Thermal-Responsive Smart Windows with Passive Dimming and Thermal Energy Storage

Area of Science:

• Materials Science
• Building Energy Efficiency
• Smart Materials

Background:

• Chromogenic smart windows are crucial for improving building energy efficiency.
• Developing advanced materials for energy-saving windows is an ongoing research area.

Purpose of the Study:

• To manufacture thermal-responsive phase change materials (TRPCMs) for energy-saving windows.
• To investigate the properties of TRPCMs based on simulated polymer hydrogels.

Main Methods:

• Simulated three-dimensional polymer hydrogel networks were used.
• Tetradecanol (TD) and a color-changing dye (CCD) were incorporated into poly(n-butyl isobutyrate) (PBB) networks.
• The optical and thermal properties of the developed TRPCMs were evaluated.

Main Results:

• The manufactured TRPCMs exhibited a transition from an opaque to a transparent state at 74.5% melting point.
• A color-changing dye (CCD) facilitated photothermal conversion, changing from blue to colorless around 45 °C.
• The TRPCMs demonstrated significant thermal storage capacity with a phase transition enthalpy over 161.9 J g⁻¹.
• The smart materials showed resistance to liquid leakage between opaque and transparent states.

Conclusions:

• The developed TRPCMs offer a novel solution for energy-saving windows.
• These materials simultaneously provide photothermal conversion, thermal energy diffusion, latent heat storage, and liquid leakage resistance.
• The smart windows present new design possibilities for energy-efficient buildings.