Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• breakage is crucial, considering that PMMA solutions with higher weight percentage (wt %) are usually preferred as they form thicker supporting layers by spin coating: Such layers are mechanically more robust, yet leave behind significant residues [20]. Annealing processes (usually 200–450 °C, under an

• crystallite area (smaller error bars). Few-layer crystals transferred with B2 are analyzed in Supporting Information File 1, Figure S3. The graphene crystal in Supporting Information File 1, Figure S3a,b is composed of four layers having a thickness of 0.4–0.5 nm (Supporting Information File 1, Figure S3c

Hierarchical Bi₂WO₆/TiO₂-nanotube composites derived from natural cellulose for visible-light photocatalytic treatment of pollutants

• Zehao Lin,
• Zhan Yang and
• Jianguo Huang

Beilstein J. Nanotechnol. 2022, 13, 745–762, doi:10.3762/bjnano.13.66

• obtained from the Milli-Q Advantage A 10 system (Millipore, Bedford, MA, USA), displaying a resistivity of 18.2 MΩ·cm. Preparation of Bi2WO6/TiO2-NT nanocomposites The fabrication process of cellulose-derived Bi2WO6/TiO2-NT nanocomposites is exhibited in Figure 1. Ten layers of ultrathin titania film were

A nonenzymatic reduced graphene oxide-based nanosensor for parathion

• Sarani Sen,
• Anurag Roy,
• Ambarish Sanyal and
• Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2022, 13, 730–744, doi:10.3762/bjnano.13.65

• lattice), and 2700 cm−1 for the 2D band (related to numbers of layers in the graphene sheet). Table 1 shows the values of ID/IG at different electrolytic buffers during one-step electroreduction of GO at a constant potential of −0.9 V. The intensity of ID/IG predominantly increased for ERGO compared to

• the electrolytic buffer during electrochemical reduction of GO. The highest value of ID/IG was found to be 1.454 for the conversion of ERGO using PBS (pH 4.5), which suggests the formation of higher defects between the graphene layers during electrochemical reduction [26][34]. Thus, 50 mM PBS, pH 4.5

• platelets of graphene sheets with varying transparencies due to thickness variation [26][31]. Dark areas of the micrograph suggest thick stacking layers of GO and/or RGO with intercalated oxygen-containing functional groups. A few layers of graphene sheet in ERGO (in PBS, pH 4.5) have areas with higher

Experimental and theoretical study of field-dependent spin splitting at ferromagnetic insulator–superconductor interfaces

• Peter Machon,
• Michael J. Wolf,
• Detlef Beckmann and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2022, 13, 682–688, doi:10.3762/bjnano.13.60

• -consistent Δ. For very thin layers (ε’ = 100) the peaks (initially at Δ) symmetrically split into their spin components. This behavior is also is similar to the Zeeman splitting in an applied field, as already measured, for example, in [41]. However, with decreasing ε’, the superconductivity persists for

Reliable fabrication of transparent conducting films by cascade centrifugation and Langmuir–Blodgett deposition of electrochemically exfoliated graphene

• Teodora Vićentić,
• Stevan Andrić,
• Vladimir Rajić and
• Marko Spasenović

Beilstein J. Nanotechnol. 2022, 13, 666–674, doi:10.3762/bjnano.13.58

• the range of 1–10 layers, in a range of different liquids, at a wide range of concentrations [13][14]. The mechanism of ultrasonic exfoliation involves ultrasonic waves in liquid media creating bubbles or voids in the liquid, which generate shear forces or cavitation bubbles upon collapsing, which

• (DMEU), and ortho-dichlorobenzene (o-DCB) [12][17][18]. Exfoliation in NMP has led to minimally oxidized graphene sheets with approximately 28% monolayer flakes, and more than 75% of sheets with a thickness of less than six layers [12]. An alternative to LPE that has subsequently been developed is

• electrochemical exfoliation, whereby graphene is exfoliated in an electrolyte from an electrode made of graphite [19]. In electrochemical exfoliation, ions from the electrolyte flow towards the graphite electrode and intercalate between the graphene layers. The electrochemical reaction provides a driving force to

Fabrication and testing of polymer microneedles for transdermal drug delivery

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

Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55

• , hence improving overall insertion safety. For the MN insertion to be mechanically safe, the safety margin (SM), which is the ratio of failure force to insertion force, should be maximized and greater than unity (SM > 1) [22]. MNs must penetrate deep enough into the skin layers to enable an effective

• adjust settings such as slicing, shell and scaffolding, laser power, and scanning speeds before converting to General Writing Language (GWL) codes. Parameters such as slicing distance of 2 µm, multiple base slide counts of 4 layers, shell and scaffolding filling method, null shear angle (0°), and laser

• simulation model was performed using ANSYS (2020 R1, ANSYS, Canonsburg, Pennsylvania, USA) Explicit Dynamics. The skin was assumed to be comprised of three layers (1) stratum corneum, (2) dermis, and (3) hypodermis with 26 μm, 2 mm, and 1.1 mm thicknesses, respectively. An Ogden (first-order) model [32] was

Sodium doping in brookite TiO₂ enhances its photocatalytic activity

• Boxiang Zhuang,
• Honglong Shi,
• Honglei Zhang and
• Zeqian Zhang

Beilstein J. Nanotechnol. 2022, 13, 599–609, doi:10.3762/bjnano.13.52

• lattice-plane indices Two octahedron layers spacing ≈3.7433 Å share corners to construct the brookite structure, as depicted in the inset of Figure 5b. The core–shell structure, defects, and twins in the brookite Considering the differences in the ionic radius and the electronegativity between Na and Ti

Revealing local structural properties of an atomically thin MoSe₂ surface using optical microscopy

• Lin Pan,
• Peng Miao,
• Anke Horneber,
• Alfred J. Meixner,
• Pierre-Michel Adam and
• Dai Zhang

Beilstein J. Nanotechnol. 2022, 13, 572–581, doi:10.3762/bjnano.13.49

• triangular flakes on top of the underlying large flake, which appear dark in the SHG image in Figure 1d. The decreased SHG intensity at increasing layer thickness indicates a mirrored orientation of neighboring layers in the MoSe2 flake, which is typical for hexagonal 2H-phase MoSe2 [28][29]. Figure 1e shows

Influence of thickness and morphology of MoS₂ on the performance of counter electrodes in dye-sensitized solar cells

• Lam Thuy Thi Mai,
• Hai Viet Le,
• Ngan Kim Thi Nguyen,
• Van La Tran Pham,
• Thu Anh Thi Nguyen,
• Nguyen Thanh Le Huynh and
• Hoang Thai Nguyen

Beilstein J. Nanotechnol. 2022, 13, 528–537, doi:10.3762/bjnano.13.44

• photoanodes, the cleaned FTO electrodes were first pretreated by immersion in a 40 mM TiCl4 solution at 70 °C for 30 min and rinsed with distilled water and ethanol. The treated FTO electrodes were then successively coated with a transparent 18NR-T titania paste (three layers) and an active opaque 18NR-AO

Ciprofloxacin-loaded dissolving polymeric microneedles as a potential therapeutic for the treatment of S. aureus skin infections

• Sharif Abdelghany,
• Walhan Alshaer,
• Yazan Al Thaher,
• Maram Al Fawares,
• Amal G. Al-Bakri,
• Saja Zuriekat and
• Randa SH. Mansour

Beilstein J. Nanotechnol. 2022, 13, 517–527, doi:10.3762/bjnano.13.43

• CIP_MN1 was investigated in ex vivo excised human skin. CIP_MN1 showed significantly more deposition of ciprofloxacin in deeper skin layers compared to the free gel of ciprofloxacin, and the released ciprofloxacin from the microneedles tends to migrate to deeper layers with time. Collectively, these

• sizes have been utilized to overcome this limitation since they can painlessly penetrate the upper skin layers [2]. Patients can self-administer microneedles and, thus, overcome the pain associated with conventional parenteral injections. Moreover, this drug delivery system can potentially overcome the

• techniques. These microneedles are manufactured of polymers incorporated with medicaments and are intended to dissolve completely in the skin, permitting the medicament to be distributed in deeper skin layers to treat local and systemic infections [5]. Previous studies have shown the advantages of dissolving

Design and characterization of polymeric microneedles containing extracts of Brazilian green propolis

• Camila Felix Vecchi,
• Rafaela Said dos Santos,
• Jéssica Bassi da Silva and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2022, 13, 503–516, doi:10.3762/bjnano.13.42

• Abstract Microneedles (MNs) are a means to break the protective skin barrier in a minimally invasive way. By creating temporary micropores, they make biologically active agents available in the skin layers. Propolis (PRP) is a gum resin with a complex chemical composition, produced by bees Apis mellifera L

• holes created and will be taken, by diffusion, to the innermost layers to have its systemic action [5][12]. Coated microneedles are solid MNs made of inert material and coated with a formulation containing the drug to be administered [5][13]. After skin perforation, this lining is retained in the

Ethosomal (−)-epigallocatechin-3-gallate as a novel approach to enhance antioxidant, anti-collagenase and anti-elastase effects

• Çiğdem Yücel,
• Gökçe Şeker Karatoprak,
• Sena Yalçıntaş and
• Tuğba Eren Böncü

Beilstein J. Nanotechnol. 2022, 13, 491–502, doi:10.3762/bjnano.13.41

• many drugs. The stratum corneum in the epidermis, which is the top layer of the skin consisting of three layers, acts as an important barrier against penetration into the skin [9][16]. To overcome penetration limitations, various techniques such as penetration enhancers, phonophoresis, electroporation

• high amounts of ethanol that can carry both hydrophilic and lipophilic drug molecules. They are also highly deformable and reach deep skin layers [18][19]. ETHs are similar to the lipid bilayer composition of cells in the epidermis, due to the presence of phospholipids in their structure, and thus

• synergistic effect of phospholipids and ethanol enables the ETHs and drug molecules to reach the deeper layers of the skin [19][22][23]. The skin penetration mechanism of drug-loaded ETHs is explained by both the ETH effect and the ethanol effect. While ethanol increases drug penetration by increasing the

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

Investigation of electron-induced cross-linking of self-assembled monolayers by scanning tunneling microscopy

• Patrick Stohmann,
• Sascha Koch,
• Yang Yang,
• Christopher David Kaiser,
• Julian Ehrens,
• Jürgen Schnack,
• Niklas Biere,
• Dario Anselmetti,
• Armin Gölzhäuser and
• Xianghui Zhang

Beilstein J. Nanotechnol. 2022, 13, 462–471, doi:10.3762/bjnano.13.39

• collision, rotational or vibrational transitions, electron attachment, electronic excitation, and ionization [4][5]. Oriented molecular layers on surfaces are particularly well suited for such studies as surface analytical tools, such as scanning tunneling microscopy (STM), allow for detailed observations

Tubular glassy carbon microneedles with fullerene-like tips for biomedical applications

• Sharali Malik and
• George E. Kostakis

Beilstein J. Nanotechnol. 2022, 13, 455–461, doi:10.3762/bjnano.13.38

• interlayer spacing in glassy carbon corresponds to the nature of the intercalating species [26]. Here the “stress” arises from the constraints of the growing glassy carbon layers from the curved alumina gas-flow tube and the intercalating species, which are gaseous species, generated when methane undergoes

Tunable superconducting neurons for networks based on radial basis functions

• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Sergey V. Bakurskiy,
• Igor I. Soloviev,
• Mikhail Yu. Kupriyanov,
• Maxim V. Tereshonok and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2022, 13, 444–454, doi:10.3762/bjnano.13.37

• , ferromagnetic, and normal layers. Keywords: networks on radial basis functions; Josephson circuits; radial basis functions (RBFs); spintronics; superconducting electronics; superconducting neural network; Introduction For modern telecommunications, probabilistic identification of various sources in a

• the chip. In thin layers of superconductors used to create parts of a neuron, the kinetic inductance is relatively large compared to the geometric one [52]. This is important for us since one can change the kinetic inductance relatively simply by controlling the concentration of superconducting charge

• proximity effect. The typical spin valve [55][56][57] is a hybrid structure containing at least a pair of ferromagnetic (FM) layers with different coercive forces. Variations in the relative orientation of their magnetizations change the spatial distribution of the superconducting order parameter. In the

The role of sulfonate groups and hydrogen bonding in the proton conductivity of two coordination networks

• Ali Javed,
• Felix Steinke,
• Stephan Wöhlbrandt,
• Hana Bunzen,
• Norbert Stock and
• Michael Tiemann

Beilstein J. Nanotechnol. 2022, 13, 437–443, doi:10.3762/bjnano.13.36

• ions, resulting in the formation of layers. This way, each phosphonate group is coordinating with two oxygen atoms, while the third one is protonated. The –C6H4-SO3 group points into the interlayer space. A network of hydrogen bonds between the sulfonate residues and coordinated water molecules as well

• as crystal water interconnect the layers into a three-dimensional network consisting of interlocked layers. In contrast, in the structure of [Pb2(HL)]·H2O, each sulfonate group is coordinating to several Pb2+ ions. A 2D inorganic building unit is observed and the coordination of the sulfonate groups

• maximum in the region from 103 to 104 Hz remains. The phase angle for the Pb-MOF sample shows only one maximum (at ca. 102 Hz) both before and after activation. We conclude that the second conductance mode in the non-activated Mg-CP material may be caused by interparticle water adsorbate layers that are

A chemiresistive sensor array based on polyaniline nanocomposites and machine learning classification

• Jiri Kroutil,
• Alexandr Laposa,
• Ali Ahmad,
• Jan Voves,
• Vojtech Povolny,
• Ladislav Klimsa,
• Marina Davydova and
• Miroslav Husak

Beilstein J. Nanotechnol. 2022, 13, 411–423, doi:10.3762/bjnano.13.34

• composed by seven different conductive sensors with composite sensing layers are measured and analyzed using machine learning. Statistical tools, such as principal component analysis and linear discriminant analysis, are used as dimensionality reduction methods. Five different classification methods

• (carbon nanotubes (CNT), SnO2, TiO2) materials in a gas sensors based on nanocomposite layers with good sensitivity, temperature stability, reversibility, which was operating at room temperature. Herein, we extended our study by applying other nanocomposite sensing layers, namely PANI/ZnO, PANI/WO3

• (nanopowder), PANI/WO3 (nanotubes), PANI/In2O3, PANI/C60 (fullerene), PANI/nanocrystalline diamond (NCD), and PANI/BaTiO3, deposited on a flexible sensor array platform with a new design. Seven different nanocomposite sensing layers deposited on the array were exposed to six different gases (ammonia, carbon

Electrostatic pull-in application in flexible devices: A review

• Teng Cai,
• Yuming Fang,
• Yingli Fang,
• Ruozhou Li,
• Ying Yu and
• Mingyang Huang

Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32

• common electrode materials are GR-Au and GR-GR. By adjusting the size of the graphene sheets, the number of layers and the gap, different pull-in voltages can be obtained. GR-Au: A typical GR-Au structure is shown in Figure 3a. As the structure requires a sacrificial layer to keep GR suspended and avoid

• , the gap was 170 nm, and the pull-in voltage was about 2 V. In 2016, Sun et al. [6] prepared a graphene cantilever switch with a thickness of about 10 layers, as shown in Figure 3a. The graphene sheet has an area of 1 µm × 2 µm, a gap of 1401 nm, and a critical voltage of 3.8 V. In addition, Liu et al

• , Huynh Van et al. [5] prepared a three-terminal fully flexible graphene switch for the first time, as shown in Figure 4. The switch is made of fully flexible materials. The three electrodes are all made of 1–2 layers of graphene, and the insulating medium layer is made of h-BN. The pull-in voltage at

Micro- and nanotechnology in biomedical engineering for cartilage tissue regeneration in osteoarthritis

• Zahra Nabizadeh,
• Mahmoud Nasrollahzadeh,
• Hamed Daemi,
• Mohamadreza Baghaban Eslaminejad,
• Ali Akbar Shabani,
• Mehdi Dadashpour,
• Majid Mirmohammadkhani and
• Davood Nasrabadi

Beilstein J. Nanotechnol. 2022, 13, 363–389, doi:10.3762/bjnano.13.31

• supports deeper layers from shear stresses [5]. The middle or transitional zone constitutes the thickest portion of articular cartilage (40–60%) and has fewer chondrocytes with a more rounded morphology [6]. In this layer, the collagen fibrils are arranged randomly and obliquely and the cells synthesize

• and vertical to the articular surface. Meanwhile, this zone provides the greatest resistance to compressive forces [6]. The calcified cartilage zone, which is presumed to be an interface layer between the upper cartilage layers and the rigid subchondral bone, contains chondrocytes, which usually

• inexpensive and abundant inorganic compound, which can be obtained from mines. Aluminosilicate layers can be rolled into a hollow cylinder structure to form tube structures less than 100 nm in diameter. Halloysite is a biocompatible nanomaterial, which does not need to be functionalized and can be a potent

Alcohol-perturbed self-assembly of the tobacco mosaic virus coat protein

• Ismael Abu-Baker and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2022, 13, 355–362, doi:10.3762/bjnano.13.30

• between in TEM. The bilayer disk has been reported in two different polymorphs: a polar disk with both layers in the same orientation or a bipolar disk with the two layers related by C2 symmetry [18][19][20]. Under basic conditions and at high ionic strength, a four-layer disk aggregate is observed [21

• presence of different alcohol additives. (A) 5.0 mol % methanol; (B) 10.0 mol % methanol; (C) 3.5 mol % isopropyl alcohol. Orange arrows indicate long rod species. PyMOL [47] schematic showing (A) one face of the disk and (B) the side view of two layers of the disk. Hydrophobic residues are coloured in red

Selected properties of Al_xZn_yO thin films prepared by reactive pulsed magnetron sputtering using a two-element Zn/Al target

• Witold Posadowski,
• Artur Wiatrowski,
• Jarosław Domaradzki and
• Michał Mazur

Beilstein J. Nanotechnol. 2022, 13, 344–354, doi:10.3762/bjnano.13.29

• an order of magnitude greater than the minimum resistance of the layers deposited at the front of the substrate. In our opinion, film deposition on the back substrate surface was possible because the sputtered particles reached the back substrate side from collisions. They condensed on the substrate

Controllable two- and three-state magnetization switching in single-layer epitaxial Pd_1−xFe_x films and an epitaxial Pd_0.92Fe_0.08/Ag/Pd_0.96Fe_0.04 heterostructure

• Igor V. Yanilkin,
• Amir I. Gumarov,
• Gulnaz F. Gizzatullina,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2022, 13, 334–343, doi:10.3762/bjnano.13.28

• the film. In a wide range of the appled field directions, the magnetization reversal proceeds in two steps via the intermediate easy axis. An epitaxial heterostructure of two magnetically separated ferromagnetic layers, Pd0.92Fe0.08/Ag/Pd0.96Fe0.04, was synthesized and studied with dc magnetometry

• . Its magnetic configuration diagram has been constructed and the conditions have been determined for a controllable switching between stable parallel, orthogonal, and antiparallel arrangements of magnetic moments of the layers. Keywords: anisotropic magnetoresistance; magnetization reversal; Pd–Fe

• ], stable parallel and antiparallel configurations of magnetic moments were obtained. However, the maximum amplitude of the triplet pairing component in the PdFe1/N/PdFe2 bilayer structure is achieved near the orthogonal magnetic configuration of the ferromagnetic layers PdFe1 and PdFe2 [6]. Therefore, it

Interfacial nanoarchitectonics for ZIF-8 membranes with enhanced gas separation

• Season S. Chen,
• Zhen-Jie Yang,
• Chia-Hao Chang,
• Hoong-Uei Koh,
• Sameerah I. Al-Saeedi,
• Kuo-Lun Tung and
• Kevin C.-W. Wu

Beilstein J. Nanotechnol. 2022, 13, 313–324, doi:10.3762/bjnano.13.26

• ., strong acids or bases or organic solvents) compared to polymer substrates. The particle size of α-Al2O3 on dense top layers of these disks is around 200 nm (information from Fraunhofer IKTS, Germany). The porosity of the disks was measured as 41.58% by mercury porosimeter measurements. The XRD patterns

Investigation of a memory effect in a Au/(Ti–Cu)Ox-gradient thin film/TiAlV structure

• Damian Wojcieszak,
• Jarosław Domaradzki,
• Michał Mazur,
• Tomasz Kotwica and
• Danuta Kaczmarek

Beilstein J. Nanotechnol. 2022, 13, 265–273, doi:10.3762/bjnano.13.21

• a much wider (several hundred nanometers) semiconducting (e.g., doped or nonstoichiometric oxide) layer. Materials used either for insulating or semiconducting layers include HfO2 [3][15][16][17][18], ZnO [19][20], CuO [21][22][23][24][25][26][27], ZrO2 [12], Ta2O5 [28][29], and NiO [3][30][31][32

• ]. The most commonly used material in resistive switching devices is TiO2−x [33][34][35][36][37][38]. In addition to the oxide layers, the material used for metal electrodes plays another crucial role in the resistive switching mechanism. Usually, materials such as Au, Ag, Ni, Ti, W, TiN, or ITO are used

• . Therefore, to increase the sputtering flux of titanium species, two Ti and one Cu targets were sputtered in the so-called simultaneous mode. The magnetrons were arranged in a confocal configuration. To obtain a gradient distribution of elements as a function of the thickness of the deposited layers