Synthesis and Morphology of Two Carbazole-Pyrazoline-Containing Polymer Systems and Their Electrical Memory Performance.

Abstract

A new atom-transfer radical polymerization (ATRP) initiator 4-[1-(2-dodecyl-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)-3-(4-nitrophenyl)-4,5-dihydro-1H-pyrazol-5-yl]phenyl 2-bromo-2-methylpropanoate (IN) as an electron acceptor (A) and a monomer 2-(9H-carbazole-9-yl)-ethyl methacrylate (MCz) as an electron donor (D) were simultaneously introduced into two different D-A polymer systems by using the end-functionalizing or blending method. The mass percentage of IN in the end-functionalized polymer PMCz-IN and the mixed polymer composite PMCz+IN were both controlled at approximately 1.0 wt %. The optical, electrochemical, and surface morphology properties of the two polymeric films prepared by means of spin-coating technology were comparatively investigated. Sandwich devices based on PMCz-IN and PMCz+IN demonstrated nonvolatile write-once-read-many-times memory (WORM) and volatile static random access memory (SRAM) characteristics, respectively, which were further verified by the Kelvin probe force microscopy (KPFM) measurements. The proposed memory mechanism could be attributed to the formation of a stable charge-transfer (CT) complex for PMCz-IN and an unstable CT complex for PMCz+IN. Furthermore, the different distribution of IN in the two polymeric films might be the main reason for the stability of the CT complex.