Research articles

In the present work, we demonstrated that the amount of both donor and acceptor materials in the fabrication of BHJ OPVs could be strongly reduced using a high viscosity P3HT solution with the M_w of 680 900. In addition, only slight fluctuations were observed in PCEs of around 3.8% for all OPVs based on P3HT for M_w ranging from 46 600 to 680 900.

When O-(4-acyloxyanilinocarbonylmethyl)-4-tert-butylcalix[8]arene films were irradiated for 60 min with 254-nm UV light from a low-pressure mercury lamp, the calixarene derivative 1 underwent a highly selective photo-Fries rearrangement in the film state to yield the corresponding Fries-rearranged product 2 along with a minor amount of the fragmentation product 3. This photochemical rearrangement enhanced the refractive index of the films by as much as 0.015.

Styrene and methyl methacrylate diblock copolymers were synthesized by sequential living anionic polymerization, and the fractal-like hierarchical micro-/ nano-rough structures of the copolymer surfaces with superhydrophobicity were prepared by using phase separation method. When the ethanol content in the mixed solvents was 60%, the copolymer surfaces with water contact angle (WCA) of 156.7° and low contact angle hysteresis (7.1°) was obtained. The copolymer surfaces had excellent self-cleaning ability.

Ion-conductive behavior of a novel polymer electrolyte without oxyethylene units, poly(ethylene carbonate) (PEC)-Li salt system, was reported. Salt-concentration dependence revealed that the LiCF₃SO₃ and LiClO₄ electrolytes exhibit typical polyether-like conduction behavior. However, the LiBETI, LiBF₄ and LiTFSI electrolytes were much different, and the conductivity increased and T_g decreased with increasing salt concentration. This behavior of salt-rich PEC electrolytes relates to the ‘polymer-in-salt’ system. Li⁺ transference number of PEC-LiBF₄ (44.4 wt%) electrolyte was measured, and the value was estimated to be ∼0.5 at 100 ^oC.

The microscopic structures and electrical properties of regioregular poly(3-hexylthiophene) (P3HT) nanofibers embedded in a poly(methyl-methacrylate) film as an insulating intermediate by means of whisker method has been investigated using the Kelvin probe force microscopy. This study demonstrated that the conducting P3HT nanofibers formed a three-dimensional network with electrical connections, which had a significant influence on the electrical properties of the polymer films as conduction pathways.

Copolymerization of polydimethylsiloxane (PDMS) macromer having two molecular weight (M_n), two types of methacrylate and crosslinker was conducted. The crosslinked copolymer was analyzed with ¹³C solid-state NMR to investigate the relationship between copolymers compositions and physical properies by molecular level approach. The T₁^H, T_1ρ^H, and T_1ρ^c values suggested the influence of PDMS M_n and methacrylate type on microstructure, mobility, and morphology change. Thus the present analysis contributes to a better understanding of the physical characteristics on the crosslinked methacrylates-siloxane copolymers.