Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• D is then estimated by [43][51]: This analysis also predicts the power law governing the growth within the fractal space. Growth of fractals in unique geometrical patterns has been predominantly a subject of theoretical treatment. The diffusion-limited aggregation (DLA) model was proposed in 1981

• -equilibrium processes predict pattern formation by considering movement/diffusion of aggregates that ultimately results in the final fractal pattern [53][54]. In the DLA model, one seed particle is placed initially at a location called “origin” of a chosen lattice. Then, another particle is placed far from

• this origin location. The second particle diffuses via random walk, reaches a site close to the seed particle, and subsequently comes to a stop. In a similar way, other particles are added one by one and allowed to move randomly or guided by diffusion [54]. The added particles eventually reach their

Irradiation-driven molecular dynamics simulation of the FEBID process for Pt(PF₃)₄

• Alexey Prosvetov,
• Alexey V. Verkhovtsev,
• Gennady Sushko and
• Andrey V. Solov’yov

Beilstein J. Nanotechnol. 2021, 12, 1151–1172, doi:10.3762/bjnano.12.86

• fundamental mechanisms of electron-induced precursor fragmentation and the corresponding mechanisms of nanostructure formation and growth using FEBID. Until recently, most computer simulations of FEBID and nanostructure growth have been performed using a Monte Carlo approach and diffusion–reaction theory [2

• nanostructures. In contrast to the earlier studies [13][15] we consider the case of low precursor surface coverage (below one monolayer), in which surface diffusion plays an important role in the formation of deposits. In particular, we focus on the atomistic characterization of the initial stage of the FEBID

• induces the release of metal-free ligands and the growth of metal-enriched deposits. It involves a complex interplay of phenomena taking place on different temporal and spatial scales: (i) deposition, diffusion, and desorption of precursor molecules on the substrate; (ii) transport of the primary

An overview of microneedle applications, materials, and fabrication methods

• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• and skin electroporation [23]. In particular, microneedles facilitate transdermal delivery of water-soluble and high molecular weight drugs. Several microneedle designs enable drug delivery into the skin. Hollow or side-open microneedles allow pressure-driven or diffusion of drugs [24]. Solid

• potentially allow lower controlled volumes of therapeutic agents to be delivered compared to hollow microneedles, which are also more prone to becoming clogged by microscopic debris during insertion [38]. The rate of drug diffusion from the microneedle surface into the patient will depend on the

Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries

• Marina Tabuyo-Martínez,
• Bernd Wicklein and
• Pilar Aranda

Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75

• were synthesized inside carbon nanotubes by the melt diffusion method (Figure 7A) [54]. The resulting capacity of the Na–S battery after 2500 cycles at 1 A·g−1 was 80 mAh·g−1. Likewise, sulfur impregnation of hollow carbon nanocages rendered cathodes of 395 mAh·g−1 at 1 A·g−1 for 850 cycles [45

A Au/CuNiCoS₄/p-Si photodiode: electrical and morphological characterization

• Adem Koçyiğit,
• Adem Sarılmaz,
• Teoman Öztürk,
• Faruk Ozel and
• Murat Yıldırım

Beilstein J. Nanotechnol. 2021, 12, 984–994, doi:10.3762/bjnano.12.74

• carriers with high energy passing easily the barrier between metal and semiconductor. Also, more charge carriers are generated with increasing light power, and thus diffusion of the charges from the barrier occurs [27]. The junction resistance (Rj) is another diode parameter to evaluate the fabricated Au

Uniform arrays of gold nanoelectrodes with tuneable recess depth

• Elena O. Gordeeva,
• Ilya V. Roslyakov,
• Alexey P. Leontiev,
• Alexey A. Klimenko and
• Kirill S. Napolskii

Beilstein J. Nanotechnol. 2021, 12, 957–964, doi:10.3762/bjnano.12.72

• electrodes with a small radius (usually less than 50 nm), which is comparable or less than the thickness of the electric double layer [1][2]. The main advantages of such systems include high mass-transfer rates under steady-state diffusion, diminished electric double layer capacitance, and short response

• nanowires are electrically connected both to the bottom and the top continuous Cu layers (Figure 1c). According to [27], the decrease in electrodeposition overpotential, which is accompanied by the decrease in the diffusion current contribution, leads to an increase in the number of nanowires that reach the

• current density is associated with the charging of the electric double layer, a decrease in the concentration of electroactive species near the electrode surface, and an increase in the diffusion layer thickness. Stage II corresponds to the growth of Cu segments inside the AAO at near constant current

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• . Due to lowered diffusion barrier and adsorption energy, the two-dimensional molecular layers can be affected by dewetting and may change into three-dimensional clusters [47]. In return, the reduced molecule–surface interaction on insulating films or bulk insulators can stabilize highly reactive

• , or metals [83]. Rothe et al. [84] demonstrated that semimetallic graphene is an appropriate buffer layer for the physical and chemical decoupling of rubrene from Pt(111). The strong molecule–surface interaction on Pt(111) is expressed by hit-and-stick adsorption due to a substantial diffusion barrier

Self-assembly of Eucalyptus gunnii wax tubules and pure ß-diketone on HOPG and glass

• Miriam Anna Huth,
• Axel Huth and
• Kerstin Koch

Beilstein J. Nanotechnol. 2021, 12, 939–949, doi:10.3762/bjnano.12.70

• which the growth of a developing crystal is restricted by the diffusion of the molecules. Thus, new molecules are added mainly at one side of an already existing crystal, resulting in a crystal growth in one direction. In the present experiment, the kinetic regime could be applied after the evaporation

Effects of temperature and repeat layer spacing on mechanical properties of graphene/polycrystalline copper nanolaminated composites under shear loading

• Chia-Wei Huang,
• Man-Ping Chang and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2021, 12, 863–877, doi:10.3762/bjnano.12.65

• boundaries, which leads to the diffusion of atoms and the gliding of the dislocations, as shown in Figure 16a1–a4. Besides, the deformation mechanism also depends on the grain size. In the case of large grains (D = 9.43 nm), the propagation of dislocations and stacking faults mainly occurs inside the grains

Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications

• Sepand Tehrani Fateh,
• Lida Moradi,
• Elmira Kohan,
• Michael R. Hamblin and
• Amin Shiralizadeh Dezfuli

Beilstein J. Nanotechnol. 2021, 12, 808–862, doi:10.3762/bjnano.12.64

• intensifies the biophysical effects of the US waves [41]. This leads to transient permeabilization of cell membranes through the formation of transient pores and/or defects in the lipid bilayer, and finally, the diffusion of surrounding molecules into the cytosol [74]. Cavitation events triggered by MBs

• cytoplasm through simple diffusion. Moreover, these stresses can activate cellular stress signaling pathways [83]. Previous studies have concluded that two mechanisms could be involved in US-mediated drug delivery and cell uptake of impermeable molecules: sonoporation and increased endocytosis [84][85

• acid was administered, had levels of bioluminescence 11-fold higher than the colon tissue of mice that received mRNA alone. This was suggested to be caused by US-induced cavitation, creating transient pores in the plasma membrane which facilitated the cellular diffusion of macromolecules [87]. In

Silver nanoparticles nucleated in NaOH-treated halloysite: a potential antimicrobial material

• Yuri B. Matos,
• Rodrigo S. Romanus,
• Mattheus Torquato,
• Edgar H. de Souza,
• Rodrigo L. Villanova,
• Marlene Soares and
• Emilson R. Viana

Beilstein J. Nanotechnol. 2021, 12, 798–807, doi:10.3762/bjnano.12.63

• strongly inhibit the growth of common microorganisms and that they may be used as an alternative way to overcome bacterial resistance to antibiotics [10][11]. This is due to a combination of antimicrobial mechanisms including the generation of reactive oxygen species (ROS) and the diffusion of silver ions

Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• provides two functions. The first is as a power engine using triacetin as fuel and achieving particle diffusion through catalytic reaction with it. The second is an active cleaning function that can degrade triglyceride droplets by about 98% within 50 min. This shows great potential for biomedical

Recent progress in magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• the microrobot will impart magnetizability. Magnetic field-based transport enables the accelerated delivery of a biomaterial to a target site by overcoming Brownian diffusion [44]. Since cobalt and nickel are quite toxic and iron oxide nanoparticles are considered to be biofriendly [45], embedding

Physical constraints lead to parallel evolution of micro- and nanostructures of animal adhesive pads: a review

• Thies H. Büscher and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2021, 12, 725–743, doi:10.3762/bjnano.12.57

• have been recently evaluated based on a reaction–diffusion model considering a two-morphogen interaction. The self-formation of different patterns in nature can be explained by the reaction–diffusion model proposed by Alan Turing [227]. This model has been previously employed to model similar patterns

Prediction of Co and Ru nanocluster morphology on 2D MoS₂ from interaction energies

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2021, 12, 704–724, doi:10.3762/bjnano.12.56

• wide range of potential applications due to the properties of a single layer, which often differ from the bulk material. They are of particular interest as ultrathin diffusion barriers in semiconductor device interconnects and as supports for low-dimensional metal catalysts. Understanding the

Electromigration-induced formation of percolating adsorbate islands during condensation from the gaseous phase: a computational study

• Alina V. Dvornichenko,
• Vasyl O. Kharchenko and
• Dmitrii O. Kharchenko

Beilstein J. Nanotechnol. 2021, 12, 694–703, doi:10.3762/bjnano.12.55

• high temperatures is electromigration, which occurs when an electric current is applied to the substrate [1][2]. Electromigration (EM) is the movement of atoms caused by an electric current. It occurs due to the scattering of conduction electrons on atoms that move in a solid due to diffusion processes

• . The electron wind force, which arises during the transmission of the momentum by the conduction electrons, pushes the ions in the direction of the electron flow. As a result, the diffusion processes in the material become anisotropic and directed. This results in the exchange of atoms and the

• the most common approaches for mathematical modeling of these processes is based on the reaction–diffusion models [49][50][51][52][53][54][55][56][57][58][59][60][61]. This approach generally allows one to make certain recommendations for adjusting the technological conditions for growing thin films

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• nitrogen, the focused helium ion beam was used to create lattice vacancies at predefined locations (in a similar manner to the related electron beam-based methods). After annealing to allow for diffusion of the vacancies, the presence of nitrogen-vacancy centers was confirmed by photoluminescence

• mechanical response, with the typical swelling also observed [90]. In contrast, studies of both helium and neon ion-irradiated polymers have shown that swelling does not occur at the threshold doses observed for crystalline targets, attributed to the significantly higher diffusion coefficients of the noble

• of the wire [97] (Figure 4a). Given the low dose applied, sputtering alone could not account for the dimension reduction observed. In fact, thickening of the adjacent unexposed regions was noted, thus adding weight to the hypothesis that ion-induced mass transport by surface diffusion was primarily

Stability and activity of platinum nanoparticles in the oxygen electroreduction reaction: is size or uniformity of primary importance?

• Kirill O. Paperzh,
• Anastasia A. Alekseenko,
• Vadim A. Volochaev,
• Ilya V. Pankov,
• Olga A. Safronenko and
• Vladimir E. Guterman

Beilstein J. Nanotechnol. 2021, 12, 593–606, doi:10.3762/bjnano.12.49

• (less than 3 nm in size) [14][20], reprecipitation of platinum from small NPs into larger ones [14][21][22], agglomeration of NPs in the process of their surface diffusion [9][22], and NP shape change [4][23]. This can happen due to the oxidation of the carbon carrier, which causes the detachment of

Influence of electrospray deposition on C₆₀ molecular assemblies

• Antoine Hinaut,
• Sebastian Scherb,
• Sara Freund,
• Zhao Liu,
• Thilo Glatzel and
• Ernst Meyer

Beilstein J. Nanotechnol. 2021, 12, 552–558, doi:10.3762/bjnano.12.45

• terraces or along step edges. A zoom on such a cluster is shown in Figure 3d. The presence of these small clusters indicates a low diffusion of the C60 molecules, contrary to the TE deposition. At higher coverages, but still below one monolayer, C60 molecules form islands dispersed on the surface, as shown

• size increases with the terrace size. This observation is compatible with the diffusion of molecules on terraces but not over step edges, yielding a larger number of molecules and, therefore, larger islands on larger terraces. Finally, small protrusions are often observed close to defects possibly

• cleavage of the surface, visible by the large terrace, would enable C60 molecules to form large islands via diffusion, no islands are observed. Only small protrusions can be distinguished. The small size of these protrusions is compatible with small clusters or single molecules. The influence of the ESD is

Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

• Paulina Filipczak,
• Krzysztof Hałagan,
• Jacek Ulański and
• Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

• probability of a successful solvent displacement (reflecting the water diffusion) was defined by the Boltzmann distribution: where T is the temperature (set as 300 K), R is the universal gas constant, and E could take two values: Ew (=Σ3k=1 εww + εaw) close to the wall or Eb (=Σ4k=1 εww) far from the wall

• using the dynamic lattice liquid model. Detailed description of the DLL algorithm and its previous implementations for diffusion studies were presented elsewhere [47][49][50]. This model was chosen because it assumes movement cooperativity, which is crucial for water systems [4]. Moreover, simulations

Interface interaction of transition metal phthalocyanines with strontium titanate (100)

• Reimer Karstens,
• Thomas Chassé and
• Heiko Peisert

Beilstein J. Nanotechnol. 2021, 12, 485–496, doi:10.3762/bjnano.12.39

• ) surface. We assume that the final work function depends critically on the diffusion of Sr ions during the final annealing step and thus slightly different evaporation conditions or sample temperatures influence the surface composition distinctly. The different termination for samples with different work

Solution combustion synthesis of a nanometer-scale Co₃O₄ anode material for Li-ion batteries

• Monika Michalska,
• Huajun Xu,
• Qingmin Shan,
• Shiqiang Zhang,
• Yohan Dall'Agnese,
• Yu Gao,
• Amrita Jain and
• Marcin Krajewski

Beilstein J. Nanotechnol. 2021, 12, 424–431, doi:10.3762/bjnano.12.34

• Information File 1. These EIS features represent the charge transfer at the electrode–electrolyte interface (Rct) and the Warburg impedance (W), which is attributed to the diffusion of Li+ ions in the bulk electrode material [25][38]. The plots for the cycled cell are slightly different. They are composed of

• equals almost 90°. This corresponds to a capacitive behavior of the electrode material. After cycling, the slope angle changes to almost 45°, which is typically associated with a semi-infinite diffusion behavior [25]. Further analyses of the EIS results yield that the value of Rct has drastically

• reversibility and rate capability. This can be associated with the specific arrangement of particles that provides effective electrolyte-accessible channels for ion transportation and shortens the distance for Li+ ion diffusion and conversion reaction. Moreover, this particular structure inhibits a volume

The impact of molecular tumor profiling on the design strategies for targeting myeloid leukemia and EGFR/CD44-positive solid tumors

• Nikola Geskovski,
• Nadica Matevska-Geshkovska,
• Simona Dimchevska Sazdovska,
• Marija Glavas Dodov,
• Kristina Mladenovska and
• Katerina Goracinova

Beilstein J. Nanotechnol. 2021, 12, 375–401, doi:10.3762/bjnano.12.31

Spontaneous shape transition of Mn_xGe_1−x islands to long nanowires

• S. Javad Rezvani,
• Luc Favre,
• Gabriele Giuli,
• Yiming Wubulikasimu,
• Isabelle Berbezier,
• Augusto Marcelli,
• Luca Boarino and
• Nicola Pinto

Beilstein J. Nanotechnol. 2021, 12, 366–374, doi:10.3762/bjnano.12.30

• heteroepitaxial growth, it may be considered valid also for solid-phase epitaxy, which occurs in our system (Mn wetting layer on Ge), since the key role in the process is the mechanism of diffusion of adatoms (i.e., Mn) occurring also during the annealing process. According to this model, the optimal island shape

Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

• Petronela Prepelita,
• Florin Garoi and
• Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

• first 2 to 6 nanometers of the surface of a sample, including the contaminant layer. The chemical composition of oxide films, obtained by XPS, can be slightly different from that of the target due to surface diffusion phenomena and surface-specific chemical processes in contact with the atmosphere. The