INTERLAMELLAR AMINO FUNCTIONALIZATION OF KAOLINITE

The interlamellar surface of kaolinite has been modified with molecule s possessing amino functionalities. Either the dimethyl sulfoxide inte rcalate of kaolinite (Kao/DMSO) or the N-methylformamide intercalate o f kaolinite (Kao/NMF) were used as starting materials. One of the prod ucts, an ethanolamine functionalized kaolinite (Kao-EOA) was resistant to thermal decomposition in both air and N-2 atmospheres up to temper atures greater than 150 degrees C. Based on results from thermal analy sis, IR analysis, C-13 CP/MAS NMR spectroscopy, and elemental analysis , a structural model is proposed in which every third interlayer surfa ce hydroxyl group on the aluminol (Al-OH) surface of kaolinite is eith er replaced with an interlayer Al-OCH2CH2NH2 group or is strongly H-bo nded to an aminoalcohol molecule. A mixture of both types of linkages could coexist. The amino groups that point away from this surface are each keyed into the -(SiO-)(6) macro-rings of the adjacent silicate su rface, resulting in an amino-functionalized ordered two-dimensional or gano-mineral assembly.