A Review of Vanadium Dioxide as an Actor of Nanothermochromism: Challenges and Perspectives for Polymer Nanocomposites

Abstract

VO 2 has been intensively studied as a model system for Metal-Insulator Transition, ever since its phase switching behavior at relatively low temperature (T c =68°C) was discovered. Its thermo-active characteristics have been studied for applications in thermal solar collectors to prevent overheating of the fluid absorber, smart windows and smart tiles to optimize thermal comfort in buildings. In the last decades, strong efforts were made to develop protocols to process VO 2 -based material into thin films, coatings, porous layers and glazings in order to provide thermo-active properties to common substrates. A selection of complementary works in both the synthesis of VO 2 nanoparticles and formulation of VO 2 -polymer nanocomposites is proposed in the present review. The perspective of this work is to provide an easy entry to the thermochromic nanocomposite research field as a tutorial to tackle future challenges such as improving the application-oriented properties, in particular transition temperature T c and solar transmittance modulation ΔT sol . Synthesis techniques to fabricate VO 2 particles and nanoparticles and strategies to insert VO 2 particles in a polymer matrix are presented.

Comparative Building Energy Simulation Study of Static and Thermochromically Adaptive Energy-Efficient Glazing in Various Climate Regions

“…Here, the member states set goals to be achieved by 2030 to build a better future by ending poverty, building economic growth and addressing a range of social Thermochromics can switch their solar infrared modulating properties from transmissive to blocking depending on the glazing temperature ( Figure 1d). Due to this self-adaptive property, which promises huge benefits in intermediate climate regions, thermochromics has been the subject of many research articles in recent decades [9][10][11][12][13][14]. The studied material is mostly monoclinic VO2, which is used as single [15,16] or multi-layer [17] coating on glass, introduced in porous coatings [18], combined with antireflective coatings [19,20] or used in nanocomposite films for glass laminates [21].…”

Al‐Doping‐Induced VO2 (B) Phase in VO2 (M) Toward Smart Optical Thin Films with Modulated ΔTvis and ΔTc

“…An efficient way to narrow the hysteresis width (Δ T c ) is to shorten the cycle time of the phase transition and thus enhance the ambient stability. According to the nucleation theory proposed by Lopez et al, the density of nucleating defects is a power function of the driving force for the transition . Among the existing methods to narrow Δ T c , doping has been proven and shows promise, as external elements can introduce defects and increase grain boundaries by promoting heterogeneous nucleation processes .…”

Precision in Thermal Therapy: Clinical Requirements and Solutions from Nanotechnology

“…For optically active nanoparticles, self-limiting systems have not yet been as established as for magnetic particle heating. Materials with low crystal phase transition temperatures (mostly VO 2 ) [75] have been suggested, [76] as the resulting change in the refractive index could shift a narrow extinction peak away from the laser wavelength, and thus self-limit the heating. However, alternative methods based on reversible thermochromism have been reported recently.…”