Tag Archives: fungi

Historic and other buildings get protection from pollution?

This Sept. 15, 2017 news item on Nanowerk announces a new product for protecting buildings from pollution,

The organic pollution decomposing properties of titanium dioxide (TiO2 ) have been known for about half a century. However, practical applications have been few and hard to develop, but now a Greek paint producer claims to have found a solution

A Sept. 11, 2017 Youris (European Research Media Center) press release by Koen Mortelmans which originated the news item expands on the theme,

The photocatalytic properties of anatase, one of the three naturally occurring forms of titanium dioxide, were discovered in Japan in the late 1960s. Under the influence of the UV-radiation in sunlight, it can decompose organic pollutants such as bacteria, fungi and nicotine, and some inorganic materials into carbon dioxide. The catalytic effect is caused by the nanostructure of its crystals.

Applied outdoors, this affordable and widely available material could represent an efficient self-cleaning solution for buildings. This is due to the chemical reaction, which leaves a residue on building façades, a residue then washed away when it rains. Applying it to monuments in urban areas may save our cultural heritage, which is threatened by pollutants.

However, “photocatalytic paints and additives have long been a challenge for the coating industry, because the catalytic action affects the durability of resin binders and oxidizes the paint components,” explains Ioannis Arabatzis, founder and managing director of NanoPhos, based in the Greek town of Lavrio, in one of the countries home to some of the most important monuments of human history. The Greek company is testing a paint called Kirei, inspired by a Japanese word meaning both clean and beautiful.

According to Arabatzis, it’s an innovative product because it combines the self-cleaning action of photocatalytic nanoparticles and the reflective properties of cool wall paints. “When applied on exterior surfaces this paint can reflect more than 94% of the incident InfraRed radiation (IR), saving energy and reducing costs for heating and cooling”, he says. “The reflection values are enhanced by the self-cleaning ability. Compared to conventional paints, they remain unchanged for longer.”

The development of Kirei has been included in the European project BRESAER (BREakthrough Solutions for Adaptable Envelopes in building Refurbishment) which is studying a sustainable and adaptable “envelope system” to renovate buildings. The new paint was tested and subjected to quality controls following ISO standard procedures at the company’s own facilities and in other independent laboratories. “The lab results from testing in artificial, accelerated weathering conditions are reliable,” Arabatzis claims. “There was no sign of discolouration, chalking, cracking or any other paint defect during 2,000 hours of exposure to the simulated environmental conditions. We expect the coating’s service lifetime to be at least ten years.”

Many studies are being conducted to exploit the properties of titanium dioxide. Jan Duyzer, researcher at the Netherlands Organisation for Applied Scientific Research (TNO) in Utrecht, focused on depollution: “There is no doubt about the ability of anatase to decrease the levels of nitrogen oxides in the air. But in real situations, there are many differences in pollution, wind, light, and temperature. We were commissioned by the Dutch government specifically to find a way to take nitrogen oxides out of the air on roads and in traffic tunnels. We used anatase coated panels. Our results were disappointing, so the government decided to discontinue the research. Furthermore, we still don’t know what caused the difference between lab and life. Our best current hypothesis is that the total surface of the coated panels is very small compared to the large volumes of polluted air passing over them,” he tells youris.com.

Experimental deployment of titanium dioxide panels on an acoustic wall along a Dutch highway – Courtesy of Netherlands Organisation for Applied Scientific Research (TNO)

“In laboratory conditions the air is blown over the photocatalytic surface with a certain degree of turbulence. This results in the NOx-particles and the photocatalytic material coming into full contact with one another,” says engineer Anne Beeldens, visiting professor at KU Leuven, Belgium. Her experience with photocatalytic TiO2 is also limited to nitrogen dioxide (NOx) pollution.

In real applications, the air stream at the contact surface becomes laminar. This results in a lower velocity of the air at the surface and a lower depollution rate. Additionally, not all the air will be in contact with the photocatalytic surfaces. To ensure a good working application, the photocatalytic material needs to be positioned so that all the air is in contact with the surface and flows over it in a turbulent manner. This would allow as much of the NOx as possible to be in contact with photocatalytic material. In view of this, a good working application could lead to a reduction of 5 to 10 percent of NOx in the air, which is significant compared to other measures to reduce pollutants.”

The depollution capacity of TiO2 is undisputed, but most applications and tests have only involved specific kinds of substances. More research and measurements are required if we are to benefit more from the precious features of this material.

I think the most recent piece here on protecting buildings, i.e., the historic type, from pollution is an Oct. 21, 2014 posting: Heart of stone.

Beatrix Potter and her science on her 150th birthday

July 28, 2016 was the 150th anniversary of Beatrix Potter‘s birthday. Known by many through her children’s books, she has left an indelible mark on many of us. Hop-skip-jump.com has a description of an extraordinary woman, from their Beatrix Potter 150 years page,

An artist, storyteller, botanist, environmentalist, farmer and impeccable businesswoman, Potter was a visionary and a trailblazer. Single-mindedly determined and ambitious she overcame professional rejection, academic humiliation, and personal heartbreak, going on to earn her fortune and a formidable reputation.

A July 27, 2016 posting by Alex Jackson on the Guardian science blogs provides more information about Potter’s science (Note: Links have been removed),

Influenced by family holidays in Scotland, Potter was fascinated by the natural world from a young age. Encouraged to follow her interests, she explored the outdoors with sketchbook and camera, honing her skills as an artist, by drawing and sketching her school room pets: mice, rabbits and hedgehogs. Led first by her imagination, she developed a broad interest in the natural sciences: particularly archaeology, entomology and mycology, producing accurate watercolour drawings of unusual fossils, fungi, and archaeological artefacts.

Potter’s uncle, Sir Henry Enfield Roscoe FRS, an eminent nineteenth-century chemist, recognised her artistic talent and encouraged her scientific interests. By the 1890s, Potter’s skills in mycology drew Roscoe’s attention when he learned she had successfully germinated spores of a class of fungi, and had ideas on how they reproduced. He used his scientific connections with botanists at Kew’s Royal Botanic Gardens to gain a student card for his niece and to introduce her to Kew botanists interested in mycology.

Although Potter had good reason to think that her success might break some new ground, the botanists at Kew were sceptical. One Kew scientist, George Massee, however, was sufficiently interested in Potter’s drawings, encouraging her to continue experimenting. Although the director of Kew, William Thistleton-Dyer refused to give Potter’s theories or her drawings much attention both because she was an amateur and a female, Roscoe encouraged his niece to write up her investigations and offer her drawings in a paper to the Linnean Society.

In 1897, Potter put forward her paper, which Massee presented to the Linnean Society, since women could not be members or attend a meeting. Her paper, On the Germination of the Spores of the Agaricineae, was not given much notice and she quickly withdrew it, recognising that her samples were likely contaminated. Sadly, her paper has since been lost, so we can only speculate on what Potter actually concluded.

Until quite recently, Potter’s accomplishments and her experiments in natural science went unrecognised. Upon her death in 1943, Potter left hundreds of her mycological drawings and paintings to the Armitt Museum and Library in Ambleside, where she and her husband had been active members. Today, they are valued not only for their beauty and precision, but also for the assistance they provide modern mycologists in identifying a variety of fungi.

In 1997, the Linnean Society issued a posthumous apology to Potter, noting the sexism displayed in the handling of her research and its policy toward the contributions of women.

A rarely seen very early Beatrix Potter drawing, A Dream of Toasted Cheese was drawn to celebrate the publication of Henry Roscoe’s chemistry textbook in 1899. Illustration: Beatrix Potter/reproduced courtesy of the Lord Clwyd collection (image by way of The Guardian newspaper)

A rarely seen very early Beatrix Potter drawing, A Dream of Toasted Cheese was drawn to celebrate the publication of Henry Roscoe’s chemistry textbook in 1899. Illustration: Beatrix Potter/reproduced courtesy of the Lord Clwyd collection (image by way of The Guardian newspaper)

I’m sure you recognized the bunsen burner. From the James posting (Note: A link has been removed),

London-born, Henry Roscoe, whose family roots were in Liverpool, studied at University College London, before moving to Heidelberg, Germany, where he worked under Robert Bunsen, inventor of the new-fangled apparatus that inspired Potter’s drawing. Together, using magnesium as a light source, Roscoe and Bunsen reputedly carried out the first flashlight photography in 1864. Their research laid the foundations of comparative photochemistry.

These excerpts do not give full justice to James’ piece which I encourage you to read in its entirety.

Should you be going to the UK and inclined to follow up further, there’s a listing of 2016 events being held to honour Potter on the UK National Trust’s Celebrating Beatrix Potter’s anniversary in the Lake District webpage.

Nanotechnology-enabled cleansers in Turkish baths

This item about Turkish baths came to me via Chinese news agency Xinhua. In a March 10, 2016 news item on ShanghaiDaily.com,

It is very common to take a bath, yet it is quite a different experience to bathe in Istanbul’s famed hamams, or bath houses.

Bathing in a hamam is similar to that of a sauna, but is more closely related to ancient Greek and ancient Roman bathing practices, and it involves services like washing, aromatherapy oil massage, reflexology, Indian head massage and facial clay mask.

Both tourists and local Turks alike are fans of Turkish baths, said Banu Cagdas, the owner of Cagaloglu.

As customers are flocking and their number growing, hygiene appears to be the most important issue for Turkish baths.

“Visually there is nothing,” said Cagdas. “It looks like every corner is clean and no one can see the germs and viruses with the naked eye.”

Generally, Turkish baths have been using the traditional ways to maintain the state of hygiene, like bleach.

“The sterilization with bleach, especially a long-lasting sterilization, is very difficult to achieve,” Cagdas said, noting that after two hours of the cleaning, micro-organisms and bacteria start to reproduce again due to the warm and humid environment.

Fungal infections are among the most common diseases in Turkish baths. “Then comes all kind of genital diseases,” said Cagdas.

The team is turning to a cleaning agent developed by Turkish engineers from Sabanci University in Istanbul. The product, the result of five-year efforts based on nanotechnology, is called Antimics.

Antimics can stunt the production of germs, viruses, bacteria and fungi.

“We have been applying the solution to Cagaloglu bath once a month and we observe the rate of bacterium has been dropping each time even further,” Menceoglu told Xinhua.

She explained that Antimics enables the bath’s surface to be covered with a tiny antimicrobial coating and “no single microbe, virus or bacterium can hold on to after the application.”

“Every time we do the cleaning we witness that the bacteria level has been dropping drastically,” she said.

In addition, the eco-friendly new product is not harmful to humans, as opposed to the traditional disinfectant detergents that contain chemicals.

It is possible to get more information about the product (Antimic Nanotego Facebook page and on antimic.com) but you do need Turkish language reading skills.