Synthesis Of Oriented Silicalite-1 Zeolite Films

Zeolite films, a kind of inorganic films developed in recent ten years, which have smalland uniform pores and the character of ion-exchengeable and Si/Al-adjustable, are wildlyused in fields of adsorption and separation, membrance reaction, chemical sensor, computerscience and space material. The straight channels of b-oriented Silicalite-1 zeolite films areperpendicular to the substrate surface, so when infiltration moleculars pass the channels ofb-oriented Silicalite-1, the distance is the shortest. Then b-oriented Silicalite-1 films haveexcellent character of adsorption and separation and are looked forward to obtaining.First, b-oriented Silicalite-1 zeolite films are synthesized on stainless steel and glass usingTPAOH as SDA. Effects of the crystallization conditions, pH values of the synthesis solution,contents of H₂O of the synthsis solution and substrates on the orientation of the zeolite filmshave been investigated. The optimized conditions is strong agitation, crystalling at 165℃for2 hours and n (TPAOH): n (TEOS): n (H₂O)=0.31:1:163.The roughness degree of the carrieraffects the oriention and the chemical character determined whether easily or not synthesisfilm on the carriers. Slick substrate is in favor of good orientation.Second, b-oriented Silicalite-1 zeolite films are synthesized on stainless steel and glassusing TPABr as SDA. The optimized conditions is crystalling at 165℃for 24 hours andn(TPABr) :n(SiO₂) : n(C₂H₇NO):n(H₂O)=0.33 :1:5.8 :33. Synthesis of oriented Silicalite-1film with TPABr is slower and worse oriented than synthesis with TPAOH, but TPABr ischeaper than TPAOH, so synthesis of oriented Silicalite-1 film with TPABr as SDA is easierto be use in industry.At last, b-oriented Silicalite-1 zeolite films are synthesized on glass and quartz glass withseed method. As far as seed method concerned, the quality of the seed layer determined thequality of the film. Continuous and oriented seed layer is beneficial for the orientation of thefilm. The chemical character of the substrates doesn't affect the orientation of the film. Seedmethod is good method for synthesis of oriented film on quartz glass and poroussubstrates.This result has great significance to our next research on chemical sensor.