From platy kaolinite to aluminosilicate nanoroll via one-step delamination of kaolinite: Effect of the temperature of intercalation

Characterization of kaolinite-cetyltrimethylammonium chloride intercalation complex synthesized through eco-friend kaolinite-urea pre-intercalation complex

“…In the XRD pattern of ZK-UMe(wet), the complete displacement of U with Me and the formation of wet kaolinite-Me complex is clearly demonstrated by the shift of the whole (001) reflection from 1.07 nm to 1.11 nm [41]. The 1.11-nm basal spacing of the wet kaolinite-Me intercalation complex synthesized using the kaolinite-U pre-intercalation complex agrees well with the literature results with kaolinite-DMSO and kaolinite-NMF pre-intercalates [10,12,15,19,29,30,[33][34][35][36]41]. After drying the wet kaolinite-Me complexes at room temperature, the (001) reflections of the expanded phase decreased to 0.86 nm (ZK-U-Me(air-dry) sample), which is close to the value (d 001 = 0.88 nm) reported by Cheng et al [38] for similar air-dried complex prepared from kaolinite-U pre-intercalate.…”

“…The kaolinite-CTAC complex was prepared according to Yuan et al [35]. 1.0 g of ZK-U-Me(wet) sample was added into 40 cm 3 of Me based solution of CTAC (1 M) and stirred at 80 °C for 24 h. Then the solid part was separated by centrifugation.…”

“…Using elemental and thermal analysis results, Tunney and Detellier [7], Komori et al [15], and Matusik and Klapyta [36] calculated the values of x=0.87, x=0.36, and x=0.48, respectively, for the supposed chemical formula of In spite of the more eco-friendly behavior of U, there are only two studies reported in the literature [34,41], where the kaolinite-U pre-intercalate was used to synthesize kaoliniteMe complexes. In our previous work with U [41], we obtained the same methanol-wet state (with the basal spacing of 1.12 nm) as prepared earlier in the literature using the kaolinite-DMSO and kaolinite-NMF pre-intercalates [10,12,15,19,29,30,[33][34][35][36]. However, the drying of our methanol-wet complex leaded to a somewhat different methoxylated kaolinite structure with x=0.3, which was far below the theoretical upper limit ratio of methoxy functionalization (x=1) of the inner surfaces.…”

“…From the DMSO and NMF pre-intercalates, the formation of a kaolinite-Me complex with basal spacing of 1.11-1.13 nm was established in methanol-wet state [10,12,15,19,29,30,[33][34][35][36]41], but on air-drying, a contraction down to 0.93-0.86 nm was observed [12,15,19,38,41]. Using elemental and thermal analysis results, Tunney and Detellier [7], Komori et al [15], and Matusik and Klapyta [36] calculated the values of x=0.87, x=0.36, and x=0.48, respectively, for the supposed chemical formula of In spite of the more eco-friendly behavior of U, there are only two studies reported in the literature [34,41], where the kaolinite-U pre-intercalate was used to synthesize kaoliniteMe complexes.…”

“…The preparation of these nanocomposites is usually carried out through multiple intercalations, where the natural platy kaolinite could transform from nanoplates into halloysite-like nanoscorolls. A promising exfoliation method for synthesizing kaolinite nanoscrolls involves the intercalation of cetyltrimethylammonium chloride (CTAC) into a kaolinite-methanol (kaolinite-Me) complex prepared from kaolinite-DMSO or kaolinite-NMF pre-intercalate [19,29,30,34,35,40].…”