Covalent grafting of pyridine-2-methanol into kaolinite layers

New insights into the molecular structure of kaolinite–methanol intercalation complexes

“…It is expected that during the filling of capillaries used for X-ray diffraction studies, both Kaol and intercalated phases will align along the c-axis due to their plate-like particle shapes (White et al, 2011). The intercalation of Kaol with DMSO, NMF, or U expands the structure along the c-axis, resulting in the dominant (001) reflection appearing at 11.2, 10.7, and 10.9 Å respectively, in agreement with previous XRD investigations on Kaol intercalation complexes (Lapides and Yariv, 2009;Li et al, 2009;Mako et al, 2009;Rutkai et al, 2009;Tonle et al, 2009;Hirsemann et al, 2011;Cheng et al, 2012b;Matusik et al, 2012a;Caglar et al, 2013). When Kaol-DMSO was used as an intermediate, a reflection at 11.2 Å was observed, indicative of the DMSO intercalation into the interlamellar spaces of Kaol (Elbokl and Detellier, 2009).…”

“…Upon intercalation of NMF molecules, bands were observed at 3678 and 3419 cm −1 and are assigned to hydrogen-bonded OH stretching and NH stretching, respectively. The band at 3419 cm −1 originates from the formation of hydrogen bonds between NMF and the inner-surface hydroxyl groups of Kaol (Caglar et al, 2013). After displacement intercalation of Kaol-NMF with Me, the above two bands are no longer observed, and a band at 3550 cm −1 is detected.…”

“…Kaolinite (Kaol) intercalation and its applications for polymer-based functional composites have attracted great interest, both in industry and in academia, because these materials frequently exhibit remarkable improvements in desired properties as compared to the virgin polymer or conventional micro and macro-composites (Frost et al, , 2004Gardolinski and Lagaly, 2005;Jia et al, 2008;Detellier and Letaief, 2013). A variety of inorganic and organic species can be used for the intercalation of the interlayer spaces of Kaol, including formamide (Churchman et al, 1984;Joussein et al, 2007), dimethylsulfoxide (DMSO) (Costanzo and Giese, 1986), methanol (Me) (Komori et al, 1999;Kuroda et al, 2011;Caglar et al, 2013), urea (U) (Nicolini et al, 2009), potassium acetate (Frost et al, 2000a;Cheng et al, 2010Cheng et al, , 2011Cheng et al, , 2012a, aniline (Luca and Thomson, 2000), and hydrazine . The intercalation of the small molecules into the interlamellar spaces of Kaol causes an increase in the basal spacing from 7.2 Å to 14.2 Å and can be used as a preliminary expansion step permitting insertion of large-sized, non-reactive molecules by displacement intercalation methods.…”

Thermal decomposition behavior and de-intercalation kinetics of kaolinite/quaternary ammonium salt complexes

“…Upon intercalation of NMF molecules, bands were observed at 3678 and 3419 cm -1 and are assigned to hydrogen-bonded OH stretching and NH stretching, respectively (not show). It was reported by Caglar et al that the band at 3419 cm -1 originates from the formation of hydrogen bonds between NMF and the inner surface hydroxyl groups of Kaol [29]. After displacement of NMF by Me, the disappearance of the two bands at 3538 and 3503 cm -1 and the appearance of two bands at 3600 and 3550 cm -1 were observed.…”

“…However, it was reported by Komori and Sugahara [23] that when Kaol-NMF was treated with Me, the d-spacing slightly increased to 1.11 nm, with this value obtained only when the sample was stored under wet conditions with Me. Furthermore, the paper of Matusik et al [26] was the only investigation to propose that two types of Me molecule arrangements existed in the Kaol interlayer space in the wet state: (1) Me molecules grafted to an octahedral sheet in the form of a methoxy group (Al-O-C bond); and (2) mobile Me and/or water molecules kept in the interlayer space via hydrogen bonds that can be partially removed during drying [27][28][29][30]. Therefore, these results indicate that the resulting Kaol-Me made from Kaol-NMF in the wet state as the starting material is inherently unstable.…”