OBJECTIVES 2015:

1. Preparation of a glass/TCO/ZnO/PF-BT/Ag hybrid structure

FIGURE 1. ( a) The schematic illustration of the hybrid structure; (b) energy levels of the investigated  hybrid structure ZnO/PF-BTcopolymer.

PF-BT layers were deposited on the TCO/ZnO substrates by spin-coating from a concentrated tetrahydrofuran (THF) solution. In such a structure, Ag was used as a top electrode and a transparent electron conducting layer (TCO) a bottom electrode. Figure 1 illustrates the schematic representation of the investigated glass/TCO/ZnO/PF-BT/Ag hybrid structure. In this configuration electrons are collected by the bottom electrode, while the holes by the top electrode.

2. Azomethine persylilated α-cyclodextrin main-chain polyrotaxanes

FIGURE 2. Chemical structures of the polyrotaxane PA•TMS-αCD and its reference PA.

TMS-αCD encapsulation of PAMs backbones leads to distinct improvements in the solubility, molecular weights, film forming ability and thermal stability. The optical investigations confirmed that the polyrotaxane exhibited higher fluorescence quantum yield and fluorescence lifetimes.

3. Polyfluorenes encapsulated into permodified cyclodextrin derivatives

FIGURE 3. The chemical structures of the polyrotaxanes PF·TM-bCD and PF·TM-gCD and its non-rotaxane PF counterpart

TM-βCD or TM-gCD encapsulations of PF backbones lead to distinct improvements in the solubility, molecular weights, film forming ability associated with enhancements of the transparency of the solid films and thermal stability. The optical investigations confirmed that the encapsulated compounds exhibited higher PL and fluorescence lifetimes. These complex architectures showed interesting electrochemical characteristics, which were consistent with optical and surface morphological results. The slightly lower ΔEg value for PF·TM-βCD was associated to the better charge injection between the polyrotaxane films and the electrode surfaces. In addition, HUMO/LUMO energy levels proved that all copolymers are electrochemically accessible in an electroluminescence configuration cell.