Flexible core-shell Cs WO₃-based films with high UV/NIR filtration efficiency and stability

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Cesium-doped tungsten bronze (CsWO₃, CWO) is a promising near-infrared (NIR) shielding material for solar filters.
• The commercial application of CWO is limited by the poor stability of CWO-dispersed films in hot, humid environments.
• Developing robust UV/NIR shielding materials is crucial for energy-efficient windows.

Purpose of the Study:

• To enhance the UV and NIR shielding performance and environmental stability of CWO nanoparticles.
• To investigate the efficacy of a core-shell CWO@polydopamine (CWO@PDA) structure for improved material properties.
• To develop advanced nanocomposite films for energy-saving window applications.

Main Methods:

• Preparation of core-shell structured CWO@PDA nanoparticles.
• Dispersion of CWO@PDA nanoparticles within a poly(vinyl alcohol) matrix to form nanocomposite films.
• Evaluation of UV/NIR shielding efficiency, visible light transparency, and stability under hot, humid conditions.

Main Results:

• The nanocomposite films exhibited efficient shielding of 88.3% UV and 85.5% NIR radiation.
• The polydopamine (PDA) shell provided UV light absorption and protected CWO nanoparticles.
• The CWO@PDA nanocomposite films demonstrated excellent stability in hot, humid environments.
• High transparency in the visible light spectrum was maintained.

Conclusions:

• Core-shell structured CWO@PDA nanoparticles significantly enhance the stability and UV/NIR shielding capabilities of nanocomposite films.
• The developed materials show great potential for creating efficient, durable energy-saving windows.
• The PDA coating effectively addresses the environmental degradation issues of CWO in previous applications.