pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• strongly depends on the surface coverage of carboxylic functions. A higher carboxylic surface coverage requires a larger proton concentration in solution to yield neutralisation of the surface layer. On the other hand, at high pH values during adsorption of the PAA layer, a low surface coverage of

Nanostructured surfaces by supramolecular self-assembly of linear oligosilsesquioxanes with biocompatible side groups

• Maria Nowacka,
• Anna Kowalewska and
• Tomasz Makowski

Beilstein J. Nanotechnol. 2015, 6, 2377–2387, doi:10.3762/bjnano.6.244

• surface roughness, thickness and the arrangement of macromolecules were noted depending on the kind of functional groups on the side chains. Specific changes in the morphology of the surface layer were observed when mica was primed with a monolayer of small organic compounds (e.g., N-acetylcysteine

• substrate also defines the structure of the assemblies of LPSQ-COOH on mica [37]. It was thus of interest to study if the morphology of the surface layer of PSAMs and its physicochemical properties can be changed by alteration of the mechanism of adsorption on mica. The structure of the PSAMs was engineered

Effect of SiN_x diffusion barrier thickness on the structural properties and photocatalytic activity of TiO₂ films obtained by sol–gel dip coating and reactive magnetron sputtering

• Mohamed Nawfal Ghazzal,
• Eric Aubry,
• Nouari Chaoui and
• Didier Robert

Beilstein J. Nanotechnol. 2015, 6, 2039–2045, doi:10.3762/bjnano.6.207

• ), which is less photoactive than the anatase form [8]. In order to prevent this poisoning effect, various strategies have been reported including ion exchange via the formation of a thin proton-exchanged surface layer [3] or a post-treatment of the TiO2 films by hydrochloric acid [9], and the usage of a

Structural and magnetic properties of iron nanowires and iron nanoparticles fabricated through a reduction reaction

• Marcin Krajewski,
• Wei Syuan Lin,
• Hong Ming Lin,
• Katarzyna Brzozka,
• Sabina Lewinska,
• Natalia Nedelko,
• Anna Slawska-Waniewska,
• Jolanta Borysiuk and
• Dariusz Wasik

Beilstein J. Nanotechnol. 2015, 6, 1652–1660, doi:10.3762/bjnano.6.167

• . This phase of iron is covered by a quite thick layer of amorphous iron, which possibly contains some contribution of oxygen atoms. Between the amorphous iron layer and surface layer, there is a very thin layer of amorphous iron oxides. Finally, the surfaces of both studied nanomaterials are composed of

Influence of the shape and surface oxidation in the magnetization reversal of thin iron nanowires grown by focused electron beam induced deposition

• Luis A. Rodríguez,
• Lorenz Deen,
• Rosa Córdoba,
• César Magén,
• Etienne Snoeck,
• Bert Koopmans and
• José M. De Teresa

Beilstein J. Nanotechnol. 2015, 6, 1319–1331, doi:10.3762/bjnano.6.136

• of the wire will be more localized towards the centre of the nanowire, thus modifying its functional ferromagnetic shape. Micromagnetic simulations Quasi-static micromagnetic simulations were carried out to study the influence of the shape profile of the Fe nanowires and oxidized surface layer on the

• nanowires due to the modification of the magnetic properties of a substantial part of the nanowire. Assuming that this oxidized layer is paramagnetic at room temperature (as the Fe/O 1:1 stoichiometry suggests), this surface layer will lose its ferromagnetic behavior. According to the simulations shown in

• marked with yellow arrows) are shown: The thickness of the oxidized surface layer (FeO) is around 4–5 nm. Sketch of the two-dimensional (y,z plane) geometrical shapes used in the micromagnetic simulation for a 250 nm wide Fe nanowire with a tNom of 20 nm: (a) Rectangular profile (case I), (b

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

• Valentin S. Teodorescu,
• Cornel Ghica,
• Adrian V. Maraloiu,
• Mihai Vlaicu,
• Andrei Kuncser,
• Magdalena L. Ciurea,
• Ionel Stavarache,
• Ana M. Lepadatu,
• Nicu D. Scarisoreanu,
• Andreea Andrei,
• Valentin Ion and
• Maria Dinescu

Beilstein J. Nanotechnol. 2015, 6, 893–900, doi:10.3762/bjnano.6.92

• greater than the laser radiation absorption length, the laser annealing takes place only in a surface layer of the film, and a gradual modification of the nanostructure or a crystallization can be induced in the film [18][19]. The surface heating of the film during the laser pulse action can be estimated

• remains amorphous after laser irradiation, but a small increase of the volume is observed at the film surface due to the laser pulse action. The morphology and the structure of the modified film surface layer strongly depend on the laser fluence (Figure 3a and Figure 3b). At a higher fluence (20 mJ/cm2

• ), the wave relief disappears and an irregular structure of nanovoids appears in the surface layer. A closer look at the transformed surface layer (see Figure 3) reveals the formation of spherical nanoparticles and nanovoids. The formed nanovoids contribute to the small volume increase even at 15 mJ/cm2

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• behavior, the abundance of certain individual proteins within the protein surface layer would increase or decrease with time. The results of Tenzer and colleagues confirm this effect by identifying protein groups that indeed show increased or reduced binding with an increasing exposure time (see Figure 6

Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

• Ognen Pop-Georgievski,
• Dana Kubies,
• Josef Zemek,
• Neda Neykova,
• Roman Demianchuk,
• Eliška Mázl Chánová,
• Miroslav Šlouf,
• Milan Houska and
• František Rypáček

Beilstein J. Nanotechnol. 2015, 6, 617–631, doi:10.3762/bjnano.6.63

• XPS, is summarized in Table 1. Considerable amounts of aluminum and silicon were observed on the pristine surfaces, most likely from the polishing pastes used by the producer. In order to produce a consistent and reproducible titanium oxide surface layer, four different chemical treatments were tested

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

• Peter Guttmann and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 595–604, doi:10.3762/bjnano.6.61

• ][29]. The information depth by using soft X-ray microscopes depends strongly on the applied method. For SPEM and X-PEEM electrons emitted from the sample surface are detected. These electrons are generated in the surface layer not deeper than 10 nm. STXM and TXM are bulk sensitive methods as they

In situ scanning tunneling microscopy study of Ca-modified rutile TiO₂(110) in bulk water

• Giulia Serrano,
• Beatrice Bonanni,
• Tomasz Kosmala,
• Marco Di Giovannantonio,
• Ulrike Diebold,
• Klaus Wandelt and
• Claudio Goletti

Beilstein J. Nanotechnol. 2015, 6, 438–443, doi:10.3762/bjnano.6.44

• deficiencies in the surface layer caused by UHV preparation [1][10]. Between the primary pattern and the streaks a second set of weaker spots can be observed that form a c(6 × 2) superstructure. As proposed by Zhang et al. [1], two possible unit cells, (orange, dashed line) and (red, dotted line) are also

X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

• Toma Susi,
• Thomas Pichler and
• Paola Ayala

Beilstein J. Nanotechnol. 2015, 6, 177–192, doi:10.3762/bjnano.6.17

• the spectra at certain excitation energies or emission angles shifted to higher binding energies by 120–194 meV, and assigned it to the surface layer [65][66]. However, this view has been disputed by others [78][85]. Graphene, a single layer of graphite, is a truly 2-dimensional solid that was

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• . [52] also evaluated the surface conductivity of catalyst layers with 10% and 40% PTFE contents. Less PTFE content in the electrode led to an improved surface conductivity due to fewer PTFE agglomerates in the surface layer. The hydrophobic nature of the PTFE binder controls the phosphoric acid

Size-dependent density of zirconia nanoparticles

• Agnieszka Opalinska,
• Iwona Malka,
• Wojciech Dzwolak,
• Tadeusz Chudoba,
• Adam Presz and
• Witold Lojkowski

Beilstein J. Nanotechnol. 2015, 6, 27–35, doi:10.3762/bjnano.6.4

• correlated with a larger contribution of the low density surface layer to the average density. To prove the existence of such a layer, the material was synthesized using 50% heavy water. Fourier transform infrared spectroscopy (FTIR) permitted the identification of the –OD groups created during synthesis. It

• effect of the surface layer on the NP density becomes particularly evident for NPs smaller than 50 nm, and thus, the density of nanoparticles is size dependent. Keywords: density; hydrothermal synthesis; hydroxy groups; nanometrology; nanopowders; zirconia; Introduction Zirconium oxide (ZrO2) has a

• conditions produced nanopowders coated with a surface layer of –OH groups. Annealing the powders at temperatures up to 500 °C did not cause an increase in the crystallite size. Annealing at a temperature of 200 °C converted the amorphous material to crystalline, which was attributed to the evaporation of

Si/Ge intermixing during Ge Stranski–Krastanov growth

• Alain Portavoce,
• Khalid Hoummada,
• Antoine Ronda,
• Dominique Mangelinck and
• Isabelle Berbezier

Beilstein J. Nanotechnol. 2014, 5, 2374–2382, doi:10.3762/bjnano.5.246

• distribution found in the islands having a Ge-rich core. In particular, Si diffusion is easier at the island border and in a thin sub-surface layer parallel to the facets (where the island composition exhibits a cylindrical symmetry), and Si atoms cannot reach the island core, while the sides of the island can

Characterization of 10,12-pentacosadiynoic acid Langmuir–Blodgett monolayers and their use in metal–insulator–metal tunnel devices

• Saumya Sharma,
• Mohamad Khawaja,
• Manoj K. Ram,
• D. Yogi Goswami and
• Elias Stefanakos

Beilstein J. Nanotechnol. 2014, 5, 2240–2247, doi:10.3762/bjnano.5.233

• the counter electrode, and Ag/AgCl as the reference electrode in a 0.01 M HCl electrolyte solution. The electrochemical measurements were made using a Voltalab PGZ301 system. MIM diode: In this experiment, 50 nm of Ni was sputtered onto a silicon wafer with a passivating surface layer of silicon

Cathode lens spectromicroscopy: methodology and applications

• T. O. Menteş,
• G. Zamborlini,
• A. Sala and
• A. Locatelli

Beilstein J. Nanotechnol. 2014, 5, 1873–1886, doi:10.3762/bjnano.5.198

• , Fe preferentially wets the Pd-covered parts of the striped template. Furthermore, at about 200 °C Fe and Pd rearrange to make a surface alloy with a Pd-rich surface layer. The magnetization of the FePd stripes was found to be along the direction perpendicular to the stripe axis, as shown in the XMCD

Probing the electronic transport on the reconstructed Au/Ge(001) surface

• Franciszek Krok,
• Mark R. Kaspers,
• Alexander M. Bernhart,
• Marek Nikiel,
• Benedykt R. Jany,
• Paulina Indyka,
• Mateusz Wojtaszek,
• Rolf Möller and
• Christian A. Bobisch

Beilstein J. Nanotechnol. 2014, 5, 1463–1471, doi:10.3762/bjnano.5.159

• structure, we conclude that the subsurface layer appears to be the major transport channel for this contact geometry. Rather sharp transitions of the potential at embedded Au islands suggest a decoupling of the Au islands from the surface layer. From in depth-profile analysis we can conclude that the Au

Magnesium batteries: Current state of the art, issues and future perspectives

• Rana Mohtadi and
• Fuminori Mizuno

Beilstein J. Nanotechnol. 2014, 5, 1291–1311, doi:10.3762/bjnano.5.143

• , i.e., discharge and charge of the battery. Therefore a discussion of the magnesium metal anode is primarily that of its interactions with the electrolytes. In fact, it is well established [7][9][10][11] that the formation of a surface layer as a result of metal–electrolyte chemical/electrochemical

Double layer effects in a model of proton discharge on charged electrodes

• Johannes Wiebe and
• Eckhard Spohr

Beilstein J. Nanotechnol. 2014, 5, 973–982, doi:10.3762/bjnano.5.111

• water model. Ion–platinum Lennard-Jones parameters were chosen as (ε, σ) = (0.218, 2.93) for Na+ and (1.345, 3.35) for Cl−, which, together with a harmonic tether potential for the Cl− ions guaranteed that the ions stayed adsorbed in the surface layer of the water molecules. Here, ε is in units of

• the proton moves out of its position as a proton in the first water layer to the state of an adsorbed hydrogen (which is much closer to the surface layer of platinum atoms), is very rapid and occurs within a few femtoseconds, a timespan not resolved in this representation. If one first focuses on the

Carbon dioxide hydrogenation to aromatic hydrocarbons by using an iron/iron oxide nanocatalyst

• Hongwang Wang,
• Jim Hodgson,
• Tej B. Shrestha,
• Prem S. Thapa,
• David Moore,
• Xiaorong Wu,
• Myles Ikenberry,
• Deryl L. Troyer,
• Donghai Wang,
• Keith L. Hohn and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2014, 5, 760–769, doi:10.3762/bjnano.5.88

• appears again in the sample that was reduced by H2. This indicates that the surface layer of the as-synthesized particles contains a small amount of Fe0 in addition to the Fe2+ and Fe3+, which is in agreement with the literature [54]. However, deconvolution of the Fe 2p region is rather difficult due to

DNA origami deposition on native and passivated molybdenum disulfide substrates

• Xiaoning Zhang,
• Masudur Rahman,
• David Neff and
• Michael L. Norton

Beilstein J. Nanotechnol. 2014, 5, 501–506, doi:10.3762/bjnano.5.58

• -pyrenemethylamine and pyrene can prevent immediate DNA origami structural disruption caused by interaction with the MoS2 substrate, the protective effect of the 1-pyrenemethylamine surface layer is much greater than that of pyrene. Conclusion MoS2 has a great potential as a transducer material in future biosensor

Change of the work function of platinum electrodes induced by halide adsorption

• Florian Gossenberger,
• Tanglaw Roman,
• Katrin Forster-Tonigold and
• Axel Groß

Beilstein J. Nanotechnol. 2014, 5, 152–161, doi:10.3762/bjnano.5.15

• this position, the average distance to the topmost surface layer is larger than on the threefold-hollow sites. Since we are interested in getting trends among the halogen atoms in order to understand and predict adsorption processes, we kept the fluorine in the threefold-hollow site positions, but

• average distance from the center of the adsorbates to the topmost surface layer is smaller than for fluorine adsorbed at the on-top position. Calculations for F atoms at the most stable adsorption site may give slightly different results in charge transfer and dipole moments. In the next step, the

Synthesis of embedded Au nanostructures by ion irradiation: influence of ion induced viscous flow and sputtering

• Udai B. Singh,
• D. C. Agarwal,
• S. A. Khan,
• S. Mohapatra,
• H. Amekura,
• D. P. Datta,
• Ajay Kumar,
• R. K. Choudhury,
• T. K. Chan,
• Thomas Osipowicz and
• D. K. Avasthi

Beilstein J. Nanotechnol. 2014, 5, 105–110, doi:10.3762/bjnano.5.10

• into a solid by means of atomic recoils through a thin surface layer of the desired metal when using an ion beam from only one ion source. When an energetic ion strikes a thin film deposited on a substrate, it loses its energy through a sequence of collisions with the atoms in the film. The recoiling

• ] have shown that recoil implantation is a useful process to introduce impurities from a thin film of metal into a thin near-surface layer of the substrate. Recoil implantation has also been studied in detail in thin films [18][19]. The ion beam induced sputtering during the irradiation of thin films

• pristine sample. (a) Cross-sectional TEM image of sample irradiated with a fluence of 3 × 1016 ions/cm2. (b) Higher magnification XTEM image of the near-surface layer. The size distribution of the recoil-implanted Au NPs after the fluence of 3 × 1016 ions/cm2. (a) HRBS spectra of pristine sample and sample

Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Neha Bhardwaj,
• Jaspal Singh,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2013, 4, 763–770, doi:10.3762/bjnano.4.87

• ) as compared to ZnO nanoparticles. XRD, UV–vis absorption, PL, FTIR and TEM studies revealed the formation of Zn(OH)2 surface layer on ZnO nanostructures upon ageing. We demonstrate that the formation of a passivating Zn(OH)2 surface layer on the ZnO nanostructures upon ageing deteriorates their

• spectra. Figure 6b shows the room temperature PL spectra of aged samples S2’ and S3’ showing an enhanced visible light emission and a suppressed near band edge (NBE) emission. The weak NBE emission from the ZnO nanocrystals strongly indicates the presence of a passivating Zn(OH)2 surface layer [16], as

• efficiency of the aged sample S2’ (78.2% of 10 μM MB) is much less than the efficiency of sample S2 (99.6% of 22.4 μM MB) for 60 min of irradiation with sun light. This shows that the formation of a Zn(OH)2 surface layer deteriorates the photocatalytic efficiency of ZnO. The enhanced photocatalytic activity

AFM as an analysis tool for high-capacity sulfur cathodes for Li–S batteries

• Renate Hiesgen,
• Seniz Sörgel,
• Rémi Costa,
• Linus Carlé,
• Ines Galm,
• Natalia Cañas,
• Brigitta Pascucci and
• K. Andreas Friedrich

Beilstein J. Nanotechnol. 2013, 4, 611–624, doi:10.3762/bjnano.4.68

• layers visible at the borders. The surface layer stiffness is quite homogeneous. The stiffness scale of the displayed area is larger after cycling although on average the stiffness has decreased. The current decreases by more than one order of magnitude after cycling and only very small spots are still

• initial carbon-rich surface and the reduction of energy dissipation values after cycling indicates a loss of carbon after cycling. The adhesion force is quite sensitive to the properties of a thin surface layer. A difference in surface hydrophobicity is visible in the adhesion force, which has been shown