Low-Voltage Haze Tuning with Cellulose-Network Liquid Crystal Gels

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Glazing's role in building energy efficiency and privacy is crucial.
• Current smart window technologies often require high voltages and fail to meet industry standards.
• Demand for tunable optical properties in windows is increasing.

Purpose of the Study:

• To develop a low-voltage smart glass technology with tunable haze and transparency.
• To meet the stringent technical requirements for architectural glazing applications.
• To enhance energy efficiency and privacy in buildings.

Main Methods:

• Introduction of a predesigned nanocellulose fiber gel infiltrated with nematic liquid crystal.
• Utilizing dielectric coupling to switch liquid crystal patterns with an external electric field.
• Achieving low-voltage (<10 V) dielectric switching of optical properties.

Main Results:

• The Haze-Switch approach allows tunable haze coefficients from 2% to 90% with high visible transmittance.
• Achieved <2% haze in the clear state using a nanocellulose network of ~10 nm nanofibers.
• Demonstrated suitability for window applications through characterization of color rendering index, haze, and switching times.

Conclusions:

• The Haze-Switch material and technology meet the rigorous demands of the glass industry.
• Envisaged products include privacy windows, skylights, sunroofs, and daylighting solutions.
• This innovation offers a viable path towards energy-efficient and adaptable architectural glazing.