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 (MoO 3 ) reinforced polyvinyl alcohol (PVA) (MoO 3 /PVA) nanocomposites (NCs) under the effect of changing UV exposure time as well as increasing wt% of nanofiller. For synthesizing self‐supporting and flexible MoO 3 /PVA NCs, solution‐casting technique was employed while MoO 3 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 MoO 3 . The calculated optical band gap ( E g ) 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 MoO 3 . 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% MoO 3 /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’.