Magnetic-field-assisted synthesis of anisotropic iron oxide particles: Effect of pH

• Andrey V. Shibaev,
• Petr V. Shvets,
• Darya E. Kessel,
• Roman A. Kamyshinsky,
• Anton S. Orekhov,
• Sergey S. Abramchuk,
• Alexei R. Khokhlov and
• Olga E. Philippova

Beilstein J. Nanotechnol. 2020, 11, 1230–1241, doi:10.3762/bjnano.11.107

• constant until the end of the synthesis (2–2.5 h). During the first several seconds, the color of the reaction mixture changes to black (Figure 1). This is consistent with the fact that the crystal nucleation happens almost instantly [6][43]. After that, only changes or reorganization of the crystalline

• ). Similar pictures depicting many primary nanoparticles attached to the surface of a larger magnetite particle were recently observed in spherical nanoparticles [9]. This was considered as evidence for magnetite nucleation and the growth mechanism, consisting of the aggregation of primary nanoparticles. As

Gram-scale synthesis of splat-shaped Ag–TiO₂ nanocomposites for enhanced antimicrobial properties

• Mohammad Jaber,
• Asim Mushtaq,
• Kebiao Zhang,
• Jindan Wu,
• Dandan Luo,
• Zihan Yi,
• M. Zubair Iqbal and
• Xiangdong Kong

Beilstein J. Nanotechnol. 2020, 11, 1119–1125, doi:10.3762/bjnano.11.96

• TiO2 NP nucleation started after adding the urea and PVP surfactant. Then, the aqueously dispersed AgNO3 solution was poured into the prepared TiO2/PVP mixture. It was assumed that the positively charged Ag+ ions interacted with the negatively charged PVP-modified TiO2 NPs due to electrostatic

Straightforward synthesis of gold nanoparticles by adding water to an engineered small dendrimer

• Sébastien Gottis,
• Régis Laurent,
• Vincent Collière and
• Anne-Marie Caminade

Beilstein J. Nanotechnol. 2020, 11, 1110–1118, doi:10.3762/bjnano.11.95

• few studies [62][63][64]. According to these studies none of the nanoparticles were obtained as a resulted of fast nucleation, which in turn should lead to spherical and uniform nanoparticles with a 2–5 nm diameter range. On the contrary, the shapes that were observed here were obtained through a

• quantity of the Girard’s T reagent was sufficient to induce the first nucleation steps. The cleavage of all the hydrazone linkages would generate dendrimers 1 or 2 that are insoluble in water; however, no precipitate was observed. The intact dendrimer 4, on the other hand, acted as a nanoreactor in water

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

• Elena I. Monaico,
• Eduard V. Monaico,
• Veaceslav V. Ursaki,
• Shashank Honnali,
• Vitalie Postolache,
• Karin Leistner,
• Kornelius Nielsch and
• Ion M. Tiginyanu

Beilstein J. Nanotechnol. 2020, 11, 966–975, doi:10.3762/bjnano.11.81

• propagation of pores was observed for the potentiostatic mode of anodization (Figure 1C). Switching the anodization voltage to 1 V stops the formation of the porous layer, since this value is below the pore nucleation potential (1.8 V) established from the I–V characteristic, which is in agreement with the

• KOH electrolyte, and the orientation of the arrays is basically random, while the nanowires produced in HNO3 electrolyte are highly oriented perpendicularly to the wafer surface. No nanowires were reported after GaAs anodization in H2SO4 electrolyte, which was used for uniform pore nucleation in a two

• number of tilted pores. One can conclude that etching in HNO3 electrolyte suppresses the nucleation of tilted pores as compared to anodization in HCl or H2SO4 electrolyte, resulting in the fabrication of non-porous GaAs nanowires, which are better suitable for photodetector applications. High-aspect

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

• K. Priya Madhuri,
• Abhay A. Sagade,
• Pralay K. Santra and
• Neena S. John

Beilstein J. Nanotechnol. 2020, 11, 814–820, doi:10.3762/bjnano.11.66

• [6][11][20][21][22]. Studies concerning the orientation of nonplanar MPcs on graphene are rare. Vanadyl phthalocyanine (VOPc) has been reported to attain edge-on configuration on a graphene surface [23]. The nucleation of CuPc on graphene is reported to be influenced by the underlying Ir(111

Evolution of Ag nanostructures created from thin films: UV–vis absorption and its theoretical predictions

• Robert Kozioł,
• Marcin Łapiński,
• Paweł Syty,
• Damian Koszelow,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2020, 11, 494–507, doi:10.3762/bjnano.11.40

• different processes [9]. In two of them, the formation of nanostructures begins with the nucleation of holes and their subsequent growth. Nucleation can be caused by small thermal density fluctuations (homogeneous nucleation) or defects in the metal film or in the interface between the film and the

• substrate (heterogeneous nucleation). In the third process, voids appear and grow as a result of an amplification of periodical fluctuations of the film thickness, which is known as spinodal dewetting [9][10]. Usually, it is difficult to state clearly whether only one of the abovementioned processes is

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• transition metals, as well as Ag and Au. However, most studies have examined single-atom adsorption or adsorbed nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first-principles

• character of Cu nanoclusters is preserved. Keywords: copper (Cu); density functional theory (DFT); 2D materials; molybdenum disulfide (MoS2); thin film nucleation; Introduction Since the successful exfoliation of monolayers of graphene by Novoselov et al., 2D materials have gained a large interest in a

• allows us to investigate the first stages in the nucleation of a Cu film on MoS2 monolayers, as well as the fundamental copper–TMD interactions, and thus gain significant insights into the range of stable configurations for Cu adsorption on MoS2. In addition, we investigate the effect of a single S

Interactions at the cell membrane and pathways of internalization of nano-sized materials for nanomedicine

• Valentina Francia,
• Daphne Montizaan and
• Anna Salvati

Beilstein J. Nanotechnol. 2020, 11, 338–353, doi:10.3762/bjnano.11.25

• macropinocytosis, extracellular fluids are engulfed by membrane ruffles and protrusions. Formation of these ruffles requires actin nucleation and in some cells also cholesterol [93][94]. Another frequently studied clathrin-independent pathway is the so-called caveolae-mediated endocytosis. Caveolae are 50–80 nm

High-performance asymmetric supercapacitor made of NiMoO₄ nanorods@Co₃O₄ on a cellulose-based carbon aerogel

• Meixia Wang,
• Jing Zhang,
• Xibin Yi,
• Benxue Liu,
• Xinfu Zhao and
• Xiaochan Liu

Beilstein J. Nanotechnol. 2020, 11, 240–251, doi:10.3762/bjnano.11.18

• excellent electrical conductivity and the 3D carbon nanonetwork. Secondly, NiMoO4 nanorods with extremely high specific capacitance are considered ideal spots for the nucleation and the growth of ZIF-67 particles. Lastly, the Co3O4 particles derived from ZIF-67 possess a nest-like structure and a porous

Size effects of graphene nanoplatelets on the properties of high-density polyethylene nanocomposites: morphological, thermal, electrical, and mechanical characterization

• Tuba Evgin,
• Alpaslan Turgut,
• Georges Hamaoui,
• Zdenko Spitalsky,
• Nicolas Horny,
• Matej Micusik,
• Mihai Chirtoc,
• Mehmet Sarikanat and
• Maria Omastova

Beilstein J. Nanotechnol. 2020, 11, 167–179, doi:10.3762/bjnano.11.14

• displayed considerable peak growth with the existence of GnPs, were in the general form of the (00x) type, being crystallographically in line with the GnP (002) plane. It has been indicated that GnPs may act as nucleation sites and that nucleation starts around the GnPs [8]. Figure 3b shows that the size of

• in Table 2. Tc for pure HDPE was found to be 116.30 °C, whereas for all HDPE/GnP nanocomposites, Tc increased by approximately 5 °C at 13.92 vol % GnP content due to the nucleation effect of the GnPs. It was clearly seen that Tm of all HDPE/GnP nanocomposites ranged from 130.43 °C to 132.17 °C, which

Internalization mechanisms of cell-penetrating peptides

• Ivana Ruseska and
• Andreas Zimmer

Beilstein J. Nanotechnol. 2020, 11, 101–123, doi:10.3762/bjnano.11.10

• , arginine-rich CPPs are mainly endocytosed, whereas rapid cytoplasmic entry occurred at higher concentration [41]. The latter is associated with the accumulation of the peptide at certain membrane areas called nucleation zones [42]. New findings of these type could further broaden what is already a very

Influence of the epitaxial composition on N-face GaN KOH etch kinetics determined by ICP-OES

• Markus Tautz,
• Maren T. Kuchenbrod,
• Joachim Hertkorn,
• Robert Weinberger,
• Martin Welzel,
• Arno Pfitzner and
• David Díaz Díaz

Beilstein J. Nanotechnol. 2020, 11, 41–50, doi:10.3762/bjnano.11.4

• and Al2O3 leads to a high dislocation density, if no strategy for defect reduction is applied. This spans the entire epitaxial layer. The most common strategy to bridge the structural mismatch is the application of AlN and GaN nucleation layers in between the sapphire substrate and bulk GaN [5][6

• ]. Nucleation layers have the second but very important effect of controlling crystal orientation, which is commonly Ga-polar (0001) [7]. Other than nucleation layers, there are several more strategies for defect reduction. These all require the insertion of additional layers or layer transitions into the

• characteristic of such devices is pixel contrast. The latter is highly affected by the thickness of the unintentionally doped bulk GaN layer (u-GaN), which separates the AlN nucleation layer from the multiple quantum well (MQW) and is needed for dislocation density reduction. By means of etching, this layer can

The different ways to chitosan/hyaluronic acid nanoparticles: templated vs direct complexation. Influence of particle preparation on morphology, cell uptake and silencing efficiency

• Arianna Gennari,
• Julio M. Rios de la Rosa,
• Erwin Hohn,
• Maria Pelliccia,
• Enrique Lallana,
• Roberto Donno,
• Annalisa Tirella and
• Nicola Tirelli

Beilstein J. Nanotechnol. 2019, 10, 2594–2608, doi:10.3762/bjnano.10.250

• solution the protonated chitosan amines (cationic species in red) are cross-linked by TPP (anionic species in blue). The complexation leads to the nucleation of the particles that increase in size likely more through the adsorption of additional chitosan and TPP species (growth) than through aggregation of

Antimony deposition onto Au(111) and insertion of Mg

• Lingxing Zan,
• Da Xing,
• Abdelaziz Ali Abd-El-Latif and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2019, 10, 2541–2552, doi:10.3762/bjnano.10.245

• was scanned negatively, the nucleation on the terraces and epitaxial 2D growth started at ≈0.6 V (see Figure 4b). The Sb monolayer islands were formed with the same height as the step height of the freshly prepared Au(111) which is 0.2 nm (see Figure 4a). With the continuous growth at the potential of

• one at 0.28 V due to the reduction of oxygenous Sb(III) species from bulk electrolyte. The coverage of the Sb monolayer was calculated to be 0.44 whereas the irreversible adsorption accounted for ≈0.3. By observation with STM, Sb nucleation prefers to start at the active sites on the terrace, and then

Abrupt elastic-to-plastic transition in pentagonal nanowires under bending

• Sergei Vlassov,
• Magnus Mets,
• Boris Polyakov,
• Jianjun Bian,
• Leonid Dorogin and
• Vahur Zadin

Beilstein J. Nanotechnol. 2019, 10, 2468–2476, doi:10.3762/bjnano.10.237

• agrees very well with the transition angles 163 ± 5.6° observed in the experiment. Dislocations nucleate from the free surface as marked by the white circles (Figure 8i). After nucleation, partial dislocations glide toward the core region of the NW and experience the impediment from the existing twin

• boundaries [42]. With the progression of bending deformation, another dislocation source is also activated, and a new dislocation nucleation and propagation lead to the second distinct load drop of the loading curve (Figure 8ii). In the following stage, the bending force gradually becomes stable at

• dislocation nucleation sites because of the stress concentration, and therefore deformation is easier to sustain by new dislocation nucleation rather than cross-slipping of existing dislocation at twin boundaries. On the basis of the conducted experiments, electron microscopy observations and simulations we

Mobility of charge carriers in self-assembled monolayers

• Zhihua Fu,
• Tatjana Ladnorg,
• Hartmut Gliemann,
• Alexander Welle,
• Asif Bashir,
• Michael Rohwerder,
• Qiang Zhang,
• Björn Schüpbach,
• Andreas Terfort and
• Christof Wöll

Beilstein J. Nanotechnol. 2019, 10, 2449–2458, doi:10.3762/bjnano.10.235

• of the orientation of the spacer group [26]. In a next step, STM images were recorded that demonstrate SAM formation of PAT on an atomically smooth Au(111) surface. As shown in the control STM data (Supporting Information File 1, Figure S3), the initially distributed smaller nucleation centers with a

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• increases as the amount of TEOS increases, while core-free silica NPs appear when the TEOS content exceeds the threshold of homogeneous nucleation [36][39][47][48][49]. Typically, a maximum diameter <50 nm can be reached with this technique [23]. Microemulsion growth processes are usually slow and laborious

• formation of new micelles [23]. Ding et al. linked these considerations to the theory of LaMer [36]. According to the LaMer theory, heterogeneous nucleation occurs when the supersaturation of the growth species is below the homogeneous nucleation threshold but above the heterogeneous nucleation threshold

• , while a higher supersaturation (above the homogeneous nucleation threshold) leads to simultaneous heterogeneous and homogeneous nucleation. In general, the processes leading to homogeneous and heterogeneous nucleation and growth in such reverse microemulsion systems are complex and depend on numerous

Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

• Nadra Bohli,
• Meryem Belkilani,
• Juan Casanova-Chafer,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2019, 10, 2364–2373, doi:10.3762/bjnano.10.227

• effect of nucleation. The power and time required for the plasma beam aperture within the cell were optimized and fixed to 30 W and 10 seconds, respectively. Functionalisation with self-assembled monolayers (SAMs) The Au-decorated MWCNT substrate was further functionalized with an alkanethiol self

Microfluidics as tool to prepare size-tunable PLGA nanoparticles with high curcumin encapsulation for efficient mucus penetration

• Nashrawan Lababidi,
• Valentin Sigal,
• Aljoscha Koenneke,
• Konrad Schwarzkopf,
• Andreas Manz and
• Marc Schneider

Beilstein J. Nanotechnol. 2019, 10, 2280–2293, doi:10.3762/bjnano.10.220

• total flow rate. Furthermore, the influence of the length of the focus mixing channel on the size was evaluated in order to better understand the nucleation–growth mechanism. Surprisingly, the channel length was revealed to have no effect on particle size for the chosen settings. In addition, curcumin

• channel, and stabilizer concentration. Furthermore, as our system allows us to cut different lengths of mixing channels, the impact of the length of the mixing channel on the nucleation–growth mechanism of the nanoprecipitation process was evaluated, which is an underestimated aspect of current

• colloidal system, thus minimizing NP agglomeration and nucleation growth [40]. Pluronic F68 was proven to be a muco-inert material [11][47] and was therefore chosen as a stabilizer. The addition of Pluronic F68 (1%) resulted in a slight decrease of the NP diameter to ≈70 nm at 0.05 flow rate ratio in

Nanostructured and oriented metal–organic framework films enabling extreme surface wetting properties

• Andre Mähringer,
• Julian M. Rotter and
• Dana D. Medina

Beilstein J. Nanotechnol. 2019, 10, 1994–2003, doi:10.3762/bjnano.10.196

• the VAC process, namely the surface roughness and the crystallite orientation on the substrate. Antifog coating with MOF films Water condensation on surfaces is a known phenomenon occurring at the dew point on substrates such as glass, which serves as a favorable nucleation site for water droplets

• surface is expected to form, hindering the nucleation of water droplets on the glass surface. For this purpose, we employed the newly developed methodology for the synthesis of nanostructured Ni-CAT-1 films on gold substrates with a slightly modified synthesis procedure in order to address larger

• examine the behavior of the antifog coating under extreme temperature differences, the MOF-modified glass substrates were cooled down to −20 °C and subsequently placed on top of the hot water reservoir. Under all examined conditions, clear vision through the glass was maintained and water vapor nucleation

Porous silver-coated pNIPAM-co-AAc hydrogel nanocapsules

• William W. Bryan,
• Riddhiman Medhi,
• Maria D. Marquez,
• Supparesk Rittikulsittichai,
• Michael Tran and
• T. Randall Lee

Beilstein J. Nanotechnol. 2019, 10, 1973–1982, doi:10.3762/bjnano.10.194

• silver nanocapsules with pNIPAM-co-AAc hydrogel cores. The Au nanoparticles act as nucleation sites (templating agents) for the growth of the Ag shells. Without these templating agents, the core–shell particles fail to form, leading to the exclusive formation of free metal particles and aggregated

• . However, the surface morphology of the porous nanoshells is rough (see Figure 4b). Possible reasons for the roughness include destabilizing intercalation of the salt precursor into the polymer matrix and insufficient nucleation sites, leading to lengthy time periods needed for nanocapsule growth. To

Oblique angle deposition of nickel thin films by high-power impulse magnetron sputtering

• Hamidreza Hajihoseini,
• Movaffaq Kateb,
• Snorri Þorgeir Ingvarsson and
• Jon Tomas Gudmundsson

Beilstein J. Nanotechnol. 2019, 10, 1914–1921, doi:10.3762/bjnano.10.186

• grow on existing columns or repeated nucleation occurs. As the peak discharge current density was increased further to JD,peak = 4 A/cm2 they observed that a film with a featureless morphology developed. Smaller grain sizes in HiPIMS-deposited films than in dcMS-deposited films have been previously

Fabrication and characterization of Si_1−xGe_x nanocrystals in as-grown and annealed structures: a comparative study

• Muhammad Taha Sultan,
• Adrian Valentin Maraloiu,
• Ionel Stavarache,
• Jón Tómas Gudmundsson,
• Andrei Manolescu,
• Valentin Serban Teodorescu,
• Magdalena Lidia Ciurea and
• Halldór Gudfinnur Svavarsson

Beilstein J. Nanotechnol. 2019, 10, 1873–1882, doi:10.3762/bjnano.10.182

• measurements, to explore structural changes and corresponding properties. It is observed that the employment of HiPIMS facilitates the formation of SiGe nanoparticles (2.1 ± 0.8 nm) in the as-grown structure, and that presence of such nanoparticles acts as a seed for heterogeneous nucleation, which upon

• crystals upon annealing. A similar phenomenon may have occurred in our structures, as depicted in Figure 4 and Figure 5. Thus, we can anticipate heterogeneous nucleation to be a dominant process during crystallization rather than conventional homogenous nucleation. This can be due to a better wetting of

• SiGe layer, which in turn reduces the nucleation barrier. It can also be argued that since heterogeneous nucleation occurs at preferential sites (as in our case), small NCs in as-grown MLs or even the crystallites that are under strain [39][40][41][42] will further reduce the surface energy and

Synthesis of nickel/gallium nanoalloys using a dual-source approach in 1-alkyl-3-methylimidazole ionic liquids

• Ilka Simon,
• Julius Hornung,
• Juri Barthel,
• Jörg Thomas,
• Maik Finze,
• Roland A. Fischer and
• Christoph Janiak

Beilstein J. Nanotechnol. 2019, 10, 1754–1767, doi:10.3762/bjnano.10.171

• reduce the Ga3+ precursor, working as a nucleation center for the Ga atoms and prevent uncontrolled coagulation of the liquid metal. Through annealing, the single-phase products can be obtained [27][42]. The all-hydrocarbon precursor GaCp* (Cp* = pentamethylcyclopentadienyl), with the Ga atom in the

Hierarchically structured 3D carbon nanotube electrodes for electrocatalytic applications

• Pei Wang,
• Katarzyna Kulp and
• Michael Bron

Beilstein J. Nanotechnol. 2019, 10, 1475–1487, doi:10.3762/bjnano.10.146

• method allows adjustment of nucleation and growth potential to control the distribution and size of the Fe nanoparticles. A nucleation potential of −1.41 V vs Ag|AgCl|KClsat. and a growth potential of −1.27 V vs Ag|AgCl|KClsat. were applied (compare also Figure S1, Supporting Information File 1). Figure

• . Additionally, the Fe nanoparticles seem to prefer to nucleate on cross junctions between primary CNTs, as observed from Figure S3a, which could be caused by improvement of electron transfer or preferential nucleation sites. The growth of secondary CNTs using the same optimized gas mixture as above and a gas

• transfer resistance with respect to the primary CNTs as determined by electrochemical impedance spectroscopy. Thus, we speculate that the improvement in Pt dispersion is due to a better conductivity within the 3D network and a facilitated electron transfer, which may facilitate Pt nucleation at the CNT