Síntese de membranas cerâmicas via método sol-gel utilizando TEOS e N,N-dimetilformamida

Química Nova

Rúbia Francisca Silva Lenza¹  Wander Luiz Vasconcelos¹ 

[1] ,Universidade Federal de Minas Gerais Departamento de Engenharia Metalúrgica e de Materiais Belo Horizonte MG

关键词: sol-gel;    membrane;    N;    N-dimethylformamide;   

DOI  :  10.1590/S0100-40422002000600002

来源: SciELO

【 摘 要 】

In this work we obtained microporous and mesoporous silica membranes by sol-gel processing. Tetraethylortosilicate (TEOS) was used as precursor. Nitric acid was used as catalyst. In order to study the affect of N,N-dimethylformamide (NDF) as drying additive, we used a molar ratio TEOS/NDF of 1/3. The performance of N,N-dimethylformamide was evaluated through monolithicity measurements. The structural evolutions occurring during the sol-gel transition and in the interconnected network of the membranes during thermal treatment were monitored by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses and nitrogen sorption. We noted that in the presence of N,N-dimethylformamide, polymerization goes through a temporary stabilization of oligomers. The Si-O(H) bonds are stronger and belong to a more cross-linked structure for the N,N-dimethylformamide containing sol. The membranes obtained in the presence of N,N-dimethylformamide have larger surface area and its pore structure is in the range of mesoporous. The membranes obtained without additive have pore structure in the range of microporous.

【 授权许可】

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