Organic Steric Entrapment

SOFC POWDER SYNTHESIS BY THE ORGANIC STERIC ENTRAPMENT METHOD... 

Abstract The organic steric entrapment was used to synthesize homogeneous powders... 

Keywords Oxide Powder Synthesis/Organic Steric Entrapment/Doped Lanthanum... 

The concept of organic steric entrapment was the focus of this work and can be divided into three categories the aqueous polyvinyl alchohol (PVA) method, the non-aqueous ethylene glycol (EG) or polyethylene (PEG) method and the nano-sol modified, PVA method. The method of organic steric entrapment was developed in our laboratory over the past 10 years and has resulted in numerous publications [1-16]. 

Figure 1. Flow chart for mixed oxide powder synthesis by the organic, steric entrapment...

Rosczyk B.R., Kriven W.M., Mason T.O., Solid oxide fuel cell materials synthesized by an organic steric entrapment method, 2003, V.24, N.3, p.287-292. 

For the synthesis of LSGM, two different synthesis concepts were applied. In both routes, nitrate salts of each constituent cation were selected as the cation source. PVA ( Steric entrapment method14), CA, TA, EDTA, or Pechini precursors (with 60% CA - 40% and EG, or 90% CA - 10% EG mixtures) were used as the organic carrier materials in solution. In the synthesis of LSGM with EDTA as the carrier material, nitric acid was the solvent. In the second production route, nitrate salt of each constituent cation was dissolved in distilled water without any organic molecule. 

THE ORGANIC-INORGANIC STERIC ENTRAPMENT METHOD OF POWDER SYNTHESIS... 

Using steric entrapment, solid oxide fuel cell materials were successfully produced by an aqueous synthesis method. The powders were more homogeneous and required lower processing temperatures than did powders made by more conventional methods. Properties of the powder and sintered microstructures were comparable with those properties attained using more complex methods such as sol-gel and with less organics than methods such as the glycine-nitrate method. Further work is needed to fully optimize the PVA to cation ratio to produce the most favorable powder characteristics. 

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