/MWCNTs to form a continuous and smooth surface, and its conductivity was increased by EG-induced phase separation. Owing to the excellent mechanical strength of PC and the toughing capacity of MWCNTs, the tensile strength of thin PC/PVDF/MWCNTs/PEDOT:PSS film attained 57.49 MPa, almost 3 times that of PVDF. The polymer-polymer or polymer-carbon tubes interaction featured as hydrogen bonding enhance the polarization of PVDF and phase separation of PEDOT:PSS. Meanwhile, sulfonated surface intensified this interaction and improved the lamellar compatibility. The increased PVDF β -phase, the PEDOT:PSS after a thorough phase separation and the well-dispersed carbon tubes all contributed to the densification of the matrix and the homogenized and continuous carrier-transferring property of the composite structure. Exhibiting a transparency surpassing 65%, PC/PVDF/MWCNTs/PEDOT:PSS film possesses a low surface resistivity (33.13 Ω/□). Moreover, owing to well dispersity of components and intensified interfacial bonding, a homogenous conductivity performance can be expected.