Long-term aging of a CeO(2) based nanocomposite used for wood protection.

A multi-scale methodology was used to characterize the long-term behavior and chemical stability of a CeO2-based nanocomposite used as UV filter in wood stains. ATR-FTIR and (13)C NMR demonstrated that the citrate coated chelates with Ce(IV) through its central carboxyl- and its α-hydroxyl- groups at the surface of the unaged nanocomposite. After 42 days under artificial daylight, the citrate completely disappeared and small amount of degradation products remained attached to the surface even after 112 days. Moreover, the release/desorption of the citrate layer led to a surface reorganization of the nano-sized CeO2 core observed by XANES (Ce L3-edge). Such a surface and structural transformation of the commercialized nanocomposite could have implications in term of fate, transport, and potential impacts towards the environment.

[1]  Jean-Joseph Max,et al.  Infrared Spectroscopy of Aqueous Carboxylic Acids: Comparison between Different Acids and Their Salts , 2004 .

[2]  X. Tao,et al.  ZnO Nanorods grown on cotton fabrics at low temperature , 2004 .

[3]  Jerome Rose,et al.  Intestinal toxicity evaluation of TiO2 degraded surface-treated nanoparticles: a combined physico-chemical and toxicogenomics approach in caco-2 cells , 2012, Particle and Fibre Toxicology.

[4]  G. Mailhot,et al.  Heterogeneous photocatalytic degradation of citric acid over TiO2 , 2011 .

[5]  H. Wan,et al.  Titanium-based mixed oxides from a series of titanium(IV) citrate complexes , 2007 .

[6]  T. Sakata,et al.  Effects of Titanium Oxide on the Optical Properties of Cerium Oxide , 2002 .

[7]  Armand Masion,et al.  TiO₂-based nanoparticles released in water from commercialized sunscreens in a life-cycle perspective: structures and quantities. , 2011, Environmental pollution.

[8]  G. Palmisano,et al.  Overview on oxidation mechanisms of organic compounds by TiO2 in heterogeneous photocatalysis , 2012 .

[9]  M Newville,et al.  IFEFFIT: interactive XAFS analysis and FEFF fitting. , 2001, Journal of synchrotron radiation.

[10]  A. Salifoglou,et al.  Delving into the complex picture of Ti(IV)–citrate speciation in aqueous media: Synthetic, structural, and electrochemical considerations in mononuclear Ti(IV) complexes containing variably deprotonated citrate ligands , 2008 .

[11]  A. Salifoglou,et al.  Mononuclear titanium(IV)-citrate complexes from aqueous solutions: pH-specific synthesis and structural and spectroscopic studies in relevance to aqueous titanium(IV)-citrate speciation. , 2005, Inorganic chemistry.

[12]  J. Field,et al.  Anaerobic degradation of citrate under sulfate reducing and methanogenic conditions , 2009, Biodegradation.

[13]  Armand Masion,et al.  Structural degradation at the surface of a TiO(2)-based nanomaterial used in cosmetics. , 2010, Environmental science & technology.

[14]  Bianconi,et al.  Specific intermediate-valence state of insulating 4f compounds detected by L3 x-ray absorption. , 1987, Physical review. B, Condensed matter.

[15]  M. Nomura,et al.  Determination of the oxidation state of cerium in rocks by Ce LIII-edge X-ray absorption near-edge structure spectroscopy , 2002 .

[16]  L. D. Finkelstein,et al.  X-ray Ce LIII absorption in CeO2 and BaCeO3: experiment and interpretation on the basis of LMTO band structure calculations , 1992 .

[17]  G. Mailhot,et al.  Heterogeneous photocatalytic degradation of citric acid over TiO2. I: Mechanism of 3-oxoglutaric acid degradation , 2011 .

[18]  José C. Ramalho,et al.  Photosynthetic Performance and Pigment Composition of Leaves from two Tropical Species is Determined by Light Quality , 2002 .

[19]  J. White,et al.  Point of zero charge of amorphous aluminum hydroxide as a function of adsorbed carbonate. , 1985, Journal of pharmaceutical sciences.

[20]  Jérôme Labille,et al.  Aging of TiO(2) nanocomposites used in sunscreen. Dispersion and fate of the degradation products in aqueous environment. , 2010, Environmental pollution.

[21]  Steffen Foss Hansen,et al.  Categorization framework to aid hazard identification of nanomaterials , 2007 .

[22]  Andrea Di Cicco,et al.  Novel XAFS capabilities at ELETTRA synchrotron light source , 2009 .

[23]  S. Trasatti,et al.  The Point of Zero Charge of CeO2 , 1994 .

[24]  J. Rose,et al.  Reply to comment on Fisichella et al. (2012), “Intestinal toxicity evaluation of TiO2 degraded surface-treated nanoparticles: a combined physico-chemical and toxicogenomics approach in Caco-2 cells” by Faust et al. , 2012, Particle and Fibre Toxicology.

[25]  P. Colavita,et al.  EXAFS analysis of the L3 edge of Ce in CeO2: effects of multi‐electron excitations and final‐state mixed valence , 1999 .

[26]  Caro,et al.  X-ray absorption studies of CeO2, PrO2, and TbO2. II. Rare-earth valence state by LIII absorption edges. , 1987, Physical review. B, Condensed matter.

[27]  R. H. Wang,et al.  UV-blocking property of dumbbell-shaped ZnO crystallites on cotton fabrics. , 2005, Inorganic chemistry.

[28]  I. Wawer,et al.  Cerium(III/IV) and Cerium(IV)–Titanium(IV) Citric Complexes Prepared in Ethylene Glycol Medium , 2007 .

[29]  P. Blanchet,et al.  COLOR STABILITY FOR WOOD PRODUCTS DURING USE: EFFECTS OF INORGANIC NANOPARTICLES , 2011 .

[30]  Arthur E. Martell,et al.  Critical Stability Constants , 2011 .