| 초록 |
Amphiphilic copolymers composed of poly(styrene-b-butadiene-b-styrene) (SBS) backbone and poly(oxyethylene methacrylate) (POEM) side chains were synthesized via free radical polymerization. The SBS-g-POEM copolymers were used as structure directing agent and mixed with hydrophilically preformed TiO2 (Pre-TiO2). The organized mesoporous TiO2 (Meso-TiO2) films result from self-assembly of SBS-g-POEM. To investigate the effect of side chain length on TiO2 structure, SBS-g-POEM with different numbers of ethylene oxide repeating units, SBS-g-POEM (500) and SBS-g-POEM (950) were used to make Meso-TiO2 films. The effect of polymer side chain length on Meso-TiO2 properties was investigated in detail using field-emission scanning electron microscope (FE-SEM), ultraviolet (UV)-visible reflectance spectroscopy, and N2 adsorption-desorption measurements. The efficiencies of dye-sensitized solar cells with using Meso-TiO2 (500, 950) was 5.7% and 5.8% at 100 mW/cm2, respectively, which was much higher than one (4.8%) with randomly-organized TiO2. |
