International Year of the Periodic Table: Sodi…

sci:

2019 has been declared by UNESCO as the Year of the
Periodic Table. To celebrate, we are releasing a series of blogs about our
favourite elements and their importance to the chemical industry. Today’s blog
focuses on sodium and its role in the next series of innovative nuclear
energy systems.

Sodium; the sixth most abundant element on the planet is being considered
as a crucial part of nuclear reactors. Implementing new safety levels in reactors
is crucial as governments are looking for environmentally friendly, risk-free
and financially viable reactors. Therefore, ensuring new safety levels is a
main challenge that is being tackled by many industries and projects.

In the wake of Fukushima, several European nations and a number of
U.S plants have shut down and switched off their ageing reactors in order to eliminate
risk and safety hazards.

The sodium- cooled fast reactor (SFR), a concept pioneered in the
1950s in the U.S, is one of the nuclear reactors developed to operate at higher
temperatures than today’s reactors and
seems to be the viable nuclear reactor model. The SFR’s main advantage is that
it can burn unwanted byproducts including uranium, reducing the need for
storage. In the long run, this is deemed cost-competitive as it can produce
power without having to use new natural uranium.

 Nuclear reactor. Source: Hallowhalls

However, using sodium also presents
challenges. When sodium comes into contact with air, it burns and when it is
mixed with water, it is explosive. To prevent sodium from mixing with water,
nitrogen – driven turbines are in the process of being designed as a solution
to this problem.

A European Horizon 2020 Project, ESFR-SMART project (European Sodium Fast Reactor Safety
Measures Assessment and Research Tools), launched in September 2017, aims to improve
the safety of Generation-IV Sodium Fast Reactors (SFR). This project hopes to
prove the safety of new reactors and secure its future role in Europe. The new
reactor is designed to be able to reprocess its own waste, act more reliably in
operation, more environmentally friendly and more affordable. It is hoped that this
reactor will be considered as one of the SFR options by Generation IV International
Forum (GIF), who are focused on finding new reactors with safety, reliability
and sustainability as just some of their main priorities.

European Horizon. Source: artjazz

Globally, the SFR is deemed an
attractive energy source, and developments are ongoing, endeavouring to meet
the future energy demands in a cost-competitive way.  

Tiffany Hionas is a Digital Media and Press officer at SCI. You can find more of her work here.

Researchers study super-repellent surfaces f…

Researchers study super-repellent surfaces for safer fruits, vegetables

Texas A&M AgriLife Research and the Texas A&M Engineering Experiment Station, TEES, were recently awarded a grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture to study and develop super-repellent and anti-fouling surfaces for foods.

The grant will be used in their collaboration to help ensure the safety of fresh food products, benefiting both consumers and the produce industry.

“There is a need to reduce those outbreaks associated with microbial contamination that may take place in different operations along the fresh produce chain,” said Dr. Luis Cisneros-Zevallos, AgriLife Research food scientist in College Station and co-principal investigator for the project. “The surfaces we are designing avoid cross-contamination and reduce the risk of biofilm formation.”

“In recent years, we have developed various types of nanotechnology-based coating with an intriguing combination of surface texture and chemistry to inhibit and prevent the attachment of microorganisms on plastics, metals, ceramic and glass at the laboratory scale,” said Dr. Mustafa Akbulut, TEES chemical engineer in College Station and principal investigator for the project.

Read more.

A video of the frictional strength of Asphal…

A video of the frictional strength of Asphalt or Bitumen on metal, showing why ‘Road Rash’ is such a serious injury in motor accidents.

Hydrogel removes toxins better than current al…

sci:

A 3D
printed hydrogel structure can absorb metal pollutants in water significantly
faster than solid alternatives.

Clean
and fresh water is essential for human life, and water is a necessity to
agricultural and other industries. However, global population growth and
pollution from industrial waste has put a strain in local fresh water
resources.

A hydrogel is made up of polymer chains that are hydrophilic (attracted to water) and are known for being highly absorbent.

Current
clean-up costs can be extremely expensive, leaving poorer and more remote
populations at risk to exposure of metal pollutants such as lead, mercury,
cadmium and copper, which can lead to severe effects on the neurological,
reproductive and immune systems.

Now,
a group of scientists at the University of Texas at Dallas, US, have developed
a 3D printable hydrogel that is capable of 95% metal removal within 30 minutes.

Clean water is also needed for one’s hygiene, including brushing your teeth and bathing.

The hydrogel is made from a cheap, abundant biopolymer chitosan
and diacrylated pluronic, which forms cDAP. The cDAP mixture is then loaded
into the printer as a liquid and allowed to cool to <4⁰C, before rising
again to room temperature to form a gel that can be used to produce various 3D
printed shapes.

The
Dallas team also tested the reusability of their hydrogel and found that it had
a recovery rate of 98% after five cycles of use, proving it to be a potentially
reliable resource to communities with limited fresh water supply.

Life without clean water. Video: charitywater

‘This
novel and cost-effective approach to remove health and environmental hazards
could be useful for fabricating cheap and safe water filtration devices on site
in polluted areas without the need for industrial scale manufacturing tools,’
the paper reads.


This
article was originally published in SCI’s Polymer
International
. DOI: 10.1002/pi.5787

Researchers develop safer electrochromic ink…

Researchers develop safer electrochromic inks

Anyone who has a rear-view mirror that automatically dims blue in reaction to annoying high-beam headlights glaring from behind has seen an electrochromic film in action.

Now, chemists at the Georgia Institute of Technology have developed a new method to more safely and, by extension, easily produce these shear films, which change their color with the help of a tiny electric current. This could make them available to many industries that have not been able to feasibly use them before.

In manufacturing, electrochromic films are often coated onto other materials, such as the surface of a mirror, as inks. They are usually based in solvents that are flammable and have toxic fumes, making them unsuitable for many work settings that rely on printing and spraying machinery to apply colors.

Georgia Tech researchers have developed electrochromic film inks that are water-based, making them safer for diffuse application in settings where the kinds of safety precautions and protective equipment that are standard in handling volatile organic chemicals would be impractical.

Read more.

The potential of flexible OLEDs as an innova…

The potential of flexible OLEDs as an innovative surface material

High-visibility clothing is an important element of any motorcyclist’s safety routine. Such products usually incorporate reflective strips for added visibility at night-time, but thanks to organic electronics, rider safety will now be improved further. Partners of the EU-funded PI-SCALE project are focusing on various applications of OLEDs, including their integration into textile designs.

According to a press release by the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, OLEDs are being incorporated into a motorcycle jacket. “Used as a material for clothing, OLEDs not only can trigger completely new aesthetic trends, they can also provide active illumination instead of just limited reflectance. This enhanced visibility from all angles means the wearer can be seen more clearly, increasing rider safety.”

The same press release notes that the technology involves “fabricating the OLEDs on flexible substrates such as plastic films and connecting them to conductive threading for their supply of electrical power.” Quoted in the press release, Claudia Keibler-Willner, head of department at the Fraunhofer FEP, summarises the outcome: “We have taken a major step forward in economical fabrication processes for OLEDs. The results are impressive: the OLED shines very uniformly.” She adds: “The use of the roll-to-roll process also promises considerable cost reductions for future components. By combining printed and vaporized layers, process throughput and production speed can be increased up to 100 times.”

Read more.

International Year of the Periodic Table 2019:…

sci:

2019 has been declared by UNESCO as the Year of the
Periodic Table. To celebrate, we are releasing a series of blogs about our
favourite elements and their importance to the chemical industry. Today we look
at arsenic and some of its effects.


What is arsenic?

image

Arsenic is a chemical element found in nature –

low levels of
arsenic are found in water, air and soil –

in man-made products. As arsenic is
distributed throughout the environment, people have high exposure to elevated
levels of inorganic arsenic through contaminated drinking water, as well as
exposure to arsenic through oceans, food and insecticides.


Is arsenic harmful?

image

Arsenic can occur in an organic and inorganic form. Organic
arsenic compounds are less harmful to our health, whereas, inorganic arsenic
compounds (e.g those found in water) are carcinogens, which are highly toxic
and dangerous. Arsenic contamination of groundwater has led to arsenic
poisoning which affects the skin, liver, lungs and kidneys.

Prominently, arsenic has attracted much attention in
Bangladesh, as 21.4% of all the deaths in a highly affected area were caused by
levels of arsenic surpassing WHO’s provisional guideline value of 10 μg/L.


Health risks

image

Long-term exposure to low doses of arsenic can cause a
negative interference in the way cells communicate, which may minimise their
ability to function, subsequently playing a role in the development of
disease and causing an increase in health risks.

For example, cells use phosphate to communicate with other
cells, but arsenate, which is one form of arsenic, can replace and imitate
phosphate in the cell. This damages cells so they can not generate energy and
impairs the ability of cells to communicate.

The health risks of arsenic in drinking water. Video: EnviroHealthBerkeley 

Symptoms of arsenic poisoning can be acute, severe or
chronic depending on the period of exposure and method of exposure. Symptoms
may include vomiting, abdominal pain and diarrhoea, and long-term exposure can
lead to cancers of the bladder and
lungs.

Certain industries
may face exposure to arsenic’s toxicity, but the maximum exposure to arsenic allowed
is limited to 10 micrograms per cubic metre of air for every 8-hour shift.
These industries include glass production, smelting, wood treatment, and the
use of pesticides. Traces of arsenic can also be found in tobacco, posing a
risk to people who smoke cigarettes and other tobacco products.


A global threat

image

Arsenic is naturally found in the Earth’s crust and can easily contaminate water and food.

WHO has ranked arsenic as one of the top 10 chemicals posing
a huge threat to public health. WHO is working to reduce arsenic exposure,
however, assessing the dangers on health from arsenic is not straightforward.

As symptoms and signs caused by long-term exposure to
inorganic arsenic varies across population groups, geographical regions, as
well as between individuals, there is no universal definition of the disease
caused by this element. However, continuous efforts and measures are being made
to keep concentrations as low as possible.


Tiffany Hionas is a Digital Media Intern at SCI. You can find more of her work here.


That&rsquo;s &lsquo;sew&rsquo; smart! Scientis…

That’s ‘sew’ smart! Scientists invent threads to detect gases when woven into clothing

Equipment- and training-free textile detectors could be used in public health, workplace safety, military and rescue applications

Tufts University engineers have developed a novel fabrication method to create dyed threads that change color when they detect a variety of gases. The researchers demonstrated that the threads can be read visually, or even more precisely by use of a smartphone camera, to detect changes of color due to analytes as low as 50 parts per million. Woven into clothing, smart, gas-detecting threads could provide a reusable, washable, and affordable safety asset in medical, workplace, military and rescue environments, they say. The study, published today in the journal Scientific Reports, describes the fabrication method and its ability to extend to a wide range of dyes and detection of complex gas mixtures.

While not replacing the precision of electronic devices commonly used to detect volatile gases, incorporation of gas detection into textiles enables an equipment-free readout, without the need for specialized training, the researchers say. Such an approach could make the technology accessible to a general workforce, or to low resource communities that can benefit from the information the textiles provide.

Read more.

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