Nanotech Polymer Film for Better Managed Home Heating

Once again, the introduction of nanoparticles into a polymer have created incredible results. This time forming a film which could be applied to a building to help keep it cool in summer and warm in winter.

Effective heat management in buildings is crucial for maintaining comfortable indoor temperatures, reducing energy consumption, and minimising environmental impact. By controlling the flow of heat through insulation, ventilation, and the use of proper raw materials, buildings can stay warmer in winter and cooler in summer. This decreases reliance on central heating and air conditioning systems—saving money and lowering greenhouse gas emissions associated with energy use.

While conventional construction materials, such as roof insulation from glass fibre, wall insulating foams, and triple glazed windows are helpful in keeping heat in during summer months, they do little to reflect the summer heat.

Realizing this, nanomaterial researchers from Germany’s University of Bayreuth, set out to create a raw material which could manage building heat sustainably by absorbing solar energy in cold seasons and reflecting it in warm ones.

Incredibly, the team were even able to use old crisp packets as a feedstock to further the discovery’s environmental claims.

Specifically, the approach is based on a lightweight film with a porous structure created by combining silica nanoparticles with polycaprolactone (PCL). The inclusion of the highly scattered nanomaterials was found to improve heat emission and solar absorption—forming an ideal material for heat management.

The first step in creating the dual-mode film was making a 5 wt.% solution of PCL and dissolving it in chloroform. Nanofibers were created using this mixture in a process called solution blow spinning (SBS). To assess the impact of the nanomaterials on the mechanical and thermal characteristics of the film, the silica nanoparticles were introduced in varying amounts.

A commercial airbrush was then used to spray the polymer/nanoadditive mixture onto a rotating collector. In order to maximise the gathering process, the collector was wrapped in recycled crisp bags or reflective aluminium foil. This configuration optimised the surface area for thermal emission and solar absorption by enabling the nanofibers to create a continuous, nonwoven film.

Related articles: Nanotechnology Rewrites the Rules for Raw Materials or 7 Ways Nanomaterials Can Improve Polymer Products

The polymer film with added nanomaterial was then tested for its heat management properties. As a recent report in the journal AzoNano describes, “To assess thermal performance, the films were exposed to two controlled light intensities: 750 W/m² and 525 W/m², representing ‘summer’ and ‘winter’ conditions. Temperature changes were recorded and compared against conventional materials, including graphite-Al foil. The film’s effectiveness was evaluated based on its ability to absorb and emit heat, demonstrating its potential as an energy-efficient solution for passive thermal regulation.”

As the study, which has now been published in the journal Advanced Functional Materials, explains, “The cooling side of the film, composed of PCL-SiO2 composite nanofibers, exhibits an impressive solar reflection of 0.98 and a mid-infrared emissivity of 0.91, resulting in sub-ambient cooling performance under intensive sunlight. Meanwhile, the heating side of the film, based on the ink side of the upcycled chip bags, efficiently harvests thermal energy from sunlight, leading to a temperature rise of 16.5 °C.”

These promising results highlight how advanced material science—particularly the integration of nanotechnology into polymers—can revolutionise the way we design for energy efficiency.

By offering a scalable, sustainable solution for passive thermal regulation, this dual-mode polymer film not only addresses the limitations of traditional insulation but also helps towards broader environmental goals. As the construction sector continues to grapple with the challenges of climate change and rising energy demands, innovations like this stand out as a practical, affordable solution. With further development and commercialisation, nanocoatings such as these could become an integral part of future building design, helping to create more comfortable, cost-effective, and eco-friendly living and working spaces.

To discover more about how nanomaterial additives can improve polymer feedstocks, visit Polymer Nano Centrum—an innovative Czech company developing unique nanostructuring technologies suitable for industry.

Photo credit: Vadim Babenko on Unsplash, Freepik, & Vectorjuice