Treger Jeremy S, Ma Vincent Y, Gao Yuan, Wang Chun-Chih, Wang Hsing-Lin, Johal Malkiat S
Department of Chemistry, Pomona College, 645 N. College Avenue, Claremont, California 91711, USA.
J Phys Chem B. 2008 Jan 24;112(3):760-3. doi: 10.1021/jp0767765. Epub 2008 Jan 3.
In this work, we investigate the emission and absorbance properties of the novel water-soluble cationic conjugated polymer poly{2,5-bis[3-(N,N,N-triethylammonium bromide)-1-oxapropyl]-1,4-phenylenevinylene}, denoted here as P2, in the presence of varying amounts of the anionic surfactant sodium dodecylsulfate (SDS). We show that the absolute photoluminescence quantum efficiency (PLQE), the absorption wavelength, and the emission wavelength of an aqueous solution of P2 can be adjusted according to the surfactant/polymer ratio in aqueous solution. In particular, we show that the addition of SDS to P2 increases the polyelectrolyte's PLQE to approximately 40%. An observed red shift in the emission spectra upon addition of the surfactant is attributed to the reduction in electrostatic repulsive interactions between side chains that minimize the benzene ring twisting along the backbone structure. At the surfactant's critical micelle concentration, the P2 chains wrap around the outer surface of the SDS micelles. This work has implications on the development of new stable poly(p-phenylenevinylene)-based photovoltaic and electroluminescent materials with tunable optical properties.
在本研究中，我们研究了新型水溶性阳离子共轭聚合物聚{2,5-双[3-(N,N,N-三乙铵溴化物)-1-氧杂丙基]-1,4-亚苯基亚乙烯基}（此处记为P2）在不同量的阴离子表面活性剂十二烷基硫酸钠（SDS）存在下的发射和吸收特性。我们表明，P2水溶液的绝对光致发光量子效率（PLQE）、吸收波长和发射波长可根据水溶液中的表面活性剂/聚合物比例进行调节。特别地，我们表明向P2中添加SDS可使聚电解质的PLQE提高到约40%。添加表面活性剂后发射光谱中观察到的红移归因于侧链之间静电排斥相互作用的降低，这使沿主链结构的苯环扭曲最小化。在表面活性剂的临界胶束浓度下，P2链缠绕在SDS胶束的外表面。这项工作对开发具有可调光学性质的新型稳定聚对苯撑乙烯基类光伏和电致发光材料具有重要意义。
