Kinetics of solvent supported tubule formation of Lotus (Nelumbo nucifera) wax on highly oriented pyrolytic graphite (HOPG) investigated by atomic force microscopy

• Sujit Kumar Dora,
• Kerstin Koch,
• Wilhelm Barthlott and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2018, 9, 468–481, doi:10.3762/bjnano.9.45

• to dissolve during the same time. For example, structures marked by white arrows in Figure 1a have dissolved in Figure 1d. This observation points to the operation of the Ostwald-ripening process. The full width at half maximum (FWHM) height of the profile in Figure 1d is ≈110 nm, and may be regarded

Photocatalytic and adsorption properties of TiO₂-pillared montmorillonite obtained by hydrothermally activated intercalation of titanium polyhydroxo complexes

• Mikhail F. Butman,
• Nikolay L. Ovchinnikov,
• Nikita S. Karasev,
• Nataliya E. Kochkina,
• Alexander V. Agafonov and
• Alexandr V. Vinogradov

Beilstein J. Nanotechnol. 2018, 9, 364–378, doi:10.3762/bjnano.9.36

• phenomenon of pillar enlargement can also be explained by Ostwald ripening [43]. Pillar growth occurs due to recondensation, i.e., via the process of dissolving relatively small TiO2 pillars in water followed by re-precipitation at high pillars. The effectiveness of decolorization for the solutions of model

A systematic study of the controlled generation of crystalline iron oxide nanoparticles on graphene using a chemical etching process

• Peter Krauß,
• Jörg Engstler and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2017, 8, 2017–2025, doi:10.3762/bjnano.8.202

• nanoparticles on graphene. After heat treatment of the graphene samples which were transferred onto TEM grids (for 24 h at 450 °C), the iron oxide nanoparticles (which are initially in the subnanometer to nanometer range and could only barely be detected) agglomerated significantly due to Ostwald ripening and

Miniemulsion copolymerization of (meth)acrylates in the presence of functionalized multiwalled carbon nanotubes for reinforced coating applications

• Bertha T. Pérez-Martínez,
• Lorena Farías-Cepeda,
• Víctor M. Ovando-Medina,
• José M. Asua,
• Lucero Rosales-Marines and
• Radmila Tomovska

Beilstein J. Nanotechnol. 2017, 8, 1328–1337, doi:10.3762/bjnano.8.134

• period and does not require massive diffusion of the components of the formulation through the aqueous phase. Ham et al. [32][33] used a so-called miniemulsion process in an attempt to cover SWCNTs with polystyrene nanoparticles, where n-pentanol was used as a hydrophobe to minimize Ostwald ripening

• . However, n-pentanol is rather water soluble and it cannot hinder Ostwald ripening. Therefore, it is doubtful that the monomer droplets were stable. Ha et al. [18] polymerized miniemulsions prepared by sonicating a mixture of surfactant-stabilized SWCNTs, monomers (styrene and isoprene) and a costabilizer

AgCl-doped CdSe quantum dots with near-IR photoluminescence

• Pavel A. Kotin,
• Sergey S. Bubenov,
• Natalia E. Mordvinova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2017, 8, 1156–1166, doi:10.3762/bjnano.8.117

• different mechanisms that could explain this process including dissolution of TPs, melting of TPs, Ostwald ripening and, which seems the most probable, their combinations. Some of these processes would lead to highly defective structures. XRF analysis and EDX/TEM imaging During storage of the samples a

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• process temperature [213]. Deng et al. synthesised rGO-conjugated Cu2O NW mesocrystals by nonclassical crystallisation under hydrothermal conditions [214]. During the synthesis process, Ostwald ripening is responsible for the formation of the NW building block. This porous 3D framework structure, Cu2O NW

The longstanding challenge of the nanocrystallization of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX)

• Florent Pessina and
• Denis Spitzer

Beilstein J. Nanotechnol. 2017, 8, 452–466, doi:10.3762/bjnano.8.49

• synthesis of 30 nm RDX in a pH 7-stabilized solution. For such sizes and even at that pH, agglomeration and Ostwald ripening occur. Therefore, to avoid the degradation of the nanoparticles, a polymer coating (PEI or poly(vinylpyrrolidone) (PVP)) is necessary. It should be mentioned that no subsequent

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

• the layer thickness [15]. Washing and pyrolysis of the molecular residues was then necessary to obtain pure metal NPs, the latter unfortunately inducing post-irradiation particle growth ascribed to Ostwald ripening and therefore deteriorating the monodispersity [15]. As an alternative, a homogeneous

• particle growth is limited by the supply of precursor material. The relatively low electron energies applied to the samples thus do not lead to further change of the particle sizes by Ostwald ripening. RAIRS reveals that the decomposition of oxalate ions under electron exposure is accompanied by the

Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate

• Rainhard Machatschek,
• Patrick Ortmann,
• Renate Reiter,
• Stefan Mecking and
• Günter Reiter

Beilstein J. Nanotechnol. 2016, 7, 784–798, doi:10.3762/bjnano.7.70

• procedure did not yield the same surface enrichment effect for layers of nanocrystals. Due to the high surface to volume ratio of the CPE45 nanocrystals, Ostwald ripening (i.e., fusion of nanocrystals) is expected to take place upon thermal annealing of nanocrystal layers [37][38]. We note that the ratio of

• molecules that could be attached to their fold surface, as annealing of polymer nanocrystals induced Ostwald ripening [37][38] instead of reorganization of the fold surface. Consequently, for the chosen experimental conditions, these nanocrystals did not allow for the attachment of a large number of

Orientation of FePt nanoparticles on top of a-SiO₂/Si(001), MgO(001) and sapphire(0001): effect of thermal treatments and influence of substrate and particle size

• Martin Schilling,
• Paul Ziemann,
• Zaoli Zhang,
• Johannes Biskupek,
• Ute Kaiser and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2016, 7, 591–604, doi:10.3762/bjnano.7.52

• coalescence, growth or Ostwald ripening by annealing can be completely avoided [15]. In the present study we investigate the possibility of a structural (re)orientation of FePt NPs and thin films on a-SiO2/Si(001), MgO(001), and sapphire(0001) after different in situ annealing steps by HRTEM and RHEED

• control over the interparticle distance guaranteed to avoid any coalescence or Ostwald ripening even after repeated annealing steps at high temperature as demonstrated by related AFM measurements. It is found that the structural and chemical differences of the various substrate surfaces influence the

Self-assembly mechanism of Ni nanowires prepared with an external magnetic field

• Xiaoyu Li,
• Hu Wang,
• Kenan Xie,
• Qin Long,
• Xuefei Lai and
• Li Liao

Beilstein J. Nanotechnol. 2015, 6, 2123–2128, doi:10.3762/bjnano.6.217

• curvature regions. The interfacial area reduction process is generally called coarsening or Ostwald ripening, which is briefly illustrated in Figure 4 [26][27][28][29]. Therefore, this interesting phenomenon may be attributed to Ostwald ripening: while the size of particles is uniformly distributed at 120 s

• . XRD pattern of nickel nanowires. SEM (a) and TEM (b) images of the final Ni samples. SEM micrographs of products prepared after the reaction proceeded for 30 s (a), 60 s (b), 120 s (c), 240 s (d), 300 s (e), and 600 s (f). Ostwald ripening: (a) the process of Ostwald ripening involves small particles

• being engulfed by larger particles; (b) process diagram of Ostwald ripening. Schematic diagram of the stepwise formation of Ni nanowires. Acknowledgements Financial support by the National Natural Science Foundation of China (Grant No. 50904046) is gratefully acknowledged.

A simple approach to the synthesis of Cu_1.8S dendrites with thiamine hydrochloride as a sulfur source and structure-directing agent

• Xiaoliang Yan,
• Sha Li,
• Yun-xiang Pan,
• Zhi Yang and
• Xuguang Liu

Beilstein J. Nanotechnol. 2015, 6, 881–885, doi:10.3762/bjnano.6.90

• structure, as shown in Figure 3f. After a reaction time of 24 h under hydrothermal conditions, the perfect dendrite was obtained through Ostwald ripening. The secondary and third level dendrite appears and leads to the formation of a dendritic net structure. Most of the product evolved into fully 2D

The impact of the confinement of reactants on the metal distribution in bimetallic nanoparticles synthesized in reverse micelles

• Concha Tojo,
• Elena González and
• Nuria Vila-Romeu

Beilstein J. Nanotechnol. 2014, 5, 1966–1979, doi:10.3762/bjnano.5.206

• into account the surface composition (Au or Pt). Another type of growth is Ostwald ripening, that is, the growth of larger particles at the expense of smaller ones by transport of material. It is assumed that the easier solubilization of the smallest particles causes their decrease in size. These atoms

Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses

• Pravin Kumar,
• Udai Bhan Singh,
• Kedar Mal,
• Sunil Ojha,
• Indra Sulania,
• Dinakar Kanjilal,
• Dinesh Singh and
• Vidya Nand Singh

Beilstein J. Nanotechnol. 2014, 5, 1864–1872, doi:10.3762/bjnano.5.197

• uniform size of NPs on the surface. The recoiled Pt atoms underneath the surface may also agglomerate during thermal spikes giving rise to the satellite Pt NPs as reported in the literature [22][45]. The Ostwald ripening [46] of these satellite NPs can result in the final size (≈5 nm as seen by HRXTEM

• analysis) of NPs which undergo diffusion into the silicon. In Ostwald ripening, bigger clusters are grown at the expense of the dissolution of smaller cluster. The necessary temperature for this process is achieved through energy deposition from the ion beam. To confirm the formation of a silicide phase

Microstructural and plasmonic modifications in Ag–TiO₂ and Au–TiO₂ nanocomposites through ion beam irradiation

• Venkata Sai Kiran Chakravadhanula,
• Yogendra Kumar Mishra,
• Venkata Girish Kotnur,
• Devesh Kumar Avasthi,
• Thomas Strunskus,
• Vladimir Zaporotchenko,
• Dietmar Fink,
• Lorenz Kienle and
• Franz Faupel

Beilstein J. Nanotechnol. 2014, 5, 1419–1431, doi:10.3762/bjnano.5.154

• observed. On in situ heating, from room temperature to 500 °C, there is an increase in the size of the nanoparticles due to Ostwald ripening, (also observed after the in situ heating of Au–TiO2 nanocomposites). In addition, evidence for the changes in the matrix at 500 °C can also be observed in the SAED

One-step synthesis of high quality kesterite Cu₂ZnSnS₄ nanocrystals – a hydrothermal approach

• Vincent Tiing Tiong,
• John Bell and
• Hongxia Wang

Beilstein J. Nanotechnol. 2014, 5, 438–446, doi:10.3762/bjnano.5.51

• duration is extended to 8 h, the Zn/Sn ratio is increased to 1/1.04 which matches well with the theoretical value of 1:1 in CZTS. With the proceeding of the reaction, the primary CZTS crystal nucleus grows to nanoparticles with different sizes. Based on Ostwald ripening process, the small crystal nucleus

Nanoscale patterning of a self-assembled monolayer by modification of the molecule–substrate bond

• Cai Shen and
• Manfred Buck

Beilstein J. Nanotechnol. 2014, 5, 258–267, doi:10.3762/bjnano.5.28

• Figure 2a. Due to the thermal treatment of the BP2 layer the smaller terraces are free of vacancy islands (VIs) and those present on more extended terraces are significantly bigger and less dense compared to samples prepared at room temperature. While Ostwald ripening accounts to some extent for this

En route to controlled catalytic CVD synthesis of densely packed and vertically aligned nitrogen-doped carbon nanotube arrays

• Slawomir Boncel,
• Sebastian W. Pattinson,
• Valérie Geiser,
• Milo S. P. Shaffer and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2014, 5, 219–233, doi:10.3762/bjnano.5.24

• carbon nanotubes, increasing [FeCp2] resulted in an increase of the diameter of the MWCNTs [55]. This phenomenon is related to Ostwald ripening [62][63][64]. However, the opposite was found in N-CNTs, which could indicate a different mechanism of growth, which will be discussed further below. Also, the

Oriented attachment explains cobalt ferrite nanoparticle growth in bioinspired syntheses

• Annalena Wolff,
• Walid Hetaba,
• Marco Wißbrock,
• Stefan Löffler,
• Nadine Mill,
• Katrin Eckstädt,
• Axel Dreyer,
• Inga Ennen,
• Norbert Sewald,
• Peter Schattschneider and
• Andreas Hütten

Beilstein J. Nanotechnol. 2014, 5, 210–218, doi:10.3762/bjnano.5.23

• particle diameter. At the same time the larger maximum shifts to an increased diameter Dlarge = 40 nm. Tailing can now be observed in the size distribution as well, indicating that Ostwald ripening occurs in the later stages of particle growth. The diminishing amount of smaller nanoparticles and the

• kinetic model for oriented attachment (OA) described by Zhang et al. [24] with Ostwald ripening (OR) dominating the later stage of nanoparticle growth. The change in diameter with time can be modelled by the proposed model [24] with d0 as the initial particle size and k1 = 3.4 × 10−5 s−1 as an oriented

• attachment kinetic reaction constant between two particles, dOR as the particle diameter at which Ostwald ripening starts, d as the particle diameter with time, k2 = 6.11 Å3 s−1 as the rate constant and t as the time. The vanishing smaller maximum in the size distribution (see Figure 2) is a further

Design criteria for stable Pt/C fuel cell catalysts

• Josef C. Meier,
• Carolina Galeano,
• Ioannis Katsounaros,
• Jonathon Witte,
• Hans J. Bongard,
• Angel A. Topalov,
• Claudio Baldizzone,
• Stefano Mezzavilla,
• Ferdi Schüth and
• Karl J. J. Mayrhofer

Beilstein J. Nanotechnol. 2014, 5, 44–67, doi:10.3762/bjnano.5.5

• platinum (Gibbs–Thomson effect) [14][15]. If the dissolved platinum is redeposited on larger platinum particles, significant particle growth can occur and the according degradation mechanism is called Ostwald ripening (3D Ostwald ripening, if the dissolved platinum species travel through the electrolyte

• , and 2D Ostwald ripening – as known from high temperature TEM studies in the absence of an electrolyte – if platinum atoms are believed to diffuse along the carbon support) [44][45][47][48]. Another possible explanation for the growth of platinum particles in the catalyst layer is coalescence [17][49

• phenomena such as Ostwald ripening or platinum deposition in the ionomer. Much of the up-to-date knowledge on degradation mechanisms of standard fuel cell catalysts has been derived from post-mortem analyses of membrane electrode assemblies (MEAs) after fuel cell operation. Electron-microscopic techniques

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• prevented, extending the catalyst lifetime [50]. Another positive effect of the use of the oxidant is the inhibition of Ostwald ripening if injected during the annealing treatment of the catalyst film; the Ostwald ripening causes the formation of large particles thus reducing the yield of the CNT synthesis

STM study on the self-assembly of oligothiophene-based organic semiconductors

• Elena Mena-Osteritz,
• Marta Urdanpilleta,
• Erwaa El-Hosseiny,
• Berndt Koslowski,
• Paul Ziemann and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 802–808, doi:10.3762/bjnano.2.88

• shorter oligomers. This phenomenon can be explained by a decrease in diffusivity as the size of the oligomers increase. However, the adsorption–desorption dynamics at the surface and the observed Ostwald ripening [21][22] lead to an almost perfect monolayer with time. The arrangement of the molecules

Generation and agglomeration behaviour of size-selected sub-nm iron clusters as catalysts for the growth of carbon nanotubes

• Ravi Joshi,
• Benjamin Waldschmidt,
• Jörg Engstler,
• Rolf Schäfer and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2011, 2, 734–739, doi:10.3762/bjnano.2.80

• parameters, led to an agglomeration of the small sub-nm iron clusters to form iron nanoparticles and hence allowing their subsequent detection under the microscope (Figure 2). This cluster growth process occurs by Ostwald ripening, which takes place as a fast process in a matter of minutes at this

• temperature [14]. Our findings are in accordance with the stability of size-selected Au clusters pinned on graphite for which strong cluster agglomeration above 600 °C was shown [11], indicating that a combination of diffusion controlled agglomeration and Ostwald ripening of Fe clusters becomes significant at

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

• sizes ranging from 7 nm to about 20 nm according to BET and XRD measurements are produced. The dependency of the particle size on the process parameters is evaluated statistically and explained with growth-rate equations derived from the theory of Ostwald ripening. The results show that the particle

• equation describes the growth rate of larger particles, which is known as Ostwald ripening, resulting in the well-known log-normal distribution of the particle sizes. Taking into account, that D = ƒ(1 = ptotal, Tx), with 1 ≤ x ≤ 2, one can give the following proportionalities for the growth rate of a

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

• -water) miniemulsion, with the monomer as the dispersed oil phase. The nanodroplets are generated by shearing this system with ultrasound. A highly hydrophobic osmotic pressure agent (costabilizer) is added to the oil phase, effectively suppressing diffusional degradation (Ostwald ripening) of the