ABSTRACT Cerium doped organic-inorganic sol-gel coatings have been formulated at different cerium... more ABSTRACT Cerium doped organic-inorganic sol-gel coatings have been formulated at different cerium nitrate contents. The sol-gel coatings were obtained from hydrolysis and condensation of the alkoxide precursors 3-metacryloxypropyltrimethoxysilane (MAPTMS) and tetramethoxysilane (TMOS). During the preparation process Ce(NO3)3·6H2O was incorporated in the organic-inorganic network. A model polyvinyl butyral (PVB) film was also applied by dip immersion on a series of these sol-gel coatings to simulate the performance of technological organic coatings. To carry out the microstructural and chemical characterization of the samples, the surface morphology was analyzed by SEM/EDX. Surface analysis was performed by XPS, obtaining the atomic percentage and oxidation states of all the elements presented in the outer nanolayers before and after the corrosion studies. Electrochemical impedance spectroscopy and cathodic delamination tests were carried out on the resulting systems to study the role of cerium salt inhibitor encapsulated into the sol-gel network. Just before the experiment was initiated, the centre of the PVB/sol-gel thin film/metal samples was damaged with an intentionally scribed linear defect. Hybrid silica-based sol-gel coatings containing Ce3+-ions behave as a conversion coating on the mild steel substrates. The critical concentration of this anticorrosive pigment (Ce3+-salt) is in the 0.4-0.6 wt % range, approximately. Higher anticorrosive pigment concentration could yield networking defects by formation of pigment-coating interfaces, which can retain water and enhance corrosion.
ABSTRACT We present here anticorrosive silica coatings doped with lanthanum ions for the protecti... more ABSTRACT We present here anticorrosive silica coatings doped with lanthanum ions for the protection of metallic surfaces as an alternative to chromate (VI)-based conversion coatings. The coatings were synthesized by the sol–gel method starting from silicon alkoxides and two different lanthanum precursors: La (III) acetate hydrate and La (III) isopropoxide. Artificial corrosion tests in acid and alkaline media showed their effectiveness for the corrosion protection of AA2024 aluminum alloy sheets for coating prepared with both precursors. The X-ray absorption Near Edge Structure and X-ray Absorption Fine Structure analysis of the coatings confirmed the key role of lanthanum in the structural properties of the coating determining its anticorrosive properties.
Se prepararon materiales silíceos amorfos dopados con nanocoloides de plata en masa y en superfic... more Se prepararon materiales silíceos amorfos dopados con nanocoloides de plata en masa y en superficie. Se obtuvieron vidrios dopados en masa por fusión convencional y láminas monolíticas dopadas por sol-gel. Asimismo se prepararon vidrios dopados superficialmente por cambio iónico y recubrimientos dopados por sol-gel. Los materiales se caracterizaron por MET y espectrofotometría UV-VIS. Dependiendo de la composición del material, del proceso de incorporación de la plata y de los tratamientos térmicos, se obtuvieron diferentes coloraciones. El control de estas variables permitió generar nanocoloides metálicos de plata en las matrices estudiadas. La agregación y crecimiento de los coloides depende de la naturaleza de la matriz y del proceso experimental utilizado.
Optical absorption and magnetic properties of silica sol-gel monoliths doped with cobalt starting... more Optical absorption and magnetic properties of silica sol-gel monoliths doped with cobalt starting from different precursors and water/1-propanol molar ratios are investigated. Structure characterization of the sol-gel by X-ray near-edge structure (XANES) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy corroborate that oxidising state of cobalt is Co 2+ . Furthermore the Co 2+ first neighbors are O atoms displaying a temperature transition from octahedral to tetrahedral coordination. The doped monoliths show thermochromic sensor activity ranging from 10 to 50 ºC, which is related to the environment of Co 2+ ions. The magnetic susceptibility also varies with Co 2+ ions environment due to changes in the orbital contribution to the magnetic moment. Thus, we achieve a better understand about environment of the Co 2+ ions in the gel matrix and explain their reversible temperature behavior in spite of the rigid state of the host matrix.
We present here some miniaturised devices designed for the detection of nanorods in water and blo... more We present here some miniaturised devices designed for the detection of nanorods in water and blood media. The devices use light emitting diodes as monochromatic light sources and Si photodiodes for detection. Devices working on transmission mode are able to detect nanorods concentration below micrograms/litre. Sensitivity is reduced is one or of magnitude for nanorods in blood. We show detection of low nanorods concentration with devices working in reflection mode, opening the possibility to perform direct imaging of nanorods in vivo. The optima condition for detection and resolution limits are also discussed.
Gold nanoparticles are commonly used in biomedical applications due to their high biocompatibilit... more Gold nanoparticles are commonly used in biomedical applications due to their high biocompatibility and easy modular functionality. Their unique optical properties, such as Surface Plasmon Resonance (SPR), lead to a great light absorption in the visible range of the spectrum. Here, we show that the synthesis of non spherical gold nanoparticles causes the maximum absorption band to shift to the near-infrared region of the spectrum, thus avoiding overlaps with other biological tissues (eg. Haemoglobin in bloodstream).
Different kinds of protective treatments based on sol-gel coatings have been designed and prepare... more Different kinds of protective treatments based on sol-gel coatings have been designed and prepared. Final application of these coatings would be used for protection and preventive conservation of a wide variety of historical glasses from several times and provenance. Historical glasses show a superficial deterioration depending on the exhibition conditions submitted by the ancient objects since their origin.
The combined element-specific X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dic... more The combined element-specific X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) study of ZnO nanoparticles (NPs) capped with organic molecules confirms the occurrence of intrinsic ferromagnetic-like (FML) behavior up to room temperature (HTFM). Zn K-edge XMCD measurements reveal the coexistence of two different magnetic contributions: a paramagnetic response from the core of the NP, and a ferromagnetic-like contribution stemming from the interface formed between the ZnO core of the NP and the organic molecule. The extent and conformation of this interface depends on the capping molecule, and as demonstrated in ZnO/ZnS heterostructures, the FML behavior is reinforced when neat interfaces are formed.
ABSTRACT We have synthesized ZnO nanoparticles capped with butanethiol, octanethiol, and dodecane... more ABSTRACT We have synthesized ZnO nanoparticles capped with butanethiol, octanethiol, and dodecanethiol. In all of the cases, the capped ZnO nanoparticles exhibit ferromagnetic-like behavior up to room temperature whose intrinsic origin has been demonstrated by using both X-ray magnetic circular dichroism (XMCD) and X-ray absorption spectroscopy (XAS) at the Zn K-edge. Using these tools, we have also determined that the occurrence of ferromagnetism does not critically depend on the details of the synthesis but on the formation of a pristine ZnS/ZnO interface. Within this interface, ferromagnetism is favored in those regions where the local order is closer to wurzite-like ZnO than to w-ZnS. The study of ZnS–ZnO films prepared by cosputtering clearly indicates that increasing the disorder of this interface weakens the onset of ferromagnetic behavior.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2007
Laser-induced breakdown spectroscopy (LIBS) has been used to determine the lead content of differ... more Laser-induced breakdown spectroscopy (LIBS) has been used to determine the lead content of different types of lead silicate glasses commercially designed as sonorous glass (which contain ∼10 wt.% PbO); crystal glass (with at least 24 wt.% PbO) and superior crystal glass (with at least 30 wt.% PbO). Seven different types of glass samples were selected, including historic-original, model and commercially available. The selected samples were artificially weathered under neutral, acid and alkaline attack. Analysis by LIBS was carried out in vacuum under excitation at 266 nm and results were compared with those obtained by conventional techniques used for glass characterization. Composition of the bulk glasses was analyzed by XRF (X-ray fluorescence) and the corroded surfaces were characterized by SEM/EDX (scanning electron microscopy/energy dispersive X-ray microanalysis). A linear correlation was obtained between the intensity of selected Pb lines in the LIB spectra and the PbO content. The effect of corrosion could be characterized by comparing successive LIB spectra recorded on the same area; acid attack resulted in a decrease of PbO, CaO and Na 2 O content in the surface with respect to the bulk of the sample, while minor changes in the composition were noticed under alkaline attack. These results show LIBS as a useful technique to classify the different types of lead glasses by their lead content and to determine and asses the degree and type of corrosion.
... Consequently, the sensors are adequate for an easy and fast monitoring in one step of relativ... more ... Consequently, the sensors are adequate for an easy and fast monitoring in one step of relative humidity and environmental acidity of engraved historical, artistic and cultural heritage assets and can help to improve the preventive conservation of this valuable legacy. ...
We present here direct experimental evidence of the magnetic polarization of Zn atoms in ZnO nano... more We present here direct experimental evidence of the magnetic polarization of Zn atoms in ZnO nanoparticles capped with different materials by means of x-ray magnetic circular dichroism ͑XMCD͒. Our results demonstrate that the magnetism in this material is intrinsic and relays in the ZnO conduction band. The analysis of both x-ray absorption spectroscopy and XMCD signals points out the formation of a well-defined interface between ZnO and the capping molecule in which the exotic magnetism arises at the hybridized band formed among Zn and the bonding atom of the molecule. The magnetic properties of these systems should critically depend on the details of this interface which may offer a new insight into the different observations for seemingly identical materials.
With the aim to study the chemical response of selected glass samples to an underwater medium, ac... more With the aim to study the chemical response of selected glass samples to an underwater medium, accelerated ageing tests were undertaken in the laboratory by immersing the samples into a solution, which simulates the average composition of sea water. Tests were conducted both at low (−15°C) and high (40°C) temperature for several time cycles. The main goal of the research was to study, through different observation and analytical techniques, chemical alteration mechanisms as a function of the glass compositions and experimental conditions (e.g., temperature, time). Results showed that glasses experience a recurrent decay process, which starts at a neutral pH medium with leaching of alkaline ions and concludes at a basic medium, as a consequence of hydrolytic attack, with destruction of glass network and loss of main forming oxides. The research has thus provided outstanding data that will be useful for future conservation and restoration of historical glasses preserved in an underwater medium.
Gold nanorods have been prepared by the seed-mediated growth method, in order to find the effect ... more Gold nanorods have been prepared by the seed-mediated growth method, in order to find the effect of stirring during the synthesis to the final shape and optical properties. The presence or absence of stirring during each step of the preparation procedure was considered a parameter to control in order to adjust the optical absorption associated with the surface plasmon resonance of the nanorods. Results show that the longitudinal surface plasmon resonance band shifts to larger wavelengths in the absence of stirring of the growth solution. Width and intensity of the absorption band associated with the longitudinal surface plasmon is reduced upon stirring during the synthesis. On the contrary, the position of the transversal surface plasmon resonance band scarcely depends upon stirring. Theoretical calculations performed using the Gans model are coherent with experimental obtained results, showing that as the aspect ratio increases, longitudinal plasmons absorption shifts toward larger wavelengths and increases both intensity and bandwidth.
New sol–gel based sensitive materials able to detect moderate doses of UV, Vis and near IR radiat... more New sol–gel based sensitive materials able to detect moderate doses of UV, Vis and near IR radiations have been designed, prepared and characterised. These glasslike detectors are respectively composed by four different sols of inorganic and hybrid organic–inorganic silica matrixes. The sols were prepared from alkoxide (TEOS) and alkylalkoxide (GLYMO) precursors with molar ratios 1:0, 1:1, 1:4 and 0:1, respectively.
Four glasses in the R2O–CaO–SiO2 (R = Na, K) system, following similar compositions to historical... more Four glasses in the R2O–CaO–SiO2 (R = Na, K) system, following similar compositions to historical glasses used for production of stained glass windows, were prepared with different CaO/R2O ratio. The samples were submitted to accelerated weathering test under different temperature and relative humidity conditions, as well as under controlled SO2-polluted atmosphere. The experimental set up was selected to simulate the
ABSTRACT Pure and quinine doped silica coatings have been prepared over sodalime glasses. The coa... more ABSTRACT Pure and quinine doped silica coatings have been prepared over sodalime glasses. The coatings were consolidated at low temperature (range 60–180 °C) preserving optical activity of quinine molecule. We designed a device to test the guiding properties of the coatings. We confirmed with this device that light injected in pure silica coatings is guided over distances of meters while quinine presence induces isotropic photoluminescence. With the combined use of both type of coatings, it is possible to design light guiding devices and illuminate regions in glass elements without electronic circuits.
ABSTRACT Cerium doped organic-inorganic sol-gel coatings have been formulated at different cerium... more ABSTRACT Cerium doped organic-inorganic sol-gel coatings have been formulated at different cerium nitrate contents. The sol-gel coatings were obtained from hydrolysis and condensation of the alkoxide precursors 3-metacryloxypropyltrimethoxysilane (MAPTMS) and tetramethoxysilane (TMOS). During the preparation process Ce(NO3)3·6H2O was incorporated in the organic-inorganic network. A model polyvinyl butyral (PVB) film was also applied by dip immersion on a series of these sol-gel coatings to simulate the performance of technological organic coatings. To carry out the microstructural and chemical characterization of the samples, the surface morphology was analyzed by SEM/EDX. Surface analysis was performed by XPS, obtaining the atomic percentage and oxidation states of all the elements presented in the outer nanolayers before and after the corrosion studies. Electrochemical impedance spectroscopy and cathodic delamination tests were carried out on the resulting systems to study the role of cerium salt inhibitor encapsulated into the sol-gel network. Just before the experiment was initiated, the centre of the PVB/sol-gel thin film/metal samples was damaged with an intentionally scribed linear defect. Hybrid silica-based sol-gel coatings containing Ce3+-ions behave as a conversion coating on the mild steel substrates. The critical concentration of this anticorrosive pigment (Ce3+-salt) is in the 0.4-0.6 wt % range, approximately. Higher anticorrosive pigment concentration could yield networking defects by formation of pigment-coating interfaces, which can retain water and enhance corrosion.
ABSTRACT We present here anticorrosive silica coatings doped with lanthanum ions for the protecti... more ABSTRACT We present here anticorrosive silica coatings doped with lanthanum ions for the protection of metallic surfaces as an alternative to chromate (VI)-based conversion coatings. The coatings were synthesized by the sol–gel method starting from silicon alkoxides and two different lanthanum precursors: La (III) acetate hydrate and La (III) isopropoxide. Artificial corrosion tests in acid and alkaline media showed their effectiveness for the corrosion protection of AA2024 aluminum alloy sheets for coating prepared with both precursors. The X-ray absorption Near Edge Structure and X-ray Absorption Fine Structure analysis of the coatings confirmed the key role of lanthanum in the structural properties of the coating determining its anticorrosive properties.
Se prepararon materiales silíceos amorfos dopados con nanocoloides de plata en masa y en superfic... more Se prepararon materiales silíceos amorfos dopados con nanocoloides de plata en masa y en superficie. Se obtuvieron vidrios dopados en masa por fusión convencional y láminas monolíticas dopadas por sol-gel. Asimismo se prepararon vidrios dopados superficialmente por cambio iónico y recubrimientos dopados por sol-gel. Los materiales se caracterizaron por MET y espectrofotometría UV-VIS. Dependiendo de la composición del material, del proceso de incorporación de la plata y de los tratamientos térmicos, se obtuvieron diferentes coloraciones. El control de estas variables permitió generar nanocoloides metálicos de plata en las matrices estudiadas. La agregación y crecimiento de los coloides depende de la naturaleza de la matriz y del proceso experimental utilizado.
Optical absorption and magnetic properties of silica sol-gel monoliths doped with cobalt starting... more Optical absorption and magnetic properties of silica sol-gel monoliths doped with cobalt starting from different precursors and water/1-propanol molar ratios are investigated. Structure characterization of the sol-gel by X-ray near-edge structure (XANES) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy corroborate that oxidising state of cobalt is Co 2+ . Furthermore the Co 2+ first neighbors are O atoms displaying a temperature transition from octahedral to tetrahedral coordination. The doped monoliths show thermochromic sensor activity ranging from 10 to 50 ºC, which is related to the environment of Co 2+ ions. The magnetic susceptibility also varies with Co 2+ ions environment due to changes in the orbital contribution to the magnetic moment. Thus, we achieve a better understand about environment of the Co 2+ ions in the gel matrix and explain their reversible temperature behavior in spite of the rigid state of the host matrix.
We present here some miniaturised devices designed for the detection of nanorods in water and blo... more We present here some miniaturised devices designed for the detection of nanorods in water and blood media. The devices use light emitting diodes as monochromatic light sources and Si photodiodes for detection. Devices working on transmission mode are able to detect nanorods concentration below micrograms/litre. Sensitivity is reduced is one or of magnitude for nanorods in blood. We show detection of low nanorods concentration with devices working in reflection mode, opening the possibility to perform direct imaging of nanorods in vivo. The optima condition for detection and resolution limits are also discussed.
Gold nanoparticles are commonly used in biomedical applications due to their high biocompatibilit... more Gold nanoparticles are commonly used in biomedical applications due to their high biocompatibility and easy modular functionality. Their unique optical properties, such as Surface Plasmon Resonance (SPR), lead to a great light absorption in the visible range of the spectrum. Here, we show that the synthesis of non spherical gold nanoparticles causes the maximum absorption band to shift to the near-infrared region of the spectrum, thus avoiding overlaps with other biological tissues (eg. Haemoglobin in bloodstream).
Different kinds of protective treatments based on sol-gel coatings have been designed and prepare... more Different kinds of protective treatments based on sol-gel coatings have been designed and prepared. Final application of these coatings would be used for protection and preventive conservation of a wide variety of historical glasses from several times and provenance. Historical glasses show a superficial deterioration depending on the exhibition conditions submitted by the ancient objects since their origin.
The combined element-specific X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dic... more The combined element-specific X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) study of ZnO nanoparticles (NPs) capped with organic molecules confirms the occurrence of intrinsic ferromagnetic-like (FML) behavior up to room temperature (HTFM). Zn K-edge XMCD measurements reveal the coexistence of two different magnetic contributions: a paramagnetic response from the core of the NP, and a ferromagnetic-like contribution stemming from the interface formed between the ZnO core of the NP and the organic molecule. The extent and conformation of this interface depends on the capping molecule, and as demonstrated in ZnO/ZnS heterostructures, the FML behavior is reinforced when neat interfaces are formed.
ABSTRACT We have synthesized ZnO nanoparticles capped with butanethiol, octanethiol, and dodecane... more ABSTRACT We have synthesized ZnO nanoparticles capped with butanethiol, octanethiol, and dodecanethiol. In all of the cases, the capped ZnO nanoparticles exhibit ferromagnetic-like behavior up to room temperature whose intrinsic origin has been demonstrated by using both X-ray magnetic circular dichroism (XMCD) and X-ray absorption spectroscopy (XAS) at the Zn K-edge. Using these tools, we have also determined that the occurrence of ferromagnetism does not critically depend on the details of the synthesis but on the formation of a pristine ZnS/ZnO interface. Within this interface, ferromagnetism is favored in those regions where the local order is closer to wurzite-like ZnO than to w-ZnS. The study of ZnS–ZnO films prepared by cosputtering clearly indicates that increasing the disorder of this interface weakens the onset of ferromagnetic behavior.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2007
Laser-induced breakdown spectroscopy (LIBS) has been used to determine the lead content of differ... more Laser-induced breakdown spectroscopy (LIBS) has been used to determine the lead content of different types of lead silicate glasses commercially designed as sonorous glass (which contain ∼10 wt.% PbO); crystal glass (with at least 24 wt.% PbO) and superior crystal glass (with at least 30 wt.% PbO). Seven different types of glass samples were selected, including historic-original, model and commercially available. The selected samples were artificially weathered under neutral, acid and alkaline attack. Analysis by LIBS was carried out in vacuum under excitation at 266 nm and results were compared with those obtained by conventional techniques used for glass characterization. Composition of the bulk glasses was analyzed by XRF (X-ray fluorescence) and the corroded surfaces were characterized by SEM/EDX (scanning electron microscopy/energy dispersive X-ray microanalysis). A linear correlation was obtained between the intensity of selected Pb lines in the LIB spectra and the PbO content. The effect of corrosion could be characterized by comparing successive LIB spectra recorded on the same area; acid attack resulted in a decrease of PbO, CaO and Na 2 O content in the surface with respect to the bulk of the sample, while minor changes in the composition were noticed under alkaline attack. These results show LIBS as a useful technique to classify the different types of lead glasses by their lead content and to determine and asses the degree and type of corrosion.
... Consequently, the sensors are adequate for an easy and fast monitoring in one step of relativ... more ... Consequently, the sensors are adequate for an easy and fast monitoring in one step of relative humidity and environmental acidity of engraved historical, artistic and cultural heritage assets and can help to improve the preventive conservation of this valuable legacy. ...
We present here direct experimental evidence of the magnetic polarization of Zn atoms in ZnO nano... more We present here direct experimental evidence of the magnetic polarization of Zn atoms in ZnO nanoparticles capped with different materials by means of x-ray magnetic circular dichroism ͑XMCD͒. Our results demonstrate that the magnetism in this material is intrinsic and relays in the ZnO conduction band. The analysis of both x-ray absorption spectroscopy and XMCD signals points out the formation of a well-defined interface between ZnO and the capping molecule in which the exotic magnetism arises at the hybridized band formed among Zn and the bonding atom of the molecule. The magnetic properties of these systems should critically depend on the details of this interface which may offer a new insight into the different observations for seemingly identical materials.
With the aim to study the chemical response of selected glass samples to an underwater medium, ac... more With the aim to study the chemical response of selected glass samples to an underwater medium, accelerated ageing tests were undertaken in the laboratory by immersing the samples into a solution, which simulates the average composition of sea water. Tests were conducted both at low (−15°C) and high (40°C) temperature for several time cycles. The main goal of the research was to study, through different observation and analytical techniques, chemical alteration mechanisms as a function of the glass compositions and experimental conditions (e.g., temperature, time). Results showed that glasses experience a recurrent decay process, which starts at a neutral pH medium with leaching of alkaline ions and concludes at a basic medium, as a consequence of hydrolytic attack, with destruction of glass network and loss of main forming oxides. The research has thus provided outstanding data that will be useful for future conservation and restoration of historical glasses preserved in an underwater medium.
Gold nanorods have been prepared by the seed-mediated growth method, in order to find the effect ... more Gold nanorods have been prepared by the seed-mediated growth method, in order to find the effect of stirring during the synthesis to the final shape and optical properties. The presence or absence of stirring during each step of the preparation procedure was considered a parameter to control in order to adjust the optical absorption associated with the surface plasmon resonance of the nanorods. Results show that the longitudinal surface plasmon resonance band shifts to larger wavelengths in the absence of stirring of the growth solution. Width and intensity of the absorption band associated with the longitudinal surface plasmon is reduced upon stirring during the synthesis. On the contrary, the position of the transversal surface plasmon resonance band scarcely depends upon stirring. Theoretical calculations performed using the Gans model are coherent with experimental obtained results, showing that as the aspect ratio increases, longitudinal plasmons absorption shifts toward larger wavelengths and increases both intensity and bandwidth.
New sol–gel based sensitive materials able to detect moderate doses of UV, Vis and near IR radiat... more New sol–gel based sensitive materials able to detect moderate doses of UV, Vis and near IR radiations have been designed, prepared and characterised. These glasslike detectors are respectively composed by four different sols of inorganic and hybrid organic–inorganic silica matrixes. The sols were prepared from alkoxide (TEOS) and alkylalkoxide (GLYMO) precursors with molar ratios 1:0, 1:1, 1:4 and 0:1, respectively.
Four glasses in the R2O–CaO–SiO2 (R = Na, K) system, following similar compositions to historical... more Four glasses in the R2O–CaO–SiO2 (R = Na, K) system, following similar compositions to historical glasses used for production of stained glass windows, were prepared with different CaO/R2O ratio. The samples were submitted to accelerated weathering test under different temperature and relative humidity conditions, as well as under controlled SO2-polluted atmosphere. The experimental set up was selected to simulate the
ABSTRACT Pure and quinine doped silica coatings have been prepared over sodalime glasses. The coa... more ABSTRACT Pure and quinine doped silica coatings have been prepared over sodalime glasses. The coatings were consolidated at low temperature (range 60–180 °C) preserving optical activity of quinine molecule. We designed a device to test the guiding properties of the coatings. We confirmed with this device that light injected in pure silica coatings is guided over distances of meters while quinine presence induces isotropic photoluminescence. With the combined use of both type of coatings, it is possible to design light guiding devices and illuminate regions in glass elements without electronic circuits.
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Papers by Noemi Carmona