Tag Archives: Coating

Revolutionary Paint-Like Coating Harvests Water from Air

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Researchers at the University of Sydney, in collaboration with Dewpoint Innovations, have engineered a porous polymer coating that can reflect as much as 97% of sunlight, dissipate heat into the atmosphere, and maintain surface temperatures up to 6 degrees cooler than the ambient air—even in direct sunlight. This mechanism fosters ideal conditions for atmospheric water vapor to transform into water droplets on these cooler surfaces, much like the condensation seen on a bathroom mirror.

Experimental equipment installed on the roof of the Sydney Nanoscience Hub. Image credit: University of Sydney.

Professor Chiara Neto from the University of Sydney stated: “This innovation not only advances cool roof coating technology, but also paves the way for sustainable, low-cost, decentralized freshwater sources—an essential requirement given the challenges of climate change and rising water scarcity.”

A six-month field study conducted on the roof of the Sydney Nanoscience Hub demonstrated that dew was collected for 32% of the year, enabling a sustainable and reliable water source even during dry spells.

Under optimal conditions, this coating can yield up to 390 mL of water per square meter daily—sufficient for a 12-square-meter home, meeting one person’s daily hydration needs.

This research illustrates the integration of passive cooling techniques and atmospheric moisture collection into scalable paint-like solutions.

The extensive collection area suggests that this coating could have diverse applications in various industries, including water supply for livestock, horticulture for premium crops, cooling through spraying, and hydrogen production.

Contrary to conventional white paints, the porous coatings utilizing polyvinylidene fluoride-co-hexafluoropropene (PVDF-HFP) do not depend on UV-reflective pigments like titanium dioxide.

Dr. Ming Chiu, Chief Technology Officer of Dewpoint Innovations, remarked, “Our design achieves superior reflectiveness through an internal porous structure, ensuring longevity without the environmental downsides of pigment-based coatings.”

“By eliminating UV-absorbing materials, we have surmounted traditional limitations of solar reflectance while avoiding glare from diffuse reflection.”

“This equilibrium between performance and visual comfort enhances its ease of integration and appeal for real-world applications.”

Throughout six months of outdoor examination, researchers documented minute-by-minute data on cooling and water collection, confirming solid performance that remained stable under the harsh Australian sun—unlike similar technologies that often degrade quickly.

In addition to water harvesting, these coatings could help mitigate urban heat islands, lower energy needs for air conditioning, and provide climate-resilient water sources for regions facing heightened heat and water stress.

“This research also challenges the notion that dew collection is confined to humid environments,” noted Professor Neto.

“While humid conditions are optimal, condensation can also occur in arid and semi-arid areas where humidity increases during the night.”

“It isn’t a substitute for rainfall; rather, it serves as a water source when other supplies are scarce.”

The team’s work was published in the October 30th issue of Advanced Functional Materials.

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Ming Chiu et al. A passive cooling paint-like coating to capture water from the atmosphere. Advanced Functional Materials published online October 30, 2025. doi: 10.1002/adfm.202519108

Source: www.sci.news

Research: How small structures in the wax coating of blue-pigmented fruit contribute to its blue color

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It is perhaps surprising that fruits with blue pigments are less common, since many visually guided fruit eaters have eyes highly adapted to blue sensitivity. However, some fruits do not contain blue pigment. In a new study, scientists from the University of Bristol and elsewhere investigated dark fruits with wax blooms, such as blueberries, plums and juniper cones, and found that structural color mechanisms are involved in their appearance. Did.

The structural color of the wax bloom gives the fruit a blue appearance across a wide range of accessions. (A) Undamaged highbush blueberries growing on the plant. (B) Blueberry (i) unmodified wax, (ii) mechanical wax removal, (iii) chloroform wax removal, (iv) surface application of (approximately) index-matched oil, (v) surface application of water; (vi) peeling off the outer skin to expose the pulp; (vii) the underside of the peeled skin; (C) Transmission light microscopy of a blueberry peel peeled from the inner edge showing red pigmentation of epidermal cells. Scale bar – 200 μm. (D) (i and ii) Plum selection (Plum) Fruits with different cell pigmentation, (i) with wax intact and (ii) with wax removed.Image credit: Middleton other., doi: 10.1126/sciadv.adk4219.

“You can't 'extract' the blue color from blueberries by crushing them, because blueberries are not present in the highly pigmented juice that can be squeezed from the fruit,” said lead author Dr Rocks Middleton, a researcher at the University of Bristol.

“That's why I knew there had to be something strange about this color.”

“So we removed the wax and recrystallized it on the card. In doing so, we were able to create a completely new blue UV coating.”

This ultra-thin colorant is about 2 microns thick, has a low reflectance, but looks blue and reflects UV well, potentially paving the way for new colorant methods.

“This shows that nature has evolved to use a very neat trick: an extremely thin layer of a vital colorant,” Dr Middleton said.

Most plants are covered with a thin layer of wax, which has multiple functions, many of which are still unknown to scientists.

They know that it is highly effective as a hydrophobic, self-cleaning coating, but only now have they realized how important this structure is for visible coloration.

Now Dr. Middleton and colleagues plan to look at easier ways to recreate and apply the coating.

This could lead to the development of more sustainable, biocompatible, and even edible UV- and blue-reflecting paints.

Additionally, these coatings may have multiple functions similar to natural biological coatings that protect plants.

“It was really interesting to discover that there was an unknown coloration mechanism just beneath the surface of the popular fruit that we grow and eat all the time,” Dr Middleton said.

“It was even more exciting to be able to recreate that color by taking wax and creating a new blue coating that no one had ever seen before.”

“Our dream is to incorporate all the functionality of this natural wax into a man-made material.”

of result It was published in the magazine scientific progress.

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Rocks Middleton other. 2024. Self-organized disordered structural colors from fruit wax blooms. scientific progress 10(6); doi: 10.1126/sciadv.adk4219

Source: www.sci.news