Keynote Novel Functional Polymeric Nanomaterials : Synthesis, Optoelectronic, Selective Dispersion of SWNTs and Photovoltaics Applications

Abstract

Novel nanomaterials such as polyimides (PIs), polyamides (PAs), conjugated polymers and polynorbornenes (PNBs) weresuccessfully prepared from various polymerization techniques including low temperature polycondensation, Suzukicoupling and ring-opening metathesis polymerization (ROMP). PIs derived from different architecture designs revealed uniquephysical-mechanical, electrical and chemical properties. In addition, the PIs films also exhibited high thermal stability (Tg >300oC), transparency above 90% in visible light region (400-700 nm) and flexibility which are important for optoelectronicapplications. PAs with the pyridine moiety displayed good film forming abilities, flexibility, high thermal resistance andyellow emission at 552 nm due to excimer generated by protonation. Conjugated polymers were used for single-walled carbonnanotube (SWCNT) wrapping to separate metallic and semiconducting nanotubes. Their chiralities such as (6,5), (9,5) or (8,7)were identified by photoluminescence-excitation (PLE) maps as well as UV/vis/NIR absorption spectra. Polytriarylamines- orpoly(triarylamine-fluorene)-based conjugated polymers with water/alcohol solubility were applied for the hole-transportingmaterials of solar cells including perovskite solar cells and organic photovoltaics (OPVs). The conjugated polymers and PNBscontaining hexa-peri-hexabenzocoronene (nanographene) were well dispersed in cyclohexylpyrrolidone (CHP) by bathsonication and possessed exfoliation emission in PLE maps. PNBs synthesized via ROMP showed excellent transparency (90%) and high thermal stability (Tgs > 160 oC). Triarylamine-containing polymers had electrochromic properties and capacity formultiple colour change reversibilities. The triphenylamine-alt-fluorene conjugated copolymer with hexaphenylbenzene (HPB)and pyrene as asymmetrical pendant groups showed the strong near-infrared (NIR) electrochromic absorbance attributed tointervalence charge transfer by the incorporation of the HPB moiety. These polymeric materials had high organo-solubilityin common solvents and as a result can be used for solar cells, organic field effect transistors, polymer memories, and smartwindows applications.