Chemically Specific Multiscale Modeling of Clay–Polymer Nanocomposites Reveals Intercalation Dynamics, Tactoid Self‐Assembly and Emergent Materials Properties

Abstract

A quantitative description is presented of the dynamical process of polymer intercalation into clay tactoids and the ensuing aggregation of polymer-entangled tactoids into larger structures, obtaining various characteristics of these nanocomposites, including clay-layer spacings, out-of-plane clay-sheet bending energies, X-ray diffractograms, and materials properties. This model of clay–polymer interactions is based on a three-level approach, which uses quantum mechanical and atomistic descriptions to derive a coarse-grained yet chemically specific representation that can resolve processes on hitherto inaccessible length and time scales. The approach is applied to study collections of clay mineral tactoids interacting with two synthetic polymers, poly(ethylene glycol) and poly(vinyl alcohol). The controlled behavior of layered materials in a polymer matrix is centrally important for many engineering and manufacturing applications. This approach opens up a route to computing the properties of complex soft materials based on knowledge of their chemical composition, molecular structure, and processing conditions.

Effect of clay and clay/essential oil in packaging films

“…The values of the interlayer spacing ( d ‐spacing) corresponding to 2θ values were calculated using Bragg's law . The XRD pattern of the clay showed a diffraction peak at 2θ of about 3.5°, corresponding to d(001) of 13.0 Å, characteristic of montmorillonite clay modified with an alkyl group , and another peak at about 8.0°, referring to d(002) of 4.5 Å. From the values displayed in Table , it can be noted that when the EO is incorporated into the nanoclay for the formation of hybrid systems, ClayC and ClayE, there is an increase in the clay interlayer of approximately 7Å and 9 Å for the clay peaks at 3.5° and 8.0°, respectively, attributed to the encapsulation of EOs between the clay lamellae.…”

Antimicrobial Nanocomposites Prepared from Montmorillonite/Ag+/Quaternary Ammonium Nitrate

“…Montmorillonite (MMT), an all-purpose clay, is widely used in a range of applications because of its high cation exchange capacity, swelling capacity, high surface areas, and strong adsorption and absorption capacities [1][2][3]. In recent years, the synthesis and application of MMT-based antibacterial materials have attracted great interest due to global concerns regarding public health.…”

Understanding Cationic Polymer Adsorption on Mineral Surfaces: Kaolinite in Cement Aggregates

“…Typically, smaller (<10 3 atoms), but more accurate electronic structure calculations based on quantum mechanics are used to validate the force fields and also to derive key parameters such as charges and key polymer-clay interactions [12]. Combined electronic structure/large-scale classical MD approaches have been used to study a range of cationic oligomers at clay mineral interfaces [13] and recent work has looked at closely coupled multi-scale modelling to go from accurate quantum simulations all the way through to macroscopic coarse-grained simulations [14]. Kaolinite has been studied using both quantum mechanical [12,[15][16][17], and classical molecular dynamics simulations [18][19][20], but not thus far in the context of its role in cement aggregates to the authors' knowledge To enable cleaner, more efficient chemistries to be designed for use in the aggregate sector, understanding of the role of polymer functional groups on the performance of inerting polymer mineral treatments needs to be gained at a molecular level.…”