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Cruz ME, Ngoc Lam Tran T, Chiasera A, Durán A, Fernandez J, Balda R, Castro Y. Novel Sol-Gel Route to Prepare Eu 3+-Doped 80SiO 2-20NaGdF 4 Oxyfluoride Glass-Ceramic for Photonic Device Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:940. [PMID: 36903818 PMCID: PMC10004841 DOI: 10.3390/nano13050940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/01/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Oxyfluoride glass-ceramics (OxGCs) with the molar composition 80SiO2-20(1.5Eu3+: NaGdF4) were prepared with sol-gel following the "pre-crystallised nanoparticles route" with promising optical results. The preparation of 1.5 mol % Eu3+-doped NaGdF4 nanoparticles, named 1.5Eu3+: NaGdF4, was optimised and characterised using XRD, FTIR and HRTEM. The structural characterisation of 80SiO2-20(1.5Eu3+: NaGdF4) OxGCs prepared from these nanoparticles' suspension was performed by XRD and FTIR revealing the presence of hexagonal and orthorhombic NaGdF4 crystalline phases. The optical properties of both nanoparticles' phases and the related OxGCs were studied by measuring the emission and excitation spectra together with the lifetimes of the 5D0 state. The emission spectra obtained by exciting the Eu3+-O2- charge transfer band showed similar features in both cases corresponding the higher emission intensity to the 5D0→7F2 transition that indicates a non-centrosymmetric site for Eu3+ ions. Moreover, time-resolved fluorescence line-narrowed emission spectra were performed at a low temperature in OxGCs to obtain information about the site symmetry of Eu3+ in this matrix. The results show that this processing method is promising for preparing transparent OxGCs coatings for photonic applications.
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Affiliation(s)
| | - Thi Ngoc Lam Tran
- IFN-CNR CSMFO Laboratory and FBK Photonics Unit, Via alla Cascata 56/C Povo, 38123 Trento, Italy
- Department of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Department of Materials Technology, Faculty of Applied Science, Ho Chi Minh City University of Technology and Education, Vo Van Ngan Street 1, Thu Duc District, 720214 Ho Chi Minh City, Vietnam
| | - Alessandro Chiasera
- IFN-CNR CSMFO Laboratory and FBK Photonics Unit, Via alla Cascata 56/C Povo, 38123 Trento, Italy
| | - Alicia Durán
- Instituto de Cerámica y Vidrio, CSIC, 28049, Madrid, Spain
| | - Joaquín Fernandez
- Donostia International Physics Center (DIPC), 20018 San Sebastian, Spain
| | - Rolindes Balda
- Department Física Aplicada, Escuela Superior de Ingeniería, Universidad del País Vasco (UPV-EHU), 48013 Bilbao, Spain
- Centro de Física de Materiales, (CSIC-UPV/EHU), 20018 San Sebastian, Spain
| | - Yolanda Castro
- Instituto de Cerámica y Vidrio, CSIC, 28049, Madrid, Spain
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Pisarski WA. Rare Earth Doped Glasses/Ceramics: Synthesis, Structure, Properties and Their Optical Applications. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8099. [PMID: 36431585 PMCID: PMC9698667 DOI: 10.3390/ma15228099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
Glasses, glass-ceramics and ceramics belong to three important classes of engineering materials, which are useful in numerous multifunctional and industrial applications [...].
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Affiliation(s)
- Wojciech A Pisarski
- Institute of Chemistry, University of Silesia, Szkolna 9 Street, 40-007 Katowice, Poland
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Secu C, Rostas AM, Secu M. Europium (II)-Doped CaF 2 Nanocrystals in Sol-Gel Derived Glass-Ceramic: Luminescence and EPR Spectroscopy Investigations. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3016. [PMID: 36080052 PMCID: PMC9457762 DOI: 10.3390/nano12173016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
The remarkable properties of Eu2+-activated phosphors, related to the broad and intense luminescence of Eu2+ ions, showed a high potential for a wide range of optical-related applications. Oxy-fluoride glass-ceramic containing Europium (II)-doped CaF2 nanocrystals embedded in silica matrix were produced in two steps: glass-ceramization in air at 800° with Eu3+-doped CaF2 nanocrystals embedded followed by Eu3+ to Eu2+ reduction during annealing in reducing atmosphere. The broad, blue luminescence band at 425 nm and with the long, weak tail in the visible range is assigned to the d → f type transition of the Eu2+ located inside the CaF2 nanocrystals in substitutional and perturbed sites, respectively; the photoluminescence quantum yield was about 0.76. The X-ray photoelectron spectroscopy and Electron paramagnetic spectroscopy confirmed the presence of Eu2+ inside the CaF2 nanocrystals. Thermoluminescence curves recorded after X-ray irradiation of un-doped and Eu2+-doped glass-ceramics showed a single dominant glow peak at 85 °C related to the recombination between F centers and Eu2+ related hole within the CaF2 nanocrystals. The applicability of the procedure can be tested to obtain an oxy-fluoride glass-ceramic doped with other divalent ions such as Sm2+, Yb2+, as nanophosphors for radiation detector or photonics-related applications.
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Affiliation(s)
- Corina Secu
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania
| | - Arpad-Mihai Rostas
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania
- National Institute for Research and Development of Isotopic and Molecular Technologies, Donat 67-103, 400293 Cluj-Napoca, Romania
| | - Mihail Secu
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania
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Shere I, Malani A. Understanding the mechanism and kinetics of the formation and breaking of ring structures during silica polymerization: a computational study. Phys Chem Chem Phys 2022; 24:11151-11168. [PMID: 35475505 DOI: 10.1039/d1cp05774j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ring structures are ubiquitous in porous materials and play a crucial role in the functioning of these materials. Understanding the ring formation and breaking mechanism is essential for designing and controlling the porosity, framework density, channels, and cage formation in porous materials. The current work attempts to understand the formation, breaking, and survival of rings using a computational approach. We have used the reaction ensemble Monte Carlo simulation technique and studied silica polymerization starting from monomers to inter-connected large silica clusters in dilute and concentrated silica systems. We calculated various properties of representative smaller and bigger rings at different stages of polymerization. We found that smaller rings form in the initial polymerization stages and larger ring sizes appear at later stages. The smaller rings have a larger residence time than the bigger rings in the silica system, and the residence time changes with the polymerization stage. Both smaller and bigger rings have a shorter residence time in the dilute system than the concentrated silica system. As a result, ring formation and breaking kinetics are faster in the dilute silica system, which causes reorganization within the silica cluster leading to a dense cluster. A slow reorganization of rings in the concentrated silica system is observed, due to which clusters retain their random, branched configuration and porous region within the cluster. We also investigated a series of ring formation and breaking steps to understand the formation mechanism of isolated and grouped rings in the studied silica systems. We found that rings form and break by all possible reactions during ring-formation and cluster-aggregation stages. In contrast, only one reaction is dominant in the initial and aging stages of polymerization. The concentration of silica affects the formation of isolated rings, whereas the kinetics of a grouped ring is not significantly altered. Detailed insights into the reaction dynamics of rings at various stages of polymerization would be helpful in the rational design of porous silica polymorphs.
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Affiliation(s)
- Inderdip Shere
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
| | - Ateeque Malani
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
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Effect of Gold Nanoparticles on the Crystallization and Optical Properties of Glass in ZnO-MgO-Al2O3-SiO2 System. CRYSTALS 2022. [DOI: 10.3390/cryst12020287] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Gold nanoparticles precipitated in transparent glass-ceramics could pave the way for the development of multifunctional materials that are in demand in modern photonics and optics. In this work, we explored the effect of gold nanoparticles on the crystallization, microstructure, and optical properties of ZnO-MgO-Al2O3-SiO2 glass containing TiO2 and ZrO2 as nucleating agents. X-ray diffraction, transmission electron microscopy, Raman, and optical spectroscopy were used for the study. We showed that gold nanoparticles have no effect on the formation of gahnite nanocrystals during the glass heat treatments, while optical properties of the glass-ceramics are strongly dependent on the gold addition. A computational model was developed to predict optical properties of glass during the crystallization, and the possibility for adjusting the localized surface plasmon resonance band position with the heat treatment temperature was shown.
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Optical Properties of Transparent Rare-Earth Doped Sol-Gel Derived Nano-Glass Ceramics. MATERIALS 2021; 14:ma14226871. [PMID: 34832273 PMCID: PMC8623871 DOI: 10.3390/ma14226871] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/04/2021] [Accepted: 11/09/2021] [Indexed: 12/11/2022]
Abstract
Rare-earth doped oxyfluoride glass ceramics represent a new generation of tailorable optical materials with high potential for optical-related applications such as optical amplifiers, optical waveguides, and white LEDs. Their key features are related to the high transparency and remarkable luminescence properties, while keeping the thermal and chemical advantages of oxide glasses. Sol-gel chemistry offers a flexible synthesis approach with several advantages, such as lower processing temperature, the ability to control the purity and homogeneity of the final materials on a molecular level, and the large compositional flexibility. The review will be focused on optical properties of sol-gel derived nano-glass ceramics related to the RE-doped luminescent nanocrystals (fluorides, chlorides, oxychlorides, etc.) such as photoluminescence, up-conversion luminescence, thermoluminescence and how these properties are influenced by their specific processing, mostly focusing on the findings from our group and similar ones in the literature, along with a discussion of perspectives, potential challenges, and future development directions.
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Recent Developments in Carbon Nanotubes-Reinforced Ceramic Matrix Composites: A Review on Dispersion and Densification Techniques. CRYSTALS 2021. [DOI: 10.3390/cryst11050457] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ceramic matrix composites (CMCs) are well-established composites applied on commercial, laboratory, and even industrial scales, including pottery for decoration, glass–ceramics-based light-emitting diodes (LEDs), commercial cooking utensils, high-temperature laboratory instruments, industrial catalytic reactors, and engine turbine blades. Despite the extensive applications of CMCs, researchers had to deal with their brittleness, low electrical conductivity, and low thermal properties. The use of carbon nanotubes (CNTs) as reinforcement is an effective and efficient method to tailor the ceramic structure at the nanoscale, which provides considerable practicability in the fabrication of highly functional CMC materials. This article provides a comprehensive review of CNTs-reinforced CMC materials (CNTs-CMCs). We critically examined the notable challenges during the synthesis of CNTs-CMCs. Five CNT dispersion processes were elucidated with a comparative study of the established research for the homogeneity distribution in the CMCs and the enhanced properties. We also discussed the effect of densification techniques on the properties of CNTs-CMCs. Additionally, we synopsized the outstanding microstructural and functional properties of CNTs in the CNTs-CMCs, namely stimulated ceramic crystallization, high thermal conductivity, bandgap reduction, and improved mechanical toughness. We also addressed the fundamental insights for the future technological maturation and advancement of CNTs-CMCs.
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Pawlik N, Szpikowska-Sroka B, Goryczka T, Pisarska J, Pisarski WA. Structural and Photoluminescence Investigations of Tb 3+/Eu 3+ Co-Doped Silicate Sol-Gel Glass-Ceramics Containing CaF 2 Nanocrystals. MATERIALS (BASEL, SWITZERLAND) 2021; 14:754. [PMID: 33562698 PMCID: PMC7915151 DOI: 10.3390/ma14040754] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 12/18/2022]
Abstract
In this work, the series of Tb3+/Eu3+ co-doped xerogels and derivative glass-ceramics containing CaF2 nanocrystals were prepared and characterized. The in situ formation of fluoride crystals was verified by an X-ray diffraction technique (XRD) and transmission electron microscopy (TEM). The studies of the Tb3+/Eu3+ energy transfer (ET) process were performed based on excitation and emission spectra along with luminescence decay analysis. According to emission spectra recorded under near-ultraviolet (NUV) excitation (351 nm, 7F6 → 5L9 transition of Tb3+), the mutual coexistence of the 5D4 → 7FJ (J = 6-3) (Tb3+) and the 5D0 → 7FJ (J = 0-4) (Eu3+) luminescence bands was clearly observed. The co-doping also resulted in gradual shortening of a lifetime from the 5D4 state of Tb3+ ions, and the ET efficiencies were varied from ηET = 11.9% (Tb3+:Eu3+ = 1:0.5) to ηET = 22.9% (Tb3+:Eu3+ = 1:2) for xerogels, and from ηET = 25.7% (Tb3+:Eu3+ = 1:0.5) up to ηET = 67.4% (Tb3+:Eu3+ = 1:2) for glass-ceramics. Performed decay analysis from the 5D0 (Eu3+) and the 5D4 (Tb3+) state revealed a correlation with the change in Tb3+-Eu3+ and Eu3+-Eu3+ interionic distances resulting from both the variable Tb3+:Eu3+ molar ratio and their partial segregation in CaF2 nanophase.
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Affiliation(s)
- Natalia Pawlik
- Institute of Chemistry, University of Silesia, 40-007 Katowice, Poland; (B.S.-S.); (J.P.); (W.A.P.)
| | - Barbara Szpikowska-Sroka
- Institute of Chemistry, University of Silesia, 40-007 Katowice, Poland; (B.S.-S.); (J.P.); (W.A.P.)
| | - Tomasz Goryczka
- Institute of Materials Engineering, University of Silesia, 41-500 Chorzów, Poland;
| | - Joanna Pisarska
- Institute of Chemistry, University of Silesia, 40-007 Katowice, Poland; (B.S.-S.); (J.P.); (W.A.P.)
| | - Wojciech A. Pisarski
- Institute of Chemistry, University of Silesia, 40-007 Katowice, Poland; (B.S.-S.); (J.P.); (W.A.P.)
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Velázquez JJ, Gorni G, Balda R, Fernández J, Pascual L, Durán A, Pascual MJ. Non-Linear Optical Properties of Er 3+-Yb 3+-Doped NaGdF 4 Nanostructured Glass-Ceramics. NANOMATERIALS 2020; 10:nano10071425. [PMID: 32708192 PMCID: PMC7408096 DOI: 10.3390/nano10071425] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/17/2020] [Accepted: 07/18/2020] [Indexed: 11/25/2022]
Abstract
Transparent oxyfluoride glass–ceramics containing NaGdF4 nanocrystals were prepared by melt-quenching and doped with Er3+ (0.5 mol%) and different amounts of Yb3+ (0–2 mol%). The selected dopant concentration the crystallization thermal treatments were chosen to obtain the most efficient visible up-conversion emissions, together with near infrared emissions. The crystal size increased with dopant content and treatment time. NaGdF4 NCs with a size ranging 9–30 nm were obtained after heat treatments at Tg + 20–80 °C as confirmed by X-ray diffraction and high-resolution transmission electron microscopy. Energy dispersive X-ray analysis shows the incorporation of rare earth ions into the NaGdF4 nanocrystals. Near-infrared emission spectra, together with the up-conversion emissions were measured. The optical characterization of the glass–ceramics clearly shows that Er3+ and Yb3+ ions are incorporated in the crystalline phase. Moreover, visible up-conversion emissions could be tuned by controlling the nanocrystals size through appropriated heat treatment, making possible a correlation between structural and optical properties.
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Affiliation(s)
- José J. Velázquez
- Centre for Functional and Surface Functionalized Glass (FunGlass), Alexander Dubček University of Trenčín, 911 50 Trenčín, Slovakia
- Correspondence:
| | - Giulio Gorni
- Instituto de Cerámica y Vidrio, ICV-CSIC, 28049 Madrid, Spain; (G.G.); (A.D.); (M.J.P.)
| | - Rolindes Balda
- Applied Physic Department I, Superior School of Engineering, Basque Country University, 48013 Bilbao, Spain;
- Materials Physics Center CSIC-UPV/EHU, 20018 San Sebastian, Spain
| | - Joaquin Fernández
- Donostia International Physics Center (DIPC), 20018 San Sebastian, Spain;
| | - Laura Pascual
- Instituto de Catálisis y Petroleoquímica-CSIC, 28049 Madrid, Spain;
| | - Alicia Durán
- Instituto de Cerámica y Vidrio, ICV-CSIC, 28049 Madrid, Spain; (G.G.); (A.D.); (M.J.P.)
| | - Maria J. Pascual
- Instituto de Cerámica y Vidrio, ICV-CSIC, 28049 Madrid, Spain; (G.G.); (A.D.); (M.J.P.)
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10
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Energy Transfer Study on Tb 3+/Eu 3+ Co-Activated Sol-Gel Glass-Ceramic Materials Containing MF 3 (M = Y, La) Nanocrystals for NUV Optoelectronic Devices. MATERIALS 2020; 13:ma13112522. [PMID: 32492852 PMCID: PMC7321446 DOI: 10.3390/ma13112522] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/18/2020] [Accepted: 05/28/2020] [Indexed: 11/25/2022]
Abstract
In the present work, the Tb3+/Eu3+ co-activated sol-gel glass-ceramic materials (GCs) containing MF3 (M = Y, La) nanocrystals were fabricated during controlled heat-treatment of silicate xerogels at 350 °C. The studies of Tb3+ → Eu3+ energy transfer process (ET) were performed by excitation and emission spectra along with luminescence decay analysis. The co-activated xerogels and GCs exhibit multicolor emission originated from 4fn–4fn optical transitions of Tb3+ (5D4 → 7FJ, J = 6–3) as well as Eu3+ ions (5D0 → 7FJ, J = 0–4). Based on recorded decay curves, it was found that there is a significant prolongation in luminescence lifetimes of the 5D4 (Tb3+) and the 5D0 (Eu3+) levels after the controlled heat-treatment of xerogels. Moreover, for both types of prepared GCs, an increase in ET efficiency was also observed (from ηET ≈ 16% for xerogels up to ηET = 37.3% for SiO2-YF3 GCs and ηET = 60.8% for SiO2-LaF3 GCs). The changes in photoluminescence behavior of rare-earth (RE3+) dopants clearly evidenced their partial segregation inside low-phonon energy fluoride environment. The obtained results suggest that prepared SiO2-MF3:Tb3+, Eu3+ GC materials could be considered for use as optical elements in RGB-lighting optoelectronic devices operating under near-ultraviolet (NUV) excitation.
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Osorno LL, Medina JDR, Maldonado DE, Mosley RJ, Byrne ME. Extended Release of Doxorubicin-Loaded 3DNA Nanocarriers from In-Situ Forming, Self-Assembled Hydrogels. J Ocul Pharmacol Ther 2020; 36:447-457. [PMID: 32466697 DOI: 10.1089/jop.2019.0145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose: Cataracts are the leading cause of blindness worldwide, resulting in over 30 million surgeries each year. These cases are expected to double within the next 10 years. About 25% of all patients develop secondary cataracts or posterior capsule opacification (PCO) postsurgery. PCO is a vision impairment disorder that develops from myofibroblasts migration and contraction that deforms the capsule surrounding the lens. Currently, Nd:YAG laser therapy is used to treat PCO; however, laser is not available worldwide and adverse side effects may arise. Thus, there is a considerable unmet need for more efficacious and convenient preventive treatments for PCO. Our work focuses on engineering an innovative, prophylactic sustained release platform for DNA-based nanocarriers to further reduce the incidence of PCO. Methods: Novel, optically clear, self-assembled poly(d,l-lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-PEG) triblock copolymer hydrogels were used for the sustained release of the DNA-based nanocarriers (3DNA®) loaded with cytotoxic doxorubicin (DOX) and targeted with a monoclonal antibody called G8 (3DNA:DOX:G8), which is specific to cells responsible for PCO. Results: The 29 (w/v)% polymer hydrogels with the 3DNA nanocarriers presented over 80% of light transmittance, soft mechanical properties (<350 Pa), and sustained release for 1 month. Conclusions: In this work, we show for the first time that the hydrophobic PLGA-PEG-PLGA hydrogels can be used as platforms for sustained delivery of nucleic acid-based nanocarriers. This work demonstrates that polymeric formulations can be used for the extended delivery of ocular therapeutics and other macromolecules to treat a variety of ocular conditions.
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Affiliation(s)
- Laura L Osorno
- Biomimetic and Biohybrid Materials, Biomedical Devices, and Drug Delivery Laboratories, Department of Biomedical Engineering, Rowan University, Glassboro, New Jersey, USA
| | - Jamie D R Medina
- Biomimetic and Biohybrid Materials, Biomedical Devices, and Drug Delivery Laboratories, Department of Biomedical Engineering, Rowan University, Glassboro, New Jersey, USA
| | - Daniel E Maldonado
- Biomimetic and Biohybrid Materials, Biomedical Devices, and Drug Delivery Laboratories, Department of Biomedical Engineering, Rowan University, Glassboro, New Jersey, USA
| | - Robert J Mosley
- Biomimetic and Biohybrid Materials, Biomedical Devices, and Drug Delivery Laboratories, Department of Biomedical Engineering, Rowan University, Glassboro, New Jersey, USA
| | - Mark E Byrne
- Biomimetic and Biohybrid Materials, Biomedical Devices, and Drug Delivery Laboratories, Department of Biomedical Engineering, Rowan University, Glassboro, New Jersey, USA
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Glass-Ceramics Processed by Spark Plasma Sintering (SPS) for Optical Applications. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10082791] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This paper presents a review on the preparation of glass-ceramics (GCs) and, in particular, transparent GCs by the advanced processing technique of spark plasma sintering (SPS). SPS is an important approach to obtain from simple to complex nanostructured transparent GCs, full densification in a short time, and highly homogeneous materials for optical applications. The influence of the different processing parameters, such as temperature, pressure, sintering dwell time on the shrinkage rate, and final densification and transparency, are discussed and how this affects the glass material properties. Normally, transparent glass-ceramics are obtained by conventional melt-quenching, followed by thermal treatment. Additionally, the GC scan is produced by sintering and crystallization from glass powders. Hot pressing techniques (HP) in which the source of heating is high-frequency induction can be also applied to enhance this process. In the case of transparent ceramics and glass-ceramics, spark plasma sintering is a promising processing tool. It is possible to enhance the material properties in terms of its compactness, porosities, crystallization, keeping the size of the crystals in the nanometric scale. Moreover, the introduction of a high concentration of active gain media into the host matrix provides functional glass-ceramics systems with enhanced luminescence intensity through reducing non-radiative transitions like multi phonon relaxation (MPR) and cross relaxations (CR), thus providing longer lifetimes. More effort is needed to better understand the sintering mechanisms by SPS in transparent GC systems and optimize their final optical performance.
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13
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Nano-Structured Optical Fibers Made of Glass-Ceramics, and Phase Separated and Metallic Particle-Containing Glasses. FIBERS 2019. [DOI: 10.3390/fib7120105] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
For years, scientists have been looking for different techniques to make glasses perfect: fully amorphous and ideally homogeneous. Meanwhile, recent advances in the development of particle-containing glasses (PCG), defined in this paper as glass-ceramics, glasses doped with metallic nanoparticles, and phase-separated glasses show that these “imperfect” glasses can result in better optical materials if particles of desired chemistry, size, and shape are present in the glass. It has been shown that PCGs can be used for the fabrication of nanostructured fibers—a novel class of media for fiber optics. These unique optical fibers are able to outperform their traditional glass counterparts in terms of available emission spectral range, quantum efficiency, non-linear properties, fabricated sensors sensitivity, and other parameters. Being rather special, nanostructured fibers require new, unconventional solutions on the materials used, fabrication, and characterization techniques, limiting the use of these novel materials. This work overviews practical aspects and progress in the fabrication and characterization methods of the particle-containing glasses with particular attention to nanostructured fibers made of these materials. A review of the recent achievements shows that current technologies allow producing high-optical quality PCG-fibers of different types, and the unique optical properties of these nanostructured fibers make them prospective for applications in lasers, optical communications, medicine, lighting, and other areas of science and industry.
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Pawlik N, Szpikowska-Sroka B, Pisarska J, Goryczka T, Pisarski WA. Reddish-Orange Luminescence from BaF 2:Eu 3+ Fluoride Nanocrystals Dispersed in Sol-Gel Materials. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E3735. [PMID: 31766107 PMCID: PMC6888203 DOI: 10.3390/ma12223735] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 12/05/2022]
Abstract
Nanocrystalline transparent BaF2:Eu3+ glass-ceramic materials emitting reddish-orange light were fabricated using a low-temperature sol-gel method. Several experimental techniques were used to verify structural transformation from precursor xerogels to sol-gel glass-ceramic materials containing fluoride nanocrystals. Thermal degradation of xerogels was analyzed by thermogravimetric analysis (TG) and differential scanning calorimetry method (DSC). The presence of BaF2 nanocrystals dispersed in sol-gel materials was confirmed by the X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). In order to detect structural changes in silica network during annealing process, the infrared spectroscopy (IR-ATR) was carried out. In particular, luminescence spectra of Eu3+ and their decays were examined in detail. Some spectroscopic parameters of Eu3+ ions in glass-ceramics containing BaF2 nanocrystals were determined and compared to the values obtained for precursor xerogels. It was observed, that the intensities of two main red and orange emission bands corresponding to the 5D0→7F2 electric-dipole transition (ED) and the 5D0→7F1 magnetic-dipole (MD) transition are changed significantly during transformation from xerogels to nanocrystalline BaF2:Eu3+ glass-ceramic materials. The luminescence decay analysis clearly indicates that the measured lifetime 5D0 (Eu3+) considerably enhanced in nanocrystalline BaF2:Eu3+ glass-ceramic materials compared to precursor xerogels. The evident changes in luminescence spectra and their decays suggest the successful migration of Eu3+ ions from amorphous silica network to low-phonon BaF2 nanocrystals.
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Affiliation(s)
- Natalia Pawlik
- Institute of Chemistry, University of Silesia, 40-007 Katowice, Poland; (B.S.-S.); (W.A.P.)
| | | | - Joanna Pisarska
- Institute of Chemistry, University of Silesia, 40-007 Katowice, Poland; (B.S.-S.); (W.A.P.)
| | - Tomasz Goryczka
- Institute of Materials Engineering, University of Silesia, 41-500 Chorzów, Poland;
| | - Wojciech A. Pisarski
- Institute of Chemistry, University of Silesia, 40-007 Katowice, Poland; (B.S.-S.); (W.A.P.)
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15
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Gorni G, Velázquez JJ, Kochanowicz M, Dorosz D, Balda R, Fernández J, Durán A, Pascual MJ. Tunable upconversion emission in NaLuF 4-glass-ceramic fibers doped with Er 3+ and Yb 3. RSC Adv 2019; 9:31699-31707. [PMID: 35527946 PMCID: PMC9072642 DOI: 10.1039/c9ra05182a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/25/2019] [Indexed: 12/01/2022] Open
Abstract
Novel glass-ceramic optical fibers containing NaLuF4 nanocrystals doped with 0.5ErF3 and 2YbF3 (mol%) have been prepared by the rod-in-tube method and controlled crystallization. NaLuF4 nanocrystals with a size around 20 nm are obtained after heat treatment at 600 °C. Intense upconverted green and red emissions due to (2H11/2, 4S3/2) → 4I15/2 and 4F9/2 → 4I15/2 transitions, respectively, together with a blue emission due to 2H9/2 → 4I15/2 transition have been observed under excitation at 980 nm. The intensity of the green and red upconversion bands shows a nearly linear dependence on the excitation power which can be explained by saturation effects in the intermediate energy states and proves that a sensitized energy transfer upconversion process is responsible for the population of the emitting levels of Er3+ ions. The upconversion emission color changes from yellow to green by increasing the excitation power density which allows to manipulate the color output of the Er3+ emission in the glass-ceramic fibers. The tunable emission color is easily detected with the naked eye. This interesting characteristic makes these glass-ceramic fibers promising materials for photonic applications. Novel glass-ceramic optical fibers containing NaLuF4 nanocrystals doped with 0.5ErF3 and 2YbF3 (mol%) have been prepared by the rod-in-tube method and controlled crystallization.![]()
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Affiliation(s)
- G Gorni
- Ceramics and Glass Institute, CSIC Madrid Spain
| | - Jose J Velázquez
- FunGlass-Centre for Functional and Surface Functionalized Glass, Alexander Dubček University of Trenčín Trenčín Slovakia
| | - M Kochanowicz
- Bialystok University of Technology, Faculty of Electrical Engineering Bialystok Poland
| | - D Dorosz
- AGH University of Science and Technology, Faculty of Materials Science and Ceramics Krakow Poland
| | - R Balda
- Applied Physic Department I, Superior School of Engineering, Basque Country University Bilbao Spain.,Materials Physics Center CSIC-UPV/EHU San Sebastian Spain
| | - J Fernández
- Donostia International Physics Center San Sebastian Spain
| | - A Durán
- Ceramics and Glass Institute, CSIC Madrid Spain
| | - M J Pascual
- Ceramics and Glass Institute, CSIC Madrid Spain
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16
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Gorni G, Velázquez JJ, Mosa J, Mather GC, Serrano A, Vila M, Castro GR, Bravo D, Balda R, Fernández J, Durán A, Castro Y. Transparent Sol-Gel Oxyfluoride Glass-Ceramics with High Crystalline Fraction and Study of RE Incorporation. NANOMATERIALS 2019; 9:nano9040530. [PMID: 30987125 PMCID: PMC6523291 DOI: 10.3390/nano9040530] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/20/2019] [Accepted: 03/26/2019] [Indexed: 11/16/2022]
Abstract
Transparent oxyfluoride glass-ceramic films and self-supported layers with composition 80SiO2-20LaF3 doped with Er3+ have been successfully synthesized by sol-gel process for the first time. Crack-free films and self-supported layer with a maximum thickness up to 1.4 µm were obtained after heat treatment at the low temperature of 550 °C for 1 min, resulting in a LaF3 crystal fraction of 18 wt%, as confirmed by quantitative Rietveld refinement. This is the highest value reported up to now for transparent oxyfluoride glass-ceramics prepared by sol-gel. This work provides a new synthesis strategy and opens the way to a wide range of potential applications of oxyfluoride glass-ceramics. The characterization by a wide range of techniques revealed the homogeneous precipitation of LaF3 nanocrystals into the glass matrix. X-ray absorption spectroscopy and electron paramagnetic resonance confirmed that the Er3+ ions are preferentially embedded in the low phonon-energy LaF3 nanocrystals. Moreover, photoluminescence (PL) measurements confirmed the incorporation of dopants in the LaF3 nanocrystals. The effective concentration of rare-earth ions in the LaF3 nanocrystals is also estimated by X-ray absorption spectroscopy.
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Affiliation(s)
- Giulio Gorni
- Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, Spain.
| | - Jose J Velázquez
- FunGlass-Centre for Functional and Surface Functionalized Glass, Alexander Dubček University of Trenčín, Trenčín 91150, Slovakia.
| | - Jadra Mosa
- Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, Spain.
| | - Glenn C Mather
- Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, Spain.
| | - Aida Serrano
- Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, Spain.
- SpLine, Spanish CRG Beamline-European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France.
| | - María Vila
- SpLine, Spanish CRG Beamline-European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France.
- Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid, Spain.
| | - Germán R Castro
- SpLine, Spanish CRG Beamline-European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France.
- Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid, Spain.
| | - David Bravo
- Departamento Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid (UAM), 28049 Madrid, Spain.
| | - Rolindes Balda
- Departamento Física Aplica I, Escuela Superior de Ingeniería, Universidad del País Vasco (UPV-EHU), 48013 Bilbao, Spain.
- Centro de Física de Materiales, (UPV/EHU-CSIC), 20018 San Sebastian, Spain.
| | - Joaquín Fernández
- Donostia International Physics Center (DIPC), 20018 San Sebastian, Spain.
| | - Alicia Durán
- Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, Spain.
| | - Yolanda Castro
- Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, Spain.
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17
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Abstract
The development of efficient luminescent systems, such as microcavities, solid-state lasers, integrated optical amplifiers, and optical sensors is the main topic in glass photonics. The building blocks of these systems are glass-ceramics activated by rare-earth ions because they exhibit specific morphologic, structural, and spectroscopic properties. Among various materials that could be used as nanocrystals to be imbedded in a silica matrix, tin dioxide presents some interesting peculiarities, e.g., the presence of tin dioxide nanocrystals allows an increase in both solubility and emission of rare-earth ions. Here, we focus our attention on Er3+—doped silica—tin dioxide photonic glass-ceramics fabricated by a sol-gel route. Although the SiO2-SnO2:Er3+ could be fabricated in different forms, such as thin films, monoliths, and planar waveguides, we herein limit ourselves to the monoliths. The effective role of tin dioxide as a luminescence sensitizer for Er3+ ions is confirmed by spectroscopic measurements and detailed fabrication protocols are discussed.
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18
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Improved Optical and Morphological Properties of Vinyl-Substituted Hybrid Silica Materials Incorporating a Zn-Metalloporphyrin. MATERIALS 2018; 11:ma11040565. [PMID: 29642404 PMCID: PMC5951449 DOI: 10.3390/ma11040565] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 12/16/2022]
Abstract
This work is focused on a novel class of hybrid materials exhibiting enhanced optical properties and high surface areas that combine the morphology offered by the vinyl substituted silica host, and the excellent absorption and emission properties of 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin-Zn(II) tetrachloride as a water soluble guest molecule. In order to optimize the synthesis procedure and the performance of the immobilized porphyrin, silica precursor mixtures of different compositions were used. To achieve the requirements regarding the hydrophobicity and the porous structure of the gels for the successful incorporation of porphyrin, the content of vinyltriacetoxysilane was systematically changed and thoroughly investigated. Substitution of the silica gels with organic groups is a viable way to provide new properties to the support. An exhaustive characterization of the synthesized silica samples was realised by complementary physicochemical methods, such as infrared spectroscopy (FT-IR), absorption spectroscopy (UV-Vis) and photoluminescence, nuclear magnetic resonance spectroscopy (29Si-MAS-NMR) transmission and scanning electron microscopy (TEM and SEM), nitrogen absorption (BET), contact angle (CA), small angle X ray and neutron scattering (SAXS and SANS). All hybrids showed an increase in emission intensity in the wide region from 575 to 725 nm (Q bands) in comparison with bare porphyrin. By simply tuning the vinyltriacetoxysilane content, the hydrophilic/hydrophobic profile of the hybrid materials was changed, while maintaining a high surface area. Good control of hydrophobicity is important to enhance properties such as dispersion, stability behaviour, and resistance to water, in order to achieve highly dispersible systems in water for biomedical applications.
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