Nitrogen-Bearing Carbon Nanoparticles by Pyrolytic Decomposition of Piperazine Citrate Macromolecules for Cellular Imaging

2020 ◽  
Vol 20 (11) ◽  
pp. 6943-6953
Author(s):  
Jae Won Lee ◽  
Seong Hee Kang ◽  
Yoon Joon Kang ◽  
Young Sung Kim ◽  
Jin-Hyo Boo ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nanoparticles ◽  
Average Particle Size ◽  
A549 Cells ◽  
Cell Labeling ◽  
Average Particle ◽  
Surface Protection ◽  
Pyrolytic Decomposition ◽  
Photolumi Nescence ◽  
N Doping

In this work, highly photoluminescent carbon nanoparticles (CNPs) are fabricated by pyrolytic decomposition of piperazine citrate at high pressure and high temperature. Piperazine serves as a hydrolytic, surface-passivating, and N-doping agent, facilitating the formation of a photopolymer. The as-synthesized CNPs, without any surface protection/passivation, exhibit excellent photolumi-nescence and a maximum quantum yield of 84%. The average particle size of the N-doped CNPs is 0.89±0.05 nm. In addition, the N-doped CNPs exhibit uniform diameters and nearly spherical shapes. The X-ray photoelectron spectroscopy results reveal that the CNPs are composed of carbon (64.4 wt%), oxygen (18.5 wt%), and nitrogen (17.1 wt%), indicating the presence of nitrogen-doped and carbon-rich moieties in the CNPs. Notably, the CNPs purified by the procedure developed in this work exhibit more stable luminescence properties than those purified with the conventional dialysis membrane. In addition, the potential application of the CNPs as fluorescent bioimaging probes, which offer a broad dosing window and exhibit multicolor emission, is investigated by directly cultur-ing A549 cells with the CNPs. The results reveal that the CNPs exhibit not only exceptional optical stability, but also outstanding biocompatibility and cell labeling capability. After incubating the A549 cells with CNPs, the CNPs are confined in perinuclear vacuole-similar shapes with a granulated form in cytoplasm preserving the nucleus. Notably, no significant morphological deterioration such as nuclear contraction is detected.

scholarly journals Olive Leaves as Biotemplates for Enhanced Solar-Light Harvesting by a Titania-Based Solid

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1057
Author(s):  
Jesús Hidalgo-Carrillo ◽  
Juan Martín-Gómez ◽  
M. Carmen Herrera-Beurnio ◽  
Rafael C. Estévez ◽  
Francisco J. Urbano ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Average Particle Size ◽  
Solar Irradiation ◽  
Bet Surface Area ◽  
Resonance Spectroscopy ◽  
Average Particle ◽  
Olive Leaves ◽  
Sem Images ◽  
X Ray

Olive leaves (by-product from olive oil production in olive mills) were used as biotemplates to synthesize a titania-based artificial olive leaf (AOL). Scanning electron microscopy (SEM) images of AOL showed the successful replication of trichomes and internal structure channels present in olive leaves. The BET surface area of AOL was 52 m2·g−1. X-ray diffraction (XRD) and Raman spectra revealed that the resulting solid was in the predominantly-anatase crystalline form (7.5 nm average particle size). Moreover, the synthesis led to a red-shift in light absorption as compared to reference anatase (gap energies of 2.98 and 3.2 eV, respectively). The presence of surface defects (as evidenced by X-ray photoelectron spectroscopy, XPS, and electron paramagnetic resonance spectroscopy, EPR) and doping elements (e.g., 1% nitrogen, observed by elemental analysis and XPS) could account for that. AOL was preliminarily tested as a catalyst for hydrogen production through glycerol photoreforming and exhibited an activity 64% higher than reference material Evonik P25 under solar irradiation and 144% greater under ultraviolet radiation (UV).

Multiferroic Bismuth Ferrite Nanoparticles: Rapid Sintering Synthesis, Characterization, and Optical Properties

2010 ◽  
Vol 152-153 ◽  
pp. 81-85
Author(s):  
Xiong Wang ◽  
Yin Lin ◽  
Jin Guo Jiang
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Bifeo3 Nanoparticles ◽  
Rapid Sintering

The homogeneous multiferroic BiFeO3 nanoparticles with average particle size of 85 nm have been successfully synthesized by a simple sol-gel route. The prepared sample was characterized by a variety of techniques, such as X-ray diffractometry, thermogravimetric analysis and differential thermal analysis, differential scanning calorimeter analysis, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The obtained results shows that rapid sintering and subsequently quenching to room temperature are the two vital important factors for the preparation of pure BiFeO3. The magnetic phase transition (TN = 369 °C) and the ferroelectric phase transition (TC = 824.5 °C) were determined, revealing the antiferromagnetic and ferroelectric nature of the as-prepared BiFeO3 nanoparticles. The optical properties of the nanopowders were investigated. The strong band-gap absorption at 486 nm (2.55 eV) of the BiFeO3 nanoparticles may bring some novel applications.

scholarly journals Structure and Properties of Cotton Fibers Modified with Titanium Sulfate and Urea under Hydrothermal Conditions

2014 ◽  
Vol 9 (1) ◽  
pp. 155892501400900 ◽  
Author(s):  
Hui Zhang ◽  
Linlin Zhu ◽  
Runjun Sun
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Anatase Phase ◽  
Diffuse Reflectance Spectrum ◽  
Average Particle Size ◽  
Cotton Fibers ◽  
Ammonium Bromide ◽  
Average Particle ◽  
Titanium Sulfate ◽  
Strawberry Juice

Cotton fibers were treated with titanium sulfate, urea and hexadecyl trimethyl ammonium bromide by low temperature hydrothermal method. The surface morphology, chemical structure, thermal stability and optical properties of cotton fibers before and after treatments were studied by scanning electron microscopy (SEM), transmission electron microscopy(TEM), Fourier transform infrared spectroscopy (FTIR), X–ray photoelectron spectroscopy (XPS), thermal gravimetric (TG) and diffuse reflectance spectrum (DRS). The properties of tensile, friction and self–cleaning capability to discolor strawberry juice stain were also measured. The results showed that titanium dioxide (TiO2) nanoparticles in anatase phase with an average particle size of 50 nm were grafted on the surfaces of cotton fibers. The crystallites of TiO2 were less than 10 nm in size. In comparison with the original cotton fibers, the thermal properties of TiO2 coated cotton fibers had almost no change. The protection against ultraviolet radiation was obtained. However, the tensile properties decreased to some extent. The coefficients of static and kinetic friction increased because of the introduction of TiO2 nanoparticles. The strawberry juice stained on cotton fibers could be discolored exposure to UV radiation.

Facile Synthesis and Characterization of Spinel NiFe2O4 Nanoparticles and Studies of Their Photocatalytic Activity for Oxidation of Alcohols

2020 ◽  
Vol 12 (3) ◽  
pp. 357-365 ◽  
Author(s):  
Xiangrong Ma ◽  
Rui Dang ◽  
Jieying Liu ◽  
Fang Yang ◽  
Huigui Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Bet Analysis ◽  
Oxidation Of Alcohols ◽  
20 Nm ◽  
Adsorption Desorption

In this paper, we report a novel and facile approach for the synthesis of spinel NiFe2O4 nanoparticles and studies of its photocatalytic activity for oxidation of alcohols. The as-synthesized catalyst was thoroughly characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental mapping, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and N2 adsorption–desorption isotherm (BET) analysis. The TEM image reveals cubic shapes with an average particle size of 10–20 nm. The as-synthesized spinel NiFe2O4 has proved to be an excellent photocatalyst for oxidation of alcohol to the aldehyde with a conversion of 80% and selectivity of 99%. The catalyst has also proved to be noteworthy as it does not loss its catalytic activity even after five cycles of reuse.

scholarly journals Synthesis and Electrochemical Performance of Polyacrylonitrile Carbon Nanostructure Microspheres for Supercapacitor Application

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mimgjie Ma ◽  
Chao Zhang ◽  
Guangxu Huang ◽  
Baolin Xing ◽  
Yuling Duan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Specific Capacitance ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Average Particle Size ◽  
Total Pore Volume ◽  
Average Particle ◽  
Carbon Nanostructure ◽  
Activation Temperature ◽  
Supercapacitor Application

Polyacrylonitrile (PAN) carbon nanostructure microspheres (CNM) with the average particle size of 200 nm were prepared in the range of 500 to 800°C. The precursors of CNM were obtained through soap-free emulsion polymerization followed by freeze drying, oxidative stabilization, and half-carbonization. KOH was employed as the activation agent of the precursor material, and the ratio between KOH and the precursor was selected as 2 : 1. The element content, pore structure, nitrogen-containing functional groups, and microstructure characterization were characterized via elemental analysis, N2adsorption at low temperature, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and the electrochemical properties were examined as well. The results revealed that the CNM displayed specific surface area as high as 2134 m2/g and the total pore volume could reach 2.01 cm3/g when the activation temperature was 700°C. Furthermore, its specific capacitance in 3 M KOH and 1 M organic electrolyte could reach 311 F/g and 179 F/g, respectively. And, also, abundant functional groups of N-5 and N-6 were rich in the surface of the material, which could cause Faraday reaction and got the increasing specific capacitance via improvement of the wettability of the electrode material.

scholarly journals Ni Nanoparticles on CeO2 (111): Energetics, Electron Transfer and Structure by Ni Adsorption Calorimetry, Spectroscopies and DFT

2020 ◽  
Author(s):  
Zhongtian Mao ◽  
Pablo Lustemberg ◽  
John R. Rumptz ◽  
M. V. Ganduglia-Pirovano ◽  
Charles T. Campbell
Keyword(s):  
Particle Size ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Density Functional ◽  
Average Particle Size ◽  
Heat Of Adsorption ◽  
Low Energy ◽  
Average Particle ◽  
Adsorption Calorimetry ◽  
Ni Clusters

<div>The morphology, interfacial bonding energetics and charge transfer of Ni clusters and nanoparticles on slightly-reduced CeO<sub>2-x</sub> (111) surfaces at 100 to 300 K have been studied using single crystal adsorption calorimetry (SCAC), low-energy ion scattering spectroscopy (LEIS), X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and density functional theory (DFT). The initial heat of adsorption of Ni vapor decreased with the extent of pre-reduction (x) of the CeO<sub>2-x</sub> (111), showing that stoichiometric ceria adsorbs Ni more strongly than oxygen vacancies. On CeO<sub>1.95</sub> (111) at 300 K, the heat dropped quickly with coverage in the first 0.1 ML, attributed to nucleation of Ni clusters on stoichiometric steps, followed by the Ni particles spreading onto less favorable terrace sites. At 100 K, the clusters nucleate on terraces due</div><div>to slower diffusion. Adsorbed Ni monomers are in the +2 oxidation state, and they bind by ~45 kJ/mol more strongly to step sites than terraces. The measured heat of adsorption versus average particle size on terraces is favorably compared to DFT calculations. The Ce 3d XPS lineshape</div><div>showed an increase in Ce<sup>3+</sup>/Ce<sup>4+</sup> ratio with Ni coverage, providing the number of electrons donated to the ceria per Ni atom. The charge transferred per Ni is initially large but strongly decreases with increasing cluster size for both experiments and DFT, and shows large differences between clusters at steps versus terraces. This charge is localized on the interfacial Ni and Ce atoms in their atomic layers closest to the interface. This knowledge is crucial to understanding the nature of the active sites on the surface of Ni-CeO<sub>2</sub> catalysts for which metal-oxide interactions play a very important role in the activation of O−H and C−H bonds. The changes in these interactions with Ni particle size (metal loading) and the extent of reduction of the ceria help to explain how previously reported catalytic activity and selectivity change with these same structural details.</div>

Preparation, characterization and dechlorination property of nano Pd-Ni/γ-Al2O3 bimetallic catalyst

2019 ◽  
Vol 12 (06) ◽  
pp. 1951003 ◽  
Author(s):  
Yu Zhang ◽  
Yiyang Wang ◽  
Yalong Liao ◽  
Muyuan Guo ◽  
Gongchu Shi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Bimetallic Catalyst ◽  
Average Particle Size ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Emission Spectrometry ◽  
Average Particle ◽  
Plasma Atomic Emission Spectrometry ◽  
X Ray

Nano Pd-Ni/[Formula: see text]-Al2O3 bimetallic catalyst was prepared by chemical precipitation method enhanced with ultrasonic wave. The influence of dosage of dispersant, ultrasonic intensity and mass ratio of Pd to Ni on the dechlorination property of the catalyst obtained was investigated in detail. The appearance morphology, composition and structure of the catalysts prepared were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption, while the specific surface area was determined using the Brunauer–Emmett–Teller (BET) isotherm and the chemical composition of active gradients was tested with inductively coupled plasma-atomic emission spectrometry (ICP-AES). Results indicate that the nano Pd-Ni/[Formula: see text]-Al2O3 bimetallic catalyst prepared has uniform distribution of active ingredients with an average particle size of 4.91[Formula: see text]nm, and the chlorine content of shellac dechlorinated with the catalyst obtained is 0.34[Formula: see text]wt.% which is lower than that reported in the literature, meaning the perfect dechlorination property of the catalyst.

Polymer composite reinforced with nanoparticles produced from graphitic carbon-rich fly ash

2016 ◽  
Vol 51 (18) ◽  
pp. 2675-2685 ◽  
Author(s):  
Abdullah Algarni ◽  
Numan Salah ◽  
Mostefa Bourchak ◽  
Asim Jilani ◽  
Ahmed Alshahrie ◽  
...  
Keyword(s):  
Fly Ash ◽  
Young’S Modulus ◽  
Epoxy Matrix ◽  
Carbon Nanoparticles ◽  
Young's Modulus ◽  
Average Particle Size ◽  
High Energy ◽  
Graphitic Carbon ◽  
Average Particle ◽  
Matrix System

Carbon nanotubes and graphene are considered effective reinforcement materials for various polymers because of their superior properties. However, they are expensive and difficult to separate and incorporate individually into matrix systems because of their tendency to exist in clustered form. In this work, carbon nanoparticles produced from graphitic carbon-rich fly ash by high-energy ball milling are evaluated as a reinforcement in a high-performance epoxy matrix system. They were used in various weight fractions ranging from 0.1 to 2 wt.%. The obtained carbon nanoparticles have an average particle size of around 20 nm, while XPS spectrum shows active carbonyl groups on their surfaces. The mechanical tensile properties of the carbon nanoparticles/epoxy nanocomposite, including their Young's modulus, stiffness, and load at fracture, were investigated. Moreover, the effect of ethanol as a dispersion medium was studied. The obtained results indicate that the Young's modulus and load at fracture changed only slightly upon the addition of carbon nanoparticles to the epoxy matrix system. On the other hand, the stiffness was improved by 60% over that of the pure epoxy matrix system. This improvement was obtained at 0.6 wt.% carbon nanoparticle content. The test results indicate that ethanol is effective in modifying the nanocomposite mechanical properties. Additionally, results show that low-cost CNPs might be useful as a reinforcement material for high-stiffness products.

scholarly journals Surface Modification of Carbon Nanofibers and Graphene Platelets Mixtures by Plasma Polymerization of Propylene

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Carlos Andrés Covarrubias-Gordillo ◽  
Florentino Soriano-Corral ◽  
Carlos Alberto Ávila-Orta ◽  
Victor Javier Cruz-Delgado ◽  
María Guadalupe Neira-Velázquez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Carbon Nanofibers ◽  
Plasma Polymerization ◽  
Carbon Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Graphene Platelets

Carbon nanofibers (CNFs), graphene platelets (GPs), and their mixtures were treated by plasma polymerization of propylene. The carbon nanoparticles (CNPs) were previously sonicated in order to deagglomerate and increase the surface area. Untreated and plasma treated CNPs were analyzed by dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and thermogravimetric analysis (TGA). DLS analysis showed a significant reduction of average particle size, due to the sonication pretreatment. Plasma polymerized propylene was deposited on the CNPs surface; the total amount of polymerized propylene was from 4.68 to 6.58 wt-%. Raman spectroscopy indicates an increase in the sp3 hybridization of the treated samples, which suggest that the polymerized propylene is grafted onto the CNPs.

scholarly journals STAT6 siRNA Matrix-Loaded Gelatin Nanocarriers: Formulation, Characterization, andEx VivoProof of Concept Using Adenocarcinoma Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Susanne R. Youngren ◽  
Rakesh K. Tekade ◽  
Brianne Gustilo ◽  
Peter R. Hoffmann ◽  
Mahavir B. Chougule
Keyword(s):  
Release Kinetics ◽  
Average Particle Size ◽  
A549 Cells ◽  
Average Particle ◽  
Formulation Development ◽  
Nonspecific Effects ◽  
Adenocarcinoma Cells ◽  
Sirna Therapy ◽  
The Stability

The clinical utility of siRNA therapy has been hampered due to poor cell penetration, nonspecific effects, rapid degradation, and short half-life. We herewith proposed the formulation development of STAT6 siRNA (S6S) nanotherapeutic agent by encapsulating them within gelatin nanocarriers (GNC). The prepared nanoformulation was characterized for size, charge, loading efficiency, release kinetics, stability, cytotoxicity, and gene silencing assay. The stability of S6S-GNC was also assessed under conditions of varying pH, serum level, and using electrophoretic assays.In vitrocytotoxicity performance was evaluated in human adenocarcinoma A549 cells following MTT assay. The developed formulation resulted in an average particle size, surface charge, and encapsulation efficiency as70±6.5 nm,+10±1.5 mV, and85±4.0%, respectively. S6S-GNC showed an insignificant (P<0.05) change in the size and charge in the presence of buffer solutions (pH 6.4 to 8.4) and FBS (10% v/v). A549 cells were treated with native S6S, S6S-lipofectamine, placebo-GNC, and S6S-GNC using untreated cells as a control. It was observed that cell viability was decreased significantly with S6S-GNC by55±4.1%(P<0.001) compared to native S6S (2.0±0.55%) and S6S-lipofectamine complex (40±3.1%). This investigation infers that gelatin polymer-based nanocarriers are a robust, stable, and biocompatible strategy for the delivery of siRNA.

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