A future where power plants feed their carbon dioxide directly into an adjacent production facility instead of spewing it up a chimney and into the atmosphere is definitely possible, because CO2 isn't just an undesirable greenhouse gas; it is also a good source of carbon for processes like polymer production. In the journal Angewandte Chemie, American scientists have now introduced a two-step, one-pot conversion of CO2 and epoxides to polycarbonate block copolymers that contain both water-soluble and hydrophobic regions and can aggregate into nanoparticles or micelles. CO2 and epoxides (highly reactive compounds with a three-membered ring made of two carbon atoms and one oxygen atom) can be polymerized to form polycarbonates in reactions that use special catalysts. These processes are a more environmentally friendly alternative to conventional production processes and have already been introduced by several companies. However, because current CO2-based polycarbonates are hydrophobic and have no functional groups, their applications are limited. In particular, biomedical applications, an area where the use of biocompatible polycarbonates is well established, have been left out.
A team led by Donald J. Darensbourg along with graduate student Yanyan Wang at Texas A&M University (USA) has provided a solution. For the first time, the researchers have been able to produce amphiphilic polycarbonateblock copolymers in which both the hydrophilic and hydrophobic regions are based on CO2. They were also able to incorporate a variety of functional and charged groups into the polymers. Because it is very difficult to find building blocks to make hydrophilic polycarbonates, the researchers used a trick: they polymerized first and attached the water-soluble groups afterwards.
The entire process is even a "one-pot reaction": The researchers first produce the hydrophobic regions by polymerizing CO2 and propylene oxide (as the epoxide component). In the same vessel, they then change to a different building block, allyl glycidyl ether (AGE), an epoxide with a double bond in its side chain, and continue the polymerization. The AGE-containing polymer grows on both ends of the existing polycarbonate, leading to a triblock copolymer. The length of the blocks can be controlled precisely. Subsequently a "thiol–ene click reaction" can be used to simply "click" a water-soluble group into place at the double bond. This makes it possible to attach acidic and/or basic groups that carry a positive or negative charge in certain pH ranges. Some of the amphiphilic polycarbonates made by this method are able to aggregate into particles or micelles in a self-organization process. This, and the ability to attach bioactive substances, for example, could provide many more possibilities for biomedical applications.
More information: "Construction of Versatile and Functional Nanostructures Derived from CO2-based Polycarbonates." Angew. Chem. Int. Ed.. doi: 10.1002/anie.201505076
Related Stories
Bristly Spheres as Capsules March 6, 2009
(PhysOrg.com) -- Amphiphilic molecules, which have one water-friendly (hydrophilic) end and one water-repellant (hydrophobic) end, spontaneously aggregate in aqueous solutions to make superstructures like capsules or bilayers. ...
Molecules can copolymerize to form longer composite chains; it turns out that nanoparticles called colloidal particles can also copolymerize to make hybrid nanostructures. The fact that these reactions occur in a very similar ...
The rise of drug-resistant microbes is a major challenge facing medicine. The World Health Organization's 2014 report on global surveillance of antimicrobial resistance warns of the very real possibility of the twenty-first ...
Sulfur fluoride exchange—a powerful new reaction for click chemistry September 1, 2014
(Phys.org) —The coupling of molecular building blocks nearly as easy as "snapping" them together can be realized by means of the "click chemistry" tool kit. American scientists have now introduced another achievement for ...
New silicon peptide biopolymers February 6, 2015
Copolymers made from synthetic and biomimetic components open new and interesting perspectives as biocompatible, biodegradable materials that can also be given biological functionality. In the journal Angewandte Chemie, French ...
Catalyst that converts carbon dioxide to carbon monoxide in water June 3, 2015
(Phys.org)—Clean energy, or energy that comes from renewable sources, is of interest in the developing world. One path toward clean energy is harnessing solar energy and converting it into electrical energy, which could ...
Graphene drives potential for the next-generation of fuel-efficient cars August 4, 2015
Harvesting heat produced by a car's engine which would otherwise be wasted and using it to recharge the car's batteries or powering the air-conditioning system could be a significant feature in the next generation of hybrid ...
Materials scientists take big step toward tougher ductile ceramics August 4, 2015
A team of materials scientists at the UCLA Henry Samueli School of Engineering and Applied Science is exploring ways to create tough ceramics, a long sought-after class of materials that would be exceptionally hard, capable ...
Sol-gel capacitor dielectric offers record-high energy storage July 30, 2015
Using a hybrid silica sol-gel material and self-assembled monolayers of a common fatty acid, researchers have developed a new capacitor dielectric material that provides an electrical energy storage capacity rivaling certain ...
It’s hard to keep track of all the greenhouse gases that are steadily collecting in the atmosphere – from auto emissions and coal plants to methane emissions from cattle and landfills. Fortunately,Ecofys has created an easy-to-understand infographic that breaks down the source and sector of the world’s largest greenhouse gas emitters.
Ecofys‘ infographic shows that many sources of greenhouse gas emissions can be reduced if the world’s governments decide to take energy conservation and renewable energy seriously. One of the biggest culprits is global coal use, which is still strong in the US, China and several developing countries, which utilize it for steel production. If renewable energy funding increases, then clean alternatives like wind and solar power will help to lessen this footprint. Scientists and inventors around the world are also working to mitigate the other major sources, which include deforestation,building emissions, methane waste and fossil fuel-powered transportation.
For a bigger version of the infographic, click here.
Perfluorotributylamine is an unregulated, long-living industrial chemical that breaks all records for potential climate impacts
Haze over the CN Tower and downtown Toronto. Researchers have discovered
a new greenhouse gas called perfluorotributylamine. Photograph: Andrew
Francis Wallace/Getty Images
A new greenhouse gas that is 7,000 times more powerful than carbon dioxide at warming the Earth has been discovered by researchers in Toronto.
The newly discovered gas, perfluorotributylamine (PFTBA), has been in use by the electrical industry since the mid-20th century.
The chemical, that does not occur naturally, breaks all records for potential impacts on the climate, said the researchers at the University of Toronto's department of chemistry.
"We claim that PFTBA has the highest radiative efficiency of any molecule detected in the atmosphere to date," said Angela Hong, one of the co-authors.
The study, published in the journal Geophysical Research Letters, found PFTBA was 7,100 times more powerful at warming the Earth over a 100-year time span than CO2.
Concentrations of PFTBA in the atmosphere are low – 0.18 parts per trillion in the Toronto area – compared to 400 parts per million for carbon dioxide. So PFTBA does not in any way displace the burning of fossil fuels such as oil and coal as the main drivers of climate change.
Dr Drew Shindell, a climatologist at Nasa's Goddard Institute for Space Studies, said:
"This is a warning to us that this gas could have a very very large impact on climate change – if there were a lot of it. Since there is not a lot of it now, we don't have to worry about it at present, but we have to make sure it doesn't grow and become a very large contributor to global warming.".
He said a number of recent studies had drawn attention to other potential new greenhouse gases which, like PFTBA, pack a lot of warming potential in each molecule but are not very prevalent in the atmosphere.
Such studies were a warning against increasing uses of such compounds without first understanding their impact on climate change, he added.
"From a climate change perspective, individually, PFTBA's atmospheric concentration does not significantly alert the phenomenon of climate change," Hong said. "Still the biggest culprit is CO2 from fossil fuel emissions."
But PFTBA is long-lived. The Toronto researchers estimated PFTBA remains in the atmosphere for about 500 years, and unlike carbon dioxide, that is taken up by forests and oceans, there are no known natural "sinks" on Earth to absorb it.
"It is so much less than carbon dioxide, but the important thing is on a per molecule basis, it is very very effective in interacting with heat from the Earth," she said. "Individually each molecule is able to affect the climate potentially and because its lifetime is so long it also has a long-lasting effect."
Hong said the discovery of PFTBA and its warming potential raises questions about the climate impacts of other chemicals used in industrial processes.
PFTBA has been in use since the mid-20th century for various applications in electrical equipment, such as transistors and capacitors. The researchers said it was unclear how widespread its use was today.
It belongs to an entire class of chemicals used for industrial applications whose effects on the atmosphere remain unknown.
"PFTBA is just one example of an industrial chemical that is produced but there are no policies that control its production, use or emission," Hong said. "It is not being regulated by any type of climate policy."
Scientists are pushing to perfect a genetically identical meat that would be better for the environment than cows are.
Cultured beef developed by professor Mark Post of Maastricht University in the Netherlands. (Photo: David Parry/PA)
MAASTRICHT, Netherlands—Selling the merits of an all-beef burger to a crowd of vegans and vegetarians is never easy. After all, as any of its proponents might tell you, a meatless diet is a slaughter-free way to eat healthy foods that cause less environmental damage.
Yet, Tobias Leenaert, the cofounder of Europe’s second-largest vegetarian organization, Ethical Vegetarian Alternative, found himself making a surprising argument at an April meeting in Belgium.
Sometime after the all-vegan potluck brunch and workshops about low-waste living and how to be a good ambassador of the meat-free lifestyle, Leenaert sang the praises of a particular kind of burger: one with a patty made of the lab-grown meat being developed at professor Mark Post’s lab at Maastricht University. The lab-grown meat is made of cells harmlessly drawn from a cow and then cultured to grow and form muscle fibers—which means there aren’t cows producing vast clouds of methane in the process, and there's no slaughter to atone for.
Theoretically, the harm-free, low-impact meat poses a challenge to some ethical qualms of vegetarians. Leenaert tried to persuade the crowd of more than 150 people to start eating cultured meat once it becomes available, in no small part because it will pull vegetarianism and veganism out of its cult status and prove that the community is interested in solving the overarching problems with meat production.
Vegans “often believe that we need to use moral arguments only, like ‘Thou shalt not kill animals,’ that attitude change can follow behavior change. So the cultured meat revolution could be the technological revolution that precedes a moral revolution,” Leenaert later told TakePart. “I think it could be the most important food revolution since the invention of farming.”
Professor Mark Post. (Photo: David Parry/Press Association)
The crowd didn’t make any promises, and even the creator of the meat isn’t too interested in converting vegetarians to eating cultured beef.
“I rather that they not touch it,” Post told TakePart, adding that he is on good terms with the Belgian vegetarian community and attends similar meetings several times a year, but “we have slightly different perspectives.”
In the quaint city of Maastricht, Post is hard at work with MosaMeat, the start-up newly launched to replace conventional beef with lab-grown ground beef. Before the product begins showing up on menus, the company is less worried about whether vegans or vegetarians will gobble up the beef with zeal and more focused on perfecting the product prior to an anticipated clash between mighty meat lobby groups and regulatory agencies. Taking a satisfying bite out of a tasty cultured beef burger is not that far away, and the product might be very competitively priced against conventional meat.
TakePart caught up with the pioneering MosaMeat team of Post and food technologist and consultant Peter Verstrate, who is MosaMeat’s CEO. We interviewed them for our "Design and Innovation" series, which highlights the people and cutting edge technology working to solve the world's most pressing problems.
Converting vegetarians to cultured beef is not the priority, confirmed Verstrate.
“I just don’t believe that the majority of consumers will step away from meat,” he told TakePart. “I can see why they say it, but it's not realistic. But that’s OK—it’s not our target group. Our target group is meat eaters.”
For Post, the science behind lab-grown meat is better used to address food security and the environmental impacts of traditional meat production—particularly raising cattle, which requires lots of land, water, and feed that could be used to grow food for humans. By the United Nations’ estimate, more than two-thirds of all farmland is used to grow feed for livestock, compared with only 8 percent that is used to grow food for people to eat. Add to that the environmental damage of manure and methane from livestock—of which cattle are the most prolific producers—and lab-grown meat can be especially appealing.
(Infographic: Marc Fusco)
MosaMeat is finalizing plans and funding it needs to scale up operation from a petri dish to a 25,000-liter bioreactor that would produce 882,000 pounds of meat a year—enough for more than 10,000 people who eat an average amount of beef.
In 2013, when the cultured meat burger was unveiled in London, the price tag was more than $300,000. Nowadays, Post’s best estimate is that an early retail price could be set at $29.50 per pound, but as production scales up, if the research holds, that price could come down to approximately $3.60 per pound.
“At first it will likely be aimed at high-end restaurants or specialty stores where people are willing to pay a premium for a product,” Post said.
To make a cultured beef burger patty, a harmless biopsy of muscle cells is taken from a cow. The cells are nurtured in the lab, multiplying and merging to create strands that grow into muscle tissue. It takes 20,000 strands of muscle tissue for one beef burger. Version 1.0 was pure protein and colored with beetroot.
“It was just muscle fiber, but meat is also fat, connective tissue, myoglobin—which is the stuff that makes meat red, gives it taste. So the burger wasn’t finished. It was a very ‘single-cell’ product, you might say,” Verstrate told TakePart.
Two experts tasted the very pricey burger in London in 2013, with food writer Josh Schonwald saying “the general bite feels like hamburger” and nutrition researcher Hanni Rützler noting the absence of fat, adding that “there is quite some intense taste; it’s close to meat, but it’s not that juicy,” the BBC reported. Fat may not sound desirable, but as chef Julia Child is known for saying, “Fat is flavor.” Besides, MosaMeat knows that to have a viable contender against traditional beef mince for version 2.0, it needs to add those missing ingredients. That means growing cultured fat in the lab and having a serum-free medium. The current method of growing cultured cells dates back more than 100 years and has depended on adding blood (serum) derived from cows to the cell-culture medium. Post pointed out that the 2013 burger also contained serum, but that won’t cut it for the next version.
Back at the lab, the current method for cultured fat comes from the medical industry. Research from Duke University, for example, indicates cells taken from fat deposits can be “reprogrammed” into replacement cells. But there hasn’t been much incentive to experiment with growing fat tissue—and the existing methods for producing fat cells are not compatible with food production.
“We had to redesign that method,” Post explained, “so the next version will have cultured fat added to the cultured muscle.”
They also want to perfect extra ingredients to improve the shelf life of the product, as well as taste and color: a sustainable hamburger that tastes great and is comparable to a traditional hamburger. When version 2.0 of the cultured beef mince is ready, it will be submitted to formal regulatory processes as soon as 2018, though “talking to EU and FDA/USDA representatives informally will probably start much earlier,” Verstrate said. Once the product is formally submitted, the process takes about a year and a half.
(Photo: David Parry/Press Association)
Under EU food guidelines, cultured meat is classified as a “novel food,” a “food that has not been consumed to a significant degree by humans in the EU prior to 1997,” and will need to be approved by a branch of the medical evaluation board. It’s comparable to getting a medicine approved: You have to prove you can feed it, safely, to people.
MosaMeat’s research has met with a variety of reactions from farmers, the meat industry, food corporations, and supermarket industry executives. Farmers are skeptical—many openly assume cultured meat isn’t something they have to worry about in their lifetime. Post thinks the beef industry is waiting and watching for the product to be launched and marketed before showing interest, though he has some early indication that he’s the subject of conversation around some important kitchen tables.
“I heard from a chief executive at Cargill who realized that her [negative] perspective may be skewed when she asked her eight-year-old son, and his response was, ‘I’d eat it!’ ” Post said.
In the U.S., in terms of governmental support, or lack thereof, for sustainable alternatives, the five-year update on the USDA Dietary Guidelines announced at the end of 2015 did not take sustainability into consideration. “We do not believe that the 2015 DGAs are the appropriate vehicle for this important policy conversation about sustainability,” the USDA blog announced.
In April of this year, powerful lobby groups including the National Cattlemen’s Beef Association sent a letter to Congress petitioning it to propose a change in the Freedom of Information Act that would prevent the public from accessing interactions between lobby groups and boards that are overseen by the USDA, according to Fortune, which obtained the letter. The move came just a few months after the CEO of the American Egg Board stepped down when emails came to light revealing his attempt to exert pressure on Whole Foods to drop Just Mayo, an egg-free mayonnaise product.
MosaMeat says, however, that it isn’t worried about possible negative influence from the beef industry lobby groups.
“I know how powerful they are, but I’m not worried, and it’s not because I’m naive,” Post told TakePart. “It’s because in the Netherlands and the U.K., the governments actually approach me to ask, ‘How can we make sure that the meat lobby doesn’t kill this at the regulatory level?’ ”
Although MosaMeat has not approached supermarkets yet, it has heard positive feedback from those within the industry. Harvard Business School professor and former Stop & Shop CEO José B. Alvarez told MosaMeat that cultured beef could be a big hit if it could be a consistent product for consumers.
“That is something that supermarkets seem to like—that you can produce something that consumers know is completely predictable,” Post said. “I use that argument myself because I feel strongly about it as a consumer, but nobody ever said it was a great characteristic until the supermarket guy said, ‘That’s going to be a killer thing.’ ”
With funding, MosaMeat hopes to work on cultured steak alongside its continued work on cultured ground beef.
“If you want to solve the meat problem, you need to make steaks as well. A lot of meat is consumed that way,” Verstrate said.
The big difference between steak and hamburger is size. The hamburger is limited in size, because if the muscle strands become too big, the center will die when it doesn’t get enough oxygen or nutrients. That’s why we have blood vessels—to carry oxygen and nutrients to cells and remove waste. To make a steak, you have to provide that channel system, lots of oxygen and nutrients to keep everything alive. You need to create an organ type of structure in which you have not only the tissue but also the blood-vessel-type system.
But cultured steak will likely be a lot more complicated and might require 3-D technology—or perhaps something beyond current imagination. Verstrate told TakePart steak might be developed through another process that doesn’t involve printing but that gives the 3-D result. MosaMeat is in talks with 3-D experts and says there might be a simpler solution. Verstrate refrained from elaborating further. In the meantime, while the company applies for more funding, its main focus is on cultured mincemeat.
Post stressed, “My primary concern and the reason why I'm doing this is food security and environmental impact.” The Food and Agriculture Organization of the United Nations describes food security as “access of all people at all times to enough food for an active, healthy life.”
A large cattle stockyard near Yuma, Arizona, like many livestock facilities, contributes to an excess use of energy, concentrated greenhouse gas emissions, and an exorbitant use of water. (Photo: Pete Mcbride/Getty Images/National Geographic)
By 2050, FAO says, the global population is expected to grow by more than 2 billion people, with most of that growth taking place in developing countries. To keep up with feeding an additional 2 billion people, food production will have to rise by 70 percent. However, current meat industry practices—from greenhouse gas emissions to water pollution to land usage—are just not sustainable.
In the U.S., agricultural soil management alone accounts for 79 percent of nitrous oxide, which feeds greenhouse gases, according to the U.S. Environmental Protection Agency. Methane gas, water pollution caused when fertilizers run off into lakes and rivers, and large amounts of the greenhouse gas nitrous oxide—emitted from soil when nitrogen is added through the use of synthetic fertilizers—are all due to traditional agriculture and could be avoided with cultured meat.
Estimates vary, but the 2006 United Nations report Livestock’s Long Shadow made an assessment that livestock are responsible for 18 percent of greenhouse gases globally, which is a larger percentage than that produced by transport. Cultured beef could produce up to 98 percent less greenhouse gas emissions compared with the way meat is produced through traditional agriculture, according to a study on the environmental impact of cultured beef that was funded by New Harvest, a previous financial backer of cultured meat research. Researcher Hanna Tuomisto’s 2011 study sets conventionally produced European meat as the standard for impacts on energy, greenhouse gases, and water and land use. The comparison results are stark:
Cultured meat could lead to
45 percent less energy use (except in the case of poultry),
up to 96 percent less greenhouse gas emissions,
up to 99 percent less land use, and
up to 96 percent less water use.
Tuomisto also pointed to the difficulty of persuading people to stop eating meat altogether.
“It’s difficult to change behavior. There’s a long tradition in many cultures to eat meat, so it might be easier to change the way we produce meat rather than try to convince people to eat vegetarian products,” she told TakePart.
Cultured meat, however, is not without drawbacks. Energy use could be one of them—and perhaps points to a need for cultured meat producers to team with solar power engineers. An Arizona State Universitystudy published in 2015 proposed that despite the lower risk of greenhouse gas contributions, the production of cultured meat could require more industrial energy than livestock production does, heralding “a new phase of industrialization with inherently complex and challenging trade-offs.”
Researcher Carolyn Mattick told TakePart a solar power plant could be built to power the cultured meat facility, or a low-carbon electricity source installed on its grid, but also notes this undertaking falls largely outside the purview of cultured meat producers.
“There are a number of ways that cultured meat producers could reduce their products’ carbon footprints," Mattick said. “Constructing new solar power plants could certainly be one, but another could simply be to improve the efficiency of their production process and reduce the energy required per serving.”
That doesn’t sound bad to Post.
“What I would love to do is to somehow design a system to make it very socially responsible,” Post said, “so that we calculate what resources we save and somehow distribute those resources to people who need it.”
Once that responsible technology is perfected, Post sees a powerful demand for it around the world, and also promises broad accessibility.
“I talked to a minister of agriculture in Zambia who said, ‘This [cultured meat] will never happen in Africa because we don’t have the skilled personnel,’ but I told him it’s a relatively simple process. You could train people. I see the technology going global.”
“We’re not there yet,” Post went on to say, “but it has to be an important part of this company to be very outspoken in its social responsibility.”
Elizabeth Rushe is a writer and photographer from Ireland who is based in Berlin. Her work has been published by NPR, Paste Magazine, Vice, and Marie Claire.
March 6, 2009 
