End-of-life of nano-enabled products by thermal ... · End-of-life of nano-enabled products by thermal decomposition: Possible environmental health and safety implications Georgios

End-of-life of nano-enabled products by thermal

decomposition: Possible environmental health and

safety implications

Georgios A. Sotiriou1,2, Dilpreet Singh2, Fang Zhang2, Lutz Hoering3,

Wendel Wohlleben2,3, Philip Demokritou2

1Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet,

Stockholm, Sweden.2Center for Nanotechnology and Nanotoxicology, Department of Environmental Health,

T.H. Chan School of Public Health, Harvard University, USA. www.hsph.harvard/nano3BASF SE, Material Physics, Germany.

email: [email protected]

Visit our lab website: www.sotirioulab.net

http://www.hsph.harvard/nano

mailto:[email protected]

http://www.sotirioulab.net/

Nanotoxicity: Realistic exposure scenarios?

So far: Nanotoxicity evaluation of “raw” nanomaterials, which is great for:

Mechanistic understanding

Occupational exposures

Realistic exposures?

Transformations of nanomaterials

during their life-cycle[1]

22 november 2016Georgios A. Sotiriou 2

TG3 White Paper Draft, June 1, 2012 2

identify various potential release scenarios for CNT used in polymers and identify the greatest

likelihood of release at the various stages throughout the lifecycle of the product and article.

Figure 1: Product life cycle of products containing nanoparticles

The focus of this white paper is on release as a prerequisite for exposure. Exposure is

defined as: “Contact of an organism with a chemical, radiological, or physical agent. Exposure is

quantified as the amount of the agent available at the exchange boundaries of the organism

(e.g.; skin, lungs, gut) and available for absorption” (source http://glossary.eea.europa.eu).

Exposure scenarios are used to describe the conditions that result in exposure, for example the

REACH definition of an exposure scenario: “Set of conditions, including operational conditions

and risk management measures, that describe how the substance is manufactured or used

during its life-cycle and how the manufacturer or importer controls, or recommends downstream

users to control, exposures of humans and the environment.” However, in the context of this

white paper, we describe release scenarios and not exposure scenarios. The definition of a

release scenario is not unambiguous, however, for the purpose of this white paper a release

scenario is defined as the operational and or environmental conditions of any treatment or

stress of CNT composite material during all life-cycle phases that results into the release of

CNT/composite material into indoor environments, e.g. workplace, dwellings, and or

[1]

150 nm

[2]

[1] Nowack, David, Fissan, Morris, Shatkin, Stintz, Zepp, Brouwer. Environ. Int. 59, 1 (2013). [2] Pirela, Sotiriou, Bello, Shafer, Bunker, Castranova, Thomas, Demokritou. Nanotoxicology 9, 760 (2015).

Knowledge gaps of nano-release at End-of-Life


Our TARGET• Obtain fundamental understanding on what

factors influence the physicochemical and morphological properties of released materials

• Burning question: Is there a nanofiller-specific effect?

[1] Wohlleben, Meier, Vogel, Landsiedel, Cox, Hirth, Tomovic. Nanoscale 5, 369 (2013).

[1]

Integrated Exposure Generation System (INEXS)


S10

Figure S1. Schematic of the Integrated Exposure Generation System (INEXS) consisting of 3 modules,

namely, the incineration of nano-enabled product under controlled conditions, the post-release aerosol

treatment and the aerosol size-fractionated collection and exposure characterization (both in-situ and ex-

situ).

Advantages

• Versatile: Easy to change thermal decomposition scenario

• Real time equipment: Monitor particle concentration, size and composition

• Collection of mg of aerosol: Allows sufficient characterization and tox studies

• In situ inhalation studies: Direct aerosol in animal chambers

• Facile collection of residual ash

NEPs panel


Matrix nanofiller

nanofiller loading

application

Polyurethane

(PU)

- -

automotive,

buildings, textiles

carbon black (CB)

0.1%

carbon

nanotubes (CNT)

0.1%

Polyethylene (PE)

- -

packaging, buildings,

constructions

Fe2O3 1-5% organic filler 2%

organic filler +

UV agent 2%

Polycarbonate (PC)

- - automotive, electronics CNT 3%

Polypropylene

(PP)

- - packaging,

electronics CNT 3%

Ethylene vinyl

acetate (EVA)

- - packaging,

biomedics TiO2 1-15%

Medicinal waste Ag biomedics

MA

RIN

AB

AS

F

PU-CNT

Um

ass

Low

ell

Nanofiller effect on aerosol size & concentration?


@ConcMax

PU-based NEPs

Pure and with two different nanofillers (carbon black-CB, and carbon nanotubes-CNTs)

No effect on released aerosol concentration and size due to the nanofiller presence

Host polymer dictates the released PM

>99% organic carbon, independent of nanofillerpresence

Is there any nanofiller in the released aerosol?


200 nm

PU-CNT (800 ˚C)

PM0.1

200 nm

PE-Fe2O

3 (800 ˚C)

PM0.1 PM0.1-2.5

SEMafter dispersion in alcohol and

drying on SEM substrate

TEMin-situ deposition on

TEM grids in CCI

ICP-MS:

0.026 wt% Fe

PU-CNT

Nanofiller effect on chemistry of aerosol?

TGA-FTIR (in situ detection of off-gases), ex-situ NMR


PU-CNT (800 ˚C) PU (800 ˚C) PU (500 ˚C)

CO2, CO and H2O,

THF, methane,

ethylene and aldehydes

CO2, CO and H2O,

methanol, methane,

ethylene, ketones

with I.G. Kavouras, Univ Arkansas

Polycyclic aromatic hydrocarbon (PAH) species

16 Environmental Protection Agency (EPA)-priority polycyclic aromatic

hydrocarbon (PAH) species


with V. Craver, Univ Rhode Island Singh et al., in preparation (2016).

Is there nanofiller in the residual ash?


• CNTs in residual ash

• Homogeneously dispersed

throughout the ash

• 18 times higher

concentration than raw NEP

500 ˚C

EC (%) OC (%)

PU 85 15

PU-CB 77 23

PU-CNT 82 18

PU-CNT

Effect of nanofiller on residual ash composition


PE-Fe2O3

Td,final = 500˚C (PE-Fe2O3)• Presence of Fe2O3 facilitates

full polymer decomposiiton

500 ˚C

EC (%) OC (%)

PE 78 22

PE-org 75 25

PE-Fe2O3 - -

• Change of Fe2O3 crystal phase

for final T = 500 ˚C (reduced

from hematite to maghemite)

ICP-MS:

75% wt% Fe

Summary

Novel integrated exposure generation system for the end-of-life thermal

decomposition of NEPs

Main question: Is there any nanofiller-specific effect?

Released aerosol:

• Not in released aerosol concentration and size

• Yes in chemical composition

Residual ash:

• Most nanofiller remains in ash

• Physicochemical properties of remaining nanofiller might not be the same

as in raw materials

Outlook

Collect and extract enough PM for tox studies (in vitro and in vivo)


Acknowledgements

HSPH

Philip Demokritou

Dilpreet Singh

Fang Zhang

BASF

Wendel Wohlleben

Lutz Hoering

Univ Arkansas

Ilias G. Kavouras

Marie-Cecile Chalbot

Carnegie Mellon

Gregory V. Lowry

Eleanor Spielman-Sun


• NSF (grant nr. 1436450)

• BASF AG

• Swiss NSF

Thank you for listening

More info:[1] G. A. Sotiriou, D. Singh, F. Zhang, W. Wohlleben, M-C. G. Chalbot, I. G. Kavouras & P. Demokritou*.

“An integrated methodology for the assessment of environmental health implications during thermal

decomposition of nano-enabled products” Environ. Sci.: Nano 2, 262-272 (2015).

[2] G. A. Sotiriou, D. Singh, F. Zhang, M-C. G. Chalbot, L. Hoering, I. G. Kavouras W. Wohlleben & P.

Demokritou*. “Thermal decomposition of nano-enabled thermoplastics: Possible environmental health

and safety implications” J. Hazard. Mater. 305, 87-95 (2016).

[3] D. Singh, G. A. Sotiriou, F. Zhang, J. Mead, D. Bello, W. Wohlleben & P. Demokritou*. “End-of-life

thermal decomposition of nano-enabled polymers: effect of nanofiller loading and polymer matrix on by-

products” Environ. Sci.: Nano in press DOI: 10.1039/C6EN00252H (2016).


Open PhD student position in our lab

visit: www.sotirioulab.net

for more info

http://www.sotirioulab.net/



Released aerosol concentration and size (PU-CNT)


• route 1 (no treatment) Td,final: final thermal decomposition temperature

NANOTOX 2012

G.A. Sotiriou, E. Diaz, M. S. Long, J. Godleski, J. Brain, S.E.

Pratsinis, P. Demokritou, “A Novel Platform for Pulmonary and

Cardiovascular Toxicological Characterization of Inhaled Engineered

Nanomaterials”, Nanotoxicology 6, 680-690 (2012).

SMALL 2013

A. Pratsinis, P. Hervella, J-C. Leroux, S.E. Pratsinis, G.A. Sotiriou,

“Toxicity of Silver Nanoparticles in Macrophages”, Small 9, 2576-

2584 (2013).

[3] Sotiriou, Pratsinis, Environ. Sci. Technol. 44, 5649 (2010).

ACS SUST

CHEM 2013

S. Gass, J. Cohen, G. Pyrgiotakis, G.A. Sotiriou, S.E. Pratsinis, P.

Demokritou, “Safer Formulation Concept for Flame-Generated

Engineered Nanomaterials”, ACS Sustainable Chem. Eng. 1, 843-

857 (2013).

ES:NANO 2014

G.A. Sotiriou, C. Watson, K.M. Murdaugh, T.H. Darrah, G.

Pyrgiotakis, A. Elder, J.D. Brain & P. Demokritou. “Engineering

Safer-by-Design, Transparent, Silica-coated ZnO Nanorods with

Reduced DNA Damage Potential”, Environ. Sci.: Nano 1, 144-

153 (2014).

P&FT 2014

N.V. Konduru, K.M. Murdaugh, G.A. Sotiriou, T.C. Donaghey, P.

Demokritou, J.D. Brain & R.M. Molina. “Bioavailability, distribution

and clearance of tracheally-instilled and gavaged uncoated or silica-

coated zinc oxide nanoparticles”, Part. Fibre Toxicol. 11:44 (2014).

ES:NANO 2015

G. A. Sotiriou, D. Singh, F. Zhang, W. Wohlleben, M-C. G. Chalbot,

I. G. Kavouras & P. Demokritou. “An integrated methodology for the

assessment of environmental health implications during thermal

decomposition of nano-enabled products” Environ. Sci.: Nano 2, 262-

272 (2015).

NANOTOXICOL

OGY 2015

S. Pirela, G.A. Sotiriou, D. Bello, M. Shafer, K. Lee Bunker, V.

Castranova, T. Thomas & P. Demokritou. “Consumer exposures to

laser printer-emitted nanoparticles: A case study of the life-cycle

implications from nano-enabled products” Nanotoxicology 9, 760-768

(2015).

J HAZARD

MATER 2016

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NANOMEDICINE

2016












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End-of-life of nano-enabled products by thermal ... · End-of-life of nano-enabled products by thermal decomposition: Possible environmental health and safety implications Georgios