Thermotropism

The temperature-dependent change in the transparency of a material that changes between a clear and a strongly scattering state is called thermotropy.

Thermotropic polymers

Regulation of transparency - Thermotropic polymers

Thermotropic polymers automatically switch from a clear to a strongly scattering state when the temperature rises. They are therefore suitable for applications in solar, glare and overheating protection and as light guide.

These materials reduce the energy requirements of buildings. In winter, the solar heat reduces the heating energy requirement. In summer, a large part of the solar radiation is reflected, thus reducing the cost of cooling and ventilation.

Another area of ​​application is solar collectors where thermotropic materials act as overheating protection. At temperatures above 80 °C, the collectors are protected from further solar heating and heat damage.

  • Adaptation to numerous matrix materials
  • Adjustable switching temperature
  • Adjustment of the reflected wavelength range

References

TILSE GmbH

Self-regulating solar control glazing SOLARDIM®-ECO

Transparent casting resins are widely used for the production of laminated glass for windows in building construction and vehicle construction, for facade elements and roof glazing. The combination with thermotropic properties enables a more efficient sun protection.

For the production of thermotropic laminated glasses specially developed pigments are added to the casting resins. This places high demands on the chemical stability of the pigments, since the precursors of casting resins are usually highly reactive components. The thermotropic casting resins cause a reflection of the solar radiation. The intensity of the turbidity and the switching temperature are adjustable. The composite windows have high long-term stability and freedom from maintenance.

Mode of operation and examples of a thermotropic sun glazing.
© Fraunhofer IAP

Mode of operation and examples of a thermotropic sun glazing.

Principle of Thermotropism based on a change of the refractive index.
© Fraunhofer IAP

Principle of Thermotropism based on a change of the refractive index.