Raman spectroscopy at temperatures between 298 and 423 K and at 77 K of kaolinites intercalated with formamide

✍ Scribed by Ray L. Frost; Willis Forsling; Allan Holmgren; J. Theo Kloprogge; Janos Kristof

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 117 KB
• Volume: 29
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(199812)29:12<1065::aid-jrs318>3.0.co;2-e

✦ Synopsis

Raman spectra of kaolinite and of the formamide-intercalated kaolinite were obtained at both 298 and 77 K using a Raman microprobe equipped with a thermal stage. Upon cooling to 77 K, the band attributed to the inner hydroxyl shifts by 5 cm-1 to lower wavenumbers and the bands assigned to the inner surface hydroxyls move to higher wavenumbers. Upon intercalation of the kaolinite with formamide, an additional Raman band attributed to the formation of a hydrogen-bonded complex between the inner surface hydroxyls and the carbonyl group of the formamide is observed at 3627 cm-1 at 298 K and at 3631 cm-1 at 77 K. Raman spectra of the deintercalation of the formamide-intercalated kaolinite are obtained by using the thermal stage to heat the intercalated kaolinite in situ. A decrease in intensity of the bands formed through intercalation and at the same time an increase in intensity of the inner surface hydroxyl bands are observed. A loss of intensity of the low-wavenumber region of the formamide-intercalated kaolinite is also observed.