How a CSIC Team in Madrid Used Advent Research Materials to Build Nanostructured Polymers That Cool Buildings Without Power

As global demand for refrigeration climbs — already accounting for roughly a fifth of the world's electricity use, and forecast to grow steeply through mid-century — researchers are searching for ways to cool spaces without adding to the energy burden. Passive daytime radiative cooling (PDRC) offers a tantalising route: a material that reflects nearly all incoming sunlight while radiating its own heat straight through the atmosphere's transparency window to the cold of outer space can sit below the surrounding air temperature with no power supply at all.

A team at the Instituto de Micro y Nanotecnología (IMN-CNM, CSIC) in Tres Cantos, Madrid, set out to push this idea further by controlling not just the chemistry of the cooling material but its three-dimensional nanostructure. Writing in Nanophotonics in 2026, Amaia Iglesias-Elcano, Luis Moreno-Sanabria, Marisol Martín-González and Cristina V. Manzano describe a template-assisted method for turning ordinary polyvinylidene fluoride (PVDF) into a nanostructured radiative cooler — and the story of that template begins with a sheet of high-purity aluminium.

Building a Nanoscale Mould From High-Purity Aluminium

The team's strategy hinged on three-dimensional anodic aluminium oxide (3D-AAO) — a self-organising nanoporous ceramic grown directly from aluminium metal, used here as a sacrificial template into which molten PVDF could be infiltrated. The fidelity of that template determines the fidelity of the final polymer nanonetwork, which in turn governs how light scatters and how efficiently the finished cooler reflects the sun.

The researchers began with high-purity aluminium foil — 99.999%, supplied by Advent Research Materials — which they cleaned in solvents of varying polarity, electropolished to reduce surface roughness, and then anodised in a two-step process to grow the ordered nanoporous oxide. 
At five-nines purity, the foil is essentially free of the trace metallic impurities that can seed irregular pore nucleation, uneven oxide growth, and defects during anodisation. For a self-ordering process as sensitive to starting-material homogeneity as AAO formation, that consistency helps produce the regular, reproducible nanostructures this kind of optical work relies on.

From Nanostructure to Measured Cooling

Working from that template, the team infiltrated PVDF, tuned its crystalline phase through three different post-infiltration cooling regimes — natural, fast and ultra-fast — and applied a UV treatment that whitened the polymer through photo-oxidation to boost its solar reflectance further. 
The optimised free-standing 3D-PVDF, produced via ultra-fast cooling, achieved an average solar reflectance of 82.4% across the 0.32–2.5 μm range and an infrared emissivity of 96.7% within the crucial 8–13 μm atmospheric window. Those figures translated to a theoretical daytime cooling power density of 182.3 W m⁻², and in outdoor testing the material held 12.9 °C below an empty reference box under peak solar irradiance of 962 W m⁻².

What This Demonstrates About Advent Research Materials

Behind a result like this sits the starting material that made it possible. The headline is a polymer that cools a surface by nearly 13 degrees in full sun — yet that polymer inherited its light-scattering nanostructure from an aluminium oxide template, and that template began as a sheet of high-purity aluminium foil. 

Citations of this kind, tucked into the experimental section of a peer-reviewed paper, are the truest measure of the role Advent plays in modern research: the reliable, well-characterised raw materials on which ambitious science is quietly built. As template-assisted nanofabrication continues to open new frontiers in photonics and energy-efficient materials, it is precisely this dependable material quality that lets researchers focus their attention on discovery rather than on the purity of their starting stock.

Citation

Title: Template-Assisted 3D-PVDF Nanonetworks for Passive Daytime Radiative Cooling
Journal: Nanophotonics (Wiley Periodicals LLC)
Authors: Amaia Iglesias-Elcano, Luis Moreno-Sanabria, Marisol Martín-González, Cristina V. Manzano
Published: 2026 (Vol. 15, article e70183; received 30 April 2026, accepted 17 June 2026)
DOI: 10.1002/nap2.70183
Abstract: Passive daytime radiative cooling (PDRC), which dissipates heat through infrared emission to outer space while reflecting solar radiation, represents a promising strategy for reducing energy consumption in cooling technologies. Here, a template-assisted strategy is introduced to fabricate nano…