L’additif alimentaire E171 (dioxyde de titane, TiO2) est un pigment blanc couramment utilisé dans l’alimentation et composé jusqu’à 40 % de particules nanodimensionnées (<100nm). Or le devenir après exposition orale et les conséquences pour l’organisme des nanoparticules (NP) de TiO2 sont très peu documentés. Des études utilisant des NP modèles (P25) ont montré une absorption de TiO2 dans l’intestin, principalement via les plaques de Peyer (PP), un tissu lymphoïde essentiel à la réponse immunitaire locale. Aucune étude ne s’est intéressée aux effets sur le système immunitaire à des doses proches de l’exposition humaine.
To read the full-text of this research,
you can request a copy directly from the authors.
ResearchGate has not been able to resolve any citations for this publication.
ResearchGate has not been able to resolve any references for this publication.
The National Research Institute for Agriculture, Food and Environment (INRAE) is a public research establishment with a staff of 12,000 working in 268 research, service and experimental units located in 18 research centres throughout France.
INRAE is among the world leaders in agricultural and...
View post October 2020
INRAE is hiring researchers who have already shown their ability to produce research of excellence under supervision, attested by high-level publications. Candidates must be prepared to work independently and propose an ambitious research project in INRAE’s main areas of research: Agriculture,...
View post January 2020
On January 1, 2020, INRA (French National Institute for Agronomical Research) and IRSTEA (National Research Institute of Science and Technology for Environment and Agriculture) merged to become the National Research Institute for Agriculture, Food and the Environment – INRAE.
In 2020, INRAE...
View post April 2016 · Materials Science Forum
Micaceous iron oxide is a mica-like structure α-Fe 2 O 3 . As anti-rot material, micaceous iron oxide, holding the performance of good thermal and chemical stability, high covering capacity and strong ultraviolet absorption, is widely used in based pearlescent pigments. This paper introduces the preliminary test method of how to prepare pearlescent pigments from covering titanium dioxide over
... [Show full abstract] micaceous iron oxide, by the analysis technology of SEM and EDS, and finally find the Optimum conditions. Read more May 2009 · Langmuir
Composite nanoparticles (NPs) having a double-shell structure, Au core, spacer layer (inner shell), and J-aggregate (JA) layer (outer shell) (Au/spacer/JA) have been synthesized. The spacer layer composed of N,N,N-trimethyl(11-mercaptoundecyl)ammonium chloride played an important role in promoting the J-aggregation of anionic cyanine dyes on the surface, as evidenced by the successful formation
... [Show full abstract] of the JA layers with four kinds of anionic cyanine dyes. It was found that the presence of a spacer layer causes a significant change in the line shape of the absorption spectrum, particularly near the J-band; there is the appearance of a peak type absorption for the composite NPs with the double-shell structure, while there is a dip type absorption for the ones without the spacer layer. The change from the peak type absorption to the dip type absorption in the Au/spacer/JA NPs occurs when the size of the Au core is varied from 5 to 15 nm. These observations would indicate that the strength of exciton-plasmon coupling between the Au core and the JA layer is enhanced with the increase in the core size or the decrease in the separation between the Au core and the JA shell. The photoluminescence arising from the JA can be detected for the composite NPs with the double-shell structure, showing that the quenching by the Au core is effectively suppressed by the spacer layer. Read more February 2013
Absorbance spectra of TiO2 and N-TiO2 nanoparticles. Description: A shoulder was observed at the edge of the absorption spectra, which extended the absorption of N-TiO2 from 380 nm to 550 nm.
View full-text July 2015 · Physics Education
This paper presents an experimental activity based on the absorption of light colours by pigments. The activity is constructed using a stepwise design and offers an opportunity for students and teachers to compare and generalize the interactions between light and pigment colours. The light colours composing an artificial rainbow produced in the classroom are subtracted using a set-up of
... [Show full abstract] refractive solutions containing pigments. Symbolic, diagrammatic and realistic representations are provided to explain and compare the findings from seven steps in the activity. Read more October 1982 · Dyes and Pigments
The complex interaction between titanium dioxide pigments, a primary anti-oxidant and a hindered piperidine compound in the photostabilisation of polypropylene has been examined using infrared absorption spectroscopy. The hindered piperidine compound, Tinuvin 770, was found to be ineffective in protecting the polymer against the photocatalytic action of anatase. In the case of rutile good
... [Show full abstract] photoprotection of the polymer was observed, the effect being greater for a coated pigment. However, the presence of the anti-oxidant, Irganox 1010, antagonised the stabilising action of the hindered piperidine compounds, the effect being greater in the presence of an uncoated pigment. The results are discussed in terms of additive adsorption onto the pigment particle surface versus the photocatalytic activity of the pigment. The effects were also found to be dependent on the ultraviolet content of the light source. Read more Article Full-text available January 2014
The effect of the modification of ZnO powders by
ZrO2, Al2O3, TiO2, SiO2, CeO2 and Y2O3 nanoparticles with a
concentration of 1-30 wt % is investigated by diffuse reflectance
spectra within the wavelength range 200 to 2500 nm before and after
100 keV proton and electron irradiation. It has been established that
the introduction of nanoparticles ZrO2, Al2O3 enhances the optical
stability of the
... [Show full abstract] pigments under proton irradiation, but reduces it under
electron irradiation. Modifying with TiO2, SiO2, CeO2, Y2O3
nanopowders leads to decrease radiation stability in both types of
irradiation. Samples modified by 5 wt. % of ZrO2 nanoparticles have
the highest stability of optical properties after proton exposure. The
degradation of optical properties under electron irradiation is not high
for this concentration of nanoparticles. A decrease in the absorption
of pigments modified with nanoparticles proton exposure is
determined by a decrease in the intensity of bands located in the UV
and visible regions. After electron exposure the absorption bands
have in the whole spectrum range. View full-text May 2009 · Polymers and Polymer Composites
TiO2 (P25) fine particles were loaded in a polyacrylic acid (PAA), which possessed a unique absorption characteristic and was synthesised by aqueous solution polymerization. The TiO2/PAA composite was taken as a photocataly st to degrade methyl orange (MO), the degradability resistance andreproducibility of the photocatalyst were investigated experimentally. The results showed that the TiO2ZPAA
... [Show full abstract] photocatalyst had a good activity and stability in degradability of organic compound. Read more October 2015 · The Journal of Physical Chemistry C
We reveal the thickness effects on optical properties for nanoparticles in the shape of hollow spheres theoretically and experimentally. Within and beyond the electrically small limit, hollow spheres are shown to have almost the same light absorption power as that of solid ones, when the ratio of inner core to whole particle radii is smaller than 0.4. It means that one can maintain the level of
... [Show full abstract] light absorption even with a large empty core. In the electrically small limit, we expand the exact solution of Mie theory in power of the thickness parameter and show that the thickness ratio has less influence on light absorption. Moreover, we synthesize highly uniform hollow spheres of TiO2 anatase through a self-sacrificing template method. A variety of particle radii from 94 to 500 nm, with 50 nm in the shell thickness, are performed experimentally in photocatalytic activity. With experimental demonstrations and theoretical simulations, our results provide a guideline in the design on the thickness for hollow-sphere nanoparticles with an optimized absorption power in light harvesting. Read more April 1999 · Applied Surface Science
Photoelectrochemical dye-sensitization of n-type titanium dioxide (n-TiO2) was investigated using thin films of oxometal phthalocyanines (MOPc's) vapor-deposited on rutile (001) surface. Their dye-sensitizing effects were affected by the morphology of deposited MOPc's which depended on substrate temperatures during deposition. At low temperature of 20°C, MOPc's grew in a thin layer composed of
... [Show full abstract] small grains, while the molecules deposited at 200°C aggregated to form heterogeneous island-like crystallites. The n-TiO2 electrodes the surface of which was all covered by the thin layers of both titanyl Pc (TiOPc) and vanadyl Pc (VOPc) yielded photoreduction currents under excitation at their visible absorption bands, based on p-type organic semiconducting properties of MOPc's. On the other hand, the island-like crystallites of TiOPC dye-sensitized the photoelectrochemical oxidation of the bare n-TiO2 surface due to its heterogeneous structure. The VOPc islands were not capable of dye-sensitization because of its lower energy level of the excited state Read more January 2017 · Journal of Colloid and Interface Science
A series of TiO2-N/SnO2X heterostructure photocatalysts were synthesized by a hydrolysis-deposition method. The structure, existing states of N and SnO2 heterostructure at the interface of TiO2-N/SnO2X were studied by EADX, XRD, Raman, FT-IR, XPS, and HRTEM. The band structure is investigated by both theoretical calculation and experiment characterization. It was found that the introduction of
... [Show full abstract] NOx surface species and SnO2 nanoparticles would enhance the absorption in visible region, increase reactive oxidative species and separate photogenerated electrons and holes efficiently. Therefore, the photocatalytic activity is improved significantly for TiO2-N/SnO2X, compared with TiO2-N and TiO2 under visible and UV light irradiation. This work may offer a new strategy to fabricate new photocatalyst with high photocatalytic performance. Read more November 2017 · Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy
Attenuated total reflectance spectra including the far-ultraviolet (FUV, ≤200nm) region of titanium dioxide (TiO2) with and without gold (Au) nanoparticles were measured. A newly developed external light-irradiation system enabled to observe spectral changes of TiO2 with Au nanoparticles upon light irradiations. Absorption in the FUV region decreased and increased by the irradiation with
... [Show full abstract] ultraviolet and visible light, respectively. These spectral changes may reflect photo-induced electron transfer from TiO2 to Au nanoparticles under ultraviolet light and from Au nanoparticles to TiO2 under visible light, respectively. Read more September 2012 · Catalysis Communications
A visible light (490–780 nm) was introduced into the process of oxidizing CO over a TiO2 supported Au nanoparticle catalyst (Au/TiO2). It is found that the visible-light irradiation can promote the oxidation of CO over Au/TiO2. Based on the results of both the optical absorption of Au/TiO2 and the adsorption of CO over Au/TiO2, it is proposed that the localized surface plasmon resonance (LSPR) of
... [Show full abstract] Au nanoparticles induced by the visible-light would promote the adsorption of CO and its activation at the surface of Au species, resulting in the promoted oxidation of CO over Au/TiO2. Read more September 2019 · Journal of the Optical Society of America B
In this paper, a novel broadband solar absorber based on TiN/TiO2 is presented. The unit cell is composed of a multi-layer disk that is surrounded by a TiN ring. By using the finite-difference time-domain method, the effects of the number of disk layers as well as the height of the ring on the absorption are comprehensively investigated. It is shown that the light with shorter wavelengths is
... [Show full abstract] trapped by the disks, while the longer wavelengths are absorbed by the ring. Also, the variation of the absorption due to the period changes is studied. According to the simulation results, the average absorption of the proposed absorber is 93% in the wavelength range of 200–4000 nm. In addition, the absorption is higher than 90% in a wide wavelength range of 200–3000 nm under normal incidence, which covers the whole spectrum of solar radiation. It is shown that the proposed absorber can absorb more than 80% of light for angles less than 50° for both the TE and TM modes. Owing to the use of TiN and TiO2, this solar absorber has high thermal and chemical stability. This structure can act as a blackbody emitter in thermal emitter devices. Due to its high absorption and subwavelength structure, the proposed solar absorber is a suitable candidate for use in many solar-based applications. Read more Last Updated: 05 Jul 2022 Looking for the full-text?
You can request the full-text of this conference paper directly from the authors on ResearchGate.