Ce Nanoparticles Research Articles

Composite Nanostructures for the Production of White Light.

In this work, two different composite nanostructures, YAG:Ce and Ga0.9In0.1N, were prepared by the Urea Glass Route method and tested for the production of white light. The first composite was prepared by synthetizing the Ga0.9In0.1N nanoparticles in the presence of YAG:Ce nanoparticles. The second one was prepared by synthetizing YAG:Ce nanoparticles in the presence of Ga0.9In0.1N nanoparticles. These systems can be useful for the production of white light. X-ray Diffraction and Transmission and Scanning Electron Microscopies (TEM and SEM) were used to evaluate their structural and morphological properties. Excitation and emission spectra, the quantum yield and colour of the emitted light were acquired to evaluate the optical properties of the systems.

Impact of cerium and tungsten doping on the structural and optical characteristics of NiO nanoparticles

Co-precipitation, a rapid and effective technique, was used to produce Ce- and W-doped NiO nanoparticles at pH values of 10 and 12. The FT-IR, UV-visible spectroscopy, and X-ray diffraction techniques were used to examine the structural and optical characteristics. The NiO nanoparticles’ distinct XRD pattern revealed their monoclinic shape and crystalline origin. According to the Debye-Scherrer formula, the crystallite size of NiO nanoparticles decreased to 5.94 nm and 7.12 nm, respectively, when 5% Ce and 5% W were added, from 20.41 nm for undoped. Using UV-VIS absorption spectra, the optical band gap and the wavelength of maximum absorption were found. It was found that both of these parameters were influenced by the pH level and the concentration of Ce and W metal dopants. It can be concluded that doping has a higher impact on Cerium compared to Tungsten and at pH 10 compared to pH 12. This work presents a comprehensive investigation of the effects of pH and dopant concentration on the properties of Ce and W-doped NiO nanoparticles.

Facile Synthesis of Sodium Alginate (SA)-Based Quaternary Bio-Nanocomposite (SA@Co-Zn-Ce) for Antioxidant Activity and Photocatalytic Degradation of Reactive Red 24

This study introduces a new strategy for the environmentally friendly catalytic degradation of Reactive Red 24 (RR24) dye using sunlight. We developed a cost-effective quaternary nanocomposite by immobilizing a sodium alginate biopolymer over bioengineered Co-Zn-Ce nanoparticles, forming an SA@Co–Zn–Ce nanocomposite (where SA means sodium alginate). This composite also demonstrated an exceptional antioxidant potential of approximately 89%, attributed to the synergistic effect of sodium alginate and green-synthesized Co–Zn–Ce nanoparticles (biosynthesized using Ocimum sanctum leaf extract as a reducing agent). Scanning electron microscopy revealed grain sizes of 28.6 nm for Co–Zn–Ce NPs and 25.59 nm for SA@Co–Zn–Ce nanocomposites (NCs). X-ray diffraction showed particle sizes of 16.87 nm and 15.43 nm, respectively. Co–Zn–Ce NPs exhibited a zeta potential of 1.99 mV, whereas the sodium alginate-anchored Co–Zn–Ce showed −7.99 mV. This indicated the entrapment of negatively charged ions from sodium alginate, altering the surface charge characteristics and enhancing the photocatalytic degradation of RR24. Dynamic light scattering revealed an average particle size of approximately 81 nm for SA@Co–Zn–Ce NCs, with the larger size due to the influence of water molecules in the colloidal solution affecting hydrodynamic diameter measurement. The SA@Co–Zn–Ce NCs exhibited a CO2 adsorption capacity of 3.29 mmol/g at 25 °C and 4.76 mmol/g at 40 °C, indicating temperature-dependent variations in adsorption capabilities. The specific surface area of Co–Zn–Ce oxide NPs, measured using Brunauer–Emmett–Teller (BET) analysis, was found to be 167.346 m2/g, whereas the SA@Co–Zn–Ce oxide nanocomposite showed a surface area of 24.14 m2/g. BJH analysis revealed average pore diameters of 34.60 Å for Co–Zn–Ce oxide NPs and 9.26 Å for SA@Co–Zn–Ce oxide NCs. Although the immobilization of sodium alginate on Co–Zn–Ce oxide NPs did not increase the adsorption sites and porosity of the composite, as evidenced by the N2 adsorption–desorption isotherms, the SA@Co–Zn–Ce oxide NCs still demonstrated a high photocatalytic degradation efficiency of RR24.

Co,Ce nanoparticles supported on stacked wire mesh cartridges. Activity and stability in diesel soot combustion

In this work, Co3O4 nanoparticles were successfully synthesized by precipitating a precursor salt solution in the form of microdroplets generated by a nebulizer, as an efficient, fast and low-cost approach. After drying and calcination, synthesized particles were deposited on stacked wire mesh monoliths by immersing the structures in a suspension containing synthesized Co3O4 particles and commercial ceria nanoparticles as a binder. These structured catalysts were evaluated for the combustion of diesel soot which constitutes a crucial step in the regeneration of catalytic particulate filters (CDPFs). Thermal and mechanical stability of Co,Ce washcoated monoliths were investigated. For this, successive catalytic evaluations of the structured system, with intermediate treatments at 900 °C (accelerated aging), were carried out indicating a very good activity and stability of the catalysts developed. Adherence tests showed good adhesion of the catalytic layer to the metallic substrate. Fresh and aged catalysts were fully characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Laser Raman Spectroscopy (LRS) and Temperature-Programmed Reduction (TPR). It was found that the catalytic coating resulted composed of nanometric CeO2 and Co3O4 along with chromium, iron and manganese oxides coming from the migration of the metallic substrate, in the catalytic cartridge calcined at 600 °C. Despite after calcination at 900 °C spinels of Co, Fe, Cr and Mn were observed, these oxides did not significantly affected the catalytic activity. Although this aging treatment at 900 °C was severe and is not expected under real conditions, it highlights the potential application of the catalytic metallic cartridges here developed.

Facile synthesis of Ce(III)-rich cerium oxyhydroxide and its unselective adsorption of Sb(III) and Sb(V) via oxygen vacancies

The introduction of oxygen vacancies (OVs) into metal oxide materials is an effective method for modifying the surface properties of environmentally functional materials. However, limited attention has been paid to their roles as pollutant adsorbent. In this study, Ce(III)-enriched cerium oxyhydroxide particles (CeO(OH)2-OVs@CS) were prepared using a drop-in phase separation method and then used as adsorbents to address the challenges of conventional metal oxides that display notably lower adsorption efficiencies for Sb(V) than Sb(III). Within 60 min, more than 96 % of both Sb(III) and Sb(V) with an initial concentration of 50 mg/L were removed, with only a 2 % difference between them. XRD, XPS, EPR, and FT-IR results demonstrated that chitosan served as a carrier for Ce nanoparticles and, due to its reductive characteristics, enhanced the air stability of Ce(III), thereby creating more OVs. Meanwhile, chitosan's abundant functional groups such as OH, NH2, and CO in its structure can also facilitate the binding of Sb species onto CeO(OH)2. Density functional theory (DFT) calculations also indicated that antimonate ions were more prone to binding with OVs compared with defect-free crystal surfaces. Additionally, CeO(OH)2-OVs@CS showed great removal performance for organic ligands in antimony(III) potassium tartrate solution, and about 97 % of tartaric acid was removed simultaneously.

Refining Al–20Si Alloy by Appending Trace Sr–Sc–Ce Nanoparticles and Ultrasonic Vibration Processing

In this study, Al–20Si alloy is modified by appending trace Sr–Sc–Ce nanoparticles and ultrasonic vibration processing (UVP). The consequences indicate that its microstructure is significantly refined and its mechanical characteristics are improved. The effect of the favorable refinements is achieved by appending 0.2% Sr–0.15% Sc–0.3% Ce and performing UVP. The primary Si is the minimum, the grain roundness coefficient and the strength of extension are the maximum, and the spheroidizing effect of α‐Al is the best. The elongation and hardness are the highest when 0.4% Ce is appended. The research consequences afford a reasonable process scheme for manufacturing high‐quality wear‐resistant material of the automotive and aerospace industries.

Biofunctionalization of nanoceria with sperminated hyaluronan enhances drug delivery performance for corneal alkali burn therapy

Corneal alkali burn (AB) injury is the most common sight-threatening injury that is highly associated with oxidative stress, inflammation, apoptosis, angiogenesis, and cell deficiency. Most therapeutic options are ineffective in improving and reversing pathological conditions. This study aims to develop a delivery system based on sperminated hyaluronan (sH)-functionalized nanoceria (Ce-sH nanoparticles (NPs)) with enhanced barrier penetration capability and increased ocular drug bioavailability. The functional surface properties and therapeutic bioactivities of Ce-sH NPs were evaluated. We observed a high tight-junction opening capacity with higher spermine content, resulting in excellent permeability and cellular uptake efficiency (fourfold that of bare Ce NPs). The NPs exhibited high drug (insulin-like growth factor 1, IGF-1) entrapment efficiency (10-fold) and hyaluronidase-triggered controlled slow release (up to 168 h) compared with bare Ce NPs. The IGF-1-loaded Ce-hsH NPs (I@Ce-hsH) had the best wound healing rate (>90 %). In contrast to a clinically used eye drop (dexamethasone), the I@Ce-hsH significantly reduced corneal defects to <1 % and restored the tissue transparency to a normal range within 7 d post-instillation in a rat model of AB. In summary, our bioactive nanoformulations successfully reversed corneal injury and has great potential in the design of biomaterials for ocular therapeutics.

Enhanced photocatalytic performance of milkvetch-derived biochar via ZnO–Ce nanoparticle decoration for reactive blue 19 dye removal

In this research, the photocatalytic removal of reactive blue 19 (RB19) dye is investigated employing zinc oxide/cerium (ZnO@Ce) nanoparticles decorated with biochar under LED irradiation. Synthesis of ZnO@Ce nanoparticles decorated with biochar was performed utilizing the co-precipitation procedure and, then, the texture and morphology of the fabricated nanocomposite were analyzed using energy dispersive X-ray (EDX), field emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), and Fourier transform infrared (FTIR) spectroscopy techniques. Moreover, FE-SEM images demonstrate that ZnO–Ce nanoparticles were successfully decorated on the surface of biochar. The specific surface areas of biochar and biochar/ZnO–Ce were 519.75 and 636.52 m2/g, respectively. To achieve the maximum yield in the removal of RB19 dye, the effects of operating variables including dye concentration, LED lamp power, biochar@ZnO–Ce catalyst dose, pH and H2O2 dose were explored. Besides, the maximum percentage of RB19 dye removal was 96.47% under optimal conditions, i.e. catalyst dosage of 100 mg, H2O2 dosage of 1 mL, pH of 9, initial dye concentration of 5 ppm, LED power of 50 W, and reaction time of 140 min. Furthermore, the kinetic analysis reveals that the removal of RB19 dye follows the pseudo-first order kinetic model, with calculated values of a reaction rate constant of 0.045 min−1 and a correlation coefficient of R2 = 0.99, respectively. Moreover, the reusability and recyclability of biochar@ZnO/Ce nanocatalyst was promising over five runs, with only a 6.08% decrease in RB19 dye removal efficiency. Therefore, it can be concluded that the biochar @ZnO/Ce photocatalyst can be promisingly applied for the removal of azo dyes in aqueous solutions.

Enhanced Coarse-Grained WC-Co(Ce) Cemented Carbide Prepared through Co-Precipitation.

The exploration of coarse-grained WC cemented carbide has become a research hotspot for its application in the fields of rock cutting and mining; a key issue is how to achieve uniform dispersion and densification of the sintered phase, as well as how to obtain better mechanical properties. In this paper, chemical co-precipitation, combined with hydrogen reduction, was adopted. CoCl2·6H2O and CeCl3 were used as precursors to coat Co nanoparticles on the surface of WC powder while introducing different contents of cerium; the samples were then sintered and densified to obtain WC-Co(Ce) hard alloy materials. On the surface of the obtained WC particles, the distribution of Co(Ce) nanoparticles was uniform and dense, and the average particle size after sintering was 4.2 μm, which lies in the coarse-grained range. The addition of cerium elements significantly improves the flexural strength and impact toughness; when the cerium content was 0.5% and 0.6%, they increased to 2487 MPa and 36.1 kJ/m2, respectively. The addition of Co(Ce) through the co-precipitation method could achieve a uniform coating of the Co phase, along with the uniform dispersion and densification of the sintered phase, giving the WC-Co(Ce) cemented carbide excellent properties.

Ag and Ce nanoparticles supported on silane-modified nitrogen-doped mesoporous carbon (Ag,Ce@SNC/A1SCA) obtained through green approach as heterogeneous catalyst towards the synthesis of 3,4-disubstituted isoxazol-5(4H)-one and polyhydroquinoline derivatives

In this report, an easy and facile approach for the fabrication of heterogenous, mesoporous nanostructure of graphitic carbon grafted with silane (AEAPTMS) and modified with nanoparticles of Ce and Ag, (Ag,Ce@SNC/A1SCA). The graphitization in carbon was induced by ionic liquid-assisted reaction between the glucose and ethylenediamine under mild conditions. It was characterized by thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), powder X-ray diffraction study (PXRD), ultraviolet–visible spectroscopy (UV-VIS), high-resolution transmission electron microscopy (HRTEM), field emission gun-scanning electron microscopy (FEG-SEM), elemental mapping, X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), inductively coupled plasma atomic emission (ICP-AES) and fourier transform infrared spectroscopy (FT-IR). Its acts as an adaptable heterogeneous nanocatalyst in the formation of 3,4-disubstituted isoxazol-5(4H)-one and polyhydroquinoline derivatives. It displayed recyclability for five runs. The recycled catalyst was characterized by PXRD and XPS analysis. XPS analysis established the synergism between metal nanoparticles of Ag and Ce in the prepared nanomaterial.

Metal oxide nanoparticles embedded in porous carbon for sulfur absorption under hydrothermal conditions

MOx (M = Zn, Cu, Mn, Fe, Ce) nanoparticles (NPs) embedded in porous C with uniform diameter and dispersion were synthesized, with potential application as S-absorbents to protect catalysts from S-poisoning in catalytic hydrothermal gasification (cHTG) of biomass. S-absorption performance of MOx/C was evaluated by reacting the materials with diethyl disulfide at HTG conditions (450 °C, 30 MPa, 15 min). Their S-absorption capacity followed the order CuOx/C > CeOx/C ≈ ZnO/C > MnOx/C > FeOx/C. S was absorbed in the first four through the formation of Cu1.8S, Ce2S3, ZnS, and MnS, respectively, with a capacity of 0.17, 0.12, 0.11, and 0.09 molS molM−1. The structure of MOx/C (M = Zn, Cu, Mn) evolved significantly during S-absorption reaction, with the formation of larger agglomerates and separation of MOx particles from porous C. The formation of ZnS NPs and their aggregation in place of hexagonal ZnO crystals indicate a dissolution/precipitation mechanism. Note that aggregated ZnS NPs barely sinter under these conditions. Cu(0) showed a preferential sulfidation over Cu2O, the sulfidation of the latter seemingly following the same mechanism as for ZnO. In contrast, FeOx/C and CeOx/C showed remarkable structural stability with their NPs well-dispersed within the C matrix after reaction. MOx dissolution in water (from liquid to supercritical state) was modeled and a correlation between solubility and particle growth was found, comforting the hypothesis of the importance of an Ostwald ripening mechanism. CeOx/C with high structural stability and promising S-absorption capacity was suggested as a promising bulk absorbent for sulfides in cHTG of biomass.

Layered Na2Mn3O7 decorated by Cerium as the robust catalysts for efficient low temperature soot combustion

Removal of soot particles by highly efficient catalysts is a research hotspot, not only because the problem of air pollution, but also because the complexity of the catalytic process that involves gas-solid-solid three-phase reaction. We synthesized single atom Ce and CeO2 nanoparticles simultaneously modified layered Na2Mn3O7 catalysts for soot combustion with unprecedented catalytic performance and high resistance to water and sulfur, using low-cost raw materials and a simple preparation protocol. The synergy between the easily available adsorbed and surface reactive oxygen species and the high yield of NO2 exploitation, leads to the beneficial transition of soot combustion process from “gas-solid-solid” into “gas-gas-solid”, thereby, shifted to low temperatures. Our findings provide a pathway to the development of cheap catalysts based on transition metal oxides, avoiding application of noble metals for successful elimination of diesel exhausts at remarkably low temperatures.

Ce nanoparticles and sol-gel hybrid organic-inorganic coatings maximize corrosion protection in the anodized AA2024-T3

We demonstrate that the corrosion resistance of the AA2024-T3 alloy can be maximized with the application of top protective sol-gel hybrid organic-inorganic coatings. Samples combining Ce nanoparticles within the pores of the anodic layer with the top sol-gel coatings were observed to outperform samples featuring only the coating. This research unravels the self-healing capability against corrosion of the sol-gel coating when Ce nanoparticles are present, as well as a good coverage of defective regions within the oxide by the hybrid layer. This research opens a paradigm aiming at maximizing the corrosion resistance for non-ferrous anodized alloys.

Silk fibroin-gelatin photo-crosslinked 3D-bioprinted hydrogel with MOF-methylene blue nanoparticles for infected wound healing.

Photo-crosslinked hydrogel (PH) is an outstanding candidate for three-dimensional (3D) printing as a wound dressing because of its high efficiency in crosslinking and injectability. In this study, methylene blue (MB)-loaded UiO-66(Ce) nanoparticles (NPs) were synthesized to prevent drug self-aggregation and achieve the photodynamic therapy (PDT) effect for efficient antibacterial action. Then, a composite photocrosslinked silk fibroin (SF)/gelatin hydrogel loaded with MB@UiO-66(Ce) NPs (MB@UiO-66(Ce)/PH) was fabricated. The printability and the improvement of the mechanical properties of the hydrogel by the NPs were clarified. The hydrogel exhibited good biocompatibility and promoted the migration and proliferation of fibroblasts. With the PDT effect of MB@UiO-66(Ce) NPs, the hydrogel showed an excellent antibacterial effect, which became more pronounced as the concentration increased. In vivo study showed that the MB@UiO-66(Ce)/PH could fill the defects without gaps and accelerate the repair rate of full-thickness skin defects in mice. The MB@UiO-66(Ce)/PH with antibacterial properties and tissue healing-promoting ability provides a new strategy involving 3D bioprinting for preparing wound dressings.

Defect-induced luminescence properties of Ce3+ ion-doped BaSO4 prepared via the co-precipitation method

We investigated the emission properties of Ce3+-doped BaSO4 (BaSO4:Ce) nanoparticles synthesized using the co-precipitation method. Rietveld refinement analysis of the X-ray diffraction patterns revealed that BaSO4:Ce was synthesized successfully without any impurities. Upon photo-excitation at λex = 247 and 267 nm, BaSO4:Ce showed two intense emission peaks at 300 and 320 nm, which were assigned to the 5d → 2F5/2 and 2F7/2 transitions of Ce3+ ions. Interestingly, we achieved modulation of the photoluminescence intensity by controlling the irradiation wavelength and irradiation time. In addition, optically stimulated luminescence and thermoluminescence characteristics were observed in the low-Ce3+ doping concentration region. These novel luminescent properties were attributed to defect states originating from the doping of Ce3+. Our results suggest that BaSO4:Ce nanoparticles prepared via the co-precipitation method have good properties for use in dosimeters as well as UV phosphors.

Enhancing Fe content tolerance in A356 alloys for achieving low carbon footprint aluminum structure castings

Low carbon footprint aluminum structure castings are the mainstream development direction of aluminum alloys in the future. Enhancing the Fe content tolerance upper limit in casting aluminum alloys is considered an effective way to promote the application of recycled aluminum production. In this work, it was found that with the Ce and TiCN NPs (nanoparticles) addition simultaneously to A356 alloys, the acicular Fe-rich phases (β-Al5FeSi) which damages the properties can be changed into beneficial phases (core-shell heterostructures) for the alloy, and hence the mechanical properties of A356 alloys can be improved. The TiCN nanoparticles and rare element Ce play crucial roles in the formation of core-shell heterostructures. The formation mechanism of core-shell heterostructure was also systematically researched from the perspective of thermodynamics and kinetics. This study provides a simple and feasible strategy to eliminate the harmful effects of Fe impurity and contributes to the industrialization of low carbon footprint aluminum structure castings.

Synthesis of Ce and Sm Co-Doped TiO2 Nanoparticles with Enhanced Photocatalytic Activity for Rhodamine B Dye Degradation

One of the major concerns that receive global attention is the presence of organic pollutants (dyes, pharmaceuticals, pesticides, phenolic compounds, heavy metals, and so on), originating from various industries, in wastewater and water resources. Rhodamine B is widely used in the dyeing of paints, plastics, textiles, and other fabrics, as well as biological products. It is highly persistent, toxic, and carcinogenic to organisms and humans when directly released into the water supply. To avoid this hazard, several studies have been conducted in an attempt to remove Rhodamine B from wastewater. Metal oxide semiconducting materials have gained great interest because of their ability to decompose organic pollutants from wastewater. TiO2 is one of the most effective photocatalysts with a broad range of applications. Several attempts have been made to improve its photocatalytic activity. Accordingly, we have prepared in this work a series of cerium (Ce) and samarium (Sm) co-doped TiO2 nanoparticles (x = 0.00, 0.25, 0.50, 1.00, and 2.00%) using a sol–gel auto-combustion approach. The influence of Ce–Sm concentrations on the structural, morphology, electronic, and optical properties, as well as the photocatalytic activity, was investigated. Structure and elemental mapping analyses proved the presence of Ce and Sm in the compositions as well as the development of the TiO2 anatase phase with a tetragonal structure and crystallite size of 15.1–17.8 nm. Morphological observations confirmed the creation of spherical nanoparticles (NPs). The examination of the electronic structure properties using density functional theory (DFT) calculations and of the optical properties using a UV/Vis diffuse spectrophotometer showed a reduction in the bandgap energy upon Ce–Sm co-doping. The photocatalytic activity of the synthesized products was assessed on the degradation of Rhodamine B dye, and it was found that all Ce–Sm co-doped TiO2 nanoparticles have better photocatalytic activities than pristine TiO2 nanoparticles. Among all of the prepared nanoparticles, the sample with x = 0.50% demonstrated the best photocatalytic activity, with a degradation efficiency of 98% within 30 min and a reaction rate constant of about 0.0616 min−1. h+ and •O2− were determined to be the most important active species in the photocatalytic degradation process. Besides the high photocatalytic degradation efficiency, these photocatalysts are highly stable and could be easily recovered and reused, which indicates their potential for practical applications in the future.

Ultra-Small YPO4 -YAG:Ce Composite Nanophosphors with a Photoluminescence Quantum Yield Exceeding 50.

Synthesis of high quality colloidal Cerium(III) doped yttrium aluminum garnet (Y3 Al5 O12 :Ce3+ , "YAG:Ce") nanoparticles (NPs) meeting simultaneously both ultra-small size and high photoluminescence (PL) performance is challenging, as generally a particle size/PL trade-off has been observed for this type of nanomaterials. The glycothermal route is capable to yield ultra-fine crystalline colloidal YAG:Ce nanoparticles with a particle size as small as 10nm but with quantum yield (QY) no more than 20%. In this paper, the first ultra-small YPO4 -YAG:Ce nanocomposite phosphor particles having an exceptional QY-to-size performance with an QY up to 53% while maintaining the particle size ≈10nm is reported. The NPs are produced via a phosphoric acid- and extra yttrium acetate-assisted glycothermal synthesis route. Localization of phosphate and extra yttrium entities with respect to cerium centers in the YAG host has been determined by fine structural analysis techniques such as X-ray diffration (XRD), solid state nuclear magnetic resonance (NMR), and high resolution scanning transmission electron microscopy (HR-STEM), and shows distinct YPO4 and YAG phases. Finally, a correlation between the additive-induced physico-chemical environment change around cerium centers and the increasing PL performance has been suggested based on electron paramagnetic resonance (EPR), X-ray photoelectronspectrometry (XPS) data, and crystallographic simulation studies.

Distribution and inflammatory cell response to intracranial delivery of radioluminescent Y2(SiO4)O:Ce particles.

Due to increasing advances in their manufacture and functionalization, nanoparticle-based systems have become a popular tool for in vivo drug delivery and biodetection. Recently, scintillating nanoparticles such as yttrium orthosilicate doped with cerium (Y2(SiO4)O:Ce) have come under study for their potential utility in optogenetic applications, as they emit photons upon low levels of stimulation from remote x-ray sources. The utility of such nanoparticles in vivo is hampered by rapid clearance from circulation by the mononuclear phagocytic system, which heavily restricts nanoparticle accumulation at target tissues. Local transcranial injection of nanoparticles may deliver scintillating nanoparticles to highly specific brain regions by circumventing the blood-brain barrier and avoiding phagocytic clearance. Few studies to date have examined the distribution and response to nanoparticles following localized delivery to cerebral cortex, a crucial step in understanding the therapeutic potential of nanoparticle-based biodetection in the brain. Following the synthesis and surface modification of these nanoparticles, two doses (1 and 3 mg/ml) were introduced into mouse secondary motor cortex (M2). This region was chosen as the site for RLP delivery, as it represents a common target for optogenetic manipulations of mouse behavior, and RLPs could eventually serve as an injectable x-ray inducible light delivery system. The spread of particles through the target tissue was assessed 24 hours, 72 hours, and 9 days post-injection. Y2(SiO4)O:Ce nanoparticles were found to be detectable in the brain for up to 9 days, initially diffusing through the tissue until 72 hours before achieving partial clearance by the final endpoint. Small transient increases in the presence of IBA-1+ microglia and GFAP+ astrocytic cell populations were detected near nanoparticle injection sites of both doses tested 24 hours after surgery. Taken together, these data provide evidence that Y2(SiO4)O:Ce nanoparticles coated with BSA can be injected directly into mouse cortex in vivo, where they persist for days and are broadly tolerated, such that they may be potentially utilized for remote x-ray activated stimulation and photon emission for optogenetic experiments in the near future.

Nonisothermal cure behavior and kinetics of cerium‐doped Fe3O4/epoxy nanocomposites

How does the cerium (Ce) doping in ferrimagnetic magnetite (Fe3O4) affect the crosslinking state and kinetics of epoxy crosslinking with amine curing agents? To answer this question, we electrochemically synthesized nanoparticles of Ce–Fe3O4 and characterized them by FTIR, XRD, FE‐SEM, EDX, TEM, and XPS analyses. The presence of Ce atoms in Fe3O4 crystalline lattice increased the surface area and active hydroxyl sites of the prepared magnetic nanoparticles (MNPs) associated with partial shrinkage of molecular lattice. The MNPs uniformly dispersed in epoxy resin and unconditionally tagged epoxy nanocomposites as Excellent cured systems. The effect of lanthanide doping on the cure kinetics of epoxy with amine was explored applying nonisothermal DSC and model‐free kinetic approaches, signifying that Ce–Fe3O4 nanoparticles facilitated epoxy ring opening by intensification of etherification reaction whatever the heating rate. Even at very low loading of Ce–Fe3O4 nanoparticles into the epoxy (0.1 wt.%), the average apparent activation energy significantly decreased by ≈10%. This outcome would highlight the role of crosslinking on the ultimate properties, such as anticorrosive and/or self‐healing characteristics contributed by Ce‐doped nanoparticles once added to epoxy coating formulation.