Electronic, mechanical and thermal properties of SiO2 nanotube interacting with poly lactic-co-glycolic acid: Density functional theory and molecular dynamics studies

Highlights: • This is the first theoretical study that investigates the interaction of PLGA monomer with SiO₂ nanotube and CNT. • The interaction of PLGA monomer with two types of nanotubes (SiO₂ NT, and CNT) was studied by the DFT method. • The binding energy for the PLGA on the SiO₂ nanotube is higher than that of CNT. • SiO₂NT was selected as the best nanofiller to reinforce the PLGA matrix. • For the first time, mechanical properties of the the PLGA matrix reinforced with SiO₂NT were investigated by MD simulation. • The inclusion of SiO₂NT to the PLGA matrix increase PLGA mechanical properties. For the first time in this work, computational investigations using density functional theory (DFT) were employed to figure out the interaction of the Poly lactic-co-glycolic acid (PLGA) monomer with Carbon nanotube (CNT) and SiO₂ nanotube (SiO₂NT). The DFT method was used to calculate the binding energy between the PLGA monomer and these nanotubes for the most stable configuration. The achieved results demonstrate that PLGA monomer chemisorbed onto the surface of SiO₂NT ($E_b=-1.11eV)$. In contrast, the nature of interaction for the CNT ($E_b=-0.27eV)$ complex is physisorption and the PLGA monomer interacts with CNT through non-covalent interaction. The findings display that the interaction between PLGA and SiO₂NT, owing to the smaller equilibrium interval and superior binding energy is more potent than CNT. Furthermore, the electronic properties of the most stable configuration were evaluated by computing the electronic density of state (DOS). Afterward, the mechanical properties of the SiO₂NT, PLGA polymer chains, and PLGA/SiO₂NT nanocomposite were studied by Molecular Dynamics (MD) simulations. The Universal, Dreiding, and COMPASS force fields were utilized to compute Young's modulus, bulk, and shear moduli of these configurations. The obtained results indicate that the interaction of PLGA with SiO₂NT surface rises Young's modulus and shear and bulk moduli of PLGA. As a result, the inclusion of SiO₂NT to the PLGA polymer matrix increase PLGA mechanical properties. We have also studied the influence of temperature on the mechanical properties of PLGA nanocomposite. The results revealed that the Young modulus of PLGA nanocomposite reduces by increasing the temperature. The outcomes of the present investigation could be precious for scholars to discover the potential uses of the PLGA nanocomposite in the bio-medical field ranging from bone tissue engineering to drug delivery.