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

• sample solutions were prepared in D2O. For quantitative NMR measurements of PDADMAC, a solution of resorcinol in D2O was used as an external standard. It was filled into a melting point capillary, which was flame-sealed on both ends and inserted on the central axis of an NMR tube containing the sample

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

• power switches. Each switching process results in a melting of the contact surface and after several hundred events in a degradation of the device properties. Therefore, the chemical and structural properties of these surfaces are of major interest. Since the melting zone is typically macroscopically

Blue and white light emission from zinc oxide nanoforests

• Nafisa Noor,
• Luca Lucera,
• Thomas Capuano,
• Venkata Manthina,
• Alexander G. Agrios,
• Helena Silva and
• Ali Gokirmak

Beilstein J. Nanotechnol. 2015, 6, 2463–2469, doi:10.3762/bjnano.6.255

• electrical contact with the ZnO structures melt during the excitation, indicating that the local temperature can exceed 3422 °C, which is the melting temperature of tungsten. The distinct and narrow peaks in the optical spectra and the abrupt increase in current at high electric fields suggest that a plasma

• flow path are likely to undergo dielectric breakdown and joule heating earlier than others. The joule heating in turn results in sublimation of ZnO into Zn vapor and O2 gas and melting of the polysilicon substrate. Thus different regions between the two probes are expected to experience these thermal

• single µs-duration pulse (Figure 6a). The pulse measurements showed a nonsteady and high current level (Figure 6b). The SEM images taken after DC electrical analysis (Figure 7) indicate melting of the materials between the contacts, and an optical image of the tungsten probes after some of the

Green synthesis, characterization and catalytic activity of natural bentonite-supported copper nanoparticles for the solvent-free synthesis of 1-substituted 1H-1,2,3,4-tetrazoles and reduction of 4-nitrophenol

• Akbar Rostami-Vartooni,
• Mohammad Alizadeh and
• Mojtaba Bagherzadeh

Beilstein J. Nanotechnol. 2015, 6, 2300–2309, doi:10.3762/bjnano.6.236

• NMR spectra were obtained on a Brucker Avance 90 MHz spectrometer, using tetramethylsilane (TMS) as an internal standard. The melting points were taken in open capillary tubes with a Büchi 510 melting point apparatus and were uncorrected. Thin-layer chromatography (TLC) was performed on silica gel

• and washed with water and ethanol. The combined organic layers were washed with brine and dried over the anhydrous MgSO4 and concentrated and crystallized with EtOAc-hexane to give different tetrazoles. All compounds were known and were characterized by spectral analysis or melting points [14

Nanoscale rippling on polymer surfaces induced by AFM manipulation

• Mario D’Acunto,
• Franco Dinelli and
• Pasqualantonio Pingue

Beilstein J. Nanotechnol. 2015, 6, 2278–2289, doi:10.3762/bjnano.6.234

• various extents in the bulk as well as in the films depending on the crystalline degree of the analyzed sample. The value, at which it typically occurs, is called glass transition temperature (Tg). In general, an AFM cannot observe the first order transition, which corresponds to crystalline melting

• rippling for the thin lamellar microphases forming in polystyrene/poly(ethylene oxide) block copolymer (PS-b-PEO) films [48]. In particular via an analysis of the ripple patterns, they have deduced local thermochemical parameters such as the melting temperature of PEO, the Tg of PS, the specific heat of PS

• -b-PEO, the melting enthalpy of PEO, and the Helmholtz free energy for unfolding (and melting) of PEO. Composite films: Another class of samples showing a peculiar pattern formation are polymer blends. They can be miscible or immiscible, presenting clear phase separation or a similar morphology to

Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001)

• Anu Baby,
• He Lin,
• Gian Paolo Brivio,
• Luca Floreano and
• Guido Fratesi

Beilstein J. Nanotechnol. 2015, 6, 2242–2251, doi:10.3762/bjnano.6.230

• potential candidate in the field of organic electronic devices [1][2][3][4][5]. It acts as a p-type organic semiconductor in its intrinsic state with high hole mobility and exhibits a very high melting point [6]. The pentacene–Al junction is known to exhibit a Schottky barrier and, hence, finds numerous

Nanofibers for drug delivery – incorporation and release of model molecules, influence of molecular weight and polymer structure

• Jakub Hrib,
• Jakub Sirc,
• Radka Hobzova,
• Zuzana Hampejsova,
• Zuzana Bosakova,
• Marcela Munzarova and
• Jiri Michalek

Beilstein J. Nanotechnol. 2015, 6, 1939–1945, doi:10.3762/bjnano.6.198

• , elemental analysis, IR spectroscopy and melting point measurements. The needle-free electrospinning process was optimized for each type of nanofiber with respect to the different physicochemical properties of polymers. SEM images revealed that the textures of all resultant samples were homogenous and free

Two-phase equilibrium states in individual Cu–Ni nanoparticles: size, depletion and hysteresis effects

• Aram S. Shirinyan

Beilstein J. Nanotechnol. 2015, 6, 1811–1820, doi:10.3762/bjnano.6.185

• temperature–composition phase diagram occur. Our calculations for individual Cu–Ni nanoparticle show that one must differentiate the solubility curves and the equilibrium loops (discussed here in term of solidification and melting loops). For the first time we have calculated and present here on the

• and foremost for pure materials) is the size-dependent melting temperature shift which is usually observed and explained in accordance to the so called capillary effect (surface-to-volume ratio or Laplace pressure) [1][2][3]. Somewhat less attention has been paid to binary and multicomponent

• nanosystems where the phase transition temperature becomes the function of composition as well [4][5][6][7]. The size and composition dependent results have been obtained mainly for melting and solidification of nanoparticles and they demonstrate the increase of solubilities of chemical elements, shift of

Thermal energy storage – overview and specific insight into nitrate salts for sensible and latent heat storage

• Nicole Pfleger,
• Thomas Bauer,
• Claudia Martin,
• Markus Eck and
• Antje Wörner

Beilstein J. Nanotechnol. 2015, 6, 1487–1497, doi:10.3762/bjnano.6.154

• as water, metals, ceramics, stones and salts. Table 1 gives an overview of sensible, latent and thermochemical TES processes using salts. The focus of this chapter is on salts in sensible and latent heat storage systems. Salt systems differ by important properties such as melting temperature and

• thermal stability which define the lower and upper limits of usable temperature in sensible heat storage systems. In latent storage systems the melting temperature defines the temperature at which the heat is stored. In thermal power plants the stored heat can be used to generate steam which drives

• turbines to produce electricity. Because the heat is generated at a specific and constant temperature and because of the temperature dependent water to steam transition the pressure of the steam can be adjusted to a level which is required by the turbine. Besides the melting temperature another important

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• melting of charge-ordered domains is observed [61]. Since the CER in bulk PCMO samples is visible in the temperature range, where the charge ordered and disordered phase coexist and the formation of percolation paths depends on the structure as well as on the electrical pre-history, the determination of a

DNA–melamine hybrid molecules: from self-assembly to nanostructures

• Rina Kumari,
• Shib Shankar Banerjee,
• Anil K. Bhowmick and
• Prolay Das

Beilstein J. Nanotechnol. 2015, 6, 1432–1438, doi:10.3762/bjnano.6.148

• –melamine) was annealed with the corresponding tri-branched counterpart having the complementary DNA sequence ((R2)3–melamine) to produce a nanoassembly in the form of a network. To investigate the outcome of the hybridization of the complementary DNA–melamine conjugates, thermal melting studies were

• performed with PAGE-purified hybrid conjugates (Figure 2). The assembly of the two complementary hybrid DNA species results in a substantial increase in the melting temperature in comparison to the unconjugated duplex DNA. The significant increase in the melting temperature for the self-assembled (R1)2

• –melamine with (R2)2–melamine of about 10 °C suggests the formation of a linear assembly upon annealing. As reported, an increase of the number of sticky-end association results in an increase in melting temperature, which is attributed to the additive effect [29][30]. In this case, a simple annealing of

The Kirkendall effect and nanoscience: hollow nanospheres and nanotubes

• Abdel-Aziz El Mel,
• Ryusuke Nakamura and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 1348–1361, doi:10.3762/bjnano.6.139

• attributed the observed frequent changes of the bismuth configuration during oxidation to the local temperature which exceeds the melting point of the residual bismuth core evaluated in the same study of about 180 °C [48]. It is important to mention that this particle results in a uniform shell thickness at

Natural and artificial binders of polyriboadenylic acid and their effect on RNA structure

• Giovanni N. Roviello,
• Domenica Musumeci,
• Valentina Roviello,
• Marina Pirtskhalava,
• Alexander Egoyan and
• Merab Mirtskhulava

Beilstein J. Nanotechnol. 2015, 6, 1338–1347, doi:10.3762/bjnano.6.138

• melting transition in circular dichroism experiments [31]. Giri and Kumar [32][33] reported that the isoquinoline alkaloid sanguinarine (Figure 3) was able to strongly interact with single-stranded poly(rA) with an association constant of about 4 × 106 M−1. Such binding induced the formation of self

• -structures in poly(rA) strands and led to cooperative melting transitions, as revealed in circular dichroism, UV and calorimetry studies. Finally, the fluorescence data showed that sanguinarine acts as an intercalator, while calorimetry experiments indicated that its binding is enthalpy-driven. In another

• an affinity of about 104 M−1. Furthermore, fluorescence quenching studies evidenced that berberine and palmatine act as partial intercalators of RNA double helices, while coralyne provides a complete intercalation. The interaction with these alkaloids significantly stabilises the melting of poly(rA

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• absorbed laser energy. Hence, the size of the laser-generated Ag nanoparticles is larger. Au and Ag have different physical properties, such as the absorption spectrum of the laser light, melting point, boiling point and thermal conductivity, which all can contribute to the size difference. The laser

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

• theoretical energy capacity. Some general differences between lithium and sodium cells are immediately apparent: The lower melting point of sodium (Tm,Na = 98 °C) as compared to lithium (Tm,Li = 181 °C) and its generally higher chemical reactivity pose additional safety issues for cells using metal anodes. On

Effects of swift heavy ion irradiation on structural, optical and photocatalytic properties of ZnO–CuO nanocomposites prepared by carbothermal evaporation method

• Sini Kuriakose,
• D. K. Avasthi and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2015, 6, 928–937, doi:10.3762/bjnano.6.96

• Cu mixture led to the deposition of ZnO–CuO nanocomposite film with excess Zn onto the substrate. When this as-deposited film is annealed at 600 °C for 1 h in oxygen atmosphere, it led to the formation of Cu–Zn eutectic nanodroplets at the film surface. Since the melting point of Zn is low (419 °C

• through an oriented attachment mechanism, leading to the formation of ZnO nanorods and nanosheets on the surface of the nanocomposites. The schematic diagram depicting the growth mechanism is shown in Figure 5. Irradiation of the ZnO–CuO nanocomposite with 90 MeV Ni7+ ions results in localized melting and

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

• are segregated in spherical amorphous nanoparticles as a result of the fast diffusion of Ge atoms in the amorphous GeTiO matrix. The temperature estimation of the film surface during the laser pulses shows a maximum of about 500 °C, which is much lower than the melting temperature of the GeTiO matrix

• morphology cannot be considered as a sign of melting. All laser treatments were conducted at low fluences, so that the films remain practically in the solid state phase, as the surface temperature estimation shows. Before and after laser irradiation, the nanostructure of the film surfaces was observed by

• , the temperature grows up to about 500 °C for a laser fluence of 30 mJ/cm2, which is about double of the average fluence measured for the laser beam. Under these conditions, it is clear that the film surface does not melt during the laser pulse action. The melting temperature for Ge is about 900 °C [17

Structure and mechanism of the formation of core–shell nanoparticles obtained through a one-step gas-phase synthesis by electron beam evaporation

• Andrey V. Nomoev,
• Sergey P. Bardakhanov,
• Makoto Schreiber,
• Dashima G. Bazarova,
• Nikolai A. Romanov,
• Boris B. Baldanov,
• Bair R. Radnaev and
• Viacheslav V. Syzrantsev

Beilstein J. Nanotechnol. 2015, 6, 874–880, doi:10.3762/bjnano.6.89

• system. In many cases, the surface tension of a liquid has a temperature dependence of the form which is valid for a certain temperature range above the melting temperature (Tm) of the material where σ(Tm) is the surface tension at the melting point of the material and dσ/dT is the rate of change of the

• surface tension with temperature [14]. The empirical dependence of the surface tension of copper with temperature is [15]. The surface tension of silicon varies as [16]. Below the melting point, when the materials are solid, the surface energy is the solid equivalent of the surface tension. The surface

• the surface energy of the particles by coating Cu with Si is likely to be the main driving force for making the Si–Cu vapour condense into Cu@silica particles. A mechanism of formation of Cu@silica particles can be proposed considering that both the melting and boiling temperatures of Si are higher

Hematopoietic and mesenchymal stem cells: polymeric nanoparticle uptake and lineage differentiation

• Ivonne Brüstle,
• Thomas Simmet,
• Gerd Ulrich Nienhaus,
• Katharina Landfester and
• Volker Mailänder

Beilstein J. Nanotechnol. 2015, 6, 383–395, doi:10.3762/bjnano.6.38

• following program: initial denaturation at 95 °C for 3 min, followed by 40 cycles of PCR (95 °C for 10 s, annealing temperature (see Supporting Information File 1, Tables S2 and S3) for 10 s and 72 °C for 30 s and ending with a melting curve analysis (65 °C to 95 °C, increment 0.5 °C for 5 min). The primer

Nanoporous Ge thin film production combining Ge sputtering and dopant implantation

• Jacques Perrin Toinin,
• Alain Portavoce,
• Khalid Hoummada,
• Michaël Texier,
• Maxime Bertoglio,
• Sandrine Bernardini,
• Marco Abbarchi and
• Lee Chow

Beilstein J. Nanotechnol. 2015, 6, 336–342, doi:10.3762/bjnano.6.32

• island formation or agglomeration at a temperature below the melting temperature of the film material. This phenomenon is generally undesirable in the field of micro- or nano-technology [34] yet has been reported to be interesting for the fabrication of nanocrystals. A wide range of materials can be used

Oxygen-plasma-modified biomimetic nanofibrous scaffolds for enhanced compatibility of cardiovascular implants

• Anna Maria Pappa,
• Varvara Karagkiozaki,
• Silke Krol,
• Spyros Kassavetis,
• Dimitris Konstantinou,
• Charalampos Pitsalidis,
• Lazaros Tzounis,
• Nikos Pliatsikas and
• Stergios Logothetidis

Beilstein J. Nanotechnol. 2015, 6, 254–262, doi:10.3762/bjnano.6.24

• the power to 40 W, the plasma effect was very prominent and dramatically affected the morphology of the scaffolds, which resulted in a melting of the fibers as shown in Figure 1c. The mild treatment conditions (high magnification of image in Figure 1b) resulted in the melting of the thinner fibers of

• functional groups are created. This leads to an increase in the polarity and the surface energy, resulting in a roughened topography. Higher plasma power (P = 40 W) significantly decreased Ra resulting into smoother nanofibrous surfaces compared to the untreated samples, due to the partial polymer melting

• the extensive polymer melting induced by the high power plasma treatment. The significant degradation of the chemical structure of the polymer in line with the deteriorated morphological and topographical characteristics observed through SEM and AFM imaging underline that the milder O2-plasma

Proinflammatory and cytotoxic response to nanoparticles in precision-cut lung slices

• Stephanie Hirn,
• Nadine Haberl,
• Kateryna Loza,
• Matthias Epple,
• Wolfgang G. Kreyling,
• Barbara Rothen-Rutishauser,
• Markus Rehberg and
• Fritz Krombach

Beilstein J. Nanotechnol. 2014, 5, 2440–2449, doi:10.3762/bjnano.5.253

• , 37 °C). Prior to incubation, the PCLS were placed in a 24-well culture dish in the incubator for re-melting the agarose and washed for 1 h by changing the culture medium three times, in order to remove the agarose. Incubation of PCLS For viability testing, PCLS were incubated with 500 µL DMEM/F-12

Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

• Cornelia Loos,
• Tatiana Syrovets,
• Anna Musyanovych,
• Volker Mailänder,
• Katharina Landfester,
• G. Ulrich Nienhaus and
• Thomas Simmet

Beilstein J. Nanotechnol. 2014, 5, 2403–2412, doi:10.3762/bjnano.5.250

• material, resulting in lower binding energy per atom with decreasing particle size. A consequence of the reduced binding energy per atom is a reduction of the melting point temperature with the particle radius [19]. Nanoparticles have a very large surface area compared to their volume, which can interact

Anticancer efficacy of a supramolecular complex of a 2-diethylaminoethyl–dextran–MMA graft copolymer and paclitaxel used as an artificial enzyme

• Yasuhiko Onishi,
• Yuki Eshita,
• Rui-Cheng Ji,
• Masayasu Onishi,
• Takashi Kobayashi,
• Masaaki Mizuno,
• Jun Yoshida and
• Naoji Kubota

Beilstein J. Nanotechnol. 2014, 5, 2293–2307, doi:10.3762/bjnano.5.238

• in Table 1 [27]. Conversely, in the DDMC/PTX complex samples 2 and 3, in spite of having normalized the vertical-axis scale to the PTX content, the endothermic peak at the melting point of 220.8 °C did not appear. From this, it is thought that PTX is carried as guest of the DDMC/PTX complex at the

Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films

• Katarzyna Grochowska,
• Katarzyna Siuzdak,
• Peter A. Atanasov,
• Carla Bittencourt,
• Anna Dikovska,
• Nikolay N. Nedyalkov and
• Gerard Śliwiński

Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219

• obtained the different velocities of the metallic (Au and Ta) film surfaces of 0.6 m/s and 1.9 m/s below and above the melting threshold, respectively [24]. Interestingly, the velocity values in the range of 20–70 m/s characteristic of the instability driven processes (i.e., film detachment from Si

• nanosecond laser pulses of energy absorbed at the film surface, transferred and converted into heat. This results in fast material melting, dewetting of the substrate and fast cooling after termination of each pulse. The process of dewetting is typical for most liquid metals on SiO2 and is characterized by