Tungsten oxide–cellulose nanocrystal composite films for electrochromic applications

Abstract

Abstract. Composite films of tungsten oxide and CNCs are prepared through a sol-gel method and their electrochromic (EC) properties investigated. After mixing CNC gel into a tungsten oxide precursor solution, indium-tinoxide-coated glass substrates are dipped into the composite solution and subsequently annealed at 170°C. The composite films consisted of CNCs dispersed in the tungsten oxide matrix. The resulting nanocomposite was found to be amorphous, exhibiting a high transmission modulation and very good cycling stability. After having tested a range of compositions, a film of WO 3 with 10% CNC was found to be the most uniform and showed good EC performance. These results bode well for further work on CNC-EC composites for specific applications, especially when used on flexible substrates.

Flexible and Tailorable Alkylviologen/Cellulose Nanocrystals Composite Films for Sustainable Applications in Electrochromic Devices

“…Stoenescu et al. prepared a composite film of tungsten oxide and CNCs by a sol‐gel method and the uniform film showed good EC performance . Zhang et al.…”

“…[34][35][36] Stoenescu et al prepared a composite film of tungsten oxide and CNCs by a sol-gel method and the uniform film showed good EC performance. [37] Zhang et al used nanocellulose to successfully improve the film forming property of polyaniline (PANI) and as-prepared nanocellulose-based PANI composites film with core-shell structure showed high contrast ratio and coloration efficiency in ECDs. [38] These pioneer works inspire us to construct uniform CNCs/viologen composite films and make use of them to design a novel viologen-based ECDs.…”

Nano-composite based Smart Electrochromic Device with escalated transmittance

“…Electrochemical analysis of the nanocomposite based EMD is investigated for ± 1.5V with 50mV/s scan rate in 1M Ferrocene of 98% purity. Cyclic voltammetry analysis is carried out which signi es that the redox response for both bleaching and colouration condition takes place within the nano-membranes of the electrochemical cell [22,23,24]. This initiates the quantum tunnelling process due to carrier transportation in the EMD.…”

Grating optical filter with angular-selective transmission for smart windows

“…Thermochromics 9 – 13 with a reversible color change and thermotropics 14 – 16 with a change in light-scattering and reflective properties that depend on the ambient temperature are fairly simple and affordable materials that require increased long-term stability and energy-saving potential. Electrochromic glasses 17 – 22 that change their optical properties with a change in the electric polarity and the magnitude of the applied voltage have such advantages as the ability to switch at any time, the transparency across the switching range, and gradual switching dependently on the voltage. For wider applications, the study of electrochromic technologies is aimed at technical and economic improvement.…”