Nanotechnology – old or new?

an article by Marina Vance (@marinavance), PhD scientist at Virginia Tech

Summer is almost over and so is a whirlwind of environmental engineering- and nanotechnology-related conferences. At a previous environmental nanotechnology-related conference, I had the great experience to participate in a lively debate on a very fundamental, albeit not often asked question in our field: is nanotechnology novel?

At first, one may think this question should not even be open for debate, since the very idea of nanotechnology evokes exciting futuristic thoughts about the future of medicine, solar energy, nanorobots, and even science fiction.

In this recently published paper, Hochella, Spencer, and Jones present an overview of this unexpected debate. Jones moderated a discussion in which Hochella and Spencer, two experts in their respective fields of nanogeoscience and electrical engineering/material science, brought their arguments for and against the following statement:

“The magic of nanomaterials is not new: nature has been playing these tricks for billions of years.”

In my view, nature’s nanostructures can be informative of how the environment responds to nanomaterials and their study is instrumental for informing environmental nanoscience and technology. However, the potential existence of natural analogues to engineered nanostructures is no evidence that there is reduced likelihood of adverse environmental effects, since after all, with the exception of a few synthetic compounds (e.g., CFC), most environmental pollutants exist in nature. We just happen to place them where they don’t belong (e.g., lead in the atmosphere).

The untended meadow of nature’s nanostructures and the
English-style garden of engineered nanomaterials

This work takes you around the universe and back to demonstrate the importance of determining whether naturally-occurring nanomaterials are representative of the novel and well-controlled structures engineered by man.


To access the full article, download a copy for free by clicking the link below:

Nanotechnology: nature’s gift or scientists’ brainchild?
Michael F. Hochella, Jr., Michael G. Spencer and Kimberly L. Jones
Environ. Sci.: Nano, 2015, 2, 114-119
DOI: 10.1039/C4EN00145A

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About the webwriter

Marina Vance is a PhD research scientist at Virginia Tech and Assocuate Director of @VTSuN. She is interested in air quality, nanotechnology and health. You can find more information about her in mevance.com.

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2015 SNO Emerging Investigator

Send your nominations now!

The SNO Emerging Investigator designation gives recognition to emerging scientists and engineers working in the area of sustainable nanotechnology.  In recognition of this designation, a certificate and a US$1500 prize will be presented at the 2015 SNO Conference.

Criteria and eligibility include:

  1. Investigators who are within the first 10 years post Ph.D.
  2. An impactful body of independent work and publications in the area of sustainable nanotechnology: environmental, societal, or economic.
  3. Attendance at the 2015 SNO Conference in Portland, Oregon November 8th – 10th 2015 and a high quality paper submission to Environmental Science: Nano within one year after receiving the award.

The nomination consists of a single (1-page max) nomination letter, a second (1-page max) support letter and a 2-page CV (self-nominations are not accepted). The nomination letter should describe how the nominee’s research impacts the field of sustainable nanotechnology.

The support letter should focus on the nominee’s teaching, service and leadership in the field of sustainable nanotechnology. Both the nomination and support letters can be made by SNO members and Environmental Science: Nano Editorial and Advisory  Board members.  Nominations are not restricted to the US or UK.

Letters and CVs are due to Environmental Science: Nano Editor-in-Chief Vicki H. Grassian (vicki-grassian@uiowa.edu) by September 15, 2015.

The selected Emerging Investigator will be honored at the SNO Awards dinner on Sunday November 8, 2015.

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2nd National Environmental Eco-Toxicology Conference

Held in Xiamen (China), April 2015

The 2nd National Environmental Eco-Toxicology Conference was held in Xiamen, China, 25th-28th of April, 2015.

This exciting conference was jointly organised by the Research Center for Eco-environmental Sciences of the Chinese Academy of Sciences (CAS), Xiamen University and the Institute of Urban Environment of CAS.

More than 700 attendees shared new ideas and recent development on the are six topics discussed during this conference:

  • Screening and assessment of high risk chemical contaminants
  • Transfer and distribution of chemical contaminants in the environment and organisms
  • Chemical hazards evaluation
  • Toxicology mechanism of chemical ecology
  • Toxicological mechanism of chemical health effects
  • Chemical risk management


During the conference, the Environmental Science (ES) series of journals sponsored three poster prizes. Let’s introduce the winners!

Environmental Science: Processes & Impacts: ‘Study on the toxicity behavior of organic phosphate ester flame retardant to pattern fish’, by Liwei Sun (Zhejiang Institute of Technology)

Environmental Science: Water Research & Technology: ‘Bioaccumulation behaviour of short chain chlorinated paraffins in Antarctic ecosystem’, by Huijuan Li and Aiqian Zhang (Research Center for Eco-Environmental Sciences)

Environmental Science: Nano: ‘Proinflammatory effects of silver nanoparticles and silver ions on human skin keratinocytes’, by Yang Di, Wei Hong-ying, Wang Bin, Fan Jing-pu, Qin Yu, Liu Yue, Guo Xin-biao and Deng Fu-rong (Peking Universty)

Congratulations to all the winners!

The judges of the prize thought the quality of the posters was really high and, from the Environmental Science team, we would like to thank all the researchers that attended or presented at the conference.

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Photochemical reactivity of single layer graphene oxide (GO) in water

a blog article by Imali Mudunkotuwa at The University of Iowa

Graphene oxide (GO) is a precursor material in the preparation of graphene. Despite its name, on the surface of this material there are different types of functional groups including epoxy, hydroxyl and carbonyl groups. As a result, GO is hydrophilic and easily dispersed in water. This has led to a variety of investigations relating to GO as a potential pollutant, as well as a possible treatment to cancer.

The disrupted π-bond structure in GO enables the absorption of significant amounts of light from solar radiation. Therefore, environmental processing of GO can be expected to include photochemical processes. One important outcome of such processing is the generation of reactive oxygen species (ROS). These ROS can include singlet oxygen (1O2), superoxide anions (O2.-) and hydroxyl radicals (.OH). Generation of ROS has a significant impact on ecological risks associated with GO and is critical in understanding the transformation pathways of carbon in the GO structure.

Therefore, Yingcan Zhao and Chad T. Jafvert at Purdue University (West Lafayette, USA) has investigated the ability of aqueous dispersions of single layered GO to generate ROS upon exposure to light within the solar spectrum (λ=300-410 nm). The generated ROS was detected using specific chemical probes, UV-vis spectroscopy and Raman spectroscopy.

The findings of this research highlighted that upon exposure to solar radiation there is electron transfer reactions occurring from GO to dissolved O2, forming O2.- and significant quantities of H2O2.

Given the fact that these are reduction reactions, this resulted in an overall oxidation of GO. Some of the generated ROS reacted directly with the GO surface and therefore, the oxidation of GO was found to be non-stoichiometric.

The exposure to light also increased the chromophores content or the absorptivity of existing chromophores, as suggested by the increased darker colour of the GO suspensions. However, Raman spectroscopic analysis also indicated an increase in non-aromatic defects.


To access the full article, download a copy for free* by clicking the link below.

Environmental photochemistry of single layered graphene oxide in water
Yingcan Zhao and   Chad T. Jafvert
Environ. Sci.: Nano, 2015, 2, 136-142
DOI: 10.1039/C4EN00209a

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About the webwriter

Imali Mudunkotuwa is a Postdoctoral Scholar and Research Assistant at The University of Iowa. She is interested in nanoscience, physical and surface chemistry. You can find more articles by Imali in her author archive .

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* Access is free until the 21/06/2015 through a registered RSC account

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Halloysite: finally a promising natural nanomaterial?

a blog article by webwriter Imali Mudunkotuwa

Halloysite nanotubes (HNT) are products of nature. In chemical composition they are similar to kaolin and can be considered as rolled kaolin sheets with inner diameter of 10-20 nm, outer diameter of 40-70 nm and a length of 500-1500 nm. The internal side of halloysite is composed of Al2O3 while the external is mainly SiO2.

These clay tubes are excavated from mines as stone minerals and processed by milling to form fine power of tubes, which is then used to dope a variety of polymers. The polymer doping has been observed to enhance various properties of these polymers including strength, adhesivity and flame retardancy. In addition, the large surface area and oppositely charged inner and out diameter facilitate loading a variety of biomolecules useful in medical applications. Given this wide range of applications there is an inevitable release of these materials back to the environment in this refined forms.

Despite the many reports on in vitro toxicity of HNTs, there is only limited information available with regard to its in vivo toxicity. Therefore, to shed light on this matter., Professor Fakhrullin and colleagues at Kazan Federal University investigated for the first time the in vivo toxicity of HNT using Caenorhabditis elegans nematode as a model organism. The C. elegans are an important tool in molecular biology because its fully sequenced genome is closely homologous to the human genome.

The findings of this research has shown that the primary pathway of the HNT entry into the organism is the intestinal uptake. The toxic effects of HNT uptake was then investigated by comparing the body size, fertility (or the number of eggs laid in other words) and longevity of the nematodes.

These comparisons did not give statistically significant differences between the controls, which suggests that these are potentially environmentally safe materials to work with. This is in fact is in contrast to the toxicities observed with other nanomaterials such as single walled carbon nanotubes (SWCNTS), graphene oxides, TiO2 nanoparticles and platinum nanoparticles.

Even coating the nematode eggs with the HNT did not result in any significant deviations from the control nematodes. At extremely high doses of HNT did inflict some mechanical stress on the alimentary systems but these levels are highly unlikely to be encountered under environmentally relevant conditions.


To access the full article, download a copy for free* by clicking the link below.

Toxicity of halloysite clay nanotubes in vivo: A Caenorhabditis elegans study
Gölnur I. Fakhrullina, Farida S. Akhatova, Yuri M. Lvov and Rawil F. Fakhrullin
Environ. Sci.: Nano, 2015, 2, 54-59
DOI: 10.1039/C4EN00135D

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About the webwriter

Imali Mudunkotuwa is a Postdoctoral Scholar and Research Assistant at The University of Iowa. She is interested in nanoscience, physical and surface chemistry. You can find more articles by Imali in her author archive .

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*Access is free through a registered RSC account.

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Great balls of fire

Particulate matter from incineration of nanowaste – is it toxic?

Environmental Science Nano Cover VejeranoPeople in modern societies produce a lot of waste. I propose that you think about it next time you buy something. How much of it is comprised of packaging? How much of that packaging is recyclable? How much of it will become waste after a short while?

With the fast advancement of nanotechnological applications to enhance consumer products, we can expect nanomaterials to become ubiquitous in our domestic waste. So what happens when we burn nanotechnology-enhanced waste (or nanowaste)? Unlike that great Jerry Lee Lewis song that everybody knows, the answer to this question is a little bit more complex.

Most modern incinerator facilities are equipped to minimize the emission of air pollutants from the incineration process, especially particulate matter (also known as fly ash).

But what if some nanomaterials lead to the production of different pollutants during the incineration process? As we know from this blog, nanomaterials are multi-talented. Some have the ability to catalyze reactions, which can lead to the production of potentially toxic combustion by-products.

There are many locations around the world that perform open burning to dispose of waste. Therefore, it is possible that air pollutants generated may be slightly different if the waste contains nanomaterials.

In their most recent work—and ES Nano cover articleVejerano and colleagues evaluated the toxic response of fly ash from waste that contained a wide variety of nanomaterials, such as nanosilver, titania, ceria, fullerenes, quantum dots, and more.

They found that waste that contained nanosilver, titania, and C60 fullerenes led to a toxic response in human lung epithelial cells, which is signalled by an increase in the production of reactive oxygen species (ROS). But, in addition to that, this study also shows that the presence of nanomaterials in waste is not expected to significantly alter the environmental and health risk of the fly ash emitted from combustion processes.


To access the full article, download a copy for free* by clicking the link below:

Toxicity of particulate matter from incineration of nanowaste
Eric P. Vejerano, Yanjun Ma, Amara L. Holder, Amy Pruden, Subbiah Elankumaran and Linsey C. Marr
Environ. Sci.: Nano, 2014, 2, 143-154
DOI: 10.1039/C4EN00182F

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About the webwriter

Marina is a PhD research scientist at Virginia Tech and Assoc. Director of @VTSuN. She is interested in air quality, nanotechnology and health. You can find more information about her in her website mevance.com.

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Introducing Advisory Board Member, Omowunmi Sadik

We are delighted to introduce Omowunmi Sadik as an Advisory Board Member for our journal Environmental Science: Nano.

Omowunmi Sadik

Wunmi is a Professor of Chemistry at the State University of New York at Binghamton, Director of the Center for Advanced Sensors & Environmental Systems and President of the Sustainable Nanotechnology Organization.

Professor Sadik received her Ph.D. in Chemistry from the University of Wollongong in Australia and did her postdoctoral research at the US Environmental Protection Agency in Las Vegas, Nevada. She has held appointments at Harvard University, Cornell University and Naval Research Laboratories in Washington, DC.

Sadik’s research currently centers on the interfacial molecular recognition processes, sensors and biomaterials, and immunochemistry with tandem instrumental techniques. Her work utilizes electrochemical and spectroscopic techniques to study human exposure assessment, endocrine disrupters, and toxicity of naturally occurring chemical compounds.

Wunmi’s research:

The driving force behind my biosensor research is the need to build sensor systems that quantitatively measure target species in a complex system.

Omowunmi Sadik, Advisory Board Member, Environmental Science: Nano

Make sure you don’t miss out on the latest journal news by registering your details to receive the regular Environmental Science: Nano e-alerts.

Follow us on Twitter @ESNano_RSC.

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Environmental Risk Modeling of Nanoparticles: Kd vs α

A blog article by webwriter Imali Mudunkotuwa

Everyone loves and hates nanoparticle aggregation. Why? Because it is a fascinating phenomenon but it complicates all of our experiments, ranging from in vitro / in vivo studies, all the way to the environmental models. For ease of study, it can be broken down into homoaggregation and heteroaggregation. Investigating the former is relatively easier than the latter (relatively!), but in the real world we are forced to deal with the latter. Simply, heteroaggregation in the environment refers to attachment of ENPs to naturally occurring solids (e.g. soil particles, suspended sediments). This plays a key role in determining ENPs bioavailability and mobility in the environment.

Large-scale fate and transport models have been adapted for modelling of ENPs. Earlier models use mass balance as a framework with partition coefficients (Kd) to describe the soil-water distribution of ENPs, but recent studies argue that particle number-based kinetic models using attachment efficiency (α) are better at this, given that colloidal suspensions never reach an equilibrium state as well as ignore the size dependent properties. Yet no agreement has been established on the best way to treat heteroaggregation in these models.

Therefore, to shed light on this matter, Amy L. Dale (Engineering and Public Policy, Carnegie Mellon University, PA), Gregory V. Lowry (Civil and Environmental Engineering, Carnegie Mellon University, PA), and Elizabeth A. Casman (CEINT, Duke University, NC) discuss in detail the ongoing practical challenges in model formulation, parameterization, and calibration for ENPs in their perspective.

A couple of highlights in this article are:

- Particle balance models are more complex, making it challenging to parameterize ENPs in the environment. Therefore, many assumptions are needed that have been discussed in detail in the perspective.

- Attachment efficiency is agreed to be the most appropriate fate descriptor for small-scale models, but at large-scale these models it is claimed to be relative insensitive to the particulate nature of ENPs.

Given the lack of scientific understanding on ENP heteroaggregation it was suggested that balance models to be the better choice, at least in the short term. Overall rates of sorption and desorption has been suggested to be used in the place of equilibrium partition coefficients to overcome concerns arising from using the equilibrium Kd.

To access the full article, download a copy for free* by clicking the link below.

Much ado about α: reframing the debate over appropriate fate descriptors in nanoparticle environmental risk modeling
Amy L. Dale, Gregory V. Lowry, Elizabeth A. Casman
Environ. Sci.: Nano, 2015, Perspective
DOI: 10.1039/C4EN00170B

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About the webwriter

Imali Mudunkotuwa is a Postdoctoral Scholar and Research Assistant at The University of Iowa. She is interested in nanoscience, physical and surface chemistry. You can find more articles by Imali in her author archive .

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* Access is free through a registered RSC account

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Introducing Advisory Board Member, Ki-Bum Kim

We are delighted to introduce Ki-Bum Kim as an Advisory Board Member for our journal Environmental Science: Nano.

Ki-Bum Kim
Professor Kim is the supervisor of the Nano Fabrication Laboratory in the Department of Materials Science and Engineering at Seoul National University.

Ki-Bum’s exciting research is focused on the fabrication of novel nanoscale materials and devices such as graphene, transparent conducting oxide, nanopore and nanochannel structures for manipulation of ions, biomolecules and DNA.

His team at the Nano Fabrication Laboratory has conducted a broad range of researches on thin film deposition, characterisation, nanoscale fabrication, and evaluation of emerging nanodevices, and they have particular interest in nanofluidic systems.

He has a broad interest on the structure and property relationship in thin film materials. In particular, he has actively worked on the development of metallisation processes for the next generation of Integrated Circuits (ICs), including the development of silicides, diffusion barriers, and interconnecting of materials and processes.

Ki Bum’s laboratory:

We are always open to creative research topics which give a new insight into novel emerging devices and nanoscale phenomena.

Ki-Bum Kim, Advisory Board Member, Environmental Science: Nano

Make sure you don’t miss out on the latest journal news by registering your details to receive the regular Environmental Science: Nano e-alerts.

Follow us on Twitter @ESNano_RSC.

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Quantum dots and a blocking model

an article by our webwriter Marina Vance (follow her on Twitter @marinavance)

Of all nanomaterials that I know and have studied in these past seven years working with environmental nanoscience, Quantum Dots (QDs) have by far been my favorites. They just sound so sci-fi. I mean, just listen to their name: Quantum dots [imagine a low, cinema narrator voice]. Also, they glow in neon multi-colors when exposed to UV light.

This interesting optical property of quantum dots is due to quantum confinement, a phenomenon that takes place when some semiconductor particles are so small that the trajectory of their electrons becomes confined. The level of confinement depends on the size of the particles, which is why QDs of different sizes emit different colors.

QDs present the potential for a wide variety of applications, such as solar cells, lasers, LEDs, medical imaging, and even quantum computing. They are just so cool!

One more thing I have learned in these few years working with environmental nanoscience is that anything with so many potential applications is bound to, somehow, end up in the environment.

Quantum dot dispersions hanging out and emitting their neon quantum confinement glow, no big deal.

A common type of QD is a nanohybrid made of a cadmium selenide (CdSe) core and a zinc sulfide (ZnS) shell (CdSe/ZnS), which has been shown to be toxic to organisms and is a known carcinogen to humans. So, it is important to understand the way in which these QDs will be transported through the environment.

QDs and other nanomaterials are often coated with surfactants or polymers to improve stability—to prevent nanoparticles from sticking to each other, which they love to do. The presence of coatings may deeply affect their interactions with the environment.

M. D. Becker and colleagues recently published a study to improve existing models for the transport of coated QDs through porous media, which is an idealized template for groundwater and soil.

They observed that QDs became increasingly stuck to the porous media as they were transported. Both the coating and the presence of other constituents in the environment (such as natural organic matter) may help QDs “slide” more easily through the porous media. But as these coatings are stripped off over time, particles end up getting stuck.

This behavior could not be explained by traditional nanoparticle transport models, so they developed a new transport model to account for the influence that coatings and other constituents may have in the transport of nanomaterials through porous media.


To access the full article, download a copy for free* by clicking the link below:

A multi-constituent site blocking model for nanoparticle and stabilizing agent transport in porous media
Matthew D. Becker, Yonggang Wang, Kurt D. Pennell and Linda M. Abriola
Environ. Sci
.: Nano, 2015, Advance Article
DOI: 10.1039/C4EN00176A


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About the webwriter

Marina is a PhD research scientist at Virginia Tech and Assoc. Director of @VTSuN. She is interested in air quality, nanotechnology and human health. You can find more information about her in her website mevance.com.

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* Access is free through a registered RSC account

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