Specific absorption rate of randomly oriented magnetic nanoparticles in a static magnetic field

• Ruslan A. Rytov and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2023, 14, 485–493, doi:10.3762/bjnano.14.39

• formula [28][29] where ρ is the density of the magnetic material and is the average magnetization of the assembly of nanoparticles. To obtain statistically reliable results, dynamic hysteresis loops are averaged over 30 independent realizations of the randomly oriented assembly containing 60 non

• , perpendicular to the ac magnetic field (see Figure 3c). As Figure 3d shows, this leads to a sharp drop in the particle hysteresis loop area. In addition to Figure 3, Figure 4 shows the evolution of the surface of the normalized energy density of a nanoparticle, W(θ,φ)/K1V, as a function of the spherical angles

• same for Hdc = 800 Oe. (d) Dynamic hysteresis loops of the nanoparticle for Hdc = 0, 200, 400, and 800 Oe, respectively. Evolution of the normalized energy density of a particle, W(θ,φ)/K1V, as a function of dc magnetic field applied perpendicular to the particle easy anisotropy axis: (a, b) Hdc = 0 Oe

Conjugated photothermal materials and structure design for solar steam generation

• Chia-Yang Lin and
• Tsuyoshi Michinobu

Beilstein J. Nanotechnol. 2023, 14, 454–466, doi:10.3762/bjnano.14.36

• can be predicted by density functional theory (DFT) calculations of the conjugated structures. This is an advantage over other carbon materials, even if they are of the same chemical composition [18][19][20][21][22]. We review the recent progress in the material development of conjugated solar

• constructing electron donor–acceptor pairs. Density functional theory (DFT) simulations indicated donor–acceptor interactions between arginine and PDA subunits, including the formation of 5,6-dihydroxyindole (DHI) and indole-5,6-quinone (IQ). Dopamine and arginine were copolymerized in an aqueous solution at

Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2023, 14, 434–453, doi:10.3762/bjnano.14.35

• epitaxial polymerization, controlling the length, density, bonding, and propagation direction of the molecules. Advances in surface scanning probe microscopy techniques have enabled the synthesis and analysis of unstable short-lived products by local probe synthesis as well as direct observation of

• . Foster, Kawai, and co-workers have investigated the zero-bias peak at the center of an armchair-type graphene nanoribbon on a AuSix/Au(111) surface using a combination of low-temperature scanning tunneling microscopy/spectroscopy and density functional theory calculations [116]. The zero-bias peak at the

Evaluation of electrosynthesized reduced graphene oxide–Ni/Fe/Co-based (oxy)hydroxide catalysts towards the oxygen evolution reaction

• Karolina Cysewska,
• Marcin Łapiński,
• Marcin Zając,
• Jakub Karczewski,
• Piotr Jasiński and
• Sebastian Molin

Beilstein J. Nanotechnol. 2023, 14, 420–433, doi:10.3762/bjnano.14.34

• ]. Afterwards, the current density tended to stabilize for NiFe and CoNiFe, which may be associated with the steady-state formation of the catalyst film on the metallic surface. The addition of cobalt to NiFe resulted in a lower overall current density during the synthesis process. In the case of the deposition

• of NiFe and CoNiFe on GO/nickel foam, the specific current density peak appeared after around 8 s and 20 s of the deposition for CoNiFe-GO and NiFe-GO, respectively. Because the metallic films were deposited on the surface of nickel foam already modified with GO, the peak may be associated with the

• reduction process of the already deposited GO. Afterwards, the current density increased due to the film formation, and then it gradually stabilized over time. A different chronoamperometric trend can be observed in the case of the electrodeposition of GO on the surface of nickel foam (Figure 1a inset). In

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• materials [7][8], such as Au nanoparticles (AuNPs), in photodynamic therapy [9][10][11]. Metal nanoparticles in general have been extensively explored in PPT applications due to their high free electron density and the possibility of intricate tuning of light absorption [12]. Noble metal nanoparticles with

• curvature [35]. Finally, changes to the material composition, such as through doping or vacancy processing, can affect the LSPR because of changes in the free electron density, the electron effective mass, and the electronic band structure in general [36][37]. An understanding of the changes in absorbance

• is the polarization density. P can be arrived at by solving the equation of motion for a single electron as Hence the expression relating the dielectric displacement (D) and the external electric field can be obtained as where is the natural frequency of oscillation of the electron cloud. Comparing

Quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles: one-pot synthesis, characterization, and anticancer and antibacterial activities

• Akif Hakan Kurt,
• Elif Berna Olutas,
• Fatma Avcioglu,
• Hamza Karakuş,
• Mehmet Ali Sungur,
• Cansu Kara Oztabag and
• Muhammet Yıldırım

Beilstein J. Nanotechnol. 2023, 14, 362–376, doi:10.3762/bjnano.14.31

• acid hydrate, Cell Proliferation Kit II test (Roche). XTT solution was added to each plate at 50 µL and was incubated for 4 h at 37 °C. Then, the absorbance (optical density, OD) of the solution in each plate was read at 450 nm by a spectrophotometer (BiotekELx800, Winooski, VT, USA). Statistical

Polymer nanoparticles from low-energy nanoemulsions for biomedical applications

• Santiago Grijalvo and
• Carlos Rodriguez-Abreu

Beilstein J. Nanotechnol. 2023, 14, 339–350, doi:10.3762/bjnano.14.29

• roughly estimated by [18]: where Ms is the surfactant molecular weight, as is the area occupied per surfactant molecule at the O/W interface, NA is Avogadro’s number, ρ0 is the density of the oil phase, Ros is the oil/surfactant mass ratio, and vL is the molar volume of the hydrophobic part of the

• solubility of polymers in the used solvents rarely exceeds 10 wt %). Experimental dP/dE ratios are above of those expected if the nanoparticles were to be obtained with a density equal to that of the polymer in the bulk, that is, by applying the formula where mP/mT is the polymer/solvent mass ratio and ρT/ρP

• is the solvent/polymer bulk density ratio (this equation assumes that each droplet generates one single nanoparticle). In other words, the polymer nanoparticles seem to be, in general, less dense than in the bulk, which could be attributed to porosity generated during solvent evaporation

Overview of mechanism and consequences of endothelial leakiness caused by metal and polymeric nanoparticles

• Magdalena Lasak and
• Karol Ciepluch

Beilstein J. Nanotechnol. 2023, 14, 329–338, doi:10.3762/bjnano.14.28

• effectiveness of NanoEL closely depends on the physicochemical properties of the NPs such as size, shape, density, and surface charge [12][19][20][21]. Moreover, it is worth to mention that the biological effects of NPs to endothelial cells also depend on the microenvironments. The adhesion of proteins and/or

• induction depends on the density of NPs, where the effective density of Si NPs ranged from 1.57 to 1.72 g/cm3 [20]. The leakage rate increases with increasing nanoparticle density. They also showed that a force of approximately 1.8 nN/μm along the boundaries of VE-cad adherens junctions mediated by

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

• Akeem Adeyemi Oladipo and
• Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

• surface charge, low carrier density, small electron effective mass, long electron mean free path, and extremely low band overlap energy, bismuth can transition from a semimetal to a semiconductor by shrinking its crystallite size [25][71][72][73][74][75][76][77]. To hasten the separation of photogenerated

• important for electronic transport and semimetal-to-semiconductor transition, as well as its highly anisotropic Fermi surface (with an electron and hole Fermi energies of 27.2 and 10.8 meV, respectively), which results in an extremely low carrier density of around 3 × 1017 cm−3 [78] and very little overlap

• semiconductor and a noble metal with an appropriate work function. A unidirectional charge transfer is enabled by the Schottky potential barrier, increasing charge density and separation [72]. Shen et al. [166] created a Schottky junction by synthesising NiSe2 nanosheets on top of BiVO4 nanosheets using a

Biocatalytic synthesis and ordered self-assembly of silica nanoparticles via a silica-binding peptide

• Mustafa Gungormus

Beilstein J. Nanotechnol. 2023, 14, 280–290, doi:10.3762/bjnano.14.25

• combination with NH3. The reaction kinetics were monitored via measuring the optical density (OD) with UV–vis spectroscopy and the conversion of substrate via gas chromatography coupled with mass spectroscopy (GC–MS). Size and net surface charge distribution of the particles were determined with dynamic light

• with different concentrations of the peptide to examine whether the peptide had a synergistic effect on the formation of SiO2 particles. Kinetic measurements The reaction rates were monitored by measuring the optical density (OD) of the particles at 445 nm (Varioskan Flash micro-plate reader, Thermo

Spin dynamics in superconductor/ferromagnetic insulator hybrid structures with precessing magnetization

• Yaroslav V. Turkin and
• Nataliya Pugach

Beilstein J. Nanotechnol. 2023, 14, 233–239, doi:10.3762/bjnano.14.22

• a standard procedure [29]: where is the spin operator in electron–hole–spin space, g is the gyromagnetic ratio for free electrons, μB is the Bohr magneton, N0 is the density of states at the Fermi level, and is the Fourier–Winger transform of the Green’s function [29][30] The expression for the

• . However, there is a possibility to induce stationary pure spin currents inside trilayer superconducting structures [1]. The distributions of spin current amplitudes into the S layer are depicted in Figure 2. The amplitudes are normalized by the factor js0 = (ℏ/2e)je0. The charge current density

• spin relaxation processes, but we do not take into account any spin relaxation mechanisms within our model for a superconductor. We should mention that both spin pumping mechanisms in superconductors and normal metals are determined by the penetration of nonequillibrium spin density from the interface

Cyclodextrins as eminent constituents in nanoarchitectonics for drug delivery systems

• Makoto Komiyama

Beilstein J. Nanotechnol. 2023, 14, 218–232, doi:10.3762/bjnano.14.21

• charges of high density can damage the membranes and organelles of normal cells. With the use of CyD-based DDSs, however, high transfection efficiency and low cytotoxicity have been accomplished with minimal immune stimulation. The preorganized three-dimensional molecular structure of CyD as well as the

A novel approach to pulsed laser deposition of platinum catalyst on carbon particles for use in polymer electrolyte membrane fuel cells

• Bogusław Budner,
• Wojciech Tokarz,
• Sławomir Dyjak,
• Andrzej Czerwiński,
• Bartosz Bartosewicz and
• Bartłomiej Jankiewicz

Beilstein J. Nanotechnol. 2023, 14, 190–204, doi:10.3762/bjnano.14.19

• graphitization were used as carbon supports. The best electrochemical measurement results were obtained for Pt deposited on Vulcan XC-72R. The peak power density measured for this material in a membrane electrode assembly (MEA) of a PEMFC (fed with H2/Air) was 0.41 W/cm2, which is a good result compared to 0.57

• and an electrochemical catalyst for electrochemical reactions under low temperatures, are typically used in automobiles and portable electronics [4][5]. The primary application potential is related to their compact size, lightweight, high power density, and low operating temperature. However, they

• and physical methods of Pt deposition [22][23][24][25][26]. Direct deposition of Pt onto carbon supports resulting in a thin catalyst layer and good dispersion of formed Pt nanoparticles (PtNPs) is of particular interest because it should allow for a high Pt mass-specific power density to be achieved

High–low Kelvin probe force spectroscopy for measuring the interface state density

• Ryo Izumi,
• Masato Miyazaki,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2023, 14, 175–189, doi:10.3762/bjnano.14.18

• of the effects of semiconductor interface states with high spatial resolution using high and low AC bias frequencies compared with the cutoff frequency of the carrier transfer between the interface and bulk states. Information on the energy spectrum of the interface state density is important for

• interface state density inside semiconductors. We derive an analytical expression for the electrostatic forces between a tip and a semiconductor sample in the accumulation, depletion, and inversion regions, taking into account the charge transfer between the bulk and interface states in semiconductors. We

• show that the analysis of electrostatic forces in the depletion region at high- and low-frequency AC bias voltages provides information about the interface state density in the semiconductor bandgap. As a preliminary experiment, high-low KPFS measurements were performed on ion-implanted silicon

A distributed active patch antenna model of a Josephson oscillator

• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2023, 14, 151–164, doi:10.3762/bjnano.14.16

• spatial distribution of the input current density in a JJ, described by the perturbed sine-Gordon equation. In the presence of a magnetic field and fluxons, the oscillating current is distributed nonuniformly within the junction. This nonuniformity is essential for the FFO operation. It determines the

• density through the JJ, which has Cooper pair and quasiparticle (QP) components, Here, Jc0 is the Josephson critical current density, η is the Josephson phase difference, and rQP = RQPab is the QP resistance per unit area. Active patch antenna model of a junction Equation 1 is the equation for an active

• TL [37] with a distributed feed-in current density Jz. Therefore, a JJ has many similarities with the microstrip patch antenna. However, there are three main differences: (i) The feed-in geometry. A patch antenna has a point-like feed-in port, through which the oscillating current is applied [34][35

Batch preparation of nanofibers containing nanoparticles by an electrospinning device with multiple air inlets

• Dong Wei,
• Chengwei Ye,
• Adnan Ahmed and
• Lan Xu

Beilstein J. Nanotechnol. 2023, 14, 141–150, doi:10.3762/bjnano.14.15

• shrink and bend as much as possible, and the change of external electric field would interact with the accumulated charges on the polymer fluid surface, making the charge density on the charged fluid surface uneven. Accordingly, the formulas to calculate these three forces are as follows: where ρ is the

• density of spinning solution (kg/m3), g is the gravitational acceleration (m/s2), h is the fluctuation height of the polymer spinning solution (m), γ is the surface tension coefficient of the spinning solution (N/m), ε0 is vacuum dielectric constant, E0 is the edge electric field intensity (V/m), Ep is

Characterisation of a micrometer-scale active plasmonic element by means of complementary computational and experimental methods

• Ciarán Barron,
• Giulia Di Fazio,
• Samuel Kenny,
• Silas O’Toole,
• Robin O’Reilly and
• Dominic Zerulla

Beilstein J. Nanotechnol. 2023, 14, 110–122, doi:10.3762/bjnano.14.12

• polaritons (SPPs) are mixed states of photons and electron density waves propagating along the interface between a conductor and a dielectric. As a result of this phenomenon, an electric field strongly confined in the z-direction is produced at the interface. As direct excitation of a smooth metallic surface

• contraction per point for the lock-in amplifier to integrate over. The time constant for the lock-in process was set to 10 ms to match the time the tip is over each pixel. The sensitivity of the LIA was set to 200 μV. The applied voltage was set based on the current density through the sample so as to match

• surrounding the sample as a function of applied current. For higher current densities, a wider distribution of the temperature is expected. A current buffer was used to ensure the current density through the element was consistent throughout an AFM scan. The probe was left electrically floating during

Antimicrobial and mechanical properties of functionalized textile by nanoarchitectured photoinduced Ag@polymer coating

• Jessica Plé,
• Marine Dabert,
• Helene Lecoq,
• Sophie Hellé,
• Lydie Ploux and
• Lavinia Balan

Beilstein J. Nanotechnol. 2023, 14, 95–109, doi:10.3762/bjnano.14.11

• centrifugation. Harvested bacteria pellets were resuspended in fresh M63G medium and the as-obtained bacterial suspensions were adjusted by dilution to an optical density at 600 nm (OD600) of 0.1 (2.9 × 107 CFU/mL of E. coli and 5 × 105 CFU/mL of C. albicans). Characterization techniques UV irradiations were

Frontiers of nanoelectronics: intrinsic Josephson effect and prospects of superconducting spintronics

• Anatolie S. Sidorenko,
• Horst Hahn and
• Vladimir Krasnov

Beilstein J. Nanotechnol. 2023, 14, 79–82, doi:10.3762/bjnano.14.9

• –ferromagnet–superconductor (SFS) structures have been predicted and calculated [26]. A quantitative study of the density of states (DOS) in bulk superconductor/ferromagnetic (S/F) bilayers in the diffusive limit has been presented. In addition, an analysis of the dependencies of DOS on magnetic and spin–orbit

Liquid phase exfoliation of talc: effect of the medium on flake size and shape

• Samuel M. Sousa,
• Helane L. O. Morais,
• Joyce C. C. Santos,
• Ana Paula M. Barboza,
• Bernardo R. A. Neves,
• Elisângela S. Pinto and
• Mariana C. Prado

Beilstein J. Nanotechnol. 2023, 14, 68–78, doi:10.3762/bjnano.14.8

• distribution histograms of these values for all four different exfoliation media under investigation here. The distributions are skewed and best described by the exponentially modified Gaussian (EMG) distribution [25]. The probability density function of the EMG distribution is given by: where μ and σ are the

• -X100 lies in between. Finally, let us add to the initial flake size discussion by analyzing the flake thickness distribution instead of the dimensionless parameters. The normalized histograms of flake thickness for all four samples (Figure 3c) are well adjusted by the EMG probability density function

Solvent-induced assembly of mono- and divalent silica nanoparticles

• Bin Liu,
• Etienne Duguet and
• Serge Ravaine

Beilstein J. Nanotechnol. 2023, 14, 52–60, doi:10.3762/bjnano.14.6

• corresponded to a nominal grafting surface density of 0.7 funct./nm2. Then, MMS-functionalized silica NPs (1.8 × 1016 part/L) were used as seeds for the seed-growth emulsion polymerization of styrene (100 g/L) stabilized by a mixture (3 g/L) of Symperonic® NP30 and SDS (5 wt %) and initiated by 1.3 mL of

Two-step single-reactor synthesis of oleic acid- or undecylenic acid-stabilized magnetic nanoparticles by thermal decomposition

• Mykhailo Nahorniak,
• Pamela Pasetto,
• Jean-Marc Greneche,
• Volodymyr Samaryk,
• Sandy Auguste,
• Anthony Rousseau,
• Nataliya Nosova and
• Serhii Varvarenko

Beilstein J. Nanotechnol. 2023, 14, 11–22, doi:10.3762/bjnano.14.2

• particles (determined by the TGA method); mn is the ratio of the inorganic core from the mass of the particles (determined by the TGA method); DTEM is the particle diameter (determined by TEM); ρn is the core material density (magnetite ρ = 5.1 g/cm3, maghemite ρ = 4.9 g/cm3); and ρs is the density of the

Atmospheric water harvesting using functionalized carbon nanocones

• Fernanda R. Leivas and
• Marcia C. Barbosa

Beilstein J. Nanotechnol. 2023, 14, 1–10, doi:10.3762/bjnano.14.1

• addition to the hydrophobicity described above. The phenomena of density increasing with temperature at constant pressure and diffusion coefficients increasing with density at constant temperature were observed in experiments and simulations in bulk water [22][23][24]. Water presents both super flow and

• during the simulation. The system shown in Figure 1 is made of a reservoir of size 50 × 54 × 50 Å3. This reservoir has two regions, namely a liquid water region on the left and a water vapor region on the right. The number of water molecules in this simulation is 1473. The density of the vapor system is

Electrical and optical enhancement of ITO/Mo bilayer thin films via laser annealing

• Abdelbaki Hacini,
• Ahmad Hadi Ali,
• Nurul Nadia Adnan and
• Nafarizal Nayan

Beilstein J. Nanotechnol. 2022, 13, 1589–1595, doi:10.3762/bjnano.13.133

• seen that the predominant peaks are (222) and (400), which are the preferred orientations before and after laser annealing. The intensities of the crystallite peaks orientation increased and attained a maximum at 200 mJ. The crystallite size (D) and the dislocation density (δ) were determined from the

• XRD peaks using the following equations [28]: where D, 0.9, λ, β, and δ are the crystallite size, the shape factor, the wavelength of the incident X-rays, the full width at half maximum of the reflection at the diffraction angle θβ, and the dislocation density, respectively. The average crystallite

• size increased with the laser energy up to 200 mJ. It decreased to reach a minimum at an energy of 240 mJ. This trend in crystallite size is due to the rearrangement of the nanostructure. The particles sizes increase, defects are reduced, and the dislocation density (δ) decreases from 6.53 × 1014 to

Observation of collective excitation of surface plasmon resonances in large Josephson junction arrays

• Roger Cattaneo,
• Mikhail A. Galin and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2022, 13, 1578–1588, doi:10.3762/bjnano.13.132

• calibrate the detector, we use a MW source with f = 74.5 GHz. Figure 6c represents a sketch of the calibration setup. The detector is placed in an optical cryostat and the gigahertz signal is guided through an optical window using two high-density polyethylene lenses. The gigahertz source is linearly

• suppression of Is corresponds to the absorbed MW power, Pa ≃ ≃ 30 nW. Thus, we can perform an absolute calibration of the absorbed power as a function of the detector resistance, as shown in Figure 6f. The absorbed power depends on the absorption efficiency, γ, the antenna area, Aa, and the power density