| 1. |
- Chateau, Denis, et al.
(författare)
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Long Distance Enhancement of Nonlinear Optical Properties Using Low Concentration of Plasmonic Nanostructures in Dye Doped Monolithic Sol-Gel Materials.
- 2016
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Ingår i: Advanced Functional Materials. - Weinheim : Wiley. - 1616-301X .- 1616-3028. ; 26:33
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Tidskriftsartikel (refereegranskat)abstract
- Monolithic sol-gel silica composites incorporating platinum-based chromophores and various types of gold nanoparticles (AuNPs) are prepared and polished to high optical quality. Their photophysical properties are investigated. The glass materials show well-defined localized surface plasmon resonance (SPR) absorbance from the visible to NIR. No redshifts of the AuNP plasmon absorption peaks due to the increase in nanoparticle doping concentration are observed in the glasses, proving that no or very small SPR coupling effects occur between the AuNPs. At 600 nm excitation, but not at 532 nm, the AuNPs improve the nonlinear absorption performance of glasses codoped with 50 × 10−3 m of a Pt-acetylide chromophore. The glasses doped with lower concentrations of AuNPs (2-5 μm average distance) and 50 × 10−3 m in chromophore, show a marked improvement in nonlinear absorption, with no or only small improvement for the more highly AuNP doped glasses. This study shows the importance of excitation wavelength and nanoparticle concentration for composite systems employing AuNPs to improve two-photon absorption of chromophores. [ABSTRACT FROM AUTHOR]
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| 2. |
- Chateau, Denis, et al.
(författare)
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Silica hybrid sol-gel materials with unusually high concentration of Pt-organic molecular guests : Studies of luminescence and nonlinear absorption of light
- 2012
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Ingår i: ACS Applied Materials and Interfaces. - Washington : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 4:5, s. 2369-2377
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Tidskriftsartikel (refereegranskat)abstract
- The development of new photonic materials is a key step towards improvement of existing optical devices and for the preparation of a new generation of systems. Therefore synthesis of photonic hybrid materials with a thorough understanding and control of the microstructure-to-properties relationships is crucial. In this perspective, a new preparation method based on fast gelation reactions using simple dispersion of dyes without strong covalent bonding between dye and matrix has been developed. This new sol-gel method is demonstrated through synthesis of monolithic siloxane-based hybrid materials highly doped by various platinum(II) acetylide derivatives. Concentrations of the chromophores as high as 400 mM were obtained and resulted in unprecedented optical power limiting (OPL) performance at 532 nm of the surface-polished solids. Static and time-resolved photoluminescence of the prepared hybrid materials were consistent with both OPL data and previous studies of similar Pt(II) compounds in solution. The impacts of the microstructure and the chemical composition of the matrix on the spectroscopic properties, are discussed.
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| 3. |
- Jiang, Xuehe, et al.
(författare)
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Multifunctional Cellulose Nanofibrils-GdF3 Nanoparticles Hybrid Gel and Its Potential Uses for Drug Delivery and Magnetic Resonance Imaging
- 2023
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 6:22, s. 21182-21193
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Tidskriftsartikel (refereegranskat)abstract
- A multifunctional hybrid gel based on cellulose nanofibrils (CNFs) was developed by grafting on its surface stearyl acrylate (PSA) and gadolinium(III) fluoride nanoparticles (GdF3 NPs) via Cu0-mediated surface-initiated radical polymerization (SET-LRP) while encapsulating antimicrobial peptides in it. GdF3 NPs were first surface-modified with 11-phosphonoundecyl acrylate (PDA) to participate in the SET-LRP and cross-linked the grafted polymer-modified CNF. Several characterizations of the hybrid material (GdF3-PSA-CNF) were carried out, such as Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), rheology, and microscopic analyses. The grafted PSA and cross-linked GdF3 NPs created sophisticated networks in the CNF-based gel, presenting outstanding rheological properties and promising three-dimensional (3D) printability of this hybrid material (GdF3-PSA-CNF). The nanostructures of GdF3 NPs and their incorporated CNF species were characterized via small-angle X-ray scattering (SAXS). In addition, due to the unique intrinsic property of the GdF3 nanoparticles, properties for magnetic resonance imaging (MRI) of GdF3-PSA-CNF were investigated, showing the potential application as a contrast agent. Finally, the encapsulation of the antimicrobial peptides added another function to the hybrid material, evaluated by an antimicrobial test against methicillin-resistant Staphylococcus aureus (MRSA) in vitro.
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| 4. |
- Lerouge, Frederic, et al.
(författare)
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In vivo targeting and multimodal imaging of cerebral amyloid-beta aggregates using hybrid GdF3 nanoparticles
- 2022
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Ingår i: Nanomedicine. - : FUTURE MEDICINE LTD. - 1743-5889 .- 1748-6963. ; 17:29, s. 2173-2187
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To propose a new multimodal imaging agent targeting amyloid-beta (A beta) plaques in Alzheimers disease. Materials & methods: A new generation of hybrid contrast agents, based on gadolinium fluoride nanoparticles grafted with a pentameric luminescent-conjugated polythiophene, was designed, extensively characterized and evaluated in animal models of Alzheimers disease through MRI, two-photon microscopy and synchrotron x-ray phase-contrast imaging. Results & conclusion: Two different grafting densities of luminescent-conjugated polythiophene were achieved while preserving colloidal stability and fluorescent properties, and without affecting biodistribution. In vivo brain uptake was dependent on the blood-brain barrier status. Nevertheless, multimodal imaging showed successful A beta targeting in both transgenic mice and A beta fibril-injected rats.
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| 5. |
- Navarro, Julien R. G., et al.
(författare)
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WO3 Nanorods Created by Self-Assembly of Highly Crystalline Nanowires under Hydrothermal Conditions
- 2014
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 30:34, s. 10487-10492
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Tidskriftsartikel (refereegranskat)abstract
- WO3 nanorods and wires were obtained via hydrothermal synthesis using sodium tungstate as a precursor and either oxalic acid, citric acid, or poly(methacrylic add) as a stabilizing agent. Transmission electron microscopy images showed that the organic acids with different numbers of carboxylic groups per molecule influence the final sizes and stacking nanostructures of WO3 wires. Three-dimensional electron diffraction tomography of a single nanocrystal revealed a hexagonal WO3 structure with preferential growth along the c-axis, which was confirmed by high-resolution transmission electron microscopy. WO3 nanowires were also spin-coated onto an indium tin oxide/glass conducting substrate, resulting in the formation of a film that was characterized by scanning electron microscopy. Finally, cyclic voltammetry measurements performed on the WO3 thin film showed voltammograms typical for the WO3 redox process.
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| 6. |
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Hybrid Materials for Optical Limiting
- 2005
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Proceedings (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Optical limiting materials based on alkynyl platinum derivatives and thiacalixarenes were produced using the sol-gel process. The molecular species were grafted to the matrix (class II hybrid) in order to maximise the concentration and the stability of the material. Broadband optical limiting performances in the visible wavelength region was observed in the prepared materials. Thermomechanical characterisation of the matrix will also be discussed.
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| 7. |
- Parola, Stephane, et al.
(författare)
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Hybrid materials for optical limiting applications
- 2006
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Ingår i: Optical Materials in Defence Systems Technology III. - Stockholm, Sweden : SPIE-INT SOC OPTICAL ENGINEERING. - 9780819464996 ; , s. U71-U78
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Konferensbidrag (refereegranskat)abstract
- Optical limiting materials are developed for applications in protection of optical sensors against laser aggressions. We have studied functionalised macrocycles (thiacalixarenes) and alkynylplatinum(H) derivatives for optical limiting applications. Glass materials based on alkynylplatinum(H) derivatives and macrocycles were prepared through the sol-gel process. The molecular species were grafted to the matrix in order to maximise the concentration and the stability of the final solid-state material. The glass materials were cut and polished to approximately 1.5 mm. The glass materials show broadband optical limiting in the visible wavelength region, for nanosecond laser pulses.
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| 8. |
- Zieba, Roman, et al.
(författare)
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Preparation of functional hybrid glass material from Platinum (II) Complexes for broadband nonlinear absorption of light
- 2009
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Ingår i: Advanced Funcitional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 19:2, s. 235-241
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of trans-di(arylalkynyl)diphosphine platinum(II) complexes bearing trialkoxysilane groups is described, as well as the preparation of siloxane-based hybrid materials from organometallic chromophores through a modified sol-gel process. Glass materials prepared from trans-[P(n-Bu)3]2Pt[(CC-p-C6H4-CC-p-C6H4-CH2O(CO)NH(CH2)3Si(OC2H5)3]2 generally show spectral transmittance, absorption and luminescence similar to that of solutions reported in the literature. Measurements of optical power limiting for the hybrid glass are carried out, and show broadband nonlinear absorption throughout the whole visible wavelength range with clamping values in the range 0.2-7 µJ at 120 mM chromophore concentration. The sol-gel process using urethane-propyltriethoxysilane-functionalized chromophores as precursors appears to be a valid method for formation of robust silicate materials with grafted diarylethynyl Pt(II) complexes for OPL devices.
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