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BIBTEX RIS

Esfoliação e hidratação da caulinita após intercalação com uréia

2001; Brazilian Chemical Society; Volume: 24; Issue: 6 Linguagem: Inglês

10.1590/s0100-40422001000600010

ISSN

1678-7064

Autores

José Eduardo Ferreira da Costa Gardolinski, Fernando Wypych, Maurício Pereira Cantão,

Tópico(s)

Iron oxide chemistry and applications

Resumo

EXFOLIATION AND HYDRATION OF KAOLINITE AFTER INTERCALATION WITH UREA.Wellordered Georgia kaolinite (Kga-1b) obtained from the source Clay Repository of the Clay Minerals Society (USA) was intercalated with urea using grinding procedures.To achieve complete intercalation 20% of urea (in weight) was used, producing Al 2 Si 2 O 5 (OH) 4 (N 2 H 4 CO) 0,86 with an interplanar basal spacing of 1,08nm.After washing with water under ultrasound stirring at 363K, urea was completely removed and kaolinite was partially exfoliated.After drying under air, the material was converted to hydrated kaolinite with the composition Al 2 Si 2 O 5 (OH) 4 (H 2 O) 0,64 and an interplanar basal spacing of 0,84nm.In this compound, water molecules positioned between the layers of the silicate can be removed after calcination at 573K, regenerating structurally disordered kaolinite.

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