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Heterogeneous doping is one effective strategy for synthesizing metal alloy nanowires. Herein, the heterogeneous doping processes of Pd on the ultrathin Au nanowires were systematically modulated and investigated. Au-Pd alloy nanowires with various morphologies and lattice structures can be obtained by adjusting the morphology of the precursor Au nanowires and the kinetics of the heterogeneous doping processes. The effects of the rate of Pd reduction and the concentration of the ligand oleylamine (OAm) on the Pd deposition and alloying mode were articulated. Generally, as the Pd deposition rate decreases, the Pd deposition and alloying mode switches from the island-forming Stransky–Krastanov (SK) mode to the epitaxial Frank-van der Merwe (FM) mode, and eventually to an unconventional twisting alloying mode, where the interdiffusion of Pd and Au causes drastic rearrangement of the lattice structure and formation of helical structures. The kinetics-related variation of alloying mode could also be observed in the Au-Ag nanowires, demonstrating a general design principle for the synthesis of alloy nanostructures. In addition, the electrocatalytic performance of various Au-Pd nanowires was evaluated, and the alloy nanowire formed via the SK mode was found to be an excellent electrocatalyst for oxygen reduction and ethanol oxidation. [ABSTRACT FROM AUTHOR]

Cs2NaInCl6 double perovskites, which have excellent photoelectric conversion properties and are non-toxic and lead-free, have recently gained significant attention. In particular, double-perovskite quantum dots (QDs) are viewed as a promising material for optoelectronic device applications. Ligands such as oleic acid (OA) and oleylamine (OAm) are essential for the synthesis of perovskite QDs, but their specific roles in double-perovskite QDs remain unclear. In this study, we have investigated the binding of OA and OAm to Cs2NaInCl6 QDs through FTIR and NMR and their effects on the surface defect reduction and stability improvement for Cs2NaInCl6 QDs. We found that only OAm was bound to the QD surfaces while OA was not. The OAm has a significant effect on the photoluminescence quantum yield (PLQY) improvement by passivating the QD surface defects. The stability of the QDs was also evaluated, and it was observed that OA played a significant role in the stability of the QDs. Our findings provide valuable insights into the roles of ligands in influencing the photophysical properties and stability of lead-free double-perovskite QDs. [ABSTRACT FROM AUTHOR]

In this study, we investigate the impact of oleic acid and oleylamine on the photoluminescence quantum yield (PLQY) and size distribution of MoS2 quantum dots (QDs) synthesized by using the colloidal heating method. The optical characteristics of MoS2 QDs are found to be dependent on OAc/OAm (mL/mL) concentrations, which are (0 mL/0 mL), (0 mL/3 mL), (3 mL/0 mL), (3 mL/3 mL), (3 mL/6 mL), and (6 mL/3 mL). The optimal amount of OAc is obtained to be 3 mL with a high PLQY and narrow size distribution of QDs with an average diameter of ≈3 nm. A maximum PLQY of 12.32% is measured for (3 mL/0 mL) QDs with blue emission showing PL maxima at ≈440 nm, while for (3 mL/3 mL) and (3 mL/6 mL), the measured PLQY values are 9.12 and 7.00%, respectively. For the remaining OAc/OAm combinations, the measured PLQY value is ≈3% with wide-size distributions. Morphological analysis using a transmission electron microscope reveals the spherical QD formation for all the different OAc/OAm combinations. FTIR results show the presence of C–H, CO, CC, and C–N, confirming OAc and OAm coverage on the MoS2 QD surface. We report the highest achieved PLQY of 12.32% for colloidally synthesized blue-emitting MoS2 QDs. With high PLQY, these QDs can find applications in light-emitting diode fabrication, sensing, and bioimaging. [ABSTRACT FROM AUTHOR]

The surface chemistry of cesium lead halide perovskite nanocrystals has been elaborately studied in recent years and has proved the critical role of carboxylic acids and amines in the formation and stability of the nanocrystals. Specifically, a slight change in the concentration and ratio of the frequently used oleic acid and oleylamine critically influences the resultant phase and physical properties. Thus, understanding the delicate surface of cesium lead halide perovskite nanocrystals mainly relies on chemical bonding and the dynamic ligand environment of these two organic species. In this aspect, this review summarizes experimental findings about the critical role of oleic acid and oleylamine on the nucleation, growth, stability, phase, and morphology of cesium lead halide perovskite nanocrystals and their effect under different circumstances.

Gold nanoparticles (GNPs) are essential in creating conductive inks vital for advancing printable electronics, sensing technologies, catalysis, and plasmonics. A crucial step in fabricating useful GNP-based devices is understanding the thermal sintering process and particularly the decomposition pathways of ligands in different environments. This study addresses a gap in the existing research by examining the sintering of oleylamine (OA)-capped GNPs in both ambient (air) and inert (N2) environments. Through a series of analyses including TGA/MS, Raman spectroscopy, and XPS, distinctive OA decomposition behaviors were identified in air and nitrogen environments. The research delineates two OA decomposition pathways resulting in different porosity, microstructure, and electrical conductivity of GNP films sintered in air and nitrogen environments. The study offers some insights that can steer the sintering and utilization of the GNP sintering process and promises to aid the future development of nanoparticle-based printable electronics. [ABSTRACT FROM AUTHOR]

The surface chemistry of cesium lead halide perovskite nanocrystals has been elaborately studied in recent years and has proved the critical role of carboxylic acids and amines in the formation and stability of the nanocrystals. Specifically, a slight change in the concentration and ratio of the frequently used oleic acid and oleylamine critically influences the resultant phase and physical properties. Thus, understanding the delicate surface of cesium lead halide perovskite nanocrystals mainly relies on chemical bonding and the dynamic ligand environment of these two organic species. In this aspect, this review summarizes experimental findings about the critical role of oleic acid and oleylamine on the nucleation, growth, stability, phase, and morphology of cesium lead halide perovskite nanocrystals and their effect under different circumstances. [ABSTRACT FROM AUTHOR]

Lithium cobalt phosphate (LiCoPO 4), a cathode material for 5 V high-voltage lithium-ion batteries, has limited its practical application due to its low conductivity and ionic diffusion. In this research, a pure-phase LiCoPO 4 with core-shell structure is successfully synthesized by oleylamine-assisted ethanol solvothermal method, and the influence of different solvothermal reaction times on the properties of the material is fully studied. The results show that pure-phase LiCoPO 4 can be prepared by calcination under pure N 2 , and carbon layers (3 nm ∼ 8 nm) with different thickness are formed on the surface of LiCoPO 4 particles synthesized under different solvothermal reaction times (1 h ∼ 18 h). The LiCoPO 4 prepared under the condition of solvothermal reaction time of 12 h has good crystallization properties and morphology characteristics, and the thickness of the carbon layer formed on the surface is about 6 nm. Electrochemical tests show that it has the largest initial discharge capacity, the best performance and the best cycle stability. Adjusting the reaction conditions enables the formation of a suitable thickness of carbon coating on the surface of LiCoPO 4 , which improves the conductivity, ion diffusion and stability of the material in high voltage environments, thereby improving the electrochemical performance of high-voltage LiCoPO 4. The thickness of the carbon layer on the surface of the high-voltage cathode material LiCoPO 4 is regulated by oleylamine, and the electrochemical performance of LiCoPO 4 is enhanced. [Display omitted] • The core-shell carbon-coated LiCoPO 4 is synthesized. • The pure phase LiCoPO 4 is prepared by adjusting the calcination atmosphere. • Uniformly distributed nanostructured LiCoPO 4 is prepared. • LiCoPO 4 particles with different thickness of carbon-layer are synthesized. [ABSTRACT FROM AUTHOR]

Cs2NaInCl6 double perovskites, which have excellent photoelectric conversion properties and are non-toxic and lead-free, have recently gained significant attention. In particular, double-perovskite quantum dots (QDs) are viewed as a promising material for optoelectronic device applications. Ligands such as oleic acid (OA) and oleylamine (OAm) are essential for the synthesis of perovskite QDs, but their specific roles in double-perovskite QDs remain unclear. In this study, we have investigated the binding of OA and OAm to Cs2NaInCl6 QDs through FTIR and NMR and their effects on the surface defect reduction and stability improvement for Cs2NaInCl6 QDs. We found that only OAm was bound to the QD surfaces while OA was not. The OAm has a significant effect on the photoluminescence quantum yield (PLQY) improvement by passivating the QD surface defects. The stability of the QDs was also evaluated, and it was observed that OA played a significant role in the stability of the QDs. Our findings provide valuable insights into the roles of ligands in influencing the photophysical properties and stability of lead-free double-perovskite QDs.

Surface functionalization of nanoparticles has shown potential in enhancing the efficacy of antibiotic-loaded nanosystems against drug-resistant bacteria. The objective of this study was to synthesize and characterize an acid-cleavable pH-responsive polymer from methoxy polyethylene glycol and oleylamine (mPEG-OA) to surface modify vancomycin (VCM)-loaded niosomes and to evaluate their antibacterial and anti-biofilm effectiveness against methicillin-resistant Staphylococcus aureus (MRSA). The novel mPEG-OA-coated niosomes were biocompatible, hemocompatible with size, polydispersity index, and zeta potential of 169.2 ± 1.6 nm, 0.21 ± 0.01 and −0.82 ± 0.22 mV, respectively. Under acidic conditions, mPEG-OA-coated niosomes exhibited a pH-responsive and sustained VCM release profile and in vitro antibacterial activity than non-coated niosomes and bare VCM. mPEG-OA-coated niosomes showed a significant reduction in biofilm formation at pH 6 compared to pH 7.4 ( p = 0,0119). The in vivo efficacy of mPEG-OA-coated niosomes in the BALB/c mice skin infection model showed a 9.9-fold reduction in MRSA load compared to bare VCM. Histomorphologically, the mPEG-OA-coated niosomes group displayed the lowest bacterial load, tissue swelling, and inflammation. The results of this study demonstrate the potential of novel pH-responsive mPEG-OA-derived polymer coating to enhance bacterial killing kinetics, and antibacterial and anti-biofilm efficacies over conventional antibiotic and non-functionalized nano delivery systems.

Generally, salt precursors have been investigated for the production of nanoparticles with semiconducting properties such as metal chalcogenides and others. They have demonstrated excellent features for the ease of converting them to nanoparticles. Thermal decomposition and solvothermal processes are often followed to produce particles with stabilizers of varied ranges of size with improved size control dependent on the set collective conditions and the intended applications. In this study, silver (Ag) and copper (Cu) nanoparticles were synthesized using the thermal decomposition method in the presence of oleylamine as a capping agent in order to produce good stable uniform monodispersed nanoparticles. Lower amounts of Ag and Cu precursors (0.1 - 0.2 g) were used to study their effect on the size and morphology of the nanoparticles. The synthesized nanoparticles under various conditions were characterized using UV/Vis and PL spectroscopy, TEM, and XRD. It was observed that an increase in the precursor concentration led to an increase in particle size with varying morphologies for both Ag and Cu nanoparticles. The TEM images of Ag nanoparticles showed that uniform morphology and spherical shape were observed with narrow diameters ranging from 5.9 to 6.8 nm. However, for Cu nanoparticles, uniform morphology and spherical shape were only observed at a precursor concentration of 0.15 g with an average diameter of 7.8 nm. The XRD results of both Ag and Cu nanoparticles showed peaks that were identified as Ag and Cu in the face-centred cubic. [ABSTRACT FROM AUTHOR]

This work presents attempts to synthesize silver-doped copper nitride nanostructures using chemical solution methods. Copper(II) nitrate and silver(I) nitrate were used as precursors and the oleylamine as a reducing and capping agent. Homogeneous Cu3N/Ag nanostructures with a diameter of ~ 20 nm were obtained in a one-pot synthesis by the addition of the copper(II) salt precursor to the already-synthesized silver nanoparticles (Ag NPs). Synthesis in a two-pot procedure performed by adding Ag NPs to the reaction medium of the Cu3N synthesis resulted in the formation of a Cu3N@Ag nanocomposite, in which Ag NPs are uniformly distributed in the Cu3N matrix. The morphology, structure, and chemical composition of the obtained specimens were studied by TEM, XRD, XPS, and FT-IR methods, while optical properties using UV–Vis spectroscopy and spectrofluorimetry. The band gap energy decreased for Cu3N/Ag (Eg = 2.1 eV), in relation to pure Cu3N (Eg = 2.4. eV), suggesting the insertion of Ag atoms into the Cu3N crystal lattice. Additionally, Cu3N and Cu3N/Ag nanostructures were loaded on graphene (GNP) and tested as a catalyst in the oxygen reduction reaction (ORR) by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The Cu3N/Ag-modified GNP hybrid material revealed catalytic activity superior to that of Cu3N-based GNP hybrid material and pure GNP, comparable to that of a commercial Pt/C electrode. [ABSTRACT FROM AUTHOR]

The state‐of‐art approach to realize the low rolling resistance of green tires is the high addition of SiO2. However, its dispersion capacity and the interface strength with rubber dominant the final properties of green tires. Here, we systematically study amphiphilic polyoxyethylene sorbitan monooleate, oleylamine, sorbitan monooleate, and oleamide to modify SiO2 through simple hydrogen‐bonded self‐assembly in order to replace the traditional silane coupling agent with low modification efficiency, many side reactions and complex reaction process. The results show that the rolling resistance and processing energy loss of the rubber composite prepared by SiO2 modified with polyoxyethylene sorbitan monooleate and oleylamine are significantly reduced, and other physical and mechanical properties (tensile strength, tear strength, and wear resistance) are also significantly improved compared with the silane coupling agent commonly used in green tire tread. Meanwhile, carbon–carbon double bonds belonging to polyoxyethylene sorbitan monooleate and oleylamine can participate in vulcanization of rubber to strongly improve the dispersion ability of SiO2 and the interface interaction between SiO2 and rubber matrix, so as to develop the fuel‐efficient green tire tread with high performance and low rolling resistance. [ABSTRACT FROM AUTHOR]

The influence of oleylamine (OLA) concentration on the crystallography, morphology, surface chemistry, chemical bonding, and magnetic properties of solvothermal synthesized CoFe2O4 (CFO) nanoparticles (NPs) has been thoroughly investigated. Varying OLA concentration (0.01–0.1 M) resulted in the formation of cubic spinel-structured CoFe2O4 NPs in the size-range of 20–14 (±1) nm. The Fourier transform spectroscopic analyses performed confirmed the OLA binding to the CFO NPs. The thermogravimetric measurements revealed monolayer and multilayer coating of OLA on CFO NPs, which were further supported by the small-angle X-ray scattering measurements. The magnetic measurements indicated that the maximum saturation (MS) and remanent (Mr) magnetization decreased with increasing OLA concentration. The ratio of maximum dipolar field (Hdip), coercivity (HC), and exchanged bias field (Hex) (at 10 K) to the average crystallite size (Dxrd), i.e., (Hdip/Dxrd), (HC/Dxrd), and (Hex/Dxrd), increased linearly with OLA concentration, indicating that OLA concurrently controls the particle size and interparticle interaction among the CFO NPs. The results and analyses demonstrate that the OLA-mediated synthesis allowed for modification of the structural and magnetic properties of CFO NPs, which could readily find potential application in electronics and biomedicine. [ABSTRACT FROM AUTHOR]

Magnetic Fluid Hyperthermia (MFH) is an emerging and safe technique for cancer treatment. Radiotherapy and Chemotherapy are widely adopted techniques for treating cancer but cause damage to the nearby healthy tissue. This paves the way for hyperthermia treatment for cancer. Since healthy cells are more heat-tolerant than malignant cells, magnetic nanoparticles with superparamagnetic properties were used in hyperthermia treatment. Surface modified magnetite (Fe 3 O 4) iron oxide nanoparticles with enhanced stability, solubility, bio-compatibility and magnetic property were employed in hyperthermia treatment. In the present study, Superparamagnetic Samarium doped magnetite (Fe 3 O 4 :Sm) nanoparticles were functionalized with Oleylamine (OAm) and polyvinyl alcohol (PVA) by the sol-gel process. The obtained nanoparticles were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM), and UV–Visible diffuse reflectance spectroscopy (UV-DRS), Thermogravimetric analysis (TGA) and Vibrating Sample Magnetometer (VSM). From XRD data, the crystallite size of oleylamine coated samarium doped magnetite (OAm–Fe 3 O 4 :Sm) and PVA-coated samarium doped Fe 3 O 4 (PVA- Fe 3 O 4 :Sm) were found to be 9.5 nm and 10.9 nm, respectively. TEM images of the functionalized nanoparticles were visualized as a spherical structure with reduced agglomeration. UV-DRS gives the bandgap value of OAm–Fe 3 O 4 :Sm and PVA- Fe 3 O 4 :Sm coated samarium doped magnetite to be 2.3 eV and 2 eV respectively. VSM measurement of OAm-Fe 3 O 4 :Sm and PVA- Fe 3 O 4 :Sm coated, showed superparamagnetic behaviour. The cytotoxicity study on the L929 cell line shows that both oleylamine and PVA-coated samarium doped magnetite were less toxic and biocompatible compared to the uncoated Fe 3 O 4 :Sm. The hyperthermia study reveals a rise in temperature within a few seconds with a high Specific Absorption Rate (SAR) value, confirming that the functionalized Samarium doped Fe 3 O 4 was an effective nanomaterial for hyperthermia application. [ABSTRACT FROM AUTHOR]

Nanocrystal self-assembly into supercrystals provides a versatile platform for creating novel materials and devices with tailored properties. While common self-assembly strategies imply the use of purified nanoparticles after synthesis, conversion of chemical precursors directly into nanocrystals and then supercrystals in simple procedures has been rarely reported. Here, the nucleation and growth of CuPd icosahedra and their consecutive assembly into large closed-packed face-centered cubic (fcc) supercrystals are studied. To this end, the study simultaneously and in situ measures X-ray total scattering with pair distribution function analysis (TS-PDF) and small-angle X-ray scattering (SAXS). It is found that the supercrystals' formation is preceded by an intermediate dense phase of nanocrystals displaying short-range order (SRO). It is further shown that the organization of oleic acid/oleylamine surfactants into lamellar structures likely drives the emergence of the SRO phase and later of the supercrystals by reducing the volume accessible to particle diffusion. The supercrystals' formation as well as their disassembly are triggered by temperature. The study demonstrates that ordering of solvent molecules can be crucial in the direct synthesis of supercrystals. The study also provides a general approach to investigate novel preparation routes of supercrystals in situ and across several length scales via X-ray scattering., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

Asphalt binder modification techniques are beneficial for the performance improvement of roads because they can be durable, present less permanent deformation, and provide longer fatigue life. The main modification agents involved in this process are polymers, fillers, fibers, and, more recently, nanomaterials, which have presented technical and economic feasibility. The nanoparticles were added to the base asphalt binder at a concentration of 3% of weight in pure and surface-modified states. This study aims to analyze the effect of surface modification of titanium dioxide nanoparticles using three different agents: oleic acid, benzyl alcohol, and oleylamine. The results have indicated that surface modification of the nanoparticles with oleylamine improved the interaction between the particles and the binder, contributing to increasing fatigue life and resistance to permanent deformation and delaying the aging process. Furthermore, the results of rheological tests have indicated that incorporating nanoparticles surface-modified with oleylamine into modified asphalt binder 55/75-E and asphalt binder 50/70 has produced higher resistance to the aging process less susceptibility to permanent deformation and cracks.

Optimizing stabilizers and solvents is crucial for obtaining highly dispersed nanoparticle inks. Generally, nonpolar (hydrophobic) ligand-stabilized nanoparticles show superior dispersibility in nonpolar solvents, whereas polar ligand (hydrophilic)-stabilized nanoparticles exhibit high dispersibility in polar solvents. However, these properties are too qualitative to select optimum stabilizers and solvents for stable nanoparticle inks, and researchers often rely on their experiences. This study presents a Hansen solubility parameter (HSP)-based analysis of the dispersibility of oleylamine-capped silver nanoparticle (OAm-Ag NP) inks for optimizing ink preparation. We determined the HSP sphere of the OAm-Ag NPs, defined as the center coordinate, and the interaction radius in 3D HSP space. The solvent's HSP inside the HSP sphere causes high dispersibility of the OAm-Ag NPs in the solvent. In contrast, the HSPs outside the sphere resulted in low dispersibility in the solvent. Thus, we can quantitatively predict the dispersibility of the OAm-Ag NPs in a given solvent using the HSP approach. Moreover, the HSP sphere method can establish a correlation between the dispersibility of the particles in inks and the sintered film morphology, facilitating electronic application of the nanoparticle inks. The HSP method is also helpful for optimizing stabilizers and solvents for stable nanoparticle inks in printed electronics. [ABSTRACT FROM AUTHOR]

CsPbBr3 perovskite nanowires (NWs) with various lengths and widths have attracted much attention because of their attractive optoelectronic properties in optoelectronic devices. This study provides an effective approach to get size-controllable CsPbBr3 perovskite NWs based on the hot injection method. Oleylamine was used as the solvent to control the reaction speed, and CsPbBr3 perovskite NWs with adjustable widths and lengths were obtained by controlling the reaction time at 180 °C. X-ray diffraction, transmission electron microscopy (TEM), high-resolution transmission electronic microscopy, optical absorption, and photoluminescence (PL) spectra were carried out to investigate the structural evolution and growth mechanism. The results show that Cs4PbBr6 nanocrystals precipitated within 10 min and their amount reduced, and α-CsPbBr3 nanocrystals appeared and grew with the reaction time extending to 30 min. Cs4PbBr6 nanocrystals disappeared, and α-CsPbBr3 NWs with a width of ∼20 nm and a length of ∼1 μm were obtained when the reaction reached 60 min. Further extending the reaction time resulted in self-assembling and growth of CsPbBr3 NWs, the width of CsPbBr3 wires reached ∼1 μm, and the length reached ∼100 μm when the reaction time was 24 h. TEM images clearly showed that CsPbBr3 NWs become wider and longer by self-assembly of CsPbBr3 nanocubes and NWs. A statistics study revealed that there is a linear relationship between the width and the reciprocal of time. The self-assembly CsPbBr3 perovskite NWs presented a high-intensity green PL around 519 nm and high PL quantum yield, which was 71.7, 76.9, 64.9, and 39.5% for the samples reacted for 10, 30, 60, and 180 min, respectively, under 375 nm laser irradiation, and the photocarrier lifetime for the sample with 180 min can reach 25.79 ns. The obtained CsPbBr3 NWs have few defects and produce less recombination during the photoemission process, which is promising for applications in the fields of optoelectronic devices, especially photodetectors, lasers, and solar cells devices. [ABSTRACT FROM AUTHOR]

The present work reports the successful coating of Fe 3 O 4 nanospheres with oleylamine utilizing a single-step solvothermal technique and its application to carbon dioxide's capture and chemical fixation. The existence of the pure cubic spinel phase of Fe 3 O 4 was established by X-ray diffraction. Fourier transform infrared spectroscopy revealed vibrations corresponding to the oleylamine structure, affirming the coating of oleylamine on Fe 3 O 4 nanospheres. X-ray photoelectron spectroscopy further confirmed the presence of oleylamine on the Fe 3 O 4 surface, along with the constituent elements Fe and O. The nanospheres exhibited a spherical shape with an average diameter of ∼17 nm, shown by morphological investigations. Magnetic properties exhibited a Verwey transition at ∼114 K and a saturation magnetization of ∼60 emu/g. The surface area measurements revealed a pore volume of 0.0717 ccg−1 and surface area of 30.558 m2g-1. The existence of oleylamine on the surface of Fe 3 O 4 nanospheres facilitated the capture of CO 2 through chemisorption due to the amine group's high selectivity and the nanospheres' large surface area. In the presence of styrene oxide and tetra-n-hexyl ammonium bromide (THAB), the oleylamine-coated Fe 3 O 4 nanospheres successfully converted CO 2 to styrene carbonate. The magnetic core and high thermal stability of the material make it suitable for recyclability for the fixation of CO 2 into products with added value. This work presents a promising approach for CO 2 capture and utilization using Fe 3 O 4 nanospheres coated with oleylamine, with potential applications in carbon capture and utilization technologies. [Display omitted] • Oleylamine-coated Fe 3 O 4 nanospheres were synthesized utilizing a single-step solvothermal technique. • In the presence of styrene oxide and tetra-n-hexyl ammonium bromide (THAB), the oleylamine-coated Fe 3 O 4 nanospheres exhibited efficient conversion of CO 2 to styrene carbonate. • Oleylamine on the surface of the Fe 3 O 4 nanospheres enhanced the adsorption of CO 2 due to the high selectivity of the amine group (-NH 2) towards CO 2. • The magnetic core and high thermal stability of the material make it suitable for recyclability for the fixation of CO 2 into products with added value. [ABSTRACT FROM AUTHOR]

CdSe/CdS with ZnS/ZnO shell quantum dots (QDs) are synthesized by a one-pot method with various oleylamine (OLA) contents. The crystal structures of the QDs were analyzed by X-ray diffractometry, which showed ZnS diffraction peaks. It was represented that the ZnS shell was formed on the surface of the CdSe/CdS core. Interestingly, QDs with a high OLA concentration exhibit diffraction peaks of ZnS/ZnO. As a result, the thermal stability of QDs with ZnS/ZnO shells exhibits better performance than those with ZnS shells. In addition, the photoluminescence intensity of QDs with ZnS/ZnO shells shows a relatively slow decay of 7.1% compared with ZnS shells at 85 °C/85% relative humidity aging test for 500 h. These indicate that QDs with different OLA modifications can form ZnS/ZnO shells and have good stability in a harsh environment. The emission wavelength of QDs can be tuned from 505 to 610 nm, suitable for micro-LED display applications. [ABSTRACT FROM AUTHOR]

Hexagonal cesium tungsten bronze (Cs x WO 3) nanocrystals have attracted great attention in the field of energy-efficient windows, which exhibit the localized surface plasmon resonance (LSPR) effect and small polaron transfer in near-infrared radiation (NIR). The enhancement of the LSPR effect can be achieved by introducing aliovalent dopant into the crystal lattice, but the improvement of small polaron transfer remains a challenge. Herein, Cs x WO 3 nanocrystals with oxygen defects were successfully prepared by a facile one-pot method. The introduction of oleylamine in the precursor can induce the formation of oxygen defects in the crystal lattice, which leads to a higher absorption coefficient. The spectrally selective coating prepared by Cs x WO 3 nanocrystals with oxygen defects exhibited superior spectral selectivity with T Vis , T NIR , T lum , and T sol of 67.11%, 11.21%, 72.59% and 49.12%, respectively. [ABSTRACT FROM AUTHOR]

The influence of oleylamine (OLA) concentration on the crystallography, morphology, surface chemistry, chemical bonding, and magnetic properties of solvothermal synthesized CoFe2O4 (CFO) nanoparticles (NPs) has been thoroughly investigated. Varying OLA concentration (0.01–0.1 M) resulted in the formation of cubic spinel-structured CoFe2O4 NPs in the size-range of 20–14 (±1) nm. The Fourier transform spectroscopic analyses performed confirmed the OLA binding to the CFO NPs. The thermogravimetric measurements revealed monolayer and multilayer coating of OLA on CFO NPs, which were further supported by the small-angle X-ray scattering measurements. The magnetic measurements indicated that the maximum saturation (MS) and remanent (Mr) magnetization decreased with increasing OLA concentration. The ratio of maximum dipolar field (Hdip), coercivity (HC), and exchanged bias field (Hex) (at 10 K) to the average crystallite size (Dxrd), i.e., (Hdip/Dxrd), (HC/Dxrd), and (Hex/Dxrd), increased linearly with OLA concentration, indicating that OLA concurrently controls the particle size and interparticle interaction among the CFO NPs. The results and analyses demonstrate that the OLA-mediated synthesis allowed for modification of the structural and magnetic properties of CFO NPs, which could readily find potential application in electronics and biomedicine.

In this study, the composite cathode material of LiCoPO 4 /C and graphene is synthesized using solvothermal method assisted by oleylamine. The effect of graphene addition on the material properties is fully investigated, and the synergistic effect of amorphous carbon and graphene is also studied. Graphene serves as a conductive skeleton and provides abundant diffusion paths for electrons. The nanoscale LiCoPO 4 material synthesized by solvothermal method is evenly distributed around the few-layer graphene with the assistance of oleylamine, and the amorphous carbon formed after the pyrolysis of oleylamine at high temperature tightly connects LiCoPO 4 to the graphene, which improves the conductivity and electrochemical performance of the sample. The results of characterization reveal that adding graphene can prepare LiCoPO 4 materials with good crystallization and improve the specific surface area and pore size of the material. At the same time, the amorphous carbon and graphene inside the material also show a good degree of graphitization. Electrochemical test results show that doping graphene with a mass ratio of 6% can enhance the electrochemical performance and cycle stability of LCPC-6%G sample. The initial discharge capacity of LCPC-6%G sample reaches 157.2 mA h g−1 at 0.1 C. In this study, nanoscale LiCoPO 4 samples are successfully synthesized on the surface of graphene, which provides a new idea for the preparation of nanoelectrode materials and conductive skeleton composite samples. • The composite materials of graphene and LiCoPO 4 is synthesized. • LiCoPO 4 nanoparticles are evenly distributed around few-layer graphene. • Amorphous carbon strengthens the connection between LiCoPO 4 and graphene. • Adding 6% mass ratio of graphene improves the cycle stability of LiCoPO 4. [ABSTRACT FROM AUTHOR]

Sub-micron LiNi 0.5 Mn 1.5 O 4 (LNMO) with uniform size distribution is synthesized by oleylamine-assisted solid-state method (oley-ss-method). Different from the traditional solid-state method (ss-method), the size distribution of LNMO sample prepared by oley-ss-method is more uniform and the particle size is smaller. Oleylamine inhibits the formation of large particles and refines the particle size of the sample during synthesis. For comparative analysis, the LNMO material without oleylamine is simultaneously synthesized by ss-method and both products are analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and electrochemical tests, respectively. XRD patterns show that the LNMO samples with a good crystalline spinel structure are successfully synthesized using ss-method and the impurities of Li x Ni 1−x O are reduced in the presence of oleylamine. SEM shows that the particle size and size distribution of LNMO sample modified by oleylamine has been significantly reduced, and large-sized particles decreased. The FTIR indicated that the LNMO sample assisted by oleylamine belongs to the Fd3m space group, not P4 3 32. Compared with the unmodified LNMO, the electrochemical performance of the oleylamine-modified LNMO sample is significantly enhanced, and the specific capacity of 97.4 mA h g−1 is still maintained after 700 cycles at a discharge rate of 5 C. [Display omitted] • LiNi 0.5 Mn 1.5 O 4 nanoparticle is prepared by oleylamine-assisted solid-state method. • The presence of oleylamine reduce the particle size of LiNi 0.5 Mn 1.5 O 4. • The electrochemical performance of Oley-LNMO is enhanced. [ABSTRACT FROM AUTHOR]

Optimizing stabilizers and solvents is crucial for obtaining highly dispersed nanoparticle inks. Generally, nonpolar (hydrophobic) ligand-stabilized nanoparticles show superior dispersibility in nonpolar solvents, whereas polar ligand (hydrophilic)-stabilized nanoparticles exhibit high dispersibility in polar solvents. However, these properties are too qualitative to select optimum stabilizers and solvents for stable nanoparticle inks, and researchers often rely on their experiences. This study presents a Hansen solubility parameter (HSP)-based analysis of the dispersibility of oleylamine-capped silver nanoparticle (OAm-Ag NP) inks for optimizing ink preparation. We determined the HSP sphere of the OAm-Ag NPs, defined as the center coordinate, and the interaction radius in 3D HSP space. The solvent’s HSP inside the HSP sphere causes high dispersibility of the OAm-Ag NPs in the solvent. In contrast, the HSPs outside the sphere resulted in low dispersibility in the solvent. Thus, we can quantitatively predict the dispersibility of the OAm-Ag NPs in a given solvent using the HSP approach. Moreover, the HSP sphere method can establish a correlation between the dispersibility of the particles in inks and the sintered film morphology, facilitating electronic application of the nanoparticle inks. The HSP method is also helpful for optimizing stabilizers and solvents for stable nanoparticle inks in printed electronics.

The effect of the functional groups of capping agents was investigated in the synthesis of copper selenide, copper sulphide and copper oxide nanoparticles using oleylamine (OLA) and trioctylphosphine (TOP). These capping molecules have demonstrated their ability to act as reducing agents, surfactants, solvents and enhancement of colloidal stabilization. They also offer electron donating abilities from the two group 5A elements, P and N. Nitrogen atom in an amine group possess stronger surface interactions and higher basicity than P atom in the phosphines. Copper chalcogenide nanoparticles were prepared using Hot-injection method and characterized using UV/Vis spectroscopy, TEM and XRD. The optical and structural properties of the yielded nanoparticles showed dependence on the type of capping interactions from the two agents. Nanoparticles synthesized using TOP produced two phases whereas a single phase was observed from OLA as confirmed by XRD. Although TOP and OLA exhibit similar features, but their affinity to metals differs resulting to significant different morphology and crystallinity of the produced nanoparticles. Amine group has higher affinity for protons than phosphine due to the lone pair of electrons it possesses which it easily donates to H+ compared to phosphine. The high proton affinity of oleylamine makes it interact faster than trioctylphosphine. OLA in overall produced larger particle sizes compared to TOP but generated a wider variety of shapes.

CdSe/CdS with ZnS/ZnO shell quantum dots (QDs) are synthesized by a one-pot method with various oleylamine (OLA) contents. The crystal structures of the QDs were analyzed by X-ray diffractometry, which showed ZnS diffraction peaks. It was represented that the ZnS shell was formed on the surface of the CdSe/CdS core. Interestingly, QDs with a high OLA concentration exhibit diffraction peaks of ZnS/ZnO. As a result, the thermal stability of QDs with ZnS/ZnO shells exhibits better performance than those with ZnS shells. In addition, the photoluminescence intensity of QDs with ZnS/ZnO shells shows a relatively slow decay of 7.1% compared with ZnS shells at 85 °C/85% relative humidity aging test for 500 h. These indicate that QDs with different OLA modifications can form ZnS/ZnO shells and have good stability in a harsh environment. The emission wavelength of QDs can be tuned from 505 to 610 nm, suitable for micro-LED display applications.

Thin films of well‐stacked two‐dimensional MXene flakes have been used in various applications, especially in sensors and microscale energy storage devices, such as micro‐supercapacitors. Miniaturization and integration of devices, as well as maximization of device performance require nanoscale patterning of MXene, beyond what can be achieved using inkjet or screen printing. However, nanoscale patterning technology for MXene is yet to be developed. In the present work, a simple fabrication method is demonstrated for manufacturing Ti3C2Tx MXene films with vertically aligned nanopatterns via soft lithography. This process involves polydimethylsiloxane (PDMS) stamping with line‐patterned PDMS molds. The feature size of the vertical line patterning of MXene is controlled with the nanometers accuracy by swelling of the PDMS mold by toluene, which also guides vertical alignment of MXene flakes. As a result, vertically aligned MXene nanopatterns are fabricated with a width of ridges less than 200 nm and 2‐µm regular spacing between the ridges. The oleylamine‐functionalized MXene flakes are also developed for better dispersion in toluene, providing a general protocol to fabricate MXene dispersions in nonpolar solvents. [ABSTRACT FROM AUTHOR]

Small size and narrow distribution are the key factors to improve performances of metal nanocrystals due to nanosize effect. Here, a silver‐alkylamine complex–mediated single micelle, a one‐pot approach, for controlled synthesis of monodisperse silver nanocrystals, in which oleylamine molecules play key roles serving both as complex agent and as micellar coalescence blocker is reported. After the synthesis, monodisperse products can be directly collected through subsequent single‐step separation as the particle size is finely adjusted during the synthesis. Dual‐soluble silver oleylamine complex is prepared through liquid phase complexing and is used as oil‐soluble precursor in single reverse micelle. The as‐synthesized silver nanocrystals are very uniform with a controlled size of 6.00 ± 0.29 or 8.0 ± 0.40 nm and a narrow size distribution with a standard deviation (σ) of ≈5.0%. The protocol offers a general platform for fast synthesis of noble metal nanocrystals with rationally designed size and structure. [ABSTRACT FROM AUTHOR]

A new approach to the synthesis of lead sulfide colloidal quantum dots has been proposed, which uses a mixture of oleic acid and oleylamine. Colloidal quantum dots of PbS with a long-wavelength excitonic peak in the range from 1.7 to 2.05 μm have been obtained. The effects of temperature, reaction time, and the ratio of lead and sulfur precursors on the spectral characteristics of PbS quantum dots obtained have been studied. [ABSTRACT FROM AUTHOR]

In this study, oleylamine (OAm) capped FeCo y Fe 2− y O 4 (0.0 ⩽ y ⩽ 1.0) nanocomposites (NCs) were prepared via a polyol route. Effect of Co3+ ion substitution on structure, morphology and magnetic properties of Fe 3 O 4 nanoparticles was investigated by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analyzer (TGA), scanning and transmission electron spectroscopy (SEM and TEM), vibrating sample magnetometer (VSM) and Mössbauer analyzer. All XRD patterns show the single phase spinel ferrite without any impurity. The crystallite size of the samples is within the range of 7.1–21.7 nm. FT-IR analysis showed that all products were successfully packed by OAm. Both SEM and TEM results confirmed that products have spherical morphology with small agglomeration. When Co3+ ions were substituted to the Fe 3 O 4 , Ms continued to decrease up to Co3+ content of y = 0.4. It was reported that Co3+ ions prefer to replace Fe2+ ions on octahedral side up to some concentration. Although the Mössbauer spectra for the all samples were composed of magnetic sextets, superparamagnetic particles are also formed for FeCo 0.6 Fe 1.4 O 4 , FeCo 0.8 Fe 1.2 O 4 and FeCoFe 2 O 4 samples. [ABSTRACT FROM AUTHOR]

Silver-Telluride 2D organometallic nanofibers (NFs), using diphenyl ditelluride (DPDT) as a precursor, were synthesized. The synthesis was carried out by reacting DPDT with AgNO 3 in acetonitrile at room temperature (RT) under an inert atmosphere. The resulting material was fully characterized using various techniques, including UV-VIS-NIR spectroscopy, steady-state and excited-state fluorescence spectroscopy, IR-FTIR-ATR spectroscopy, HR-ESI MS spectrometry, high-resolution transmission electron microscopy (HRTEM), BF-STEM or HAADF-STEM, confocal fluorescence microscopy images and conductivity measurements. Initially, the nanofibers were almost non-emissive. However, a remarkable modification was observed after treating the nanofibers with oleylamine under ultrasound treatment. This methodology induced an aggregation emission effect (AIE) in the solution and in the solid state, resulting in the formation of a highly red emissive fluorescent nanomaterial. This research provides valuable insights for developing new fluorescent materials with potential applications in various optical fields. [Display omitted] • Diphenyl ditelluride Applications. • Nobel Metal based Silver-Telluride 2d Nanomaterials. • Fluorescent Nanothermometer Properties. • Aggregation Induced Emission (AIE). [ABSTRACT FROM AUTHOR]

In this research, a novel modified wet impregnation method has been successfully developed to synthesize 5% Ni/SiO2 nanocatalyst with high catalytic activity and stability for the partial oxidation of methane. Oleylamine was used as a capping agent in the impregnation solution to improve Ni dispersion and interaction with silica surfaces. The product was analyzed and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, N2 physisorption measurement and transmission electron microscopy (TEM) and temperature- -programmed H2 reduction (H2-TPR). Partial oxidation of methane over the modified catalyst was performed in a continues-flow fixed-bed reactor under atmospheric pressure at 700°C. The modified catalyst showed 91% CH4 conversion, 86% H2 yield and 95% CO selectivity, and these results almost remained constant within 5 h reaction on stream. The excellent catalytic performance of the catalyst was reasonably attributed to the small and uniform distribution of Ni nanoparticles on the support, and structural characterization confirmed this conclusion.

A simple one-step solvothermal method is proposed to prepare hydrophobic Fe3O4 nanoparticles (MNPs) using iron acetylacetonate (Fe(acac)3), oleylamine (OAm), and ethylene glycol (EG). X-ray powder diffraction, scanning electron microscope, infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectrometry, and vibrating sample magnetometer are used to characterize the structure, morphology, and properties of products. The testing results indicate that the as-synthesized products are spherical-like hydrophobic MNPs, superparamagnetic at room temperature, with a saturation magnetization up to 76.8 emu/g. The good hydrophobic property of MNPs is attributed to the coverage of oleylamine, without causing a remarkable loss of magnetic property. In addition, the influences of material ratio, aging time, oleic acid, and stearic acid used as additives are studied in our research. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Mucoadhesive olaminosomes are novel nanocarriers designed to control agomelatine release and enhance its bioavailability. Olaminosomes were prepared using oleic acid, oleylamine and sorbitan monooleate adopting thin film hydration technique. Chitosan HCl was added to impart the mucoadhesive properties to the olaminosomes. Mucoadhesive olaminosomes were characterized for their particle size, in-vitro drug release and irritation potentiality in rabbit eyes. The reduction in intraocular pressure (IOP) through 8 h in male New Zealand Albino rabbits was measured after administration of the selected formulations. Histopathological changes in rabbits' eye were also evaluated. Results revealed that increasing the amount of the added oleylamine decreased the particle size of the resulted vesicles and increased the drug release rate. Olaminosomes showed enhanced drug absorption, hence more reduction in IOP was observed. Moreover, using chitosan HCl might increase the residence time of the formulation in the eye and hence improved the absorption of the drug. No histopathological changes in rabbits' eye were detected after the application of mucoadhesive olaminosomes concluding their safety on the ocular tissues. In conclusion, mucoadhesive olaminosomes succeeded in enhancing agomelatine bioavailability in rabbits' eyes confirming the development of a novel ocular nanocarrier for insoluble drugs. [ABSTRACT FROM AUTHOR]

Abstract This work reports a simple and cost-effective synthesis path to fabricate manganese dioxide nanostructures with controlled morphologies. Herein, we have used oleylamine as a reducing, surfactant, and structure directing agent. The treatment of MnO 2 precursor with the varying concentration of oleylamine led to the formation of different morphologies of MnO 2 (nanorods, nanoflowers and three-dimensional MnO 2 spheres). The as-synthesized nanostructures were characterized by various techniques and their electrochemical performances were studied. When used as an electrode material for supercapacitors, 3D-MnO 2 exhibited a higher specific capacitance of 450 Fg−1 and admirable cyclic stability (~91.7%) after 5000 cycles, which were higher than that of the other formulations. Moreover, an asymmetric supercapacitor was assembled by using as-prepared 3D-MnO 2 and nitrogen-doped graphene hydrogels as the positive and negative electrodes, respectively. As-fabricated asymmetric device delivered specific capacitance of 49.44 Fg−1 at 1 Ag−1 an outstanding energy density of 20 Whkg−1 at 857.14 Wkg−1, and retained ~93.15% stability after 5000 cycles. The obtained results showed that the as-synthesized 3D-MnO 2 can be considered as the positive electrode material in supercapacitors. Graphical abstract Unlabelled Image Highlights • Single step fabrication method was employed to fabricate different MnO 2 nanostructures. • 3D-MnO 2 spheres possessed high specific capacitance of 450 F/g at 1 A/g. • Asymmetric device delivered energy density of 20 Wh/kg at 857 W/kg. [ABSTRACT FROM AUTHOR]

Synthesis of copper tin selenide (Cu2SnSe3) nanoparticles was performed using colloidal hot-injection method under nitrogen atmosphere. Non-phosphine solvents such as oleylamine (OLAM), oleic acid (OLA), 1-octadecene (1-ODE) were employed for the synthesis of nanoparticles. Different mixture of these solvents was used to synthesis Cu2SnSe3 nanoparticles at 230 °C. X-ray diffraction analysis shown that the synthesized nanoparticles under different phosphine-free solvents are possessed with cubic structure. Scanning electron microscopy, transmission electron microscopy analysis were carried out to find the size, shape of the nanoparticles synthesized through OLAM/1-ODE. The formation mechanism and coordinating effect of solvents on the structural and morphological properties of nanoparticles were discussed. [ABSTRACT FROM AUTHOR]

The grain boundary and lattice mismatch among CuO and Cu 2 O work properly to facilitate the formation of ethylene and C 2+ products during CO 2 RR. [Display omitted] • Cu catalysts were prepared by thermal reduction of organic copper reagent complexation. • CuOAm reduced at 180 °C exhibits FEs as 79% for C 2+ products. • Grain boundary and lattice mismatch formed due to different crystal structures. • In-situ Raman measurements confirms catalyst reconstruction and reaction pathways. Cu-based catalysts for CO 2 electrochemical reduction reaction suffer from both activity and selectivity towards C 2+ products. Here, Cu-Oleylamine (CuOAm) based catalysts with adjustable Cu chemical state are synthesized through thermal reducing method with oleylamine as the only surfactant, solvent, and reducing agent. The catalyst exhibits a high faradaic efficiency of 54% and 79% with a partial current density of 186 mA cm−2 and 245 mA cm−2 at −1.0 V (vs. RHE) for C 2 H 4 and C 2+ products, respectively. Further characterizations of the size, morphology and surface composition of CuOAm by XRPD, XPS, SEM, HRTEM, and EDS showed that the presence of different crystal structures (CuO and Cu 2 O) with comparable amounts were vital for the formation of grain boundary and lattice mismatch during CO 2 RR. The sequential reduction of CuO x and CO 2 at abundant grain boundary and lattice mismatch could facilitate the formation of ethylene and C 2+ products, which was confirmed by in-situ Raman measurements under varied potentials. [ABSTRACT FROM AUTHOR]

Pa Fan Hsiao,1–3 Sydney Peng,4 Ting-Cheng Tang,4 Shuian-Yin Lin,5 Hsieh-Chih Tsai4 1Department of Dermatology, Mackay Memorial Hospital, 2Mackay Medicine, Nursing and Management College, 3Mackay Medical College, New Taipei City, 4Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, 5National Applied Research Laboratories, Instrument Technology Research Center, Hsinchu, Taiwan Abstract: In this study, we investigated the effect of (ethylene glycol) (PEG) and PEG–oleylamine (OAm) functionalization on the skin permeation property of gold nanoparticles (GNS) in vivo. Chemisorption of polymers onto GNS was verified by a red shift in the ultraviolet–visible spectrum as well as by a change in the nanoparticle surface charge. The physicochemical properties of pristine and functionalized nanoparticles were analyzed by ultraviolet–visible spectroscopy, zeta potential analyzer, and transmission electron microscopy. Transmission electron microscopy revealed that the interparticle distance between nanoparticles increased after GNS functionalization. Comparing the skin permeation profile of pristine and functionalized GNS, the follicular deposition of GNS increased twofold after PEG–OAm functionalization. Moreover, PEG- and PEG–OAm-functionalized nanoparticles were able to overcome the skin barrier and deposit in the deeper subcutaneous adipose tissue. These findings demonstrate the potential of PEG- and PEG–OAm-functionalized GNS in serving a multitude of applications in transdermal pharmaceuticals. Keywords: skin penetration, amphiphilic copolymer, gold nanoparticle, oleylamine, poly(ethylene glycol)

NaYF4:Yb3+/Er3+ nanoparticles were synthesized by thermal decomposition of lanthanide trifluoroacetates using oleylamine (OM) as both solvent and surface binding ligand. The effect of reaction temperature and time on the properties of the particles was investigated. The nanoparticles were characterized by transmission electron microscopy (TEM), electron diffraction (ED), energy dispersive spectroscopy (EDX), dynamic light scattering (DLS), thermogravimetric analysis (TGA), elemental analysis and X-ray diffraction (XRD) to determine morphology, size, polydispersity, crystal structure and elemental composition of the nanocrystals. TEM microscopy revealed that the morphology of the nanoparticles could be fine-tuned by modifying of the synthetic conditions. A cubic-to-hexagonal phase transition of the NaYF4:Yb3+/Er3+ nanoparticles at temperatures above 300 °C was confirmed by both ED and XRD. Upconversion luminescence under excitation at 980 nm was observed in the luminescence spectra of OM–NaYF4:Yb3+/Er3+ nanoparticles. Finally, the OM–NaYF4:Yb3+/Er3+ nanoparticles were coated with a silica shell to enable further functionalization and increase biocompatibility and stability in aqueous media, preventing particle aggregation.