Fiber optic sensors based on hybrid phenyl-silica xerogel films to detect n-hexane: determination of the isosteric enthalpy of adsorption

• Jesús C. Echeverría,
• Ignacio Calleja,
• Paula Moriones and
• Julián J. Garrido

Beilstein J. Nanotechnol. 2017, 8, 475–484, doi:10.3762/bjnano.8.51

• magnitude of the isosteric enthalpy of n-hexane increased with the relative response and reached a plateau that stabilized at approximately −31 kJ mol−1 for Ph40 and Ph50 and at approximately −37 kJ mol−1 for Ph30. This indicates that the adsorbate–adsorbent interaction was dominant at lower relative

• pressure and condensation of the adsorbate on the mesopores was dominant at higher relative pressure. Keywords: fiber optic sensors; isosteric enthalpy of adsorption; n-hexane; phenyl-silica; xerogel films; Introduction Fiber optic chemical sensors (FOCSs) that employ sensitive films for the detection of

• common in most N2 isotherms. This phenomenon is related to the irreversible adsorption in pores with opening diameters close to the kinetic diameter of the adsorbate [25]. For the PhTEOS hybrid xerogels, the non-closure of the hysteresis loop could be associated with the presence of cage-like domains in

Tailoring bifunctional hybrid organic–inorganic nanoadsorbents by the choice of functional layer composition probed by adsorption of Cu²⁺ ions

• Veronika V. Tomina,
• Inna V. Melnyk,
• Yuriy L. Zub,
• Aivaras Kareiva,
• Miroslava Vaclavikova,
• Gulaim A. Seisenbaeva and
• Vadim G. Kessler

Beilstein J. Nanotechnol. 2017, 8, 334–347, doi:10.3762/bjnano.8.36

• isotherms of n-hexane, water and acetonitrile were obtained at 20 °C using a vacuum microbalance (balance sensitiveness: 1.9–2.8 mg/mm). The samples were first evacuated at 105 °C to a constant weight. Air was removed from the adsorbate by cycles of freezing/defreezing during vacuum pumping. Acid–base

Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals

• Ivan Shtepliuk,
• Jens Eriksson,
• Volodymyr Khranovskyy,
• Tihomir Iakimov,
• Anita Lloyd Spetz and
• Rositsa Yakimova

Beilstein J. Nanotechnol. 2016, 7, 1800–1814, doi:10.3762/bjnano.7.173

• sheet. Due to the chemical nature of the interaction between the graphene and lead atom, hybridization of the molecular orbitals has occurred and thus the HOMO is shared by lead adsorbate and graphene sheet. On the other hand, the LUMO of Pb@C30H14 is delocalized over the graphene sheet. In principle

Active and fast charge-state switching of single NV centres in diamond by in-plane Al-Schottky junctions

• Christoph Schreyvogel,
• Vladimir Polyakov,
• Sina Burk,
• Helmut Fedder,
• Andrej Denisenko,
• Felipe Fávaro de Oliveira,
• Ralf Wunderlich,
• Jan Meijer,
• Verena Zuerbig,
• Jörg Wrachtrup and
• Christoph E. Nebel

Beilstein J. Nanotechnol. 2016, 7, 1727–1735, doi:10.3762/bjnano.7.165

• atmospheric adsorbate layer on top of the H-terminated surface which is required for the generation of a two-dimensional hole channel. In this way, the hole channel and thus the diode properties are preserved to temperatures up to 550 °C in air. Chemically, this stability is supported by the fact that both

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

• Jakub S. Prauzner-Bechcicki,
• Lukasz Zajac,
• Piotr Olszowski,
• Res Jöhr,
• Antoine Hinaut,
• Thilo Glatzel,
• Bartosz Such,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

• organic adsorbate are necessary. The method of choice for investigating the local environment of a single dye molecule is high-resolution scanning probe microscopy. Microscopic results combined with the outcome of common spectroscopic methods provide a better understanding of the mechanism taking place at

• low conversion efficiencies [1]. However, when the surface of a wide-band-gap material is covered with a sensitizer that absorbs light in the visible spectrum and enables charge transfer through the semiconductor–adsorbate interface, the situation changes dramatically. The optical absorption, and

• to the oxide takes place, and an interface dipole is formed. To further understand the energy level alignment between a semiconducting substrate and an organic adsorbate, Lackinger, Janson and Ho [59] studied interactions between zinc(II) etioporphyrin (ZnEP) and oxygen vacancies, which are point

Graphene-enhanced plasmonic nanohole arrays for environmental sensing in aqueous samples

• Christa Genslein,
• Peter Hausler,
• Eva-Maria Kirchner,
• Rudolf Bierl,
• Antje J. Baeumner and
• Thomas Hirsch

Beilstein J. Nanotechnol. 2016, 7, 1564–1573, doi:10.3762/bjnano.7.150

• that this type of plasticizers adsorbs on polystyrene resins by multiple adsorbent–adsorbate interactions such as hydrogen bonding and π-stacking [38], which makes them an ideal analyte for the evaluation of the graphene-modified gold surfaces in SPR. Nanostructured surfaces are promising in enhancing

Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II) oxalate precursor layers

• Kai Rückriem,
• Sarah Grotheer,
• Henning Vieker,
• Paul Penner,
• André Beyer,
• Armin Gölzhäuser and
• Petra Swiderek

Beilstein J. Nanotechnol. 2016, 7, 852–861, doi:10.3762/bjnano.7.77

• number of secondary electrons released in the first case. This also points to a significant contribution of electron-induced chemistry to the formation of CO which can be detected in RAIRS as adsorbate on the emerging copper nanoparticles. Conclusion This study confirms the previous finding [26] that

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

• reconstruction of clean Au(111). This surface morphology changes related to adsorbed molecules can be visualized by STM techniques and provided us a reliable description of the interactions between adsorbate and substrate. Not only thiols but also sulfides (R–S–R), which form weaker molecule–substrate bonds than

• formed by the adsorption of normal n-alkylthiols 5 and bidentate analogues 3, 4 having similar chain lengths, to provide systematic control in packing density (Figure 2). The comparison showed that the SAMs of tridentate adsorbate 2 have lower packing densities of alkyl chains than the SAMs of bidentate

• thiol-terminated adsorbate films of 7, there is still a significant fraction of anchoring groups (approx. 35%) that are not bound to the gold surface. To improve a binding affinity of adsorbates to the metal substrates, several research groups have employed rigid platforms based on adamantane and

Surface-site reactivity in small-molecule adsorption: A theoretical study of thiol binding on multi-coordinated gold clusters

• Elvis C. M. Ting,
• Tatiana Popa and
• Irina Paci

Beilstein J. Nanotechnol. 2016, 7, 53–61, doi:10.3762/bjnano.7.6

• stabilities on metal site coordination, in the reduced model of methylthiol–Au20 interaction. We find that, despite the limited size of the adsorbate, dispersive interactions play an important role in determining preferred adsorption sites. The strongest adsorption occurred at sites that were relatively

• the configurational space through four variables: the distance from the adsorbate headgroup to a gold binding site d, the polar angle θ (the angle between the principal axis of the adsorbate and the axis normal to the binding surface), the azimuthal angle (describing the in-plane orientation of the

• projection of the adsorbate principal axis), and the relative location of the headgroup with respect to the substrate atoms (Figure 1). Three initial molecule–surface distances were used for all adsorbates (4.1, 4.3 and 4.5 Å), equilibrating to an average S–Au distance of 2.5 Å. Initial configurations were

Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

• Urs Gysin,
• Thilo Glatzel,
• Thomas Schmölzer,
• Adolf Schöner,
• Sergey Reshanov,
• Holger Bartolf and
• Ernst Meyer

Beilstein J. Nanotechnol. 2015, 6, 2485–2497, doi:10.3762/bjnano.6.258

• this picture of a strongly defect and adsorbate-influenced Fermi-level pinning of the SiC surface. A well-known technique to address and quantify the influence of surface defects in semiconductors are surface photo voltage (SPV) measurements. Charge carriers are excited by an incident photon flux and

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

• LPSQ-COOH/X allow for a very efficient polymer anchoring on the surface due to both multipoint ionic substrate–adsorbate interactions and adsorbate–adsorbate hydrogen bonding [37]. The formation of ordered SAMs and PSAMs at the liquid–solid interface can occur only if it is energetically allowed by

• particles. This can be ascribed to the preferential formation of dimeric hydrogen bonds (intra/intermolecular and surface-P1) involving carboxyl moieties and the lack of predominant, chain-straightening interactions with mica. This phenomenon illustrates the importance of strong surface–adsorbate

Focused particle beam-induced processing

• Michael Huth and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2015, 6, 1883–1885, doi:10.3762/bjnano.6.191

• well as the secondary and backscattered) electrons of the focused beam dissociate the precursor adsorbate, a permanent deposit is formed. Depending on the precursor and other process parameters, amorphous, nanogranular, nanocrystalline or polycrystalline nanostructures are obtained. Their position and

Continuum models of focused electron beam induced processing

• Milos Toth,
• Charlene Lobo,
• Vinzenz Friedli,
• Aleksandra Szkudlarek and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1518–1540, doi:10.3762/bjnano.6.157

• the molecular properties of each adsorbate and the electron flux profile(s) at the solid–vacuum interface. Simple continuum FEBIP models can be solved analytically, yielding governing laws delineating the so-called “reaction-rate” and “mass transport” limited process regimes, and resolution scaling

• laws. Numerical models can account for adsorbate diffusion and enable modeling of processes such as simultaneous FEBIE and FEBID performed using a mixture of precursor gases. Here we provide software that can be used to simulate a wide range of processes reported in the FEBIP literature, and review the

• underlying continuum FEBIP models (recent general reviews of FEBIP can be found in [4][10][18][19][20][21]). We begin with a discussion of the reaction rate limited regime and the most common continuum model input parameters: initial adsorbate coverage, electron flux profile and the gas flux distribution

Transformations of PTCDA structures on rutile TiO₂ induced by thermal annealing and intermolecular forces

• Szymon Godlewski,
• Jakub S. Prauzner-Bechcicki,
• Thilo Glatzel,
• Ernst Meyer and
• Marek Szymoński

Beilstein J. Nanotechnol. 2015, 6, 1498–1507, doi:10.3762/bjnano.6.155

• ordered layer. In contrast, our main concern here is the transformation of the molecular structure driven by thermal annealing. Thus, we systematically analyse the impact of post-deposition annealing and deposition at elevated temperatures on the self-assembly processes for different adsorbate coverage

Stick–slip behaviour on Au(111) with adsorption of copper and sulfate

• Nikolay Podgaynyy,
• Sabine Wezisla,
• Christoph Molls,
• Shahid Iqbal and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2015, 6, 820–830, doi:10.3762/bjnano.6.85

• structure. At the potential of zero charge (pzc) at E = 0.22 V, just positive of peak A2 or A1, only a small amount of adsorbate covers the gold surface, according to [28] ΘCu = 9%; Θsulfate = 5%. In Figure 2 the friction image (difference image of trace and retrace signals) of the Au(111) surface at the

• potentials corresponding to different adsorbate structures. As already reported before [11], a transition in the coefficient of friction is observed for a copper monolayer at FN = 70 nN. Here, we extended the study to lower normal loads and observed another transition in the friction coefficient at a normal

• load of FN ≈ 15 nN. The dependency of friction force on potential is shown in Figure 3b. The friction force is independent of potential as long as the adsorbate structure is preserved but changes when the adsorbate structure is changed; it is minimal at the pzc (E = 0.22 V). Due to adsorption of

Combination of surface- and interference-enhanced Raman scattering by CuS nanocrystals on nanopatterned Au structures

• Alexander G. Milekhin,
• Nikolay A. Yeryukov,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Victor A. Gridchin,
• Evgeniya S. Sheremet and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2015, 6, 749–754, doi:10.3762/bjnano.6.77

• ] the electromagnetic field has a maximum in the vicinity of an adsorbate/oxide interface due to constructive interference. The SERS intensity is proportional to the forth order of electromagnetic field and, therefore, can be significantly enhanced for the adsorbate (or CuS NCs) located in the local

Electromagnetic enhancement of ordered silver nanorod arrays evaluated by discrete dipole approximation

• Guoke Wei,
• Jinliang Wang and
• Yu Chen

Beilstein J. Nanotechnol. 2015, 6, 686–696, doi:10.3762/bjnano.6.69

• molecular adsorbate and in turn an enhanced SERS intensity, here we take the surface area effect into account and compare the total SERS enhancement (EFsum). As shown in Figure 5b, the surface effect is clearly visible at certain ARs and seems also depending on the structures of target units, although EFsum

Nanoparticle shapes by using Wulff constructions and first-principles calculations

• Georgios D. Barmparis,
• Zbigniew Lodziana,
• Nuria Lopez and
• Ioannis N. Remediakis

Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35

• with surfactants Metal-only nanoparticles or metal-adsorbate interactions have been the leading force that has helped the evolution of the presented methodology for the shape of nanocrystals. However, recent developments to design colloidal suspensions of nanoparticles with interesting physical and

The fate of a designed protein corona on nanoparticles in vitro and in vivo

• Denise Bargheer,
• Julius Nielsen,
• Gabriella Gébel,
• Markus Heine,
• Sunhild C. Salmen,
• Roland Stauber,
• Horst Weller,
• Joerg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 36–46, doi:10.3762/bjnano.6.5

• the particles whereas a secondary or third layer is interchanging with other proteins or lipids [21]. One explanation for different results could be the size of particles in relation to the protein size. In most studies NPs >40 nm were used and thus the size of the adsorbate (here transferrin with 9

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

• Gemini 2360 apparatus with nitrogen as the adsorbate. The particle size was calculated based on the BET data, assuming spherical particles, using: Where σ is the average particle diameter, S is the specific surface area of the powder and ρ is the density of zirconia. The powders were analyzed with an X

Gas sensing properties of nanocrystalline diamond at room temperature

• Marina Davydova,
• Pavel Kulha,
• Alexandr Laposa,
• Karel Hruska,
• Pavel Demo and
• Alexander Kromka

Beilstein J. Nanotechnol. 2014, 5, 2339–2345, doi:10.3762/bjnano.5.243

• evidence of the integrator property was observed. Overall, the hydrogenated diamond sensors exhibited a response to each sequence of NH3. These behaviors indicated that the H-terminated NCD sensors were able to accumulate NH3 gas in its water adsorbate layer, which confirms the integrator-type gas sensor

Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

• Dan Lis and
• Francesca Cecchet

Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237

• intensity can be measured as well. This non-resonant term, which may be significant, is considered as a background signal, and origins from electronic contributions either from the substrate and/or from the molecular adsorbate [3][24][25][26][27][28]. Thus, the electrical susceptibility tensors are

• experimental proof, the CARS signal enhancement was limited to two orders of magnitude. Opposite to SFG, a major drawback of CARS is the uneven amplification of the electronic contribution from the nanostructure body that can be orders of magnitude stronger than the molecular signal from the adsorbate [21][80

Spectroscopic mapping and selective electronic tuning of molecular orbitals in phosphorescent organometallic complexes – a new strategy for OLED materials

• Pascal R. Ewen,
• Jan Sanning,
• Tobias Koch,
• Nikos L. Doltsinis,
• Cristian A. Strassert and
• Daniel Wegner

Beilstein J. Nanotechnol. 2014, 5, 2248–2258, doi:10.3762/bjnano.5.234

• overall weak adsorbate-substrate interaction [37]. The close-up images exhibit submolecular resolution and clearly reflect the chemical building blocks. By superimposing the corresponding molecular structures we can attribute the highest round protrusions to the Pt atom in the center of the complexes

Advances in NO₂ sensing with individual single-walled carbon nanotube transistors

• Kiran Chikkadi,
• Matthias Muoth,
• Cosmin Roman,
• Miroslav Haluska and
• Christofer Hierold

Beilstein J. Nanotechnol. 2014, 5, 2179–2191, doi:10.3762/bjnano.5.227

• the theoretical and experimental achievements of the past few years in understanding the interaction of individual, single-walled carbon nanotubes with their environment. First, a summary of the effects of adsorbate molecules on electronic transport is presented, after which the effect of nearby

• influence the electron transport in the devices by changing the transfer characteristics. However, the devices also react strongly to charges in their vicinity, which leads to problems such as hysteresis and noise. We will examine these effects in detail in the next sections. Effect of adsorbate gases The

• sensitivity of carbon nanotube devices to adsorbate gases was reported in 2000 by two groups. Collins et al. [8] showed that carbon nanotube mats contacted by metal showed oxygen sensitivity, while Kong et al. [7] showed the sensitivity of individual CNFETs to NO2 and NH3, and discussed the possible

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

• XPEEM provides the chemical map of the resulting heterogeneous surface; and finally XMCD-PEEM reveals the magnetization distribution of this nanostructured surface. Stress-induced adsorbate stripes have been recently observed on crystalline surfaces at high temperatures. The mechanism is based on the