The Research Of Zinc-based Aerogels

Aerogels are the one characterized by high surface area, large porosity and low density materials, consisting of three dimensional network solids with interconnected nanoscale pores. The inherent characteristics of aerogels have been widely applied, such as thermal insulators, heterogeneous catalysis, energy, space and capacitors. To the best of our knowledge, the preparations and applications of monolithic Zn-based aerogels are not studied in depth. Therefore, it is a state-of-art way to prepare Zn-based aerogels with the dispersed inorganic sol-gel method, and the aerogels have subsequent thermal and reduction treatments. The properties of the zinc-based aerogel, such as the density and surface area, are related to the amounts of catalyst, water and polyacrylic acid (PAA) in sol-gel process. The proper molar ratios between these reactants play a crucial factor in mediating the morphology of the zinc-based aerogel. The viscosities of colloidal systemsis are discussed using a rheometer, while the elastic modulus and the viscous modulus are demonstrated in the sol-gel process. With regard to the temperature in different atmospheres, it was an integrated result of the complicated decomposition of organic compounds and the preparation of the zinc oxide aerogel. The innovation demonstrates a zinc template method to prepare carbon aerogel through thermal treatment in CO. The unusual preparation of carbon aerogel was promising for advanced nanodevices because of its outstanding nanoscale porosity structures.As far as we know, this is a novel report on producing the Zn-based aerogels through the polyacrylic acid and citric acid template method. Furthermore, the aerogels are difference owing to the long or short molecular chains of the templates. This paper offers an explicit explanation on the microstructure and surface area of the Zn-based aerogels under the influence of ZnCl2and the molecular chains of the templates. The N2adsorption/desorption of the Zn-based aerogel which the molar ratio of PAA to ZnCl2is1:40has a high surface area about470m2/g and pore volume about1.846cm3/g, and the field-emission scanning electron microscope (FESEM) demonstrates the aerogel possesses the typical characteristic mesopore. Additionly, The N2adsorption/desorption of the Zn-based aerogel which is prepared with ZnCl2and citric acid has a surface area about54m2/g and pore volume about0.126cm3/g, and the characteristic mesopore is compact with FESEM measurement.The gelation mechanism of sol-gel process is discussed in the present dissertation, such as the value of water, propylene oxide (PO), and PAA of the system in gelation process. Therefore, the properties of the zinc-based aerogel of the density and surface area are studied that they are related to the amounts of water, PO, and PAA in sol-gel process. The viscosities of the reaction system are discussed using a rheometer, and the elastic modulus and the viscous modulus are measured the different amounts of water, PO, and PAA in the gelation. Molecular dynamics method to build different molecular weight PAA in ethanol solution model, while the model simulation of the ethanol solution of different concentrations of polyacrylic acid. Solution model the radius of gyration (Rg) is determined by external conditions affect different model polyacrylic acid. While the radial distribution function g(r) is calculated and found carbonyl O and on the hydroxyl group of O, and ethanol H of PAA, there are strong hydrogen bonding interactions, there is also has a strong van der Waals mutual role.As a result, the molecular weight of1800PAA is adapted to the Zn-based aerogel template, and its concentration controlled0.11g·mL"1is more reasonable.Monolithic pure zinc oxide aerogel was prepared successfully through the dispersed inorganic sol-gel method (DIS method) combined with a furnace of500℃in mixed atmosphere which the molar ratio of N2to O2is50:1. The aerogel exhibited many desirable properties, such as uniform nanoscale pores, high porosity and large specific surface area. The N2adsorption/desorption of the aerogel has a high surface area about125m2/g and pore volume about0.25cm3/g, and FESEM demonstrates the typical characteristic mesopore. It is an integrated result of the hexagonal system of the zinc oxide aerogel, and its crystalline structure is refined with Rietveld structure refinement. After being annealed at different temperatures, the photoluminescence (PL) spectra of the aerogel were measured. The PL with no temperature-dependent shifts of the maximum of the spectral PL intensity concerning the zinc oxide aerogel being investigated suggests that it is relative to the structural and optical properties.The innovation of a zinc template method is the preparation of carbon aerogel through thermal treatment in CO. As a result, the measurements of XPS and EDS confirm only the presence of C atoms. This paper offers an explicit explanation on the microstructure and surface area of carbon aerogels under the amount influence of ZnCl2and PAA. In summary, carbon oxide aerogel of high specific surface area (1560m2/g), continuous porosity, narrow particle size distribution and excellent crystallinity is successfully prepared with zinc salt and PAA. As far as we know, this is a novel report on producing carbon aerogel through the metal template method. Our work, surely, is able to provide a simple and metal tempale method for designing new porous carbon aerogel nanoarchitectures, which is promising for a wide range of future applications.