Wang Tao, Pearson Andrew J, Dunbar Alan D F, Staniec Paul A, Watters Darren C, Coles David, Yi Hunan, Iraqi Ahmed, Lidzey David G, Jones Richard A L
Department of Physics and Astronomy, University of Sheffield, UK.
Eur Phys J E Soft Matter. 2012 Dec;35(12):9807. doi: 10.1140/epje/i2012-12129-3. Epub 2012 Dec 14.
We report surface and interface effects in dynamics and chain conformation in the thin film of conjugated polymer PCDTBT. To probe dynamic anomalies, we measure the glass transition temperature (T(g)) of PCDTBT films as a function of thickness, and find that there is a significant depression in T(g) for films less than 100 nm thick; a result qualitatively similar to that observed in many other polymer film systems. However, for films less than 40 nm, the T(g) converges to a constant value of 20 K below its bulk value. Grazing incidence X-ray diffraction shows depth-dependent molecular organization that is associated with the unusual thickness-dependent dynamics.
我们报告了共轭聚合物聚[2,6-(4,4-双十二烷基-4H-环戊二烯并[2,1-b;3,4-b']二噻吩)-alt-4,7-(2,1,3-苯并噻二唑)]（PCDTBT）薄膜中动力学和链构象的表面和界面效应。为了探测动力学异常，我们测量了PCDTBT薄膜的玻璃化转变温度（T(g)）作为厚度的函数，发现对于厚度小于100nm的薄膜，T(g)有显著降低；这一结果在定性上与许多其他聚合物薄膜系统中观察到的相似。然而，对于厚度小于40nm的薄膜，T(g)收敛到比其本体值低20K的恒定值。掠入射X射线衍射显示了与不寻常的厚度依赖性动力学相关的深度依赖性分子排列。
