Chen Jiao, Li Linling, Zhou Dongshan, Wang Xiaoliang, Xue Gi
Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of High Performance Polymer Materials and Technology (Nanjing University), Ministry of Education, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, People's Republic of China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Sep;92(3):032306. doi: 10.1103/PhysRevE.92.032306. Epub 2015 Sep 14.
The glass transition behavior of polystyrene (PS) nanotubes confined in cylindrical alumina nanopores was studied as a function of pore diameter (d) and polymer tube thickness (δ). Both the calorimetric glass transition temperature and the microstructure measured by a nonradiative energy transfer method indicated that the polymer nanotube, or concave polymer thin film, exhibited significant differences in vitrification behavior compared to the planar one. A closer interchain proximity and an increased T_{g} were observed for polymer nanotubes with respect to the bulk polymer. T_{g} for polymer nanotubes was primarily dependent on the curvature radius d of the template, while it was less dependent on the thickness δ of the PS tube wall in the range of 11-23 nm. For small nanotubes (d=55nm), the T_{g} increased as high as 18 °C above the bulk value. This vitrified property reverted back to the bulk value when the substrate was chemically removed, which indicated the crucial importance of the interfacial effect imposed by the hard wall with a concave geometry.
研究了限制在圆柱形氧化铝纳米孔中的聚苯乙烯（PS）纳米管的玻璃化转变行为与孔径（d）和聚合物管厚度（δ）的关系。量热玻璃化转变温度和通过非辐射能量转移方法测量的微观结构均表明，聚合物纳米管或凹面聚合物薄膜与平面聚合物薄膜相比，在玻璃化行为上表现出显著差异。相对于本体聚合物，观察到聚合物纳米管链间距离更近且玻璃化转变温度升高。聚合物纳米管的玻璃化转变温度主要取决于模板的曲率半径d，而在11 - 23 nm范围内，它对PS管壁厚度δ的依赖性较小。对于小纳米管（d = 55nm），玻璃化转变温度比本体值高出18°C。当化学去除基底时，这种玻璃化性质恢复到本体值，这表明具有凹面几何形状的硬壁所施加的界面效应至关重要。
