Correlation of surface-enhanced Raman scattering (SERS) with the surface density of gold nanoparticles: evaluation of the critical number of SERS tags for a detectable signal

• Vincenzo Amendola

Beilstein J. Nanotechnol. 2019, 10, 1016–1023, doi:10.3762/bjnano.10.102

• serves to prevent particle agglomeration after drying the drop [42]. Characterization UV–visible spectroscopy was performed with a Varian Cary 5 spectrometer in 2 mm optical path length quartz cells. The AuNP concentration was estimated from UV–visible spectra and the application of Mie theory, as

Structural and optical properties of penicillamine-protected gold nanocluster fractions separated by sequential size-selective fractionation

• Xiupei Yang,
• Zhengli Yang,
• Fenglin Tang,
• Jing Xu,
• Maoxue Zhang and
• Martin M. F. Choi

Beilstein J. Nanotechnol. 2019, 10, 955–966, doi:10.3762/bjnano.10.96

• precipitation technique can reduce the ability of a solvent to disperse clusters by adding a miscible non-solvent to the cluster agglomeration point. The larger clusters are first aggregated due to the greater van der Waals attraction between the clusters, and the clusters aggregated can be precipitated by

Reduced graphene oxide supported C₃N₄ nanoflakes and quantum dots as metal-free catalysts for visible light assisted CO₂ reduction

• Md Rakibuddin and
• Haekyoung Kim

Beilstein J. Nanotechnol. 2019, 10, 448–458, doi:10.3762/bjnano.10.44

• ) compared to CN-10 (207.8 m2/g) and CN-20 (195.4 m2/g), thus increasing the number of catalytic active sites. The lower surface area of CN-20 was responsible for its poorer activity compared to CN-10, which is probably because of the agglomeration of CN-20, as suggested by TEM. The photoreduction ability of

A Ni(OH)₂ nanopetals network for high-performance supercapacitors synthesized by immersing Ni nanofoam in water

• Donghui Zheng,
• Man Li,
• Yongyan Li,
• Chunling Qin,
• Yichao Wang and
• Zhifeng Wang

Beilstein J. Nanotechnol. 2019, 10, 281–293, doi:10.3762/bjnano.10.27

• related to the agglomeration of Ni(OH)2 nanopetals. Performance of energy storage devices In order to further show the good energy storage performance of the as-prepared sandwich-like electrodes, the SC devices were assembled using Ni(OH)2/Ni-NF/MG-7. The CV and GCD curves of a single SC device are shown

Study of silica-based intrinsically emitting nanoparticles produced by an excimer laser

• Imène Reghioua,
• Mattia Fanetti,
• Sylvain Girard,
• Diego Di Francesca,
• Simonpietro Agnello,
• Layla Martin-Samos,
• Marco Cannas,
• Matjaz Valant,
• Melanie Raine,
• Marc Gaillardin,
• Nicolas Richard,
• Philippe Paillet,
• Aziz Boukenter,
• Youcef Ouerdane and
• Antonino Alessi

Beilstein J. Nanotechnol. 2019, 10, 211–221, doi:10.3762/bjnano.10.19

• displays the central part, evidencing the different shapes of the obtained particles and their states of aggregation/agglomeration. Another group of particles (Figure 3c) illustrates the variety of observed sizes and shapes. In this image, we can distinguish some spherical nanoparticles among other

• aggregation/agglomeration is also evidenced. More results are further highlighted in Figure 3d in which the particles seem to be merged or at least feature large contact regions. Furthermore, this image is recorded with a sufficiently high magnification to evidence the absence of a crystalline structure

• about 50 nm, even if larger particles with diameter above 100 nm are also detected. An example is reported in Figure 5d that illustrates the presence of large and small particles. Such an image also confirms the state of aggregation/agglomeration of the investigated system. Figure 5e reports the STEM

Wet chemistry route for the decoration of carbon nanotubes with iron oxide nanoparticles for gas sensing

• Hussam M. Elnabawy,
• Juan Casanova-Chafer,
• Badawi Anis,
• Mostafa Fedawy,
• Mattia Scardamaglia,
• Carla Bittencourt,
• Ahmed S. G. Khalil,
• Eduard Llobet and
• Xavier Vilanova

Beilstein J. Nanotechnol. 2019, 10, 105–118, doi:10.3762/bjnano.10.10

• decorated CNT’s morphology, decoration uniformity and decoration homogeneity. Methanol and ethanol were found to allow for a more uniform and homogenous decoration along the CNTs and also better powder morphology. On the other hand, DMF and acetone resulted in the formation of agglomeration islands on the

Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties

• Florian Dumitrache,
• Iuliana P. Morjan,
• Elena Dutu,
• Ion Morjan,
• Claudiu Teodor Fleaca,
• Monica Scarisoreanu,
• Alina Ilie,
• Marius Dumitru,
• Cristian Mihailescu,
• Adriana Smarandache and
• Gabriel Prodan

Beilstein J. Nanotechnol. 2019, 10, 9–21, doi:10.3762/bjnano.10.2

• case, a mixture of tetragonal rutile-type and minority orthorhombic tin dioxide phases was identified [44]. The crystalline phases identified from SAED (see Figure 3b) images are consistent with those from XRD, indicating structural uniformity up to the level of nanoparticle agglomeration containing

Characterization and influence of hydroxyapatite nanopowders on living cells

• Przemyslaw Oberbek,
• Tomasz Bolek,
• Adrian Chlanda,
• Seishiro Hirano,
• Sylwia Kusnieruk,
• Julia Rogowska-Tylman,
• Ganna Nechyporenko,
• Viktor Zinchenko,
• Wojciech Swieszkowski and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2018, 9, 3079–3094, doi:10.3762/bjnano.9.286

• their aggregates or agglomerates, the impact of their physicochemical properties (such as particle size, surface area, purity, details of structure and degree of agglomeration) on living cells is not yet fully understood. Significant differences in these properties, resulting from different

• in the application of novel NPs in medicine and biology. Adverse effect of NOAA on living organisms may be influenced by many factors such as size, shape, solubility, exposure time, surface charge, surface area, crystallinity, agglomeration or chemical composition [7][8][9]. Since the properties of

• very similar to the ratio present in tooth enamel (1.62) [30]. Characterization methods Based on the work of Oberdörster et al. [7] and OECD recommendations [31], various features including density, morphology, average particle size, particle shape expressed by aspect ratio, state of agglomeration

Graphene-enhanced metal oxide gas sensors at room temperature: a review

• Dongjin Sun,
• Yifan Luo,
• Marc Debliquy and
• Chao Zhang

Beilstein J. Nanotechnol. 2018, 9, 2832–2844, doi:10.3762/bjnano.9.264

• experiment with the ZnO–rGO sensor, a pure rGO sensor and a sensor fabricated by physically mixing ZnO and graphene dispersions. The last sensor exhibited the worst gas-sensing performance to NO2 due to the agglomeration of graphene sheets and ZnO particles. Similarly, this group [69] demonstrated that a

• preferential growth of SnO2 nanoparticles and prevented SnO2 nanoparticles from agglomeration. The response of the composite sensor to NH3 at 10 ppm was 5.09% and the response/recovery time was less than 1 min at room temperature, whereas the sensor based on SnO2 did not respond to NH3 and the sensor based on

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

• of agglomeration – a prerequisite for meaningful cell culture studies [47][86]. Note that the hydrodynamic diameter determined by DCS is systematically underestimated because of the hydration shell [87]. The average diameter of all particles was in the range between 5 and 10 nm. These results agree

• cell culture medium and no agglomeration or sedimentation was observed. Only silver nanoparticles had a discernible effect on the viability of hMSC after 24 h of exposure (Figure 6). They had a cytotoxic effect starting at 25 µg mL−1. The cell viability further decreased with increasing silver

• higher metal concentrations (50 µg mL−1). Even at prolonged incubation times (up to 7 days), no cell toxicity was observed (data not shown) for these metals. Neither agglomeration nor sedimentation of the nanoparticles was observed in the cell culture medium in any case, indicating good dispersion. As

Non-agglomerated silicon–organic nanoparticles and their nanocomplexes with oligonucleotides: synthesis and properties

• Asya S. Levina,
• Marina N. Repkova,
• Nadezhda V. Shikina,
• Zinfer R. Ismagilov,
• Svetlana A. Yashnik,
• Dmitrii V. Semenov,
• Yulia I. Savinovskaya,
• Natalia A. Mazurkova,
• Inna A. Pyshnaya and
• Valentina F. Zarytova

Beilstein J. Nanotechnol. 2018, 9, 2516–2525, doi:10.3762/bjnano.9.234

• agglomeration of the particles). The zeta potential of the studied samples was evaluated by phase analysis light scattering. The value of zeta potential of Si–NH2 is positive due to positively charged amino groups in neutral medium. When the nanoparticles were bound to an oligonucleotide, the zeta potential

Enhanced antineoplastic/therapeutic efficacy using 5-fluorouracil-loaded calcium phosphate nanoparticles

• Shanid Mohiyuddin,
• Saba Naqvi and
• Gopinath Packirisamy

Beilstein J. Nanotechnol. 2018, 9, 2499–2515, doi:10.3762/bjnano.9.233

• agglomeration and enhanced colloidal stability [29]. Since the particle stability mainly depends on the electrical charge of the surface, properties such as cellular uptake, rate of drug release, and blood retention time are directly correlated with the zeta potential value. Furthermore, the zeta potential

Nanocellulose: Recent advances and its prospects in environmental remediation

• Katrina Pui Yee Shak,
• Yean Ling Pang and
• Shee Keat Mah

Beilstein J. Nanotechnol. 2018, 9, 2479–2498, doi:10.3762/bjnano.9.232

• are still rare since researchers mainly focused on adsorption of metals from diluted aqueous solution or photocatalysis as discussed in previous sections. Agglomeration remains an issue in the application of CNCs as flocculants. This is due to the hydrogen bond networks arising from the –OH groups on

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

• -WO3 NTs toward 5 ppm toluene at 400 °C is measured. A negligible NO response (1.25 for the Pt-WO3 NTs and 1.04 for the Pd-WO3 NTs at 5ppm) at 400 °C was found. One problem associated with surface functionalization of NPs (3–50 nm) is their agglomeration. Traditional functionalization methods have

Synthesis of a MnO₂/Fe₃O₄/diatomite nanocomposite as an efficient heterogeneous Fenton-like catalyst for methylene blue degradation

• Zishun Li,
• Xuekun Tang,
• Kun Liu,
• Jing Huang,
• Yueyang Xu,
• Qian Peng and
• Minlin Ao

Beilstein J. Nanotechnol. 2018, 9, 1940–1950, doi:10.3762/bjnano.9.185

• composite is the most effective strategy [14]. Through this strategy, catalysts with controllable particle size, better dispersion and decreased agglomeration are easy to be synthesized and are expected to significantly increase the contact between active sites and contaminants. In addition, with the

Cryochemical synthesis of ultrasmall, highly crystalline, nanostructured metal oxides and salts

• Elena A. Trusova and
• Nikolai S. Trutnev

Beilstein J. Nanotechnol. 2018, 9, 1755–1763, doi:10.3762/bjnano.9.166

• dispersity by 3–18 times and to increase their specific surface area by an order of magnitude. The proposed approach also reduces the agglomeration of the nanoparticles, and at the same time, results in NiO, Fe2O3 and CeO2 crystallite sizes of less than 10 nm (quantum dot size regime). The diameter of NaNO3

• of the chain aggregates was related to the ice structure formed during freezing [10]. The cryoprocessing of liquid media, solutions and colloids can be used to limit the growth and agglomeration of the formed particles, to stabilize their surface, and thus, to obtain discrete particles of

• cryogel (labeled as B in Figure 3) is formed during the treatment of sol A with liquid N2 (−196 °C ). The resulting water crystallite shell prevents the agglomeration of the sol particles. The obtained organic–inorganic cryogel powders consisted of capillary porous granules (Figure 2) and contained the

Controllable one-pot synthesis of uniform colloidal TiO₂ particles in a mixed solvent solution for photocatalysis

• Jong Tae Moon,
• Seung Ki Lee and
• Ji Bong Joo

Beilstein J. Nanotechnol. 2018, 9, 1715–1727, doi:10.3762/bjnano.9.163

• macroscopic morphology. In this study, we optimized these factors to control the size of the TiO2 particles and prevent particle agglomeration. Figure 1 compares the as-synthesized amorphous TiO2 particles prepared by varying the solvent composition. As shown in Figure 1a, when only pure ethanol was used as

• , the particle diameter decreased to ≈340 nm and most of the particles were individually isolated without particle agglomeration (Figure 1b). When the volume ratio of EtOH/ACN was 2:2, the particle size of the spherical TiO2 particles became even smaller, reducing to ≈250 nm without apparent particle

• the TiO2 particles, and therefore, suppressed interparticle agglomeration. Consistent with other syntheses, synthesizing uniform TiO2 particles was also controlled by changing the concentration of the precursor [14][31]. When 1 mL of TBOT was used, the as-synthesized TiO2 particles formed as small

Nanocomposites comprised of homogeneously dispersed magnetic iron-oxide nanoparticles and poly(methyl methacrylate)

• Sašo Gyergyek,
• David Pahovnik,
• Ema Žagar,
• Alenka Mertelj,
• Rok Kostanjšek,
• Miloš Beković,
• Marko Jagodič,
• Heinrich Hofmann and
• Darko Makovec

Beilstein J. Nanotechnol. 2018, 9, 1613–1622, doi:10.3762/bjnano.9.153

• colloidal stability and prevent the agglomeration of the nanoparticles during the preparation of the nanocomposites. The PMMA chains are strongly attached to the surfaces of the nanoparticles, as indicated by the inhibited Fe ion dissolution under highly acidic conditions. The nanocomposites exhibit

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

• aggregation and agglomeration of particles. On increasing ZnO content in the ZnO/TiO2 composite, the rate of reduction of Cr(VI) was increased and the sample containing 2.0 mol % ZnO exhibited a maximum photocatalytic reduction of Cr(VI) in aqueous solution as the recombination of charge carriers is

• with further increase in the calcination temperature because of the decrease in the specific surface area induced by the aggregation and agglomeration of particles [157]. TiO2/Fe3O4 composite photocatalysts were synthesized through a polymerizable sol−gel route to investigate the photocatalytic

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

• stabilize active metal and prevent the occurrence of leaching or metal agglomeration. The authors further mention that supports can not only transport the reactants to the reaction center, but can also control diffusion rates of reactants and products and donate protons or electrons to alter total

• particles. Moreover, the addition of MgO in this catalyst prevented the agglomeration of Ni particles and increased the basicity of the catalyst; consequently, more CO2 was adsorbed on the catalyst surface. The adsorption and activation of CO2 decreased the carbon deposition. Notably, the catalyst

• 550 °C to 850 °C as exhibited in Figure 12. This finding indicates a small particle size distribution, good morphology, and high surface area of the catalyst, as well as high diffusion of active metal without agglomeration during the reaction. Moreover, the average particle size was 11.6 nm, which was

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

Single-crystalline FeCo nanoparticle-filled carbon nanotubes: synthesis, structural characterization and magnetic properties

• Rasha Ghunaim,
• Maik Scholz,
• Christine Damm,
• Bernd Rellinghaus,
• Rüdiger Klingeler,
• Bernd Büchner,
• Michael Mertig and
• Silke Hampel

Beilstein J. Nanotechnol. 2018, 9, 1024–1034, doi:10.3762/bjnano.9.95

• –Co. The CNTs act as templates for the encapsulation of magnetic nanoparticles and provide a protective shield against oxidation as well as prevent nanoparticle agglomeration. By variation of the reaction parameters, we were able to tailor the sample purity, degree of filling, the composition and size

• to be used in potential applications. Due to their high surface-to-volume (S/V) ratio, MNPs are more susceptible to oxidation, agglomeration, aggregation [31][32]. Therefore, it is necessary to produce MNPs with a protective layer which preserves their properties. Compared to polymer or silica

• the CNTs allowed the control of the particle size, and to a large extent, prevented particle agglomeration in both samples. Furthermore, a strong divergence between the size distribution of the as-prepared and the annealed samples is obvious. Hence, for very regular particles with high homogeneity and

Surface-plasmon-enhanced ultraviolet emission of Au-decorated ZnO structures for gas sensing and photocatalytic devices

• T. Anh Thu Do,
• Truong Giang Ho,
• Thu Hoai Bui,
• Quang Ngan Pham,
• Hong Thai Giang,
• Thi Thu Do,
• Duc Van Nguyen and
• Dai Lam Tran

Beilstein J. Nanotechnol. 2018, 9, 771–779, doi:10.3762/bjnano.9.70

• agglomeration, but also bind to the crystal seed surface. These are believed to play an important role in the weakening of grain growth and the assembly of nanorods. Owing to the stronger bonding between the active component of the deposition solution and substrate surface, the self-assembly of the nanorod

Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces

• Sven Oras,
• Sergei Vlassov,
• Marta Berholts,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2018, 9, 660–670, doi:10.3762/bjnano.9.61

• common particle shapes were pentagonal dipyramids and octahedrons [26]. The synthesis of so-called “bare” Au NPs, described in more details in the experimental section, involved addition of sodium citrate [27] in order to prevent the agglomeration of the NPs in the solution. Sodium citrate molecules

• hydrophilic coating, the previously used method [47] was slightly modified according to [52] by adding NaOH solution to improve the stability of the colloidal solution. Indeed, a high pH stabilizes the mixture, and prevents agglomeration of the NPs. The overview of the molecules used for functionalization and

Mechanistic insights into plasmonic photocatalysts in utilizing visible light

• Kah Hon Leong,
• Azrina Abd Aziz,
• Lan Ching Sim,
• Pichiah Saravanan,
• Min Jang and
• Detlef Bahnemann

Beilstein J. Nanotechnol. 2018, 9, 628–648, doi:10.3762/bjnano.9.59

• from Au one can find that palladium (Pd) in the form of NPs with a diameter of <10 nm is limited to the UV spectrum [25]. Nevertheless, the larger particle size and agglomeration of palladium particles contribute to the enhanced absorption of visible light. Mohapatra and coworkers demonstrated this