Experimental and modeling investigation of organic modified montmorillonite with octyl quaternary ammonium salt

Abstract

The sodium montmorillonite was organic modified with three kinds of quaternary ammonium salts containing 1 to 3 octyl chains, and then the organic montmorillonite was studied by FT-IR, XRD, and TG characterization as well as Monte Carlo simulations, to explore the influence of the number of octyl chains and the loading of intercalated cations on the basal spacing (d001) of the modified montmorillonite complexes. According to the distribution of intercalated quaternary ammonium cations and the energy change of the montmorillonite complexes, a reasonable explanation was given for the enlargement of the interlayer space. The results of experimental characterization and Monte Carlo simulations show that all the three intercalation agents can enlarge the interlayer space of montmorillonite complexes. The more the number of octyl chains in the salt, the more significant expanding effect on the interlayer space. The three intercalation cations exhibited a distribution arranged from mono-layered to multi-layered structure as the loading of intercalated cations increases.

An improved protection of alanine for atmospheric corrosion of mild steel using carbon dots-montmorillonite hybrid materials

“…In contrast to OMT, the XRD pattern of OMT-ALA shows double diffraction peak in Figure S1 (c). The peak of OMT-ALA near 6.89° can be attributed to the 002 reflection, indicating that the OMT-ALA becomes more crystalline due to the addition of ALA (Liu et al , 2022).…”

Multifunctional montmorillonite/polyhydroxy butyrate composites using surfactant structure modulation strategy for packaging applications

“…The hydroxyl (-OH) stretching vibration of the composite films at 3640 and 3430 cm À1 disappears. 18,[28][29][30] Among the nanocomposites, C18M7@PHB has the strongest peak intensity of C=O, demonstrating that OMMT has superior nucleation, with C18-OMMT having the greatest impact. Curve fitting and integration of the stretching vibrational area of hydrogen-bonded carbonyls in the infrared spectra can be used for semi-quantitative analysis of hydrogen-bonded carbonyls and free carbonyls (Figure 2E-H).…”

“…There exists a sharp peak at 1470 cm À1 corresponding to the bending vibration of the methylene (-CH 2 -) group and the significant peaks of OMMT at 2918 and 2851 cm À1 , respectively, indicate that the surfactant has penetrated the MMT interlayer. 18,27,28 As the number of alkyl groups increases and the modifier's chain length rises, the OMMT intensity in the methylene (-CH 2 -) group peaks improve (Figure 2A). The asymmetric stretching vibrational peaks of Al-O-Al and Si-O-Si were seen in the vicinity of 1097 and 1044 cm À1 , respectively, with little alterations in intensity and displacement.…”

“…The asymmetric stretching vibrational peaks of Al-O-Al and Si-O-Si were seen in the vicinity of 1097 and 1044 cm À1 , respectively, with little alterations in intensity and displacement. 18,[28][29][30] This suggests that the pristine MMT layers' structure is largely unaffected by the surface modifier's embedding. The presence of montmorillonite nanosheets and alkyl surfactants with varying chain lengths, bound together by potent van der Waals forces, is confirmed by these peaks.…”

“…Conversely, OMMT facilitates PHB nucleation and increases film crystallinity, and the hydrogen bonding between the two can facilitate adhesion at the interface, improve the material's mechanical characteristics, and decrease elongation at break. 13,19,28,40,42 The modification of surfactant resulted in altered layer spacing, a rise in matrix and filler compatibility, and a more notable improvement in mechanical properties. In contrast, MMT was less compatible with PHB and agglomerated in the PHB matrix, resulting in a less dense composite film structure.…”