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The preparation process of zirconia mesoporous membranes on porous stainless substrate(PSS)and amorphous nickel deposites by electroless plating process with palladium-free activation on zirconia mesoporous membanes as well as the mircostrure of the composite membranes were investigated in this dissertation.After characteraztion of the phase in mesoporous zirconia membrane, microstructure,pore distribution and diameters ,the processing parameters involved were studied. The micros tructure of the amorphous nickel membrane, crystallization temperature were also characterized. The palaldium-free activation process was optimized.This dissertation was mainly discussed as follows:Zirconia mesoporous membrane was prepared by sol-gel process.The reaction mechanism, aging time,drying regime,organic additives,pore evolution during annealing, crystal size, pore distributionpore diameters,phase evolution were analyzed. Through stiring and heating,highly dispersed sol was prepared.Crackless membrane on porous stainless substrate(PSS)with pore diameters about 0.5μm was deposited by dip-coating after introduction of drying inhibitor ,film promotor ,combined with proper drying regime.The as-prepared 8YSZ membrane has pores with pore size of several nanometers and high porosity.Differential thermal analysis (DSC)and X-ray Diffraction(XRD),SEM,TEM results show that zirconia membrans produced by this method can transformed into nanocrystalline with cubic phase at the temperature about 300℃.It was founded that the pore formation mechanisim was as follows:1.first , Zirconium oxychloride hydrolysised into zirconia hydroxide and zirconia hydroxide condensed into small particals.2.small particals connected with each other by condesation and small pores within several nanometers was formed.3. after aging, small particlas gatherd together and transformed into big particals.The big particals also interacted with each other by condesation to form big pores with pore size.4.during heating treatment,the hydrolyzed particles crystalize into nanocrystalline. The water additon, PEG volume in sols, aging time and heat treat- ment temperature determined the surface morphology, pore size and porosity.Using nickel chloride as raw material, Sodium hypophosphite as reducing agent, sodium citrate as buffering agent,adjusting the PH value of the plating bath,plating time,and sensitized the substrate by cheap nickel chloride solution, amorphous membrane on porous ceramic substrate was fabricated . XRD and DSC were used to characterize the crystallization temperature of amorphous nickel membrane.Using nickel chloride as raw material, Sodium hypophosphite as reducing agent, sodium citrate as buffering agent,adjusting the PH value of the plating bath,plating time,and activating the substrates by cheap nickel chloride solution, amorphous membrane on porous substrate was fabricated.XRD and SEM were used to characterize the phase of amorphous nickel membrane,the crystallization temperature and the surface morphology.The results show that nickel(0) particles on the surface can activate secondary nucleation and then grow only when enough nickle nuclei exist.Also,only enough amount of nickle nuclei can ensure the fabrication of completely covered membrane.After addition of surfactant DMF,the wetting property of activation solution was improved largely. The aboundance of nickel(0) particles after activation on the surface of substrate successfully initiated the electroless plating process.
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