The different ways to chitosan/hyaluronic acid nanoparticles: templated vs direct complexation. Influence of particle preparation on morphology, cell uptake and silencing efficiency

• Arianna Gennari,
• Julio M. Rios de la Rosa,
• Erwin Hohn,
• Maria Pelliccia,
• Enrique Lallana,
• Roberto Donno,
• Annalisa Tirella and
• Nicola Tirelli

Beilstein J. Nanotechnol. 2019, 10, 2594–2608, doi:10.3762/bjnano.10.250

• all a higher aspect ratio (Rg/RH) and a lower fractal dimension. We then compared the kinetics of uptake and the (antiluciferase) siRNA delivery performance in murine RAW 264.7 macrophages and in human HCT-116 colorectal tumor cells. The preparative method (and therefore the internal particle

• . DLS data were analysed using the Zetasizer Nano software (Malvern). The data were also used to calculate: ρ = Rg/Rh (shape factor). This parameter defines key geometrical characteristics of a colloid. ρ values are given in literature [23] for a variety of particle morphologies. For example, ρ = 0.775

• provides also information about the colloid compactness through parameters such as their average radius of gyration Rg (it depends on the mass distribution), the shape factor ρ defined as the Rg/RH ratio, and the mass fractal dimension Dm defined as the exponent in the relation between mass of a colloidal

Semitransparent Sb₂S₃ thin film solar cells by ultrasonic spray pyrolysis for use in solar windows

• Jako S. Eensalu,
• Atanas Katerski,
• Erki Kärber,
• Lothar Weinhardt,
• Monika Blum,
• Clemens Heske,
• Wanli Yang,
• Ilona Oja Acik and
• Malle Krunks

Beilstein J. Nanotechnol. 2019, 10, 2396–2409, doi:10.3762/bjnano.10.230

• at rest in VOC condition for 230 days at room temperature (RT), relative humidity (RH) <30%, and exposed to both indoor light and daylight incident through the laboratory windows (Figure 6). In the 7.1 mm2 cell, over 230 days, VOC increased slightly, whereas JSC was halved, FF decreased slightly due

• up to 363 days at ≈20 °C, RH <30%. Photoconversion parameters of 100 nm Sb2S3 solar cells without aging (black dots) or after 180 days of aging (red triangles) as a function of light intensity. The dotted lines are a guide to the eye. The light intensity was attenuated from AM1.5G, 100 mW cm−2 with

Ion mobility and material transport on KBr in air as a function of the relative humidity

• Dominik J. Kirpal,
• Korbinian Pürckhauer,
• Alfred J. Weymouth and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2019, 10, 2084–2093, doi:10.3762/bjnano.10.203

• . Typically, air is composed of different gases, a small fraction of aerosols and water vapor. The relative humidity (RH) usually ranges from about 25% to 70%, depending on weather and season. A thin film of water molecules adsorbs on every surface exposed to humid gases [1][2][3]. The thickness of these

• time of exposure to the humid air. The layer thickness ranges from partial coverage at very low humidities (RH < 10%) up to several nanometers near saturation. Arima et al. performed XPS measurements on potassium bromide (KBr) thin films under UHV conditions (4·10−10 mbar) in order to determine the

• thickness as a function of the relative humidity [4]. They observed an increase of the coverage up to one monolayer at RH = 30%. This thickness remained constant up to a relative humidity of about 60%. A small increase up to RH = 80% and large increase up to 2 nm for higher humidities was recorded. It has

Magnetic properties of biofunctionalized iron oxide nanoparticles as magnetic resonance imaging contrast agents

• Natalia E. Gervits,
• Andrey A. Gippius,
• Alexey V. Tkachev,
• Evgeniy I. Demikhov,
• Sergey S. Starchikov,
• Igor S. Lyubutin,
• Alexander L. Vasiliev,
• Vladimir P. Chekhonin,
• Maxim A. Abakumov,
• Alevtina S. Semkina and
• Alexander G. Mazhuga

Beilstein J. Nanotechnol. 2019, 10, 1964–1972, doi:10.3762/bjnano.10.193

• temperature range of 10–300 K with a standard MS-1104Em spectrometer operated in the constant acceleration regime [30][31]. The gamma ray source 57Co(Rh) was maintained at room temperature. The calibration was performed with a metal α-Fe standard absorber. The XRD patterns were collected using the Rigaku

Pulsed laser synthesis of highly active Ag–Rh and Ag–Pt antenna–reactor-type plasmonic catalysts

• Kenneth A. Kane and
• Massimo F. Bertino

Beilstein J. Nanotechnol. 2019, 10, 1958–1963, doi:10.3762/bjnano.10.192

• Kenneth A. Kane Massimo F. Bertino Department of Physics, Virginia Commonwealth University, Richmond, Virginia, 23220, USA 10.3762/bjnano.10.192 Abstract Ag, Pt, and Rh monometallic colloids were produced via laser ablation. Separate Ag–Rh and Ag–Pt heterostructures were formed by mixing and

• resulted in groupings of Rh/Pt nanoparticles adsorbing to the concavities of the larger Ag nanostructures. The 400 nm Ag plasmonic absorption peak was slightly blue-shifted for Ag–Pt and red-shifted for Ag–Rh heterostructures. Catalytic activity for the reduction of 4-nitrophenol increased significantly

• for Ag–Pt and Ag–Rh compared to the monometallic constituents, and persisted at lower loading ratios and consecutive reduction cycles. The enhancement is attributed to the Rh and Pt nanoparticles forming antenna–reactor-type plasmonic catalysts with the Ag nanostructures. Keywords: Ag; antenna

High-temperature resistive gas sensors based on ZnO/SiC nanocomposites

• Vadim B. Platonov,
• Marina N. Rumyantseva,
• Alexander S. Frolov,
• Alexey D. Yapryntsev and
• Alexander M. Gaskov

Beilstein J. Nanotechnol. 2019, 10, 1537–1547, doi:10.3762/bjnano.10.151

• humidity (RH = 0% and RH = 30% at 25 °C) was used as a background gas. The test gases containing CO (20 ppm) and NH3 (20 ppm) were created from certified gas mixtures by the dilution with purified air with a pre-assigned humidity The corresponding gas flows were controlled by electronic mass-flow

Selective gas detection using Mn₃O₄/WO₃ composites as a sensing layer

• Yongjiao Sun,
• Zhichao Yu,
• Wenda Wang,
• Pengwei Li,
• Gang Li,
• Wendong Zhang,
• Lin Chen,
• Serge Zhuivkov and
• Jie Hu

Beilstein J. Nanotechnol. 2019, 10, 1423–1433, doi:10.3762/bjnano.10.140

• derived from temperature, the working temperature of a sensor is a key factor related to its sensing properties [21]. Therefore, it becomes necessary to optimize the working temperature. Unless otherwise stated, all gas sensing measurements were carried out at a humidity of ≈35 RH%. Figure 6 shows the

• 284.6 eV was used to calibrate the binding energy scale. The gas sensing measurements were carried out on a CGS-4TP device under standard laboratory conditions (≈35 RH%, 21 °C). Gas sensing characteristics Gas sensors based on pure WO3 and Mn3O4/WO3 composites were fabricated using a typical procedure

Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices

• Giulia Lo Dico,
• Bernd Wicklein,
• Lorenzo Lisuzzo,
• Giuseppe Lazzara,
• Pilar Aranda and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2019, 10, 1303–1315, doi:10.3762/bjnano.10.129

• -casting from the 0.2% w/v dispersion on polyester Petri dishes and dried at 30 °C and 60% relative humidity (RH) in a CLIMACELL EVO Stability Chamber (Incubator model 111L). The bionanocomposite foams were prepared by freeze-drying (Cryodos-80, Telstar) of the 8% w/v dispersion, which was cast in

Co-doped MnFe₂O₄ nanoparticles: magnetic anisotropy and interparticle interactions

• Bagher Aslibeiki,
• Parviz Kameli,
• Hadi Salamati,
• Giorgio Concas,
• Maria Salvador Fernandez,
• Alessandro Talone,
• Giuseppe Muscas and
• Davide Peddis

Beilstein J. Nanotechnol. 2019, 10, 856–865, doi:10.3762/bjnano.10.86

• 1000 Hz. Mössbauer spectra were recorded at room temperature using a source of 57Co in Rh, in transmission geometry. The velocity scale was calibrated using a 25 μm Fe foil; the isomer shift values are referred to metal iron. The spectra were analysed as a superposition of two components with peaks of

Topochemical engineering of composite hybrid fibers using layered double hydroxides and abietic acid

• Liji Sobhana,
• Lokesh Kesavan,
• Jan Gustafsson and
• Pedro Fardim

Beilstein J. Nanotechnol. 2019, 10, 589–605, doi:10.3762/bjnano.10.60

• measurements were conducted by using a L&W tensile tester SE 060 according to ISO 1924-2:2008, with a slight variation of elongation rate (12 mm·min−1) and test span (100 mm). The tensile tests were performed at 23 °C and 50% RH. Tensile strength tests were also performed with an unmodified ISO standard (ISO

• ISO brightness value of the dry fiber materials made into sheets. Both reference and modified fiber sheets were analyzed. The ISO brightness tests were performed at 23 °C and 50% RH. Results and Discussion Bleached (pine) and unbleached (spruce) kraft pulp fibers (F), refined (BKPR, UBKPR) and

Mo-doped boron nitride monolayer as a promising single-atom electrocatalyst for CO₂ conversion

• Qianyi Cui,
• Gangqiang Qin,
• Weihua Wang,
• Lixiang Sun,
• Aijun Du and
• Qiao Sun

Beilstein J. Nanotechnol. 2019, 10, 540–548, doi:10.3762/bjnano.10.55

• ), including Sc to Zn, Mo, Ru, Rh, Pd and Ag, supported on a boron nitride (BN) monolayer with boron vacancies, were investigated as electrocatalysts for the CO2 reduction reaction (CRR) using comprehensive density functional theory (DFT) calculations. The results demonstrate that a single-Mo-atom-doped boron

• (TM = Sc to Zn, Mo, Rh, Ru, Pd and Ag) anchored on the boron vacancy in a BN monolayer as electrocatalysts for CO2 conversion through comprehensive density functional theory (DFT) calculations. Based on the calculated results, single Mo doped onto a BN (Mo-doped BN) monolayer was selected as the

• onto BN monolayers (TM-doped BN) as the SACs, the interaction between CO2 and various TM (Sc to Zn, Mo, Ru, Rh, Pd and Ag) doped BN monolayers were considered. Moreover, for efficient reduction of CO2, the interaction between CO2 and the catalyst should be stronger than that between H2O and the

Temperature-dependent Raman spectroscopy and sensor applications of PtSe₂ nanosheets synthesized by wet chemistry

• Mahendra S. Pawar and
• Dattatray J. Late

Beilstein J. Nanotechnol. 2019, 10, 467–474, doi:10.3762/bjnano.10.46

• annealed in a vacuum furnace at 170 °C to improve the contact resistance and adhesion of the nanosheets with the substrate. The humidity sensing performance was investigated by exposing the sensor device to various relative humidity (RH) levels ranging from 11.3–97.3% as described in detail previously [26

• conductivity of the sensor device, similar to that observed for other 2D materials such as SnSe2 [35], MoS2 [36], BP [26], and MoSe2 [37]. Figure 7b shows a typical current–time (I–t) plot where cycles of 11.3% and 97.3% RH levels were used to calculate the response and recovery time. The response and recovery

• function of temperature. PtSe2 nanosheet based humidity sensor: (a) Typical resistance versus relative humidity plot and (b) current–time (I–t) plot taken after switching 11% RH and 97% RH. The photodetector application of PtSe2 nanosheets: (c) I–V in dark conditions and with green LED light and (d

Investigation of CVD graphene as-grown on Cu foil using simultaneous scanning tunneling/atomic force microscopy

• Majid Fazeli Jadidi,
• Umut Kamber,
• Oğuzhan Gürlü and
• H. Özgür Özer

Beilstein J. Nanotechnol. 2018, 9, 2953–2959, doi:10.3762/bjnano.9.274

• two main groups, i.e., “strongly bonded” and “weakly bonded”. Graphene–Ni, graphene–Co and graphene–Rh are classified as strongly bonded and others such as graphene–Cu, graphene–Au and graphene–Ir are classified as weakly bonded. Moreover, graphene–metal interaction can result in a lattice-matched

Comparative biological effects of spherical noble metal nanoparticles (Rh, Pd, Ag, Pt, Au) with 4–8 nm diameter

• Alexander Rostek,
• Marina Breisch,
• Kevin Pappert,
• Kateryna Loza,
• Marc Heggen,
• Manfred Köller,
• Christina Sengstock and
• Matthias Epple

Beilstein J. Nanotechnol. 2018, 9, 2763–2774, doi:10.3762/bjnano.9.258

• /bjnano.9.258 Abstract For a comparative cytotoxicity study, nanoparticles of the noble metals Rh, Pd, Ag, Pt, and Au (spherical, average diameter 4 to 8 nm) were prepared by reduction in water and colloidally stabilized with poly(N-vinyl pyrrolidone) (PVP). Thus, their shape, size, and surface

• after unintended exposure [10][11][12][13][14]. Noble metal nanoparticles such as Au, Pt, Pd, and Rh have distinct catalytic properties in biology, and have been reported to show several enzyme-like activities in vitro, including reactive oxygen species scavenger activity [15][16][17][18][19][20][21][22

• ][52]. This previously prompted us to carry out a multicentre study where the same silver nanoparticles were investigated in different laboratories with different biological assays [44]. Following the same approach, we have synthesized and thoroughly characterized nanoparticles of the noble metals Rh

High-temperature magnetism and microstructure of a semiconducting ferromagnetic (GaSb)_1−x(MnSb)_x alloy

• Leonid N. Oveshnikov,
• Elena I. Nekhaeva,
• Alexey V. Kochura,
• Alexander B. Davydov,
• Mikhail A. Shakhov,
• Sergey F. Marenkin,
• Oleg A. Novodvorskii,
• Alexander P. Kuzmenko,
• Alexander L. Vasiliev,
• Boris A. Aronzon and
• Erkki Lahderanta

Beilstein J. Nanotechnol. 2018, 9, 2457–2465, doi:10.3762/bjnano.9.230

• sample are shown in Figure 3a and Figure 3b. The Hall resistivity in magnetic systems can be divided into two parts: where RH is the Hall constant, used for the determination of Np and μ (see Table 1), and Rs is the anomalous Hall constant, which is defined by several parameters of the system [22]. Thus

• presented curves we used a simple linear fit of the high field region. In this case the fitting function has two variables, the slope (RH) and an offset, which corresponds to the saturated AHE amplitude RAHE. A second sign for the interaction between magnetic and conducting subsystems is the appearance of a

• ], while the total magnetic moment of isolated Mn atoms can be substantially smaller than that of MnSb inclusions. The temperature dependence of ΔRH is more complicated. But in the present case of a large AHE contribution, MR and AHE itself can strongly affect RH through the relations of conductivity and

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

• functionalized MOx NFs with superior sensitivity and fast response in a high humidity environment (95% relative humidity (RH)). WO3 NFs functionalized by RuO2 [189] and Rh2O3 [106] NPs show improved response toward acetone at 350 °C. The fibers have an average diameter in the range 250–300 nm with no significant

• ) exhibited high response (Rair/Rgas = 5.06) toward 1 ppm acetone at 400 °C with high selectivity, and fast response (20 s) and recovery (64 s) time under a highly humid atmosphere (95% RH) [192]. Gas sensing experiments were performed at an optimum temperature of 350 °C for detection of toluene in the

A variable probe pitch micro-Hall effect method

• Maria-Louise Witthøft,
• Frederik W. Østerberg,
• Janusz Bogdanowicz,
• Rong Lin,
• Henrik H. Henrichsen,
• Ole Hansen and
• Dirch H. Petersen

Beilstein J. Nanotechnol. 2018, 9, 2032–2039, doi:10.3762/bjnano.9.192

• measurements are the definitions of the resistance difference for the pairs, ΔRXX′ ≡ RX − RX′, as well as their resistance average, , where . For an equidistant four-point probe placed parallel to an insulating boundary, the resistance difference for the (B, B’) pair is where RH is the Hall sheet resistance, s

• multipoint-probes. After y0 has been calculated using either method, the Hall sheet resistance RH and the sheet resistance R0 can be determined by means of respectively, with . Finally, the Hall sheet carrier density, NHS, and the Hall mobility, μH, can be found from [4] and where Z is the sign of the charge

• increased error with increasing distance from the boundary. The largest error is found for NHS and the lowest for R0. Interestingly, the error of μH is lower than that of NHS, indicating a correlation of the errors of R0 and RH. This effect has previously been observed experimentally [9]. For the sheet

A differential Hall effect measurement method with sub-nanometre resolution for active dopant concentration profiling in ultrathin doped Si_1−xGe_x and Si layers

• Richard Daubriac,
• Emmanuel Scheid,
• Hiba Rizk,
• Richard Monflier,
• Sylvain Joblot,
• Rémi Beneyton,
• Pablo Acosta Alba,
• Sébastien Kerdilès and
• Filadelfo Cristiano

Beilstein J. Nanotechnol. 2018, 9, 1926–1939, doi:10.3762/bjnano.9.184

• %. Scattering correction must be accounted for when extracting Hall effect parameters. The measured values of Hall carrier concentration and Hall mobility are therefore corrected by using the Hall scattering factor, rH, [33][34][35] which depends on the studied material, i.e., on Ge content, doping type and

• with the more precise value of 88.60 ± 0.27 cm2·V−1·s−1 that can be extracted from the raw mobility data (cf. Figure 3c, rH = 0.4) obtained from much thicker layers (between 15 and 20 nm thick). Also, these mobility values are perfectly compatible with those predicted by analytical models for a doping

• factor rH = 1 was chosen in this case [20]). The results indicate that both annealing treatments yield high dopant activation, with millisecond-DSA resulting in slightly better parameters, i.e., a higher active dopant density and an overall lower sheet resistance compared to spike-RTA. Indeed, using the

Understanding the performance and mechanism of Mg-containing oxides as support catalysts in the thermal dry reforming of methane

• Nor Fazila Khairudin,
• Mohd Farid Fahmi Sukri,
• Mehrnoush Khavarian and
• Abdul Rahman Mohamed

Beilstein J. Nanotechnol. 2018, 9, 1162–1183, doi:10.3762/bjnano.9.108

• support and active metal particles [16][17][18]. The loss of catalytic activity or selectivity over time of production affects the cost of catalyst replacement, process shutdown, and product quality and quantity. Numerous researchers have reported that noble metal-based catalysts, such as Pt, Rh, Pd, Ru

Electrostatic force spectroscopy revealing the degree of reduction of individual graphene oxide sheets

• Yue Shen,
• Ying Wang,
• Yuan Zhou,
• Chunxi Hai,
• Jun Hu and
• Yi Zhang

Beilstein J. Nanotechnol. 2018, 9, 1146–1155, doi:10.3762/bjnano.9.106

• adiabatic hoses, forming the gas transmission loop. The temperature fluctuations were below 0.2 °C and the error of humidity control was about 2% relative humidity (RH). To avoid influences on EFM or SPFM imaging from the dielectric constant change of the mica substrate, all the SPM-based operations were

Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells

• Hana Krýsová,
• Josef Krýsa and
• Ladislav Kavan

Beilstein J. Nanotechnol. 2018, 9, 1135–1145, doi:10.3762/bjnano.9.105

• ) equipped with a Rh anode end window and a 4GN-type X-ray tube fitted with a 50 μm Be window. The obtained data were evaluated by Uniquant 4 software. Photo-electrochemical and electrochemical experiments were carried out in a one-compartment three-electrode cell using an Autolab Pgstat 101 instrument

Scanning speed phenomenon in contact-resonance atomic force microscopy

• Christopher C. Glover,
• Jason P. Killgore and
• Ryan C. Tung

Beilstein J. Nanotechnol. 2018, 9, 945–952, doi:10.3762/bjnano.9.87

• indented into a mica surface with a force of 100 nN in an environment with a relative humidity (RH) of 41% and scanned in a direction orthogonal to the long axis of the cantilever (scan angle of 90°). The resulting in-contact natural frequencies of the cantilever are measured while the tip is moved across

• believe that the presence of a thin film of water and hydrodynamic lift explains the scan speed-dependent phenomenon observed on our mica sample at 41% RH. Many studies have found that an “ice-like” or “solid-like” layer of structured water is found on hydrophilic surfaces under the right temperature

• be approximately 1 nm in thickness and formed at approximately 40% RH on mica [26][27]. The water film was found to have elastic, viscous, and energy dissipation properties that changed when the driving amplitude was varied [30][33][34]. Hofbauer et al. found that “the mechanical stress exerted by

Nanoscale mapping of dielectric properties based on surface adhesion force measurements

• Ying Wang,
• Yue Shen,
• Xingya Wang,
• Zhiwei Shen,
• Bin Li,
• Jun Hu and
• Yi Zhang

Beilstein J. Nanotechnol. 2018, 9, 900–906, doi:10.3762/bjnano.9.84

• 18–25 °C, and relative humidity (RH) 35–60%) (Figure 2a,c). However, the contrast of the corresponding adhesion images increases significantly (Figure 2b,d). When the tip bias was lowered back to 0 V, both height and adhesion images returned to the original state before the dc voltage was applied

• AFM tip changed very little, which is quite different from the result in our previous SPFM experiment, in which the apparent height of RGO sheets under a biased tip usually increased sharply when RH was lower than 40% [32]. This is because the set point of the force, which is used as the feedback

• temperature 18–25 °C, RH 35–60%). All of the sheets in the height image have similar contrast (Figure 3a) but are quite different in the adhesion force images (Figure 3b,c). When the tip bias was 0 V, although the contrast of all sheets is darker than that of the mica substrate, the sheets can still be

Optimal fractal tree-like microchannel networks with slip for laminar-flow-modified Murray’s law

• Dalei Jing,
• Shiyu Song,
• Yunlu Pan and
• Xiaoming Wang

Beilstein J. Nanotechnol. 2018, 9, 482–489, doi:10.3762/bjnano.9.46

• -like microchannel network with N branches and m levels, the total hydraulic resistance of the fluid flow in the entire network can be obtained using the electric circuit analogy based on the physical similarities between microfluidics and electronics as follows [17][27]. where RH is the total hydraulic

Facile synthesis of ZnFe₂O₄ photocatalysts for decolourization of organic dyes under solar irradiation

• Arjun Behera,
• Debasmita Kandi,
• Sanjit Manohar Majhi,
• Satyabadi Martha and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 436–446, doi:10.3762/bjnano.9.42

• , FESEM, UV–vis DRS, PL, FTIR and photocurrent measurements. The photocatalytic activity of the prepared material is studied with regard to the degradation of rhodamine B (Rh B) and Congo red under solar irradiation. The kinetic study showed that the material exhibits zeroth and first order reaction

• kinetics for the degradation of Rh B and Congo red, respectively. The photocatalytic behaviour of ZnFe2O4 was systematically studied as a function of the activation temperature. ZnFe2O4 prepared at 500 °C showed the highest activity in degrading Rh B and Congo red. The highest activity of ZnFe2O4-500 °C

• correlates well with the lowest PL intensity, highest photocurrent and lowest particle size. Keywords: Congo red; electrochemical study; phenol; photocatalyst; rhodamine B (Rh B); ZnFe2O4; Introduction Photocatalysis is a “green” technology for the treatment of environmental pollutants with solar energy [1