摘要：Molecular self-assembly of nylon-12 rods in self-organized nanoporous alumina cylinders with two different diameters (65 and 300 nm) is studied with transmission electron microscopy (TEM) and wide-angle X-raydiffraction (WAXD) in symmetrical reflection mode. In a rod with a 300 nmdiameter, the tendency of the hydrogen-bonding direction of a γ-form crystalparallel to the long axis of the rod is not clear because of weak two-dimensional confinement. In a rod with a diameter of 65 nm, the tendency of the hydrogen-bonding direction of a γ-form crystal parallel to the long axis of the rod is more distinct because of strong two-dimensional confinement. For the first time, selected-area electron diffraction (SAED) is applied in atransmission electron microscope to a polymer nanorod in order to determine the hydrogen-bonded sheet and lamellar orientations. Results of TEM–SAED and WAXD showed that the crystals within the rod possess the γ-form of nylon-12 and that the b axis (stem axis) of the γ-form crystals is perpendicular to the long axis of the rod. These results revealed that only lamellae with <h0l> directions are able to growinside the nanopores and the growth of lamellae with <hkl> (k≠0)directions is stopped owing to impingements against the cylinder walls. The dominant crystal growth direction of the 65 nm rod in stronger two-dimensional confinement is in between the [-201] and [001] directions due to the developmentof a hydrogenbonded sheet restricted along the long axis of the rod.
主讲人介绍：Dr. Cao obtained a master of polymer engineering at South China University of technology in 2003. In 2012, she was awarded Ph. D. of polymer physics(Adviser: Prof. Stephen Z. D. Cheng) at The University of Akron. During the period of 2012-2014, she went to Fukuoka, Japan and joined the Takahara ERATO project as a postdoc researcher at Kyushu University. In 2015, she joined the Institute of Advanced Study at Shenzhen University as an assistant professor (principle investigator).She is an expert in electron diffraction of transmission electron microscopy.She is engaged in establishing the lab of advanced structure and interface for new materials at Shenzhen University.
