Recent years have seen significant interest in the mechanical properties of clay–polymer hybrids due to their suitability for possible application as sustainable materials in green chemistry. The objective of the present study was to investigate the mechanical properties of clay–polymer hybrids and their corresponding pristine smectite clay minerals. The density functional theory (DFT) method, employing the D3 scheme for corrections of dispersion interactions, was used to calculate elastic constants (Cij) of models of pristine smectites, particularly montmorillonite, beidellite, saponite, and hectorite, and their hybrids built on the polymer poly(2-methyl-2-oxazoline), PMeOx. Following that, the elastic moduli, encompassing the bulk modulus (KVRH), shear modulus (GVRH), Young’s modulus (EVRH), and Poisson’s ratio (ν), were calculated. The results revealed a reduction in elastic constants and elastic moduli following the intercalation of smectite clay minerals with the PMeOx polymer. The findings highlighted a distinctive ranking of mechanical properties among pristine smectite clay minerals and clay–polymer hybrids, with hectorite and its hybrid (Htr-PMeOx) demonstrating better performance compared with saponite, montmorillonite, and beidellite and their respective hybrids.

A software for the calculation of diffraction elastic constants (DEC) for materials both with and without preferred orientation was developed. All grain-interaction models that can use the crystallite orientation distribution function (ODF) are incorporated, including Kröner, Hill, inverse Kröner, and Reuss. The functions of the software include: reading the ODF in common textual formats, pole figure calculation, calculation of DEC for different (hkl,φ,ψ), calculation of anisotropic bulk constants from the ODF, calculation of macro-stress from lattice strain and vice versa, as well as mixture ratios of (hkl) of overlapped reflections in textured materials.

The structural, mechanical, and electronic properties of rhenium, osmium, and tungsten tetranitrides, XN4 (X = Re, Os, W) with the orthorhombic ReP4-type structure have been investigated by first-principles calculations using density functional plane-wave pseudopotential method. The calculated formation enthalpies and elastic constants show that these tetranitrides are energetically and mechanically stable. It is appeared from the calculated band structures and density of states that ReN4 and new proposed WN4 are metallic, while OsN4 is semiconductor with a band gap of 0.64 eV. The hardness values of all compounds obtained from different hardness methods indicate that these tetranitrides are superhard materials.