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 Univ