July 2018 - ACS Axial | ACS Publications

Getting to Know the New Members of the Nano Letters Early Career Advisory Board

Nano Letters started its Early Career Advisory Board with the mission of developing a channel for early career scientists to share their experiences and perspectives on scientific publishing. As the future of the field, members also provide insights into emerging disciplines. In addition, Early Career Advisory Board members organize virtual issues highlighting topics such as nanomaterials and perovskite nanocrystals.

Now in its third year, the Nano Letters Early Career Advisory Board is pleased to announce four new members. Take a few minutes to get to know them.

Weiyang (Fiona) Li

Tell us a little about yourself

I graduated with B.S. and M.S. degrees in chemistry from Nankai University (Tianjin, P.R. China), and a Ph.D. in biomedical engineering from Washington University in St. Louis. I then worked as a Postdoctoral Associate in the Department of Materials Science & Engineering at Stanford University from 2011 to 2015.  I joined the Thayer School of Engineering of Dartmouth College as an Assistant Professor in 2016.

Describe your current research (or areas of interest).

The research in my group primarily focuses on the development of functional materials with finely tailored composition and architecture to tackle critical problems in diverse energy-related applications, especially in cost-effective and high-energy battery systems.

What are the major challenges facing early career chemists?

Some of the challenges include: achieving a balance between curiosity-driven and problem-solving research, difficulty in securing jobs, and intense work demands.

Deep Jariwala

Tell us a little about yourself.

I am an early career scientist who has recently (Jan. 2018) started a tenure-track position in Electrical and Systems Engineering at University of Pennsylvania. Before that, I was a Resnick Fellow at Caltech, and prior to that, I received my Ph.D. from Northwestern University. I am originally from Mumbai, India, where I completed my undergraduate degree in 2010 at the Indian Institute of Technology in Varanasi. I am passionate about my work and making a positive change through science education and technology related research.

What do you hope to bring to the Early Career Advisory Board?

The younger generation of scientists has the important responsibility of communicating science and the merits/impact of science and science education to the broader section of the society, not just in the U.S. but also beyond the U.S., particularly in Asia where the science community is growing at a much faster pace. Thus, as a member of the Early Career Advisory Board, I hope we can take some initiatives to reach out to more people through Nano Letters and engage the community to communicate the impacts of nanoscience and nanotechnology in everyday lives to the layperson. Besides that, I hope to interact with the editors and have a positive impact on the journal’s future.

What are the major challenges facing early career scientists?

One of the biggest challenges facing early career scientists is competition and hence lack of resources. It is important to note that there are more people in scientific careers today than there have ever been in the past. On the other hand, the resources available for science, particularly in the western world have not increased proportionately. This puts an enormous pressure on the resources available to do science. A major contributor to this is the public perception that scientific research does not contribute much to society as well as the lack of public trust in scientific discoveries and findings. Therefore, unless the science community can help change this public perception of science, the younger generation of scientists will continue to face an uphill battle to make breakthrough discoveries and have successful career trajectories.

Michael Saliba

Tell us a little about yourself.

My research group at the Merkle Institute in Fribourg, Switzerland is working on novel materials for a sustainable energy future. I was a Marie Curie Fellow at EPFL, obtained a Ph.D. at Oxford University, an MSc with the Max Planck Institute for Solid State Research, and BSc degrees in mathematics and physics from Stuttgart University.

I was awarded the Young Scientist Award of the German University Association, the Postdoctoral Award of the Materials Research Society (MRS); I was also named as one of the World’s 35 Innovators Under 35 by the MIT Technology Review. I am a member of the National Young Academy of Germany as well as the Global Young Academy working, for example, on improving science awareness in society.

Describe your current research (or areas of interest).

I study novel materials focusing on perovskites and interfaces for a sustainable energy future. Solar cells and optoelectronic research are very exciting as they sit at the intersection of physics, chemistry, materials science, engineering, etc. This brings diverse research communities together creating a very stimulating environment.

I also have worked in the fields of plasmonics, lasers, LEDs, and nanostructuring. I am always excited to look at the combination of two topics.

I particularly enjoy working with students/colleagues/collaborators who have a different research background or seemingly unobvious ideas. This creates some of the most interesting research and can open entirely new directions.

What are the major challenges facing early career chemists?

I believe one major challenge is changing gears and to learning new skills. We often get very good at one thing during our training. For many, this is the necessary process of producing good research that gets published.

Then, all the sudden, we need to write grants, supervise students, prepare lectures, manage administration, etc. This transition frequently occurs without much formal training and is very challenging for almost anyone. It takes years to become good at anything and the same is true here. It is therefore essential to keep an open mind to learning new skills, moving out of the comfort zone, taking courses if necessary and being open to changing gears.

At the same time, it is important to maintain the original enthusiasm that led most of us to science – the joy of discovering new things and to advance scientific knowledge one-step at a time.

Nicolò (Nico) Maccaferri

Tell us a little about yourself.

I obtained the B.S. and M.S. in Physics at the University of Ferrara (Italy) in 2010 and 2012, respectively. From 2013 to 2016, I was Ph. D. student at the Nanoscience Research Center CIC nanoGUNE (Donostia-San Sebastian, Spain) under the supervision of Prof. Paolo Vavassori. During my Ph.D. studies, I contributed to the development, of a new class of magnetically tunable nanophotonic and bio-sensing applications. I am a dynamic and energetic person with a real passion for science in general. I am also a philosophy and history enthusiast. I am also a really meticulous and detail-oriented person. For me it is very important to do things in the best way in all aspects of life.

What do you hope to bring to the Early Career Advisory Board?

First, I hope to be able to bring within the Early Career Advisory Board a nice atmosphere of collaboration. I also hope that we could identify specific conferences or events to attend all together to better expand our knowledge in nanoscience and interact directly between us and with young colleagues to find new topics suitable for the journal, or new perspectives that can help the journal to face the challenges of the world of scientific publications. I also plan to bring new ideas that help bring together the community of young scientists working on different fields of nanoscience.

What are the major challenges facing early career scientists?

Despite phenomenal accomplishments in chemistry, young researchers are facing a new paradigm in science, namely the interdisciplinary aspect of every forefront research project nowadays with respect to the past. As scientific inventions become embedded within human societies, the challenges are further multiplied. Here are some additional challenges:

  • Interlinking theoretical knowledge and experimental approaches from different backgrounds (for instance applied physics, biology, medicine);
  • Implementing the principles of sustainability at the roots of the chemical design;
  • Defining science from a philosophical perspective that acknowledges both pragmatic and realistic aspects thereof;
  • Instigating interdisciplinary research within the projects they handle;
  • Learning to recognize and appreciate the aesthetic aspects of scientific knowledge and methodology, and to promote truly inspiring education in chemistry.

In conclusion, nowadays the evolution of human knowledge inherently depends upon our ability to adopt creative problem-solving attitudes towards a multidisciplinary scientific environment, which should embrace not only the academia but also the whole society.

Nano Letters Early Career Advisory Board Virtual Issues

The members of the Nano Letters Early Career Advisory Board organized three virtual issues on important topics in nanoscience. Check them out today:

Contact Charges Flip Expectations

Contact electrification—the proper name for what’s commonly called ”static electricity”—happens when two surfaces are brought together then separated. Any child who has ever rubbed a balloon on her head then watched as strands of hair rose up is familiar with it. Despite its familiarity, there’s very little scientific understanding of the mechanisms behind the phenomenon. Now one group of researchers has deepened the mystery, discovering that surfaces often don’t charge as expected. The team finds that when certain inorganic materials are brought into contact, both surfaces can develop the same charges instead of producing opposite charges.

Contact electrification forms the basis of technologies as old as photocopying and as new as nanoelectric generators. It even plays a role in how sandstorms form and has been known to cause equipment jams and explosions in industrial processes. When a pair of surfaces makes contact and separates, the law of conservation of charge says that one surface ought to become positively charged while the other becomes negatively charged. But in the new study, researchers at the National University of Singapore found that with certain pairings involving inorganic materials, both surfaces take on the same charge, either both positive or both negative. “Our results do, at least initially, seem to contradict theory,” says Siow Ling Soh, a chemical engineer at NUS.

The team had been studying the fundamental mechanism of contact electrification and so were testing inorganic surfaces, some coated with organosilane functional groups. “We were constantly getting results that we could not understand,” Soh says.

They found that when they brought together two pieces of mica, both took on positive charges. The same was true of silicon, sodium chloride, aluminum oxide, magnesium aluminate, zinc selenide, and potassium bromide. When they brought together two pieces of quartz or calcium fluoride, both surfaces charged negatively.

They also found that touching mica to the other positively charging inorganic materials or to organic surfaces, such as mica coated with organosilane groups or a sheet of polyethylene glycol diacrylate, left both surfaces with positive charges. When quartz contacted calcium fluoride, polystyrene, or polyvinyl chloride, both surfaces charged negatively. Touching quartz to mica, however, resulted in negatively charged quartz and positively charged mica.

Further investigation revealed that charge conservation was maintained: Initially the same-charging surfaces took on opposite charges, but the polarity of one would flip approximately one second later for most pairings. “We do not fully understand the mechanism,” Soh says. “Because we found changes in the chemical composition of the surface of the inorganic materials after leaving the materials in air, we believe air is involved in the switch of polarity.” The researchers plan to investigate the process further.

Daniel J. Lacks, a biochemical engineer at Case Western Reserve University, says the paper “is an exciting new finding that will open new doors towards understanding contact charging.” Scientists generally can’t predict the direction of charging based on material properties and don’t even know what is being transferred—electrons, ions, or bits of material—to generate the charge, he says. It may be, Lacks says, that adsorbed water is becoming ionized and carrying charge. Understanding how the process works could lead to better designs of devices that use, or want to avoid, such electrification.

Last year, Lacks and his colleagues used molecular dynamics simulations to predict charge distributions in water confined between layers of quartz and alumina. “I think that the experimental findings of Fang, et al., are a manifestation of the phenomenon we described in our theory paper,” he says. Soh agrees that humidity in the air may play a role, but doubts that it’s the only mechanism involved.

This article is reproduced with permission from C&EN (© American Chemical Society). The article was first published on June 11, 2018.

ACS Divisions Invite National Meeting Attendees to a New Booth Experience

The ACS National Meeting & Exposition takes place in Boston from August 19-23, as chemistry professionals from around the world meet to share ideas and advance scientific and technical knowledge. This year’s meeting, with the theme, “Nanoscience, Nanotechnology & Beyond,” features thousands of presentations on discoveries in fields such as food and nutrition, medicine, the environment, energy, and other areas where chemistry plays a central role.

In addition to bringing together chemistry professionals, ACS is fusing the meeting spaces for three of its divisions (Membership, CAS, and Publications) into a single, unified booth. The new ACS Booth is your one-stop shop to discover ACS resources, get information about ACS initiatives, learn about publishing, and meet editors and staff from business divisions across the society.

Each kiosk within the booth offers information about the programs and services ACS offers to help members advance their careers and share their science.

  • Membership staff will be on hand to support you and answer questions about your benefits as an ACS member.
  • Learn about getting published or reviewing articles in one of 50-plus ACS journals at the ACS Publications area.
  • Visit CAS to discuss research technology and scientific discovery with our scientists, technologists, and business leaders.
  • At the ACS Career Navigator™ kiosk, you’ll discover products and services to help you achieve your career goals, develop your leadership skills, and stay on top of your professional game.

You’ll also have the opportunity to win prizes, collect giveaways, and participate in games and contests!

Don’t leave the ACS booth without visiting the new-and-improved ACS Store! It has been redesigned with an open layout and more retail-like feel for a more interactive and seamless shopping experience. You will be able to touch and test the merchandise before deciding to purchase, take advantage of sales on select merchandise, and explore new products.



This Chili Pepper Compound Will Self-Destruct

Capsaicin, the compound that gives chili peppers their heat, is added to some medical creams because of its ability to ease pain and itch. But along with this relief, capsaicin and some of its derivatives can deliver troubling side effects. Now researchers have modified a derivative of capsaicin so that it is inactivated within hours by enzymes in the skin, averting some of these side effects while demonstrating pain and itch relief in mice.

Capsaicin soothes pain and itch by propping open an ion channel called TRPV1 in cells. But not surprisingly, given its spicy reputation, it also burns. Related derivatives made in part by replacing hydrogen with iodine in one spot in the capsaicin molecule also help with pain and itch via a different mechanism—by blocking the same channel. These versions don’t burn but can disrupt temperature regulation in the body, leading to fever spikes called hyperthermia. And both types of these TRPV1-acting compounds can foster skin tumor formation in mice when combined with a tumor promoter, like sunlight. Sun exposure is a special concern for topical application, particularly because capsaicin is lipophilic and stays in the skin for a long time.

To overcome these problems, Asia Fernandez-Carvajal of Miguel Hernández University, Tracey Pirali of the University of Eastern Piedmont, and their colleagues made a variety of capsaicin derivatives with a built-in self-destruct switch, with the goal of relieving pain and itch in the short term while avoiding some of these side effects. The switch took the form of an ester bond in the tail of the compounds, which they introduced using the Passerini reaction, a type of reaction seldom used in medicinal chemistry because it makes molecules more degradable in the body. This bond is hydrolyzed by esterase enzymes in skin into two metabolites that the body easily eliminates. This so-called “soft drug” approach has been used in other medicines, such as the beta blocker esmolol, to control their elimination in the body.

The researchers first tested the compounds for activity on the TRPV1 channel in human neuroblastoma cells, and then assayed the most potent candidates in human skin cells to determine those that were significantly hydrolyzed. Finally, they tested in mice a molecule that performed well in both tests. They injected the paws of one group of mice with an emulsion containing heat-killed bacteria—which causes inflammation that makes the paws more sensitive to heat and touch—and two other groups with histamine and chloroquine, respectively, to stimulate itch. Then they injected the capsaicin derivative or a control substance into the paws of the mice. The molecule reduced sensitivity to heat and touch in the first set of mice and to itch in the other two sets, without producing hyperthermia. The effects lasted up to 90 minutes after injection; however, study coauthor Antonio Ferrer-Montiel of Miguel Hernández University says that relief may last longer with a topical cream because the compound would need to pass through the epidermis to the dermis before encountering esterases that could degrade it.

Baskaran Thyagarajan, a pharmaceutical scientist at the University of Wyoming who studies this family of channels, calls the study convincing. He says that the molecule’s biological availability, pharmacokinetics, and pharmacodynamics must be tested, which the researchers plan to do next. He adds that the study opens up a new direction for developing modulators of the TRPV1 channel to potentially treat other conditions thought to be linked to TRPV1 activity, such as type 2 diabetes and hypertension.

This article is reproduced with permission from C&EN (© American Chemical Society). The article was first published on June 6, 2018.

ACS Applied Bio Materials Celebrates Its First Issue

The first issue of ACS Applied Bio Materials is now available. The new journal, which joins ACS Applied Energy Materials, and ACS Applied Nano Materials in the family of journals that started with ACS Applied Materials & Interfaces, focuses on original research covering all aspects of biomaterials and biointerfaces, including traditional biosensing, biomedical, therapeutic applications, and beyond.

ACS Applied Bio Materials CoverThe journal seeks to integrate knowledge in the areas of materials, engineering, physics, bioscience, and chemistry into important bio applications. The journal is specifically interested in work that addresses the relationship between structure and function and assesses the stability and degradation of materials under relevant environmental and biological conditions. Sample research topics that span the journal’s scope are inorganic, hybrid, and organic materials for bio applications including antibacterial/antimicrobial and anticancer materials, biofouling and antifouling materials, biomolecular imaging/sensing materials, biomimetic materials, self-healing materials, bio-assembly materials, sustainable biomaterials, as well as novel approaches to synthesis of new and existing materials for drug delivery/targeting and photodynamic/photothermal therapy. Descriptions of the design and development of materials and devices that enable more rapid advancement of new bio applications in areas such as bioenergy, biocatalysis, bioaerosols, bioelectronics, environment, and water safety are encouraged.

ACS Applied Materials & Interfaces Editor-in-Chief Kirk S. Schanze oversees the journal, but Deputy Editor Professor Shu Wang leads its editorial direction. Professor Wang says he hopes the new journal can focus on practical applications of groundbreaking techniques, such as sensory image therapeutics, bioelectronics, and biocatalysis. He points to early cancer diagnosis tools as one area of research that particularly excites him at the moment.

Professor Wang is the Deputy Director of Key Laboratory of Organic Solids, and the Office Director of Beijing National Research Center for Molecular Sciences at Institute of Chemistry, Chinese Academy of Sciences. He has served on the Editorial Advisory Boards of Langmuir and ACS Omega, and been an Associate Editor of ACS Applied Materials & Interfaces since 2011 and an Executive Editor of the journal since 2016. He has authored or co-authored more than 200 peer-reviewed articles and three books and six book chapters. He is listed as a co-inventor in 30 patents or disclosures. His research currently focuses on the design, synthesis, and properties of light-harvesting conjugated polymers, the self-assembly of biohybrid materials, biosensors, cell imaging, and disease therapeutics, as well as organic bioelectronics.


Watch a video introducing ACS Applied Bio Materials Deputy Editor Professor Shu Wang:

Read an editorial from the editors of ACS Applied Bio Materials and browse the inaugural issue.

ACS Editors’ Choice: Global Survey of Antibiotic Resistance Genes in Air — and More!

This week: Global survey of antibiotic resistance genes in air — and more!

Each and every day, ACS grants free access to a new peer-reviewed research article from one of the Society’s journals. These articles are specially chosen by a team of scientific editors of ACS journals from around the world to highlight the transformative power of chemistry. Access to these articles will remain open to all as a public service.

Check out this week’s picks!
Dynamic Remodeling of Covalent Networks via Ring-Opening Metathesis Polymerization

ACS Macro Lett., 2018, 7, pp 933–937
DOI: 10.1021/acsmacrolett.8b00422
Highly Effective Radioisotope Cancer Therapy with a Non-Therapeutic Isotope Delivered and Sensitized by Nanoscale Coordination Polymers

ACS Nano, Article ASAP
DOI: 10.1021/acsnano.8b02400
Global Survey of Antibiotic Resistance Genes in Air

Environ. Sci. Technol., Article ASAP
DOI: 10.1021/acs.est.8b02204=
Electronic Preresonance Stimulated Raman Scattering Microscopy

J. Phys. Chem. Lett., 2018, 9, pp 4294–4301
DOI: 10.1021/acs.jpclett.8b00204
Boron-Catalyzed O–H Bond Insertion of α-Aryl α-Diazoesters in Water

Org. Lett., Article ASAP
DOI: 10.1021/acs.orglett.8b01988
Development of an Efficient Manufacturing Process for Reversible Bruton’s Tyrosine Kinase Inhibitor GDC-0853

Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.8b00134
Kinetics and Mechanisms of Dehydration of Secondary Alcohols Under Hydrothermal Conditions

ACS Earth Space Chem., Article ASAP
DOI: 10.1021/acsearthspacechem.8b00030
Love ACS Editors’ Choice? Get a weekly e-mail of the latest ACS Editor’s Choice articles and never miss a breakthrough!

Isotopes Could Sniff Out Fake Truffles

In 2012, a routine check by authorities of a Bologna, Italy, restaurant led to the seizure of more than 300 kg of contraband. If the counterfeit material had been what it purported to be—white truffle puree—today it would sell for over $1 million. A new method offers a way to detect such fungus fraud—distinguishing the aroma of real Alba white truffles, Tuber magnatum Pico, from synthetic truffle aroma in food.

Growing under certain Italian trees and harvested only a few months per year, Alba white truffles are among the priciest of delicacies, fetching almost $7,000 per kg last season. The key to their flavor and aroma is bis(methylthio)methane, an aromatic compound that can be synthesized and added to foods to deliver truffle taste. “You may fool some people with cheap truffles, but spiking them with artificial aroma will make it easier to get away with false labeling,” says Simon Cotton of the University of Birmingham, who was not involved with the new work. Consumer desire for genuine products drives a need for analytical tests to prevent such food fraud, according to Luigi Mondello of the University of Messina and colleagues in their new study.

When isolated from a natural white truffle, bis(methylthio)methane contains carbon-12 and carbon-13 in a ratio unique to the environment in which the fungus grew. Meanwhile, the synthetic version of this molecule contains a carbon isotopic signature unique to its origins in petrochemical or plant-based feedstocks.

Mondello and colleagues used this difference to test bis(methylthio)methane from natural truffles, several synthetic samples, and various truffle-flavored foods. They collected white truffles from around Italy, chopped them up, and sealed them in vials containing fibers to adsorb volatile compounds evaporating from the truffles. Then the researchers extracted the adsorbed compounds and used a gas chromatograph to isolate bis(methylthio)methane. They injected the purified compound into an isotope ratio mass spectrometer, which measures the relative amounts of 12C and 13C in samples by weighing carbon dioxide released when the molecules are burned inside the instrument.

The researchers repeated this process to measure the relative 13C abundance in bis(methylthio)methane synthesized from petrochemicals. Natural white truffles had a higher proportion of 13C than petrochemically derived flavor—a large enough difference to distinguish between the two origins in a sample.

Next, the researchers repeated the experiments on samples of commercial truffle-flavored olive oil, honey, pasta, fresh cheese, sauce, and cream purchased from Italian stores. Products labeled as containing lower quality truffles or added truffle aroma had the isotopic signature of artificial bis(methylthio)methane, whereas products labeled as containing white truffle had the isotopic signature of the natural fungus. Thus, the researchers detected no fraud but verified that the technique successfully distinguished real from synthetic truffle flavor.

Using their instrument design, this analysis is ready to go into other labs, says coauthor Danilo Sciarrone of the University of Messina.

Tom Brenna of the University of Texas, Austin, says, “The data show that 13C/12C isotope ratios of key flavor molecules in truffles may be a good test for authentication and warrant a wider survey of truffles in other regions.”

This article is reproduced with permission from C&EN (© American Chemical Society). The article was first published on June 1, 2018.

Stiff-Yet-Supple Plastic Can be Reshaped and Recycled

eat-cured plastics called thermosets can’t be beat for their long lives. But these resilient polymers, used to make coatings, car parts, and dishes, have a flaw: they can’t be reshaped or recycled. Now, a new plastic features the toughness of thermosets in a more sustainable package. Unlike its predecessors, it can be melted and reformed into a new object that is just as strong as the original, or broken down into its starting material, which can be reused to make new polymers.

Thermoset plastics, which include materials like epoxy resin and melamine, are produced by heating liquid raw materials or reacting them with a catalyst. They are hard, strong, and resist chemical corrosion and high temperatures. But those impressive mechanical properties mean that once a melamine plate cracks, it typically ends up in a landfill.

In recent years, researchers have developed a more malleable class of thermoset called a vitrimer that can be shaped like glass when heated, but keeps its toughness when cool. These are based on cross-links that break and reform at elevated temperatures. But so far, it has been difficult to make a vitrimer with high mechanical strength that can be easily melted and remolded multiple times, and broken down into its raw materials to be recycled, says chemist Zhibin Guan at the University of California, Irvine.

Guan’s group examined boron-oxygen bonds because they are “thermodynamically very stable and strong bonds,” he says. From previous work, they knew that boron-oxygen bonds could be made flexible. In particular, he and his graduate student William Ogden turned to boroxine, a compound with a six-membered ring of alternating boron and oxygen atoms made by dehydrating boronic acid.

The researchers started with diboronic acid monomers. They made a solution of the monomers and a pyridine-based plasticizer, poured it into a dish, and heated it to 80°C for 12 hours. This dehydration produced a stiff, strong boroxine-based thermoset insoluble in organic solvents.

The material could be reshaped when the researchers applied pressure and heat, and even at room temperature if pressure was applied for a long enough time. Boroxine rings are fluid: They break and then reform in another part of the polymer network when they react with residual boronic acid groups. “It’s like a harder, more robust version of silly putty,” Guan says.

These properties also allowed the polymer to be reprocessed. The researchers repeatedly cut the sample into pieces and hot-pressed them in a mold to reform a new sample without any loss in mechanical properties.

But the last test demonstrated the full recyclability of the material: They dissolved the plastic in boiling water and cooled the solution to recover the starting monomer, a white powder of diboronic acid.

The plastic could be tailored for coatings, adhesives, fillers for composites, and for 3-D printing, Guan says. Plus, the chemical components are inexpensive and readily available, so large quantities should be easy to make.

This is a nice design strategy for malleable thermoset polymers, says Wei Zhang, a chemist at the University of Colorado, Boulder. The ability to degrade plastics to their constituent monomers would minimize chemical waste and provide a greener, more eco-friendly approach to plastics, he says. Practically, however, the researchers need to thoroughly study this new material’s resistance to moisture; This new material fully dissolves in boiling water, which could limit its applications.

Guan says that there are many ways to tune the properties of this initial proof-of-concept system. “By putting more hydrophobic components in the monomer unit, we should be able to make it much more stable toward water.”

This article is reproduced with permission from C&EN (© American Chemical Society). The article was first published on May 31, 2018.

Introducing the “Emerging Investigators” Special Issue from the Journal of Chemical & Engineering Data

This article is part of the Emerging Investigators special issue.

Any field of science or engineering is characterized by the research conducted by those who work in the discipline. A specific field will evolve over time not only because of the changing interests of the people working in it, but also due to changes brought as researchers enter and leave (one might notice an analogy to fluid mechanics here!). Each generation of young investigators matures in a different technological environment, and consequently, they come to an academic field with very different skills and goals as compared to their predecessors. Generally, this is good, as each new group will embrace the truly valuable advances made by the previous generations while leaving behind methods, topics, and attitudes that have remained only because of sentiment or habit.

With this in mind, we are pleased to present our latest issue of Journal of Chemical & Engineering Data, which focuses on “Emerging Investigators” in chemical thermodynamics. These are the researchers who will be defining our field over the coming decades. By seeing and understanding the perspectives of this group, we get a sense of the shape of things to come.

A quick review of the contents shows a healthy mix of new and old. Studies of fluid-fluid coexistence and adsorption remain an important topic, though in some cases the substances involved are of more recent interest (e.g., metal-organic frameworks). Bulk material properties remain important subjects of measurement as well, again with some more recent twists (e.g., ionic liquids). We are struck, however, by the significant presence of computational methods for evaluating properties. Another notable element is the diversity of phenomena and materials that is spanned by the studies, showing that although certain “hot topics” dominate the news, there is still a broad representation of property and phase coexistence data among the research interests of those entering the field.

We hope this snapshot of the future of JCED is informative and of interest to our readership. Apart from the presentation of research topics, this issue is notable also for highlighting the people who will form the next generation of chemical thermodynamics. We will be eagerly following their contributions in the decades to come (or at least for those years before our own retirement!).

Read the Special Issue Today.

Tackling Sustainable Fertilizer Production with an Alternative Electrolyte

mmonia is a vital ingredient in the fertilizers that sustain global agriculture, but it comes with a huge environmental cost. The Haber-Bosch process, which combines nitrogen and hydrogen to make ammonia, consumes about 2% of the world’s energy supply, and its hydrogen feedstock is made by steam reforming methane at high temperature and pressure, producing significant CO2 emissions. An electrochemical system that relies on an unusual electrolyte could now point the way to a more sustainable form of ammonia production.

Chemists have long sought alternatives to the Haber-Bosch process that could use solar or wind power to reduce nitrogen electrochemically at ambient temperature and pressure with the help of a catalyst. But these electrochemical cells have struggled with poor efficiency because nitrogen is not very soluble in water, so protons in the aqueous electrolyte are reduced to hydrogen gas instead. The result is “a process that makes hydrogen and a tiny bit of ammonia along with it,” says Douglas R. MacFarlane of Monash University.

Some researchers have surmounted this hurdle by eschewing the iron-based catalyst used in Haber-Bosch in favor of a catalyst with a lower affinity for protons, such as gold nanorods. But MacFarlane is tackling the problem by swapping the aqueous electrolyte for an ionic liquid—a salt that cannot crystallize at ambient conditions and so exists in liquid form. Last year, he and colleagues developed a cell using a fluorinated ionic liquid called 1-butyl-1-methypyrrolidinium tris(pentafluoroethyl)trifluorophosphate. Nitrogen is about 20 times as soluble in this ionic liquid as in water, and while the protons necessary to produce ammonia are delivered via water vapor along with nitrogen, there are none in the electrolyte, slashing the extent of the competing reaction to hydrogen. This cell achieved a 60% Faradaic efficiency, meaning 60% of the current applied went to produce ammonia, far surpassing the approximately 10% Faradaic efficiency of the most-efficient systems using heterogeneous electrocatalysts under ambient conditions. But the rate of the reaction itself—the amount of ammonia produced per unit time—was about a tenth that of other systems because the high viscosity of the ionic liquid slowed down the reacting molecules.

Now, he and his team have blended an aprotic fluorinated solvent, 1H,1H,5H-octafluoropentyl 1,1,2,2-tetrafluoroethyl ether, with the ionic liquid to lower the electrolyte’s viscosity while still retaining high nitrogen solubility and limiting proton reduction. The researchers also increased the accessible surface area of their iron-oxide-based catalyst by growing it into nanorods on carbon fiber paper. The result is a system with 32% Faradaic efficiency and a reaction rate about ten times higher than last year’s test system.

Shelley D. Minteer, a chemist at the University of Utah who is designing bioelectrocatalysis systems that use nitrogen-fixing enzymes, says she is impressed by the study. “The majority of times, scientists are focused on the catalyst and not thinking about the importance of rationally designing the electrolyte,” she says. “This clearly shows the importance of the electrolyte in this very difficult reaction.” Bioelectrocatalysis systems match the efficiency of the new system but have slower reaction rates by orders of magnitude, she says.

MacFarlane and his colleagues plan to spin out the system from Monash University to bring it from a small, lab-scale reactor to commercial scale. Australia’s abundant potential for solar and wind energy is driving interest in ammonia production systems run by large solar or wind farms, MacFarlane says. Though toxicity is often a concern when using fluorinated solvents, MacFarlane says that the closed system they have designed would prevent release of the electrolyte into the environment during its use.