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

Abstract

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 (Eb=-1.11eV). In contrast, the nature of interaction for the CNT (Eb=-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.