Transformation of aggregated C60 in the aqueous phase by UV irradiation

Jaesang Lee, Min Cho, John D. Fortner, Joseph B. Hughes, Jae Hong Kim

Research output: Contribution to journalArticle

76 Citations (Scopus)

Abstract

This study demonstrates that water-stable C60 cluster (nC 60) undergoes a photochemical transformation(s) when irradiated with monochromatic UV light at 254 nm. Upon UV exposure, characteristic absorption of nC60 in the visible (ca. 450-550 nm, indicative of a cluster structure) and UV regions (indicative of underivatized molecular C60) gradually disappeared. Concurrently, a new product with absorption centered at 210 nm formed. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses confirmed a complete reduction in aggregation and formation of a soluble product. Negligible loss of total organic carbon (TOC) and drastic retardation in degradation kinetics in the absence of oxygen collectively implied that photochemical transformation was accomplished via oxidative pathway without carbon mineralization. MS (LDI), FTIR, and XPS analyses indicated a 60 carbon cage product, containing various oxygen functional groups such as epoxides and ethers. In addition, this product demonstrated significantly less antibacterial effects on Escherichia coli when compared to the parent nC60. The results of this study suggest that accurate assessment of C60 in environmental life cycles and impact should consider the light-mediated transformation of C60 in the aqueous phase and resulting water-soluble products.

Original languageEnglish
Pages (from-to)4878-4883
Number of pages6
JournalEnvironmental Science and Technology
Volume43
Issue number13
DOIs
Publication statusPublished - 2009 Jul 1
Externally publishedYes

Fingerprint

irradiation
Carbon
Irradiation
Oxygen
Ethers
Water
Epoxy Compounds
Dynamic light scattering
Light transmission
Organic carbon
Ultraviolet radiation
Escherichia coli
Functional groups
Life cycle
Agglomeration
X ray photoelectron spectroscopy
Fourier Transform Infrared Spectroscopy
Ultraviolet Rays
Transmission electron microscopy
Life Cycle Stages

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

Cite this

Transformation of aggregated C60 in the aqueous phase by UV irradiation. / Lee, Jaesang; Cho, Min; Fortner, John D.; Hughes, Joseph B.; Kim, Jae Hong.

In: Environmental Science and Technology, Vol. 43, No. 13, 01.07.2009, p. 4878-4883.

Research output: Contribution to journalArticle

Lee, Jaesang ; Cho, Min ; Fortner, John D. ; Hughes, Joseph B. ; Kim, Jae Hong. / Transformation of aggregated C60 in the aqueous phase by UV irradiation. In: Environmental Science and Technology. 2009 ; Vol. 43, No. 13. pp. 4878-4883.
@article{73b1207cec384e11b84857c9d90832ef,
title = "Transformation of aggregated C60 in the aqueous phase by UV irradiation",
abstract = "This study demonstrates that water-stable C60 cluster (nC 60) undergoes a photochemical transformation(s) when irradiated with monochromatic UV light at 254 nm. Upon UV exposure, characteristic absorption of nC60 in the visible (ca. 450-550 nm, indicative of a cluster structure) and UV regions (indicative of underivatized molecular C60) gradually disappeared. Concurrently, a new product with absorption centered at 210 nm formed. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses confirmed a complete reduction in aggregation and formation of a soluble product. Negligible loss of total organic carbon (TOC) and drastic retardation in degradation kinetics in the absence of oxygen collectively implied that photochemical transformation was accomplished via oxidative pathway without carbon mineralization. MS (LDI), FTIR, and XPS analyses indicated a 60 carbon cage product, containing various oxygen functional groups such as epoxides and ethers. In addition, this product demonstrated significantly less antibacterial effects on Escherichia coli when compared to the parent nC60. The results of this study suggest that accurate assessment of C60 in environmental life cycles and impact should consider the light-mediated transformation of C60 in the aqueous phase and resulting water-soluble products.",
author = "Jaesang Lee and Min Cho and Fortner, {John D.} and Hughes, {Joseph B.} and Kim, {Jae Hong}",
year = "2009",
month = "7",
day = "1",
doi = "10.1021/es8035972",
language = "English",
volume = "43",
pages = "4878--4883",
journal = "Environmental Science and Technology",
issn = "0013-936X",
publisher = "American Chemical Society",
number = "13",

}

TY - JOUR

T1 - Transformation of aggregated C60 in the aqueous phase by UV irradiation

AU - Lee, Jaesang

AU - Cho, Min

AU - Fortner, John D.

AU - Hughes, Joseph B.

AU - Kim, Jae Hong

PY - 2009/7/1

Y1 - 2009/7/1

N2 - This study demonstrates that water-stable C60 cluster (nC 60) undergoes a photochemical transformation(s) when irradiated with monochromatic UV light at 254 nm. Upon UV exposure, characteristic absorption of nC60 in the visible (ca. 450-550 nm, indicative of a cluster structure) and UV regions (indicative of underivatized molecular C60) gradually disappeared. Concurrently, a new product with absorption centered at 210 nm formed. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses confirmed a complete reduction in aggregation and formation of a soluble product. Negligible loss of total organic carbon (TOC) and drastic retardation in degradation kinetics in the absence of oxygen collectively implied that photochemical transformation was accomplished via oxidative pathway without carbon mineralization. MS (LDI), FTIR, and XPS analyses indicated a 60 carbon cage product, containing various oxygen functional groups such as epoxides and ethers. In addition, this product demonstrated significantly less antibacterial effects on Escherichia coli when compared to the parent nC60. The results of this study suggest that accurate assessment of C60 in environmental life cycles and impact should consider the light-mediated transformation of C60 in the aqueous phase and resulting water-soluble products.

AB - This study demonstrates that water-stable C60 cluster (nC 60) undergoes a photochemical transformation(s) when irradiated with monochromatic UV light at 254 nm. Upon UV exposure, characteristic absorption of nC60 in the visible (ca. 450-550 nm, indicative of a cluster structure) and UV regions (indicative of underivatized molecular C60) gradually disappeared. Concurrently, a new product with absorption centered at 210 nm formed. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses confirmed a complete reduction in aggregation and formation of a soluble product. Negligible loss of total organic carbon (TOC) and drastic retardation in degradation kinetics in the absence of oxygen collectively implied that photochemical transformation was accomplished via oxidative pathway without carbon mineralization. MS (LDI), FTIR, and XPS analyses indicated a 60 carbon cage product, containing various oxygen functional groups such as epoxides and ethers. In addition, this product demonstrated significantly less antibacterial effects on Escherichia coli when compared to the parent nC60. The results of this study suggest that accurate assessment of C60 in environmental life cycles and impact should consider the light-mediated transformation of C60 in the aqueous phase and resulting water-soluble products.

UR - http://www.scopus.com/inward/record.url?scp=67649965229&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=67649965229&partnerID=8YFLogxK

U2 - 10.1021/es8035972

DO - 10.1021/es8035972

M3 - Article

C2 - 19673279

AN - SCOPUS:67649965229

VL - 43

SP - 4878

EP - 4883

JO - Environmental Science and Technology

JF - Environmental Science and Technology

SN - 0013-936X

IS - 13

ER -