Morphology Controllable Fabrication And Optical Property Of Nanocomposite Materials Based On NanoPAA Substrate

Nanomaterials have attracted researchers' prolonged enthusiasm due to their excellent characteristics.Nano porous anodic alumina?nanoPAA?,as a substrate for the preparation of nano-materials,has an orderly and controllable nano-porous array with stable physicalchemical properties,high temperature resistance and hardness,has become one of the preferred substrates for the preparation of nanomaterials.Nanomaterials prepared based on nanoPAA substrate have promising application prospects in luminescence,catalysis,bioinstrumentation,corrosion resistance and solar cells,etc.In this paper,the nanoPAA was prepared by the standard two-step anodic oxidation method,and the main influencing factors of its structure were studied,so as to realize the controllable adjustment of nanopores on nanoPAA.NanoPAA-Zn-Al LDH and nanoPAAZnO/ZnCl₂ composite materials were prepared on the basis of nanoPAA.The main factors affecting the morphology and structure of these composites were systematically studied.For the nanoPAA-Zn-Al LDH,the main influencing factors were as follows: the concentration of reactants?zinc acetate and hexamethylenetetramine?,the reaction working temperature and reaction time.With the change of concentration ratio between two reactants and the extension of reaction time,the morphology and structure of nanoPAA-Zn-Al LDH will change from flocculent structure to nano-flake structure to nano-flower structure.The optimum temperature is 60 ?.In addition,the relationship between morphology of nanoPAA-Zn-Al LDH and its photoluminescence?PL?property as well as surface fluorescence enhancement?SEF?effect were stuided,the optimal morphology corresponding to the maximum PL intensity and SEF enhanced factor were concluded,moreover,the mechanism of its PL and SEF were carefully explained.For the nanoPAAZnO/ZnCl₂,the main influencing factors of morphology and structure are: the pore diameter of substrate nanoPAA,the concentration of precursor ZnCl₂ solution,and the time required for growth.Among these factors,the growth time needs to reach 7 days,so that the ZnO/ZnCl₂ crystal can be grown.In addition,the pore diameter of substrate nanoPAA and the concentration of precursor ZnCl₂ solution all play a decisive role in the size of ZnO/ZnCl₂ nanosheet of nano-composite.The surface enhanced Raman scattering?SERS?property of nanoPAA-ZnO/ZnCl₂ composite was also researched,as a SERS substrate,the Raman spectrum of Rhodamine 6G?Rh6G?with concentration of 1*10-8 M can be accurately measured on the surface of nanoPAA-ZnO/ZnCl₂ composite.Furthermore,the self-maded reflection interference spectroscopy?RIFS?system is used to realize the nondestructive monitoring of the growth of nano-composite,and the large-area controllable preparation of the nanoPAA-ZnO/ZnCl₂ composite has been realized.The relationship between the wettability of nano-composite and its constructured morphology has been investigated systematically.By adjusting the length of ZnO/ZnCl₂ nano-flake,the superhydrophilic nanoPAA-ZnO/ZnCl₂ composite was obtained,its superhydrophilicity can be maintained for more than 50 days.In addition,the detailed process of water droplet spread on the surface of nanoPAA-ZnO/ZnCl₂ composite was studied by a high-speed camera,after fitted the spreading diameter and velocity of water droplet,and analyzed its force conditions,we present the cooperation effect of 3D capillary effect,true volume and inconsistency hight of nano-flake caused the durable superhydrophilicity of the nanoPAA-ZnO/ZnCl₂ composite.The two nanocomposites have practical prospects in the fields of luminescent materials,biomolecular sensing,water resource collection and microfluidic chips,respectively.