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Search for "surfactant" in Full Text gives 229 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.
Hematopoietic and mesenchymal stem cells: polymeric nanoparticle uptake and lineage differentiation
Beilstein J. Nanotechnol. 2015, 6, 383–395, doi:10.3762/bjnano.6.38
- functionalized polystyrene nanoparticles as described in [18]) or by a combination of miniemulsion and emulsion/solvent evaporation techniques (PLLA nanoparticles without and with magnetite, as described in [19][20]). In all cases, SDS was used as a surfactant for the synthesis or formation of the nanoparticles
- . The nanoparticles were purified from the surfactant excess by dialysis using Amicon Ultra membrane filters with MWCO 100 kDa (Millipore). The main characteristics of the nanoparticles are described in Table 1. Uptake and toxicity of polymeric nanoparticles Before the nanoparticles were used for
Nanoparticle shapes by using Wulff constructions and first-principles calculations
Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35
- ). Right: With adsorbed SCH3 radicals (29 nm in diameter, 502900 atoms, 10600 of which are step-edge atoms; (211) faces occupy almost 100% of the total area). Schematic representation of the adsorption of a surfactant on a gold surface. Spheres represent gold (yellow), silver (grey) and bromine (red) and
- the tails of the surfactant are represented by sticks. Wulff construction for the nanoparticles of LiBH4. The blue spheres are for lithium, red for boron and white are hydrogen atoms. Acknowledgements INR acknowledges valuable discussions on Wulff construction with Prof. Phoebus Rosakis. ZL
Exploiting the hierarchical morphology of single-walled and multi-walled carbon nanotube films for highly hydrophobic coatings
Beilstein J. Nanotechnol. 2015, 6, 353–360, doi:10.3762/bjnano.6.34
- , assay >90%, diameter: 5–50 nm) were dispersed in aqueous solution (80 μg·mL−1) with 2% w/v sodium dodecyl sulfate (Sigma-Aldrich, assay >98.5%) anionic surfactant. In addition, to better disperse the suspension, the carbon nanotubes were tip-ultrasonicated (Branson S250A, 200 W, 20% power, 20 kHz) in an
- two different film layers were obtained. Subsequently, rinsing in water and in a solution of ethanol, methanol and water (15:15:70) to remove as much surfactant as possible was performed. Samples were made uniformly depositing by the dry-transfer printing method carbon nanotube films on Carlo Erba
Synthesis of boron nitride nanotubes and their applications
Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9
- assess the toxicity of the BNNTs. Similar to CNTs, one of the major problems in toxicity assessment of BNNTs is their low dispersibility in aqueous media, due to their high hydrophobicity. In order to increase the dispersion, either a surfactant or hydrophilic polymer is used to alter the surface
Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating
Beilstein J. Nanotechnol. 2014, 5, 2479–2488, doi:10.3762/bjnano.5.257
- Planck Institute for Biology of Ageing, Joseph-Stelzmann-Straße 9b, 50931 Cologne, Germany 10.3762/bjnano.5.257 Abstract In this work, we study epithelial cell growth on substrates decorated with gold nanorods that are functionalized either with a positively charged cytotoxic surfactant or with a
- cell migration and no significant particle internalization occurred. Concerning cell adhesion and spreading as compared to cell growth on bare substrates after 3 days of incubation, a reduction by 45% and 95%, respectively, for the surfactant particle coating was observed, whereas the amino-terminated
- decorated with various amounts of surfactant-coated particles. A surface density of 65 particles/µm2 (which corresponds to 0.5% of surface coverage with nanoparticles) diminishes micromotion by 25% as compared to bare substrates after 35 hours of incubation. We conclude that the surface coating of the gold
Nanoparticle interactions with live cells: Quantitative fluorescence microscopy of nanoparticle size effects
Beilstein J. Nanotechnol. 2014, 5, 2388–2397, doi:10.3762/bjnano.5.248
- adsorbed amphiphiles, the anionic surfactant SDS or cetyltrimethylammonium (CTMA) chloride to yield negatively (PS−) and positively (PS+) charged NPs, respectively. The hydrodynamic diameters of these NPs suspended in PBS, pH 7.4, were determined by dynamic light scattering (DLS) (Table 1). Furthermore
Si/Ge intermixing during Ge Stranski–Krastanov growth
Beilstein J. Nanotechnol. 2014, 5, 2374–2382, doi:10.3762/bjnano.5.246
- dot assembly [1][2][3][4][5][6][7]. The focus of these investigations was devoted to understanding the shape of the islands and density variations versus stress (or strain) or substrate surface modifications (e.g., patterning, Si(Ge) buffer or surfactant variations) [6][7][8][9][10][11], using
Inorganic Janus particles for biomedical applications
Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244
- nanoparticles [75][76][77]. Inspired by the idea of the formation of a complex composed of the metal ion and the ligand, the strategy of direct employment of a metal-surfactant complex was used. For instance, manganese(II)oleate [77] and iron(III)oleate [64][75][78] can be handled easily and safely due to their
- permission from [29]. Copyright 2008 The Royal Society of Chemistry. (a) Schematic representation of bimetallic Janus particles at the hexane–water interface (gold: gold part with surfactant; gray: iron oxide part). (b) Interfacial tension vs time as measured by pendant drop tensiometry (NP: homogeneous
Liquid-phase exfoliated graphene: functionalization, characterization, and applications
Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242
- the production of highly reactive chemical species including peroxides and radicals formed from the sonochemical reaction of the solvent in air [20]. The combined mechanochemical effects of ultrasonication prompt the exfoliation of graphite in organic solvents, surfactant solutions, or mixed organic
- the square of the zeta potential of the surfactant-coated sheets. This means that the concentration is proportional to the magnitude of the electrostatic potential barrier, which prevents graphene π–π stabilization. In contrast, for non-ionic surfactants, the dispersed graphene concentration increased
Characterization of 10,12-pentacosadiynoic acid Langmuir–Blodgett monolayers and their use in metal–insulator–metal tunnel devices
Beilstein J. Nanotechnol. 2014, 5, 2240–2247, doi:10.3762/bjnano.5.233
- MIM structures. Experimental Overview of the deposition of PDA, LS films Langmuir monolayers and LB films: For these experiments, PDA was obtained from Sigma-Aldrich in the form of 10,12-pentacosadiynoic acid (≥97.0%, HPLC grade). A 0.2 mg/mL solution of the surfactant PDA was prepared in chloroform
Hybrid spin-crossover nanostructures
Beilstein J. Nanotechnol. 2014, 5, 2230–2239, doi:10.3762/bjnano.5.232
- [FeIICrIII(CN)6]@CsI[NiIICrIII(CN)6] systems [26]. These core–multishell coordination nanoparticles were fabricated using a straightforward, surfactant-free manipulation with precise size control of the sample by controlling the addition rate and the concentration of the components. It is worth noting that
Influence of stabilising agents and pH on the size of SnO2 nanoparticles
Beilstein J. Nanotechnol. 2014, 5, 2192–2201, doi:10.3762/bjnano.5.228
- material increases the selectivity and sensitivity and shortens the response time of a sensor. However, the synthesis of SnO2 nanoparticles presents many difficulties. The following article presents a simple and inexpensive method for the synthesis of SnO2 nanoparticles. The influence of the surfactant and
- factor essential for good stabilisation of the nanoparticles was an appropriate acidity level of the solution. Under optimal conditions, nanoparticles having an average diameter of about 10 nm are reproducibly formed. Keywords: nanoparticles; polyethylenimine; polyvinylpyrrolidone; surfactant; tin
- composition, and a non-ionic surfactant. The influence of the individual reactants as well as the solution acidity on the dimensions of the resulting nanoparticles was analysed. The understanding of the interaction between these components of the solution is critical both for the synthesis of metal
Biopolymer colloids for controlling and templating inorganic synthesis
Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222
- ” geometries. In a very recent work, Taheri et al. [63] have presented the formation of potato starch capsules decorated with silver nanoparticles, which could have applications as drug carriers or antibacterial coatings. The capsules are prepared in an inverse (water-in-oil) miniemulsion and the surfactant
The impact of the confinement of reactants on the metal distribution in bimetallic nanoparticles synthesized in reverse micelles
Beilstein J. Nanotechnol. 2014, 5, 1966–1979, doi:10.3762/bjnano.5.206
- surfactant which accumulates at the oil–water interface. The flexibility of the surfactant film surrounding micelles is a parameter associated with the interfacial curvature, which depends on the interactions on both sides of the interface. The flexibility is dictated by the microemulsion composition (mainly
- by the surfactant), and is directly related to the facility with which intermicellar channels can be established. The intermicellar exchange of material takes place through the intermicellar channel, thus the kinetics of the nanoparticle formation will strongly depend on the channel feature. Two
- aspects must be taken into account in order to establish how surfactant film flexibility is included in the simulation model. First, the material exchange between micelles will only be possible if the dimer remains intact for a sufficient amount of time. The longer that two colliding micelles stay
The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions
Beilstein J. Nanotechnol. 2014, 5, 1774–1786, doi:10.3762/bjnano.5.188
- (organosiloxane) nanoparticles: Poly(organosiloxane) NPs are synthesized in an aqueous dispersion by co-condensation of mixtures of dialkyldialkoxysilanes and alkyltrialkoxysilanes in the presence of a surfactant. By sequential addition of mixtures with different ratios of bi- to tri-functional monomers
- nanotoxicology research: the investigation of the interaction of nanoparticles with the components of the alveolar surfactant film [71][72][73]. As the lung surfactant is the first barrier that inhaled nanoparticles encounter after passing the respiratory tract [74], interactions with this barrier are crucial in
- nanomaterial is mainly determined by three factors. The first one is the question of how the nanomaterial interacts with biological barriers. Here, interactions with the alveolar surfactant film are of special interest, because it is the first biological barrier after exposure via the lung. Therefore, the
Controlling the dispersion of supported polyoxometalate heterogeneous catalysts: impact of hybridization and the role of hydrophilicity–hydrophobicity balance and supramolecularity
Beilstein J. Nanotechnol. 2014, 5, 1749–1759, doi:10.3762/bjnano.5.185
- hybrids are deposited. For instance, surfactant-encapsulated clusters of POM anions, formed through electrostatic interactions, were reported to form well-ordered straight nanorods on graphite [17], whereas hybrid materials formed through covalent functionalization of POM formed planar layer-by-layer
- surface, the alkyl chains of DODA are known to orient with a tilt angle of θ ≈ 30° with respect to the normal of the surface [30]. As expected, no epitaxial arrangement of DODA was observed. The conformation of the DODA surfactant, as shown here, can thus be tuned as a function of the surface properties
- driven through the electrostatic interaction of POM anions with the positively charged DODA surfactant. Firstly, we study the DODA–POM hybrids deposited on HOPG. Drop-casting of a small amount (about 9.5 µL) of a very dilute solution (0.025 g·L−1) allows for the formation of molecular layers that are of
Nanocrystalline ceria coatings on solid oxide fuel cell anodes: the role of organic surfactant pretreatments on coating microstructures and sulfur tolerance
Beilstein J. Nanotechnol. 2014, 5, 1712–1724, doi:10.3762/bjnano.5.181
- coatings from aqueous solution, were applied to anodes of solid oxide fuel cells. The cells were then operated in hydrogen/nitrogen fuel streams with H2S contents ranging from 0 to 500 ppm. Two surfactant treatments were studied: immersion in dodecanethiol, and a multi-step conversion of a siloxy-anchored
- [6][19][20][28]. In the present work the microstructural changes and the degree of sulfur tolerance were related to the presence or absence of the ceria coating, its morphology (which depended on the prior surfactant treatment), and the extent of sulfur exposure. Results First we illustrate general
- characteristics of the performance of the cells in sulfur-containing environments. Then SEM and EDXS analyses of the microstructures of the cells, before and after operation, with and without surfactant pretreatments are presented. The performance of the cells, grouped by type of anode treatment, is then
Non-covalent and reversible functionalization of carbon nanotubes
Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178
- ionic surfactant such as sodium dodecyl sulfate (SDS). The chemical adsorption of SDS molecules on the surface of the nanotube induces electrostatic repulsion between polar heads that expose in the aqueous solution thus preventing CNTs aggregation and inducing the formation of stable aqueous black
- ultracentrifugation to equilibrium by exploiting a density gradient (see Figure 2) [62]. Different papers have faced the possible organizations of surfactant molecules on the surface of CNTs and still several conflicting evidences are reported in the literature. Richard et al. were among the first authors envisaging
- surfactant on the individual SWCNTs (see Figure 3, arrangement C). Analogously, we have evidenced [66][67] that gemini surfactants, characterized by two alkyl chains and two polar head groups separated by a spacer in a single molecule, are relatively effective dispersants also below their CMC or at very low
Silica nanoparticles are less toxic to human lung cells when deposited at the air–liquid interface compared to conventional submerged exposure
Beilstein J. Nanotechnol. 2014, 5, 1590–1602, doi:10.3762/bjnano.5.171
- , the importance of shear forces to exacerbate NP-induced toxicity has been described previously [8][33]. Another explanation could also be the secretion of surfactant by A549 cells under ALI conditions [34] which may have a protective effect due to binding of surfactant proteins to the particles [35
Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties
Beilstein J. Nanotechnol. 2014, 5, 1542–1552, doi:10.3762/bjnano.5.166
- from the chalcocite to the digenite phase. According to Wang et al., the growth and rearrangement of the nanodisks are dependent on the concentration of precursors, amount of surfactant, the reaction temperature, and the reaction time. We found that this rearrangement of nanodisks is necessary for the
Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays
Beilstein J. Nanotechnol. 2014, 5, 1523–1541, doi:10.3762/bjnano.5.165
- controlled independently while their uniquely high purity is retained. Hence, this article will highlight totally surfactant-free size control strategies for laser-fabricated nanoparticles and will comment on the stability of these particles in biological fluids. Additionally, laser-based synthesis methods
In vitro interaction of colloidal nanoparticles with mammalian cells: What have we learned thus far?
Beilstein J. Nanotechnol. 2014, 5, 1477–1490, doi:10.3762/bjnano.5.161
- , proteins which are initially bound to the NP surface can later be replaced by others [140][141], which also is referred to as the Vroman effect [142]. It has been shown, for example, that surfactant lipids bound on multiwall carbon nanotubes are replaced with blood plasma proteins after a subsequent
- effects can result from the NPs themselves (e.g., by their catalytic surface or by their organic coating, such as in the case of cetyltrimethylammonium bromide (CTAB), a surfactant commonly used to synthesize gold nanorods) or by ions released from the NPs [154][155]. Ion release from certain materials
Protein-coated pH-responsive gold nanoparticles: Microwave-assisted synthesis and surface charge-dependent anticancer activity
Beilstein J. Nanotechnol. 2014, 5, 1452–1462, doi:10.3762/bjnano.5.158
- influence on the shape of the nanoparticle [22]. We observed that, by using a single protocol, we could obtain four different gold nanostructures depending on the surfactant used for the capping. For this purpose sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTA), N-dodecyl-N,N-dimethyl-3
The protein corona protects against size- and dose-dependent toxicity of amorphous silica nanoparticles
Beilstein J. Nanotechnol. 2014, 5, 1380–1392, doi:10.3762/bjnano.5.151
- MTT assay (Figure 6). Similar to the lung surfactant [32], also epithelial cell of the GI tract are covered by an additional biobarrier, i.e., by mucous matrices [33]. To investigate the impact of mucus associated to GI tract cells on the observed effects, we included the mucus-secreting colorectal
- and thus, results in a reduced intracellular NP dose. However, whether reduced uptake is the (only) major determinant of the cytoprotective impact of the protein corona remains to be verified [44]. Clearly, the underlying mechanisms are not yet fully resolved. Of note, similar to the lung surfactant
Nanoporous composites prepared by a combination of SBA-15 with Mg–Al mixed oxides. Water vapor sorption properties
Beilstein J. Nanotechnol. 2014, 5, 1226–1234, doi:10.3762/bjnano.5.136
- attributed to the basic synthesis conditions. A basic medium can cause a partial destruction of the SBA-15 network [15]. Since the HT/SBA(NC) still presents the organic surfactant and TEOS during the coprecipitation of Mg and Al salts, the dissolution of the silanols species is not strongly affected by the
- that preserve the textural SBA-15 properties and also the basic properties. Indeed, Mg–Al precursors are homogenously dispersed mainly on the mesoporous SBA-15 surface. Furthermore, if the SBA-15 still contains surfactant (i.e., not calcined), the grafting through the HT coprecipitation of metal salts
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