Molybdenum Trioxide/Poly Vinyl Alcohol Polymer Nanocomposites: An Investigation of Structural, Optical, Mechanical and Photochromic Properties for Application in Smart Windows

Abstract

The current work elucidates the investigation of optical, mechanical and photochromic behavior of molybdenum trioxide (MoO3) reinforced polyvinyl alcohol (PVA) (MoO3/PVA) nanocomposites (NCs) under the effect of changing UV exposure time as well as increasing wt% of nanofiller. For synthesizing self‐supporting and flexible MoO3/PVA NCs, solution‐casting technique was employed while MoO3 was synthesized using hydrothermal treatment. X‐Ray Diffraction (XRD) confirms the orthorhombic phase while transmission electron microscopy (TEM) and scanning electron microscopy (SEM) illustrates the sheet‐like morphology of MoO3. The calculated optical band gap (Eg) of PVA decreases from 4.83 0.16 eV to 2.77 0.06 whereas the refractive index (n) increases from 1.46 to 2.04 after embedding 10 wt% of MoO3. The young's modulus for PVA was found to increase from 102.33 to 192.68 MPa after incorporation of 10 wt% of nanofiller. The photochromic studies reveal that the maximum optical modulation (relative reflectance % value ~19.08) and maximum coloration efficiency (~0.0916) corresponds to 10 wt% MoO3/PVA NC. Thus, the ability of fabricated NCs to modulate solar light transmittance automatically in response to UV exposure and reduce energy consumption by adjusting the indoor atmosphere makes them a highly sought‐after choice for ‘photochromic smart windows’.