Plasma Chemical Functionalisation of a Cameroonian Kaolinite Clay for a Greater Hydrophilicity

• Published in: Plasma chemistry and plasma processing Vol. 36; no. 6; pp. 1449 - 1469
• Main Authors: Sop Tamo, B., Kamgang-Youbi, G., Acayanka, E., Medjo Simo, L., Tiya-Djowe, A., Kuete-Saa, D., Laminsi, S., Tchadjie, L.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2016; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Classical Mechanics; Functional groups; Infrared spectroscopy; Inorganic Chemistry; Kaolinite; Mechanical Engineering; Original Paper; Spatial post-discharge; Gliding arc plasma; Kaolinite clay; Hydroxyl groups
• ISSN: 0272-4324; 1572-8986
• DOI: 10.1007/s11090-016-9731-4

A Cameroonian kaolinite powder was treated with gliding arc plasma in order to increase the amount of hydroxyl functional groups present on its external surfaces. The functional changes that occurred were monitored by Fourier transform infrared spectroscopy. The crystalline changes were followed by the X-ray diffraction. The ionisation effect, acid effect, and water solubility of the treated samples were also evaluated. Results showed that there is breaking of the bonds in the Si–O–Si and Si–O–Al groups, followed by the formation of new aluminol (Al–OH) and silanol (Si–OH) groups at the external surface of kaolinite after exposing the clay to the gliding arc plasma. The increase in hydroxyl groups on the surface of kaolinite leads to the increase of its hydrophilicity. Moreover, new charges appear on its surfaces and no significant change in crystallinity has occurred. This study shows that clays in powder form being can effectively be functionalised by gliding arc plasma in spatial post discharge processing mode. Knowing that the treatment in spatial post discharge offers the possibility to process large amounts of clay, this work is of great interest to the industry.