Vapor-phase transfer synthesis

The vapor-phase transfer (VPT) synthesis method consists of two steps covering the support with a synthesis gel and crystallization of the dried gel in saturated steam at a similar temperature or a mixture of steam and a structure-directing agent (SDA) under autogenous pressure [22-24]. Since one of the nutrient sources is limited to the support surface, zeolite membrane formation will be limited to the support surface. With this method, the membrane thickness can be well controlled since the amount of nutrient for growing zeolite is controlled directly by the amount of gel applied. However, the crystals produced are most likely randomly oriented. Furthermore, since the density of gel is much lower than that of zeolite crystals, the crystallization process... 

The approaches used for preparation of inorganic nanomaterials can be divided into two broad categories solution-phase colloidal synthesis and gas-phase synthesis. Metal and semiconductor nanoparticles are usually synthesized via solution-phase colloidal techniques,4,913 whereas high-temperature gas-phase processes like chemical vapor deposition (CVD), pulsed laser deposition (PLD), and vapor transfer are widely used for synthesis of high-quality semiconductor nanowires and carbon nanotubes.6,7 Such division reflects only the current research bias, as promising routes to metallic nanoparticles are also available based on vapor condensation14 and colloidal syntheses of high-quality semiconductor nanowires.15... 

Syngas (typically a mixture of CO, H, and CO ) reacts over the active catalyst (Cu/Zn/AljOj) dispersed in an inert oil medium. This process offers considerable advantages over the conventional vapor phase synthesis of methanol in the areas of heat transfer, exothermicity, and selectivity toward methanol. However, this process suffers from the drawback that the methanol synthesis reaction is a thermodynamically governed equilibrium reaction. 

The synthesis of methanol from carbon monoxide and hydrogen is carried out in a continuous vapor-phase reactor at 5.00 atm absolute. The feed contains CO and H2 in stoichiometric proportion and enters the reactor at 25 C and 5.00 atm at a rate of 17.1 m /h. The product stream emerges from the reactor at 127 C. The rate of heat transfer from the reactor is 17.05 kW. Calculate the fractional conversion achieved and the volumetric flow rate (m /h)of the product stream. (See Example 9.5-4.)... 

Method of synthesis polymer In final form cannot be processed, therefore precursor polymer Is synthesized first and then converted into film or the final forms. Precursor polymer can be obtained by one of the following methods Wessling route, ring opening polymerization, chemical vapor deposition, electropolymerization, condensation, phase transfer catalysis, or anionic polymerization Rnk, J K, High Performance Polymers, William Andrew, 2008. 

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