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The nanocomposites current research in the field of materials, wide range of applications in the field of catalytic, optical, electrochemical. Supercritical fluid deposition technique is an effective way of metal particles in the nanoscale pores of mesoporous substrate load. In this paper, mesoporous silica as the substrate, the deposition of metal nanoparticles in the pore. Paper composites influencing factors, mechanism of preparing, during the preparation of the thermodynamics and kinetics problems. Main work and the results are as follows: (1) In the KIT-6 as the substrate, AgNO3 as precursor, the supercritical CO 2 for the solvent, ethanol, ethylene glycol doing a co-solvent, in the 20-24MPa, 50 ℃ under the conditions of preparation nanocomposite by Ag/KIT-6. It was found that the Ag deposition within the bore in KIT-6 can be realized in the amount of ethanol and ethylene glycol, respectively, 3mL (3.59mol%) and 0.5 ml (0.6 mol%), 3h. Ag in Ag/KIT-6 composite material exists in the form of metal particles, the average particle diameter of about 5.3nm, and uniformly dispersed in the pores of KIT-6. (2) changing the deposition time the metal loadings gradually increases with time until adsorption equilibrium is reached, the loading amount does not change; changing the mass ratio of the substrate and the precursor was found that the greater the mass of the precursor, the same under the deposition conditions, the greater the amount of metal loading in a ratio 1:1, the loading amount of up to 26.3wt%. Repeated experiments and found that the application SCFD prepared Ag/KIT-6 nanocomposites good repeatability. (3) SBA-15 as the substrate, HAuCl4 · 4H2O as precursor, ethanol, ethylene glycol as a co-solvent, prepared under the conditions of 50 ° C, 20-24MPa Au/SBA-15 nanocomposites. It was also found that, when in water, ethanol co-solvent may also be deposited in channels of SBA-15 Au, the form of particles or nanowires; larger metal loadings can be obtained in the case of a smaller concentration of the precursor. Application ethanol, ethylene glycol to do a co-solvent, 0.5h can be deposited Au/SBA-15 composite materials. Au in the composite material in the form of nanowires and nanoparticles exist more evenly dispersed in the pores of SBA-15, the average diameter of the nanowires is 5.8nm, the nano-particle size of 5-6nm. (4) in the case of the same guarantee scCO2 density at 35 ° C, 50 ° C, 60 ° C under enough for a long time, the determination of different concentrations composite metal loadings. It was found that under the same conditions of concentration, low temperature metal loadings higher temperature; the same temperature increases with the concentration of the precursor, the loading amount increases. Experimental data applications Langmuir model, modified Langmuir model, Freundlich model association. (5) the establishment of the adsorption model, SCFD process dynamics simulations. It was found that adsorption equilibrium time of Cu (NO3) 2 2000-3000s AgNO3 about 10000s, consistent with the experimental results. Simulation, Langmuir and modified Langmuir model of adsorption equilibrium concentration or less, the equilibrium concentration of the modified Langmuir model than the Langmuir model, can be a good description of the experimental data.
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