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

• future as well as the toxicity and environmental compatibility. Grirate [28] did investigate granite, basalt, quartzite, marble and hornfels from Morocco. The natural stones were analysed in terms of form, colour, grain size, hardness as well as the presence of carbonate elements. Additionally, physical

• the high compressive strength and hardness. Similar investigations of natural stones have been performed by Martin [29]. Basalt, diabas and quartzite were chosen as potential filler materials due to their high density and compressive strength. Initially, the thermal stability up to 900 °C in air and

Electroburning of few-layer graphene flakes, epitaxial graphene, and turbostratic graphene discs in air and under vacuum

• Andrea Candini,
• Nils Richter,
• Domenica Convertino,
• Camilla Coletti,
• Franck Balestro,
• Wolfgang Wernsdorfer,
• Mathias Kläui and
• Marco Affronte

Beilstein J. Nanotechnol. 2015, 6, 711–719, doi:10.3762/bjnano.6.72

• are deposited on the same substrate as the exfoliated graphene. Here, we found that the EB process leads to a breaking of the graphene devices only after the patterning of a constriction. This hardness with respect to exfoliated graphene suggests that the different morphology of the edges also plays a

Mandibular gnathobases of marine planktonic copepods – feeding tools with complex micro- and nanoscale composite architectures

• Jan Michels and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2015, 6, 674–685, doi:10.3762/bjnano.6.68

• it would be rather difficult to get reliable results. For insect mandibles, many of which are known to contain relatively high concentrations of zinc and manganese [40][41], it has been shown that the metal incorporations increase the hardness of the mandible material [42][43]. Copepod gnathobases

• silica very likely increases the hardness and stiffness of the gnathobase teeth and therefore has a similar effect as zinc and manganese have in insect mandibles. Mandibular gnathobases, diatom frustules and the evolutionary arms race In addition to the presence of mechanically stable silica-containing

Influence of grain size and composition, topology and excess free volume on the deformation behavior of Cu–Zr nanoglasses

• Daniel Şopu and
• Karsten Albe

Beilstein J. Nanotechnol. 2015, 6, 537–545, doi:10.3762/bjnano.6.56

• hardness and a low elastic modulus as compared to their bulk counterparts [8]. In light of these interesting results, further studies on the mechanical properties of this new type of material seem to be mandatory. Critical questions are, if and how mechanical properties of NGs change by varying the grain

Multifunctional layered magnetic composites

• Maria Siglreitmeier,
• Baohu Wu,
• Tina Kollmann,
• Martin Neubauer,
• Gergely Nagy,
• Dietmar Schwahn,
• Vitaliy Pipich,
• Damien Faivre,
• Dirk Zahn,
• Andreas Fery and
• Helmut Cölfen

Beilstein J. Nanotechnol. 2015, 6, 134–148, doi:10.3762/bjnano.6.13

• hardness and fracture resistance to the material. An intriguing and much investigated material is nacre which is the inner protecting layer of some marine sea shells. It is well-known for its beautiful iridescence but also for the outstanding mechanical properties. Nacre has a layered structure of

• nacre scaffold [3]. Inside this organic gelatin matrix we synthesize magnetite nanoparticles to form a highly mineralized organic–inorganic hybrid body. The resulting material should mimic the fracture resistance of nacre and the hardness and abrasion resistance of the chiton teeth. Results and

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• compared to HA alone, an increase in elasticity of up to 120%, a 129% increase in hardness, and an 86% increase in fracture toughness were possible. The BNNT–HA composite also showed a 75% increase in the wear resistance. It was noted that the addition of BNNTs to HA did not have any adverse effect on

Carbon-based smart nanomaterials in biomedicine and neuroengineering

• Antonina M. Monaco and
• Michele Giugliano

Beilstein J. Nanotechnol. 2014, 5, 1849–1863, doi:10.3762/bjnano.5.196

• stimulation and functional scaffolds for tissue engineering). Nanodiamonds (NDs): As a result of the complete sp3 hybridisation of its carbon atoms and its characteristic tetrahedral configuration, diamond shows interesting and peculiar properties such as an extreme hardness, low friction coefficient, high

Mechanical properties of sol–gel derived SiO₂ nanotubes

• Boris Polyakov,
• Mikk Antsov,
• Sergei Vlassov,
• Leonid M Dorogin,
• Mikk Vahtrus,
• Roberts Zabels,
• Sven Lange and
• Rünno Lõhmus

Beilstein J. Nanotechnol. 2014, 5, 1808–1814, doi:10.3762/bjnano.5.191

• -known, that mechanical properties of silica gels strongly depends on post-treatment procedures (aging time and annealing temperature). With an increase of annealing temperature, the density of macroscopic samples of silica gel is increasing as are its hardness and Young’s modulus, approaching values of

Surface topography and contact mechanics of dry and wet human skin

• Alexander E. Kovalev,
• Kirstin Dening,
• Bo N. J. Persson and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 1341–1348, doi:10.3762/bjnano.5.147

• stress (or penetration hardness) of human skin was taken as σY = 50 MPa [10], which is similar to the yield stress of most polymers, which are of the order of 100 MPa. We note that the yield stress of the skin is about 5% of its Young’s modulus, which is typical for many materials, e.g., for dry

• thick top layer (stratum corneum) has a Young’s modulus of E0 = 7 MPa, in the wet state and of E0 = 1 GPa, in the dry state with a Poisson ratio of ν0 = 0.5. A penetration hardness of 50 MPa was assumed for dry skin. The friction coefficient of skin for a glass ball (R = 0.8 cm) at a sliding velocity of

Template-directed synthesis and characterization of microstructured ceramic Ce/ZrO₂@SiO₂ composite tubes

• Jörg J. Schneider and
• Meike Naumann

Beilstein J. Nanotechnol. 2014, 5, 1152–1159, doi:10.3762/bjnano.5.126

• the mixed ceria/zirconia solid solution of the composition Ce0.13/Zr0.87O2 which is connecting the SiO2 particles as a ceramic binder. Based on these findings future studies may investigate the effect of this phase on the hardness, viz. the mechanical properties. Results and Discussion Synthesis of

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

• , with a toughness of about 0.17 MPa·m0.5 [81]. The brittleness was also observed with nanointendation measurements, giving an elastic modulus of about 37 GPa and a Berkovich hardness of about 0.47 GPa [84]. However, when the TMA+EG hybrid with an additional H2O pulse was employed as an interlayer

• , after which there was a larger drop to 1.5 Å per cycle at 135 °C. The TiCl4+EG hybrid thin films were unstable: The thickness diminished by 15% over five days and after 25 days the total reduction was 20%. The elastic modulus and hardness values measured by using nanointendation were extremely low, i.e

• these films was between 130 and 210 °C. The GPC value at 130 °C was 2.8 Å per cycle and dropped with increasing temperature gradually to 2.1 Å per cycle at 210 °C. A small increase of film thickness was observed when thin films were exposed to air. The elastic modulus and hardness were both higher for

A nanometric cushion for enhancing scratch and wear resistance of hard films

• Katya Gotlib-Vainshtein,
• Olga Girshevitz,
• Chaim N. Sukenik,
• David Barlam and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2014, 5, 1005–1015, doi:10.3762/bjnano.5.114

• relatively low hardness values results in susceptibility to surface damage. Transparent polymers, for example, are widely used in ophthalmology and the automobile industry, but scratches degrade their optical and mechanical properties [4][5]. There are several ways to improve the scratch resistance of

• scratch protection due to their hardness [6]. There are literature reports of the effect of hard-on-soft coatings wherein the soft component is only marginally softer and more compliant than the stiffer and harder film [12]. The softer underlying substrate is proposed to promote sliding and energy

• . According to the ASTM standard G171 (03) – standard test method for scratch hardness of materials using a diamond stylus [33], scratch hardness changes inversely with the scratch width at a given load. In the work reported herein, a two-layer coating is used to alter the hardness and friction of a titania

Molecular biology approaches in bioadhesion research

• Marcelo Rodrigues,
• Birgit Lengerer,
• Thomas Ostermann and
• Peter Ladurner

Beilstein J. Nanotechnol. 2014, 5, 983–993, doi:10.3762/bjnano.5.112

• vary depending on tissue hardness and size and must be empirically tested for every tissue. If permeability and transparency cannot be achieved in a whole mount specimen, it may be necessary to perform the ISH on tissue sections [48]. After pre-treatments of the tissue, the DIG-labelled RNA probe is

Scale effects of nanomechanical properties and deformation behavior of Au nanoparticle and thin film using depth sensing nanoindentation

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2014, 5, 822–836, doi:10.3762/bjnano.5.94

• tests (global deformation) were performed with a nanoindenter using a sharp Berkovich tip and a flat punch, respectively. Data from nanoindentation studies were compared with bulk to study scale effects. Nanoscale hardness of the film was found to be higher than the nanoparticles with both being higher

• than bulk. Both nanoparticles and film showed increasing hardness for decreasing penetration depth. For the film, creep and strain rate effects were observed. In comparison of nanoindentation and compression tests, more pop-ins during loading were observed during the nanoindentation of nanoparticles

• . Repeated compression tests of nanoparticles were performed that showed a strain hardening effect and increased pop-ins during subsequent loads. Keywords: gold (Au); Hall–Petch; hardness; nanoindentation; nano-objects; Introduction The characterization of mechanical properties is crucial for a fundamental

Biocalcite, a multifunctional inorganic polymer: Building block for calcareous sponge spicules and bioseed for the synthesis of calcium phosphate-based bone

• Xiaohong Wang,
• Heinz C. Schröder and
• Werner E. G. Müller

Beilstein J. Nanotechnol. 2014, 5, 610–621, doi:10.3762/bjnano.5.72

• acid (Asp, D) and glutamic acid (Glu, E) [50]. The hardness, elastic modulus and creep of the two forms of the calcium carbonate deposits, the calcitic prisms and the round-shaped vaterite deposits were determined by nanoindentation. The load–displacement curves obtained for the two calcium carbonate

• cells retain their capacity to synthesize HA crystallites. Furthermore, the mechanical properties, including surface roughness and hardness, of the hydrogel were determined. If silica is included in the hydrogel matrix, the encapsulated SaOS-2 cells were found to increasingly express the gene encoding

Challenges in realizing ultraflat materials surfaces

• Takashi Yatsui,
• Wataru Nomura,
• Fabrice Stehlin,
• Olivier Soppera,
• Makoto Naruse and
• Motoichi Ohtsu

Beilstein J. Nanotechnol. 2013, 4, 875–885, doi:10.3762/bjnano.4.99

• substrate can be a serious problem, because substrates with large Ra values induce defects or dislocations in the deposited active layer [4]. Diamond is a promising material for future power devices because of its many excellent characteristics including high values for hardness and thermal conductivity

• , and excellent semiconductor properties such as a high dielectric breakdown field and a high carrier mobility [5]. However, at the same time, the hardness of diamond makes it difficult to realize a flattened surface, and therefore the performance of diamond devices has not been as good as expected

• . Furthermore, diamond is also a promising material for future quantum computing, because diamond with nitrogen vacancies can be a stable single-photon emitter at room temperature [6]. However, the high surface roughness of the diamond due to its hardness limits its performance. Conventionally, mechanical

Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

• Sidney R. Cohen and
• Estelle Kalfon-Cohen

Beilstein J. Nanotechnol. 2013, 4, 815–833, doi:10.3762/bjnano.4.93

• curve by Oliver and Pharr (O&P) [23]. The latter developed a nanoindentation model and measurement protocol to quantitatively deduce the elastic modulus and the hardness of materials by loading an axisymmetric indenter into a sample while recording the applied force and displacement. The indenter “area

• function” is determined by performing this experiment on a well-known material, typically fused quartz. The principle quantities derived from a nanoindentation experiment are elastic modulus and hardness. The former is a fundamental property of the material, which, in principle, can be calculated from bond

• sample. Er is the reduced modulus which accounts for both sample and indenter Poisson ratio and modulus – υs, Es and υi, Ei respectively: Several depth sensing indentation methods were developed to evaluate A [23][24][25], which allow for evaluation of hardness and modulus without imaging the indentation

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

• sample that was coated by the doctor blade technique are displayed. Before cycling, the height differences are larger than in the SC-PVDF sample. However, the highest current of 1.7 nA is much smaller than the 30 nA measured at the SC-PVDF sample. Most of the surface has similar hardness and low energy

• approximately 2–3 μm are visible, which possess a high hardness, no conductivity, and show low deformation and energy dissipation. The region in between these crystallites exhibits a finite but very small conductivity, one order of magnitude smaller than before cycling. Here, several small conductive soft

Grating-assisted coupling to nanophotonic circuits in microcrystalline diamond thin films

• Patrik Rath,
• Svetlana Khasminskaya,
• Christoph Nebel,
• Christoph Wild and
• Wolfram H.P. Pernice

Beilstein J. Nanotechnol. 2013, 4, 300–305, doi:10.3762/bjnano.4.33

• diamond has found a wealth of applications for the fabrication of windows that permit transmission in the long-IR or microwave regions [14]. In addition, diamond provides attractive material properties, such as biocompatibility, chemical inertness, high thermal conductivity, and mechanical hardness [15

Size variation of infrared vibrational spectra from molecules to hydrogenated diamond nanocrystals: a density functional theory study

• Mudar A. Abdulsattar

Beilstein J. Nanotechnol. 2013, 4, 262–268, doi:10.3762/bjnano.4.28

• extraordinary properties of bulk diamond that include high hardness, inertness and high thermal conductivity. The additional properties added by reduction to the nanoscale make diamonds and related carbon materials a focus for recent investigations [1][2][3][4][5][6][7][8][9]. One of the first steps of

Effect of normal load and roughness on the nanoscale friction coefficient in the elastic and plastic contact regime

• Aditya Kumar,
• Thorsten Staedler and
• Xin Jiang

Beilstein J. Nanotechnol. 2013, 4, 66–71, doi:10.3762/bjnano.4.7

• tribological processes is fundamental to many basic and applied problems, such as wetting, capillarity, adhesion, lubrication, sealing, hardness, micro/nanoindentation, atomic-scale probing, surface modification and manipulation [1][2][3]. The contact of two bodies may be defined by the influential parameters

• roughness on the contact characteristics we calculated various plasticity indices that have been proposed in the literature. The first here is the one given by the GW model [5][6], (E*/H)(σsks)1/2, where H is the hardness, E* is the reduced Young’s modulus, σs is the surface roughness, and ks is the

• curvature constant. In the case of the fused silica it was found to be less than unity, whereas both DLC samples feature plasticity indices greater than unity (Table 2). Another modified plasticity index given by the KE model [9] was calculated as (2E*/πKH)(σsks)1/2, where K represents the hardness

Friction and durability of virgin and damaged skin with and without skin cream treatment using atomic force microscopy

• Bharat Bhushan,
• Si Chen and
• Shirong Ge

Beilstein J. Nanotechnol. 2012, 3, 731–746, doi:10.3762/bjnano.3.83

• , the maximum indentation displacement was controlled to be 1000 nm [6]. The method for the hardness (H) and the elastic modulus (E) determination was based on established methods [37][38]. Briefly, H was calculated from where Pmax is the maximum imposed load, and A is the projected contact area. The

Nanotribology at high temperatures

• Saurav Goel,
• Alexander Stukowski,
• Gaurav Goel,
• Xichun Luo and
• Robert L. Reuben

Beilstein J. Nanotechnol. 2012, 3, 586–588, doi:10.3762/bjnano.3.68

• are available for a tool tip for nanotribological applications at elevated temperatures, if not diamond. We attempt to answer this question below. Discussion Principally, ultra-hard materials – materials whose hardness is attributable to covalent bonding – can be represented using the “composition

• cycle” shown in Figure 1. This cycle involves the four elements carbon (C), boron (B), silicon (Si) and nitrogen (N). The combination of any two chemical species from this composition cycle produces a compound exhibiting ultra-high hardness, e.g., CBN, SiC, Si3N4, B4C and the recently recognized C3N4

• materials from this composition cycle, diamond (C) and cubic boron nitride (CBN), possess ultra-high hardness (attributed both to sp3-bonding and relatively short bond lengths) and, for this reason, they are frequently used to manufacture cutting tips. While diamond resides in a cubic lattice structure, CBN

Formation of SiC nanoparticles in an atmospheric microwave plasma

• Martin Vennekamp,
• Ingolf Bauer,
• Matthias Groh,
• Evgeni Sperling,
• Susanne Ueberlein,
• Maksym Myndyk,
• Gerrit Mäder and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 665–673, doi:10.3762/bjnano.2.71

• high mechanical toughness at evaluated temperatures, and the extreme hardness and chemical resistance of SiC, it is often used as welding flux. Phase separation during the welding process is a major technical challenge, and using nanosized particles may help to overcome this problem. So far, no

Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

• Lars Borchardt,
• Martin Oschatz,
• Robert Frind,
• Emanuel Kockrick,
• Martin R. Lohe,
• Christoph P. Hauser,
• Clemens K. Weiss,
• Katharina Landfester,
• Bernd Büchner and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 638–644, doi:10.3762/bjnano.2.67

• . Important requirements concerning these materials are chemical inertness and temperature stability. A material with high temperature stability, as well as excellent heat conductivity, hardness and mechanical stability is SiC [18]. Next to bulk SiC, also composites [19], porous [20][21][22][23][24][25], and