Field-controlled ultrafast magnetization dynamics in two-dimensional nanoscale ferromagnetic antidot arrays

• Anulekha De,
• Sucheta Mondal,
• Sourav Sahoo,
• Saswati Barman,
• Yoshichika Otani,
• Rajib Kumar Mitra and
• Anjan Barman

Beilstein J. Nanotechnol. 2018, 9, 1123–1134, doi:10.3762/bjnano.9.104

• irradiation of laser light. A PMMA/MMA bilayer resist was used for electron-beam lithography to prepare the resist pattern on the Py thin film followed by argon ion milling at a base pressure of 1 × 10−4 Torr with a beam current of 60 mA for 6 min for etching out the Py film from everywhere except the

P3HT:PCBM blend films phase diagram on the base of variable-temperature spectroscopic ellipsometry

• Barbara Hajduk,
• Henryk Bednarski,
• Bożena Jarząbek,
• Henryk Janeczek and
• Paweł Nitschke

Beilstein J. Nanotechnol. 2018, 9, 1108–1115, doi:10.3762/bjnano.9.102

• coefficient, which can be detected as change in the slope of d(T) plots [26]. Variable-temperature spectroscopic ellipsometry has been applied to study thin films of polymers such as polystyrene (PS) [27][28][29][30][31], poly(α-methylstyrene) [32], poly(methyl methacrylate) (PMMA) [33][34] and polyester [35

The effect of atmospheric doping on pressure-dependent Raman scattering in supported graphene

• Egor A. Kolesov,
• Mikhail S. Tivanov,
• Olga V. Korolik,
• Olesya O. Kapitanova,
• Xiao Fu,
• Hak Dong Cho,
• Tae Won Kang and
• Gennady N Panin

Beilstein J. Nanotechnol. 2018, 9, 704–710, doi:10.3762/bjnano.9.65

• elsewhere [29]. The grown graphene was transferred to various substrates using a “PMMA-mediated” method [30]. PMMA (molecular weight = 996 000, dissolved in anisole) was spin-coated (3000 rpm, 1 min) on graphene supported by Cu foil. A 0.1 M (NH4)2S2O8 aqueous solution was used to etch Cu and a water

• /isopropyl alcohol mixture was used to wash graphene from etching products [31]. PMMA was removed by submerging the sample in glacial acetic acid (extra pure) [32] for 4 h. Graphene, doped with nitrogen, was prepared using a nitrogen-plasma treatment described elsewhere [33]. The Raman spectra were obtained

Al₂O₃/TiO₂ inverse opals from electrosprayed self-assembled templates

• Arnau Coll,
• Sandra Bermejo,
• David Hernández and
• Luís Castañer

Beilstein J. Nanotechnol. 2018, 9, 216–223, doi:10.3762/bjnano.9.23

• of recent literature shows that opals made of polystyrene or poly(methyl methacrylate) (PMMA) [15][16][17][18][19][20][21][22][23][24] nanoparticles can be orderly assembled in larger areas and thicknesses, however, such materials do not achieve the same optical performance as inverse opals, due to

Review on optofluidic microreactors for artificial photosynthesis

• Xiaowen Huang,
• Jianchun Wang,
• Tenghao Li,
• Jianmei Wang,
• Min Xu,
• Weixing Yu,
• Abdel El Abed and
• Xuming Zhang

Beilstein J. Nanotechnol. 2018, 9, 30–41, doi:10.3762/bjnano.9.5

• membrane-based reactors were reported as well, for instance, mesoporous CdS/TiO2/SBA-15@carbon paper composite membranes [77] and copper-decorated TiO2 nanorod thin films [78]. In addition to the PDMS/PMMA-based microchannel reactors, bacterium has been shown to be a good microreactor as well. Yang et al

Inelastic electron tunneling spectroscopy of difurylethene-based photochromic single-molecule junctions

• Youngsang Kim,
• Safa G. Bahoosh,
• Dmytro Sysoiev,
• Thomas Huhn,
• Fabian Pauly and
• Elke Scheer

Beilstein J. Nanotechnol. 2017, 8, 2606–2614, doi:10.3762/bjnano.8.261

• lithography is performed with a double layer of electron beam resists (copolymer/PMMA). After developing the resists, Au of around 70 nm in thickness is deposited, the electron-beam mask is lifted off in warm acetone, and then the polyimide layer is partially etched away (thickness reduction of ca. 700 nm) by

Amplified cross-linking efficiency of self-assembled monolayers through targeted dissociative electron attachment for the production of carbon nanomembranes

• Sascha Koch,
• Christopher D. Kaiser,
• Paul Penner,
• Michael Barclay,
• Lena Frommeyer,
• Daniel Emmrich,
• Patrick Stohmann,
• Tarek Abu-Husein,
• Andreas Terfort,
• D. Howard Fairbrother,
• Oddur Ingólfsson and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2017, 8, 2562–2571, doi:10.3762/bjnano.8.256

• by the PMMA cleaning process within the critical point dryer. Figure 4b and its inset (green box) clearly reveal the formation of a freestanding membrane. This confirms the observation of a mechanically stable and easily transferable CNM from 2-I-BPT after 3 min of irradiation, documenting that a

• CNM from the gold, PMMA was used as a coating for the nanomembrane. With the help of aqueous iodine, the PMMA–CNM stack was detached from the gold substrate. Subsequently, the PMMA was dissolved by acetone within a critical-point dryer. Negative halogen ion yield curves for dissociative electron

Increasing the stability of DNA nanostructure templates by atomic layer deposition of Al₂O₃ and its application in imprinting lithography

• Hyojeong Kim,
• Kristin Arbutina,
• Anqin Xu and
• Haitao Liu

Beilstein J. Nanotechnol. 2017, 8, 2363–2375, doi:10.3762/bjnano.8.236

• ]. A wide range of DNA nanostructures, including DNA nanotubes, 1D λ-DNA, 2D DNA brick crystals with 3D features, hexagonal DNA 2D arrays, and DNA origami triangles, were tested for the pattern replication process to poly(methyl methacrylate) (PMMA), poly(L-lactic acid) (PLLA), and photo-cross-linked

• acryloxy perfluoropolyether (a-PFPE). The resulting negative imprints of the DNA nanostructures on the PMMA and PLLA polymer stamps further served as molds to transfer the patterns to positive imprints on a-PFPE films. In our method, the separation of the polymer film from the DNA nanostructure master

• . Our approach has one substantial technical problem, however, which is that the DNA nanostructure master templates cannot be used in a repetitive manner. The DNA nanostructures were partially damaged during the release of the PMMA and PLLA hydrophobic stamps from the hydrophilic master template. It

Fabrication of gold-coated PDMS surfaces with arrayed triangular micro/nanopyramids for use as SERS substrates

• Jingran Zhang,
• Yongda Yan,
• Peng Miao and
• Jianxiong Cai

Beilstein J. Nanotechnol. 2017, 8, 2271–2282, doi:10.3762/bjnano.8.227

• nanoparticles on a poly(methyl methacrylate) (PMMA) template, and malachite green on fish skin [27] was successfully detected. A flexible and transparent substrate consisting of silver nanoparticles on polyethylene terephthalate (PET) sheets was fabricated for in situ detection of R6G and thiram residues with a

A systematic study of the controlled generation of crystalline iron oxide nanoparticles on graphene using a chemical etching process

• Peter Krauß,
• Jörg Engstler and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2017, 8, 2017–2025, doi:10.3762/bjnano.8.202

• additional polymer coating is often deposited on the monolayer prior to the etching process to provide mechanical support for the graphene, preventing it from tearing and ripping [14][22][23][24][29][30][31]. Most common are thin layers of poly(methyl methacrylate) (PMMA) which can be easily deposited by

Identifying the nature of surface chemical modification for directed self-assembly of block copolymers

• Laura Evangelio,
• Federico Gramazio,
• Matteo Lorenzoni,
• Michaela Gorgoi,
• Francisco Miguel Espinosa,
• Ricardo García,
• Francesc Pérez-Murano and
• Jordi Fraxedas

Beilstein J. Nanotechnol. 2017, 8, 1972–1981, doi:10.3762/bjnano.8.198

• silicon wafer, left in the Figure) and the block copolymer domains. The first DSA (two steps) process uses electron beam lithography (EBL) [12] on a poly(methyl methacrylate) (PMMA) resist with a subsequent substrate functionalization with oxygen plasma of the uncovered areas (top of Figure 1). The two

• the brush surface while applying a voltage under high humidity conditions. Details on the preparation methods can be found in the Experimental section. Results and Discussion Two-step electron beam and oxygen plasma modification Figure 2 shows SEM images of directed self-assembled films of PS-b-PMMA

• the same scale of the distribution of the generated patterns is shown in the right of the figure as a guide. Before imaging, the PMMA blocks were removed by exposing the sample to 50 sccm of oxygen flow at 500 W for 18 s in order to visualize the efficiency of the DSA process. From the figure, it

Fabrication of carbon nanospheres by the pyrolysis of polyacrylonitrile–poly(methyl methacrylate) core–shell composite nanoparticles

• Dafu Wei,
• Youwei Zhang and
• Jinping Fu

Beilstein J. Nanotechnol. 2017, 8, 1897–1908, doi:10.3762/bjnano.8.190

• , College of Materials Science and Engineering, Donghua University, Shanghai 201620, China 10.3762/bjnano.8.190 Abstract Carbon nanospheres with a high Brunauer–Emmett–Teller (BET) specific surface area were fabricated via the pyrolysis of polyacrylonitrile–poly(methyl methacrylate) (PAN–PMMA) core–shell

• nanoparticles. Firstly, PAN–PMMA nanoparticles at high concentration and low surfactant content were controllably synthesized by a two-stage azobisisobutyronitrile (AIBN)-initiated semicontinuous emulsion polymerization. The carbon nanospheres were obtained after the PAN core domain was converted into carbon

• and the PMMA shell was sacrificed via the subsequent heat treatment steps. The thickness of the PMMA shell can be easily adjusted by changing the feeding volume ratio (FVR) of methyl methacrylate (MMA) to acrylonitrile (AN). At an FVR of 1.6, the coarse PAN cores were completely buried in the PMMA

Parylene C as a versatile dielectric material for organic field-effect transistors

• Tomasz Marszalek,
• Maciej Gazicki-Lipman and
• Jacek Ulanski

Beilstein J. Nanotechnol. 2017, 8, 1532–1545, doi:10.3762/bjnano.8.155

• polymer insulators bear much higher application potential in organic transistor technology. There are only few commercial dielectric polymer materials that meet the requirements: poly(methylmethacrylate) (PMMA) [42], polyvinylphenol (PVP) [43], amorphous fluoropolymer (CYTOP®) [44] and poly-p-xylylene

• energy exhibited a mobility of μ = 0.006 cm2/V·s. More detailed studies were carried out for tetracene semiconductor films deposited on various dielectric materials, namely organic polystyrene (PS), Parylene C, and poly(methyl methacrylate) (PMMA) as well as on inorganic SiO2, with and without HMDS

• modification [50]. AFM measurements of tetracene semiconductor films show that the regularly shaped islands on the polymer dielectrics (PS, Parylene C, PMMA) lead to a complete substrate coverage at low nominal thickness, between 10 and 17 nm (Figure 8). Interconnected islands were formed at thicknesses of 10

Micro- and nano-surface structures based on vapor-deposited polymers

• Hsien-Yeh Chen

Beilstein J. Nanotechnol. 2017, 8, 1366–1374, doi:10.3762/bjnano.8.138

• ) surface and a poly(4-ethynyl-p-xylylene-co-p-xylylene) surface, respectively. Various substrates were successfully verified for the coating and patterning modifications: metal (silver, titanium, stainless steel), polystyrene (PS), poly(methyl methacrylate) (PMMA), silicon, glass, poly(dimethylsiloxane

The integration of graphene into microelectronic devices

• Guenther Ruhl,
• Sebastian Wittmann,
• Matthias Koenig and
• Daniel Neumaier

Beilstein J. Nanotechnol. 2017, 8, 1056–1064, doi:10.3762/bjnano.8.107

• the ex situ transfer by reinforcing the graphene layer with a polymer film, e.g., poly(methyl methacrylate) (PMMA), and etching off the Cu growth substrate. There are several options for subsequent graphene deposition onto the final substrates discussed in [19] (Figure 1). Focusing on wafer-level

• incompletely removed supporting polymer layers such as PMMA. Though, these residues usually can be removed by an appropriate vacuum annealling [42]. 3 Substrate interactions Because graphene consists only of surface, every interaction with its environment changes its properties. Hence, also the dielectric

Bio-inspired micro-to-nanoporous polymers with tunable stiffness

• Julia Syurik,
• Ruth Schwaiger,
• Prerna Sudera,
• Stephan Weyand,
• Siegbert Johnsen,
• Gabriele Wiegand and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2017, 8, 906–914, doi:10.3762/bjnano.8.92

• demonstrate that a foam of a stiff polymer such as poly(methyl methacrylate) (PMMA) can exhibit a gradually changing effective elastic modulus when the local morphology of the sample undergoes a transition from microcellular to nanocellular. Porous PMMA films with a controlled gradient of the pore size were

• fabricated and investigated by dynamic flat-punch nanoindentation in order to obtain insight into the influence of the graded pore structure on the local viscoelastic properties. Experimental Materials and foaming process Porous poly(methyl methacrylate) (PMMA) films were produced from PMMA (Topacryl AG

• , Switzerland) sheets of 500 μm thickness, with a glass-transition temperature (Tg) of 105 °C (measured by thermogravimetric analysis (TGA) for the PMMA sheets) and a bulk elastic modulus of 3300 MPa. The as-purchased PMMA films were cut to 20 mm × 20 mm chips and clamped between two flat metal plates with four

First examples of organosilica-based ionogels: synthesis and electrochemical behavior

• Andreas Taubert,
• Ruben Löbbicke,
• Barbara Kirchner and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2017, 8, 736–751, doi:10.3762/bjnano.8.77

• where the IL confinement leads to an intermediate state between liquid and solid (conductivity vs mechanical strength, respectively), since σ298 K = 3.15 × 10−3 S·cm−1 and σ343 K = 1.12 × 10−2 S·cm−1 for one of the best polymer nanocomposite ionogel composed of modified PMMA bearing trimethoxysilane

Ion beam profiling from the interaction with a freestanding 2D layer

• Ivan Shorubalko,
• Kyoungjun Choi,
• Michael Stiefel and
• Hyung Gyu Park

Beilstein J. Nanotechnol. 2017, 8, 682–687, doi:10.3762/bjnano.8.73

• vapor deposition (CVD) according to a previously developed method [19]. This method is optimized for maximal grain connectivity resulting in uniform graphene films. Then, graphene was transferred to silicon/silicon-nitride frames with openings of a few micrometers in diameter. A PMMA-based graphene

Graphene functionalised by laser-ablated V₂O₅ for a highly sensitive NH₃ sensor

• Margus Kodu,
• Artjom Berholts,
• Tauno Kahro,
• Mati Kook,
• Peeter Ritslaid,
• Helina Seemen,
• Tea Avarmaa,
• Harry Alles and
• Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

• allowed to cool slowly, 15 °C/min in Ar flow. The as-grown graphene film was transferred onto a Si/SiO2 substrate by using poly(methyl methacrylate) (PMMA; MW ≈997,000 Da, GPC, Alfa Aesar) as a supporting material. The PMMA solution (1% in chlorobenzene) was spin-coated onto graphene/Cu, dried, and the Cu

• foil was dissolved in ammonium persulfate solution overnight. The floating PMMA/graphene film was rinsed with deionized water and transferred onto the Si/SiO2 substrate (see Figure 6) equipped with Pt electrodes (60 nm thick) that were deposited through a shadow mask by magnetron sputtering. The gap

• between the electrodes was 1 × 4 mm. The sample was dried in air and then heated on a hot plate to allow the PMMA film to soften, which improved the contact between graphene and the substrate. Then the PMMA layer was removed by dissolving in dichloromethane (Alfa Aesar). In the PLD process, a ceramic V2O5

Advances in the fabrication of graphene transistors on flexible substrates

• Gabriele Fisichella,
• Stella Lo Verso,
• Silvestra Di Marco,
• Vincenzo Vinciguerra,
• Emanuela Schilirò,
• Salvatore Di Franco,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Amaia Zurutuza,
• Alba Centeno,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2017, 8, 467–474, doi:10.3762/bjnano.8.50

• large area (100 mm diameter) of the target substrate by a PMMA-assisted wet transfer procedure and patterned by soft O2 plasma etching. Figure 4a shows the tAFM morphology of graphene. The typical, wrinkled morphology of CVD-synthesized graphene [13] is less evident on PEN substrates compared with

• = −0.4 eV). This positive shift is a clear indication of graphene p-type doping, as estimated by p = Cg(VNP − VNP,id)/q ≈ 1.2 × 1013 cm−2 [20], where q is the electron charge. This doping can be ascribed to the effect of the chemical (PMMA) residues which normally persist after the graphene transfer. It

• mobility of large area Gr-FETs on flexible substrates will be expected by the use polymeric substrates with optimized lower roughness and by further improvements in the graphene transferring methods, e.g., adopting alternative transfer layers different than common PMMA, leaving a very limited amount of

In-situ monitoring by Raman spectroscopy of the thermal doping of graphene and MoS₂ in O₂-controlled atmosphere

• Aurora Piazza,
• Filippo Giannazzo,
• Gianpiero Buscarino,
• Gabriele Fisichella,
• Antonino La Magna,
• Fabrizio Roccaforte,
• Marco Cannas,
• Franco Mario Gelardi and
• Simonpietro Agnello

Beilstein J. Nanotechnol. 2017, 8, 418–424, doi:10.3762/bjnano.8.44

• ] and chemical vapor deposition (CVD) on catalytic metals [9][10] followed by the poly(methyl methacrylate) (PMMA) assisted transfer [11][12], enlarged the interest and perspectives for applications. In particular in view of the realization of electronic devices and to obtain Gr-based field effect

• monolayer Gr and mechanically exfoliated MoS2 deposited on SiO2. The Gr samples were produced by chemical vapor deposition process on a Cu foil [11][19]. After Gr growth the foils were covered by PMMA and Cu was removed in a FeCl3 bath. Successively, a transfer process on a 300 nm thick SiO2 layer on Si

Methods for preparing polymer-decorated single exchange-biased magnetic nanoparticles for application in flexible polymer-based films

• Laurence Ourry,
• Delphine Toulemon,
• Souad Ammar and
• Fayna Mammeri

Beilstein J. Nanotechnol. 2017, 8, 408–417, doi:10.3762/bjnano.8.43

• for technological applications is of primary importance. Results: In this work, well-characterized exchange-biased perfectly epitaxial CoxFe3−xO4@CoO core@shell NPs, which were isotropic in shape and of about 10 nm in diameter, were decorated by two different polymers, poly(methyl methacrylate) (PMMA

• decoration of NPs by oleic acid followed by ligand exchange with the desired bromopropionyl ester groups. We then built various assemblies of NPs directly on a substrate or suspended in PMMA. Conclusion: The alternative two-step strategy leads to better dispersed polymer-decorated magnetic particles, and the

• and aggregation as far as possible in the first stage of polymer grafting, mechanical stirring and dilute suspensions of reactants were used, even if the functionalization of large amounts of particles becomes difficult. We specifically graft poly(methyl methacrylate) (PMMA) and polystyrene (PS

Functionalized TiO₂ nanoparticles by single-step hydrothermal synthesis: the role of the silane coupling agents

• Antoine R. M. Dalod,
• Lars Henriksen,
• Tor Grande and
• Mari-Ann Einarsrud

Beilstein J. Nanotechnol. 2017, 8, 304–312, doi:10.3762/bjnano.8.33

• and PMMA. Here, we report on a novel and versatile in situ aqueous hydrothermal synthesis route to surface-functionalized TiO2 nanoparticles using selected silane coupling agents. The nanoparticles were characterized with respect to crystal structure, size, size distribution, specific surface area

Flexible photonic crystal membranes with nanoparticle high refractive index layers

• Torben Karrock,
• Moritz Paulsen and
• Martina Gerken

Beilstein J. Nanotechnol. 2017, 8, 203–209, doi:10.3762/bjnano.8.22

• -linked polymer with reduced surface hydrophobicity. The mixture is thoroughly stirred for 5 min at 500 rpm (IKA ULTRA-TURRAX Tube Drive). The mixture is degassed in vacuum for 30 min. The mixed PDMS is poured into a poly(methyl methacrylate) (PMMA) mold which defines the form and size for the photonic

• grating depth of 140 nm (AMO GmbH, Aachen, Germany) in a lithographic nanoimprint process. Details on the process are given in [4]. As only the bearing structures that support the flexible photonic crystal membrane are milled out of the PMMA mold, the main part of the mold has a smooth surface. When

• placing the Amonil stamp on the overly filled mold, not all of the PDMS flows out and a thin film that later forms the ≈60 µm thick membrane remains. The filled PMMA mold with the nanostructure stamp on top is heated at 120 °C for 45 min (Figure 6a1–6a3). Figure 6a4 shows a picture of the PMMA mold that

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• consists of mechanical exfoliation, which imposes severe mechanical, uncontrolled defects in the sample. The most common and preferable is the wet-chemical etching of the catalyst (substrate). Usually a poly(methylmethacrylate) (PMMA) scaffold is applied to coat the graphene surface and support it during

• the catalyst consumption, followed by underside contaminant cleaning, then placement on the destination substrate. However, the PMMA removal from the graphene after the film transfer (which involves high-temperature Ar/H2 forming gas annealing [18], O2-based annealing [19], and in situ annealing [20