Fabrication of carbon nanospheres by the pyrolysis of polyacrylonitrile–poly(methyl methacrylate) core–shell composite nanoparticles

• Dafu Wei,
• Youwei Zhang and
• Jinping Fu

Beilstein J. Nanotechnol. 2017, 8, 1897–1908, doi:10.3762/bjnano.8.190

• nanoparticles. Firstly, PAN–PMMA nanoparticles at high concentration and low surfactant content were controllably synthesized by a two-stage azobisisobutyronitrile (AIBN)-initiated semicontinuous emulsion polymerization. The carbon nanospheres were obtained after the PAN core domain was converted into carbon

• . In this study, PAN-based carbon nanopsheres were fabricated from the PAN–PMMA core–shell nanoparticles precursor. Specifically, PAN–PMMA core–shell latexes at high concentration and low surfactant content were first synthesized via a two-stage AIBN-initiated semicontinuous emulsion polymerization

• surfactant content [39]. Here, a PAN nanolatex with an average diameter of 96 nm and a polydispersity index of 0.03 at an AN concentration of 100 g/L (based on the volume of water) and an SDS content of 3.3% (based on the weight of monomers) was firstly fabricated by the novel emulsion polymerization

Synthesis and functionalization of NaGdF₄:Yb,Er@NaGdF₄ core–shell nanoparticles for possible application as multimodal contrast agents

• Dovile Baziulyte-Paulaviciene,
• Vitalijus Karabanovas,
• Marius Stasys,
• Greta Jarockyte,
• Vilius Poderys,
• Simas Sakirzanovas and
• Ricardas Rotomskis

Beilstein J. Nanotechnol. 2017, 8, 1815–1824, doi:10.3762/bjnano.8.183

• . The mean diameter of the synthesized core and core–shell nanoparticles was ≈8 and ≈16 nm, respectively. Hydrophobic UCNPs were converted into hydrophilic ones using a nonionic surfactant Tween 80. The successful coating of the UCNPs by Tween 80 has been confirmed by Fourier transform infrared (FTIR

• that the nonionic surfactant Tween 80 helps different nanoparticles (gold, silver and iron oxide) to become well-dispersed in aqueous solution even in the presence of biological molecules, such as different serum proteins [19][20][21]. However, information about Tween 80-coated gadolinium-based UCNPs

• demonstrate the effective surface modification method that uses a surfactant polysorbate 80 (Tween 80, polyoxyethylene sorbitan laurate). Hexagonal phase β-NaGdF4 was chosen as host lattice for its ability to combine optical and MRI. Tween 80 was used to make the UCNPs colloidally stable and dispersible in

Near-infrared-responsive, superparamagnetic Au@Co nanochains

• Varadee Vittur,
• Arati G. Kolhatkar,
• Shreya Shah,
• Irene Rusakova,
• Dmitri Litvinov and
• T. Randall Lee

Beilstein J. Nanotechnol. 2017, 8, 1680–1687, doi:10.3762/bjnano.8.168

• ]. By varying the surfactant added, we were able to obtain Au-coated Co nanochains. As the standard reduction potentials for the AuCl4−/Au pair is much higher than that of the Co2+/Co pair, Co nanoparticles were immediately oxidized to Co2+ when the K–gold solution was added. Given the rapid nature of

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• , wherein micro- and nanostructures assemble spontaneously by supramolecular interactions to form larger functional units [58]. This self-assembly of nanoparticles is very useful for various applications. In the surfactant-assisted ternary self-assembly of metal oxides with functionalized graphene sheets

• , an anionic surfactant gets adsorbed on the surface of graphene sheets and helps in the dispersion of graphene sheets. Then, the surfactant micelles with graphene sheets bind with metal cations and hence act as building block for self-assembly of metal oxides. Finally metal oxides become crystallized

Development of polycationic amphiphilic cyclodextrin nanoparticles for anticancer drug delivery

• Gamze Varan,
• Juan M. Benito,
• Carmen Ortiz Mellet and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1457–1468, doi:10.3762/bjnano.8.145

• during chemotherapy. Amphiphilic cyclodextrins are favored oligosaccharides as drug delivery systems for anticancer drugs, having the ability to spontaneously form nanoparticles without surfactant or co-solvents. In the past few years, polycationic, amphiphilic cyclodextrins were introduced as effective

• -formulation studies were used as a basis for selecting the suitable organic solvent and surfactant concentration for the novel polycationic cyclodextrin nanoparticles. The nanoparticles were then extensively characterized with particle size distribution, polydispersity index, zeta potential, drug loading

• optimized for selection of organic solvent, ratio of organic phase to aqueous phase and surfactant concentration to obtain monodisperse particles with a diameter range around 80 to 125 nm. Intended as chemotherapeutic nanocarriers, various PCX-loaded amphiphilic CD nanoparticles were also evaluated for

Cationic PEGylated polycaprolactone nanoparticles carrying post-operation docetaxel for glioma treatment

• Cem Varan and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1446–1456, doi:10.3762/bjnano.8.144

• may be effective for the spontaneous formation of nanoparticles at the interface and at obtaining a smaller particle size. Another important parameter affecting the final nanoparticle properties is reported to be the presence and concentration of the surfactant, which can influence particle size

• distribution and surface properties. According to the results in Table 2, the addition of surfactant did not reduce the particle size; on the contrary, the mean particle size significantly increased proportional to the concentration of PF68 for both polymer PCL and mePEG-PCL (p < 0.05). Although it has been

• shown in literature that addition of surfactant causes increased solubility of polymer in aqueous media and decreases the particle size [60], the exact opposite of this situation has been found, too [61]. In our studies, the addition of surfactant for both nanoparticle formulations may have led to the

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

• . 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

• (hexadecane), finding that the surfactant was transferred to the latex during the reaction; this led to nanotube aggregation. Donescu et al. [34] carried out the miniemulsion polymerization of styrene, styrene/acrylonitrile and methyl methacrylate (MMA) in the presence of MWCNTs. Grafting of the polymer on

• surfactant on the kinetics of miniemulsion polymerization of butyl acrylate (BA) in the presence of CNTs. Waterborne polymer dispersions are mainly used for coatings and adhesives, which involve the formation of films directly cast from the dispersion, usually at ambient temperature [22][24]. This limits the

Fabrication of hierarchically porous TiO₂ nanofibers by microemulsion electrospinning and their application as anode material for lithium-ion batteries

• Jin Zhang,
• Yibing Cai,
• Xuebin Hou,
• Xiaofei Song,
• Pengfei Lv,
• Huimin Zhou and
• Qufu Wei

Beilstein J. Nanotechnol. 2017, 8, 1297–1306, doi:10.3762/bjnano.8.131

• distribution. Nevertheless, it can be observed that with decreasing relative content of TBT/paraffin oil, the surface morphology looks worse, and the distribution of the fiber diameter becomes increasingly non-uniform. This is because the butoxyl groups in TBT serve as additional surfactant, which is

Enhanced catalytic activity without the use of an external light source using microwave-synthesized CuO nanopetals

• Govinda Lakhotiya,
• Sonal Bajaj,
• Arpan Kumar Nayak,
• Debabrata Pradhan,
• Pradip Tekade and
• Abhimanyu Rana

Beilstein J. Nanotechnol. 2017, 8, 1167–1173, doi:10.3762/bjnano.8.118

• provide the necessary thermal energy for the morphological transformation. This can be inferred on the basis of the similarity in the morphological parameters of both the nanostructures. The growth of these surfactant-free nanostructures depends on certain parameters, including the concentration of NaOH

• S4).This confirms that the same as-synthesized CuO nanopetals can also be optimized for the efficient degradation of hazardous dyes other than MB. Conclusion In summary, we have synthesized CuO nanoflowers and nanopetals in the absence of any surfactant and/or template using a microwave-assisted wet

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

• having improved photocatalytic properties due to the effective charge anti-recombination of graphene and the high catalytic activity of the facets [88]. An anionic surfactant-mediated growth of the self-assembled TiO2–graphene hybrid nanostructure synthesis was introduced by Wang et al., which shows

Carbon nanotube-wrapped Fe₂O₃ anode with improved performance for lithium-ion batteries

• Guoliang Gao,
• Yan Jin,
• Qun Zeng,
• Deyu Wang and
• Cai Shen

Beilstein J. Nanotechnol. 2017, 8, 649–656, doi:10.3762/bjnano.8.69

• . Liang et al. [20] employed a simple and easy hydrothermal method for the synthesis of α-Fe2O3 microspheres by using sodium citrate as surfactant. A reversible discharge capacity of 489.5 mAh·g−1 was obtained at a current density of 100 mA·g−1 of up to 50 cycles. The specific capacity of the synthesized

Investigation of the photocatalytic efficiency of tantalum alkoxy carboxylate-derived Ta₂O₅ nanoparticles in rhodamine B removal

• Subia Ambreen,
• Mohammad Danish,
• Narendra D. Pandey and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2017, 8, 604–613, doi:10.3762/bjnano.8.65

• in chloroform were prepared by using the surfactant trioctylphosphine oxide (TOPO). TOPO molecules provide stability and uniformity to the nanoparticles in chloroform. Table 2 shows the obtained particle sizes and distributions of Ta2O5 in chloroform dispersions. It can be seen that the TOPO-coated

Gas sensing properties of MWCNT layers electrochemically decorated with Au and Pd nanoparticles

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Riccardo Rossi,
• Gennaro Cassano,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2017, 8, 592–603, doi:10.3762/bjnano.8.64

• analyte gaseous molecules and CNTs, making their desorption difficult [11][12]. Several attempts have been made to improve the CNT-based sensor performance by modifying CNTs with polymeric composites [13], and/or catalyst metals, hybrid, and other catalytic materials [14]. Recently, a surfactant-free

• 12 ± 2 nm and 5.0 ± 0.5 nm, respectively, as reported in the TEM images in Figure 1. The net positive surface charge of colloidal metal NPs, given by the quaternary ammonium surfactant [36][37], was used to functionalize the surface of the MWCNTs by electrophoresis. The lipophilic interactions

• between the alkyl group of the surfactant and MWCNTs assured the anchorage of the colloidal metal NPs on the surface of the MWCNTs [38]. MWCNT-based chemiresistors were functionalized by electrophoresis based on a three-electrode cell in which a Pt wire was the counter electrode. The MWCNT-based device

Formation and shape-control of hierarchical cobalt nanostructures using quaternary ammonium salts in aqueous media

• Ruchi Deshmukh,
• Anurag Mehra and
• Rochish Thaokar

Beilstein J. Nanotechnol. 2017, 8, 494–505, doi:10.3762/bjnano.8.53

• strong magnetic dipolar interactions during the evaporation of 6 nm cobalt nanoparticles on oriented pyrolytic graphite [19]. Cobalt wires were obtained by the reduction of cobalt salt at high temperatures [20], and discs were produced by applying high temperature in a mixed surfactant system of oleic

• the XPS spectrum shown in Figure S7 (Supporting Information File 1). Oxide formation was inevitable since the analyses required drying or separation of cobalt nanoparticles that might lead to interactions of the surfactant with metal surfaces [46]. Polycrystalline nanorods show a higher value of Ms

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

• microscopy (SEM) for the highest temperature (70 °C) and lowest concentration of RDX in acetone (5 mM). It is worth mentioning that dynamic light scattering (DLS) measurements were found to be not reliable when compared to SEM analysis, which can be explained by the lack of surfactant to stabilize the

• size of 340 nm claimed. The particles also exhibit a certain degree of agglomeration which can be explained again by the pool of surfactant and the air-drying method used. Luo et al. [20] reached an impressive mean diameter of 30 nm of RDX. They used an unusual technique where RDX is dispersed in

Comparison of four methods for the biofunctionalization of gold nanorods by the introduction of sulfhydryl groups to antibodies

• Xuefeng Wang,
• Zhong Mei,
• Yanyan Wang and
• Liang Tang

Beilstein J. Nanotechnol. 2017, 8, 372–380, doi:10.3762/bjnano.8.39

• cationic surfactant bilayer [17][24], because of the replacement of CTAB by thiolated anti-IgG [17][25]. Anti-IgG were detected in thiolation and nanoconjugates with GNRs, but not in free GNRs, by gel electrophoresis followed by Coomassie brilliant blue staining (Figure S1, Supporting Information File 1

• incubated at 25–27 °C for at least 2 h. The solution was added to growth media and kept at 27 °C overnight to complete rod growth. GNRs with LSPR wavelengths longer than 850 nm were synthesized using a CTAB and NaOL bi-surfactant system [30]. GNRs were purified and characterized as previously described in

Nanoscale isoindigo-carriers: self-assembly and tunable properties

• Tatiana N. Pashirova,
• Andrei V. Bogdanov,
• Lenar I. Musin,
• Julia K. Voronina,
• Irek R. Nizameev,
• Marsil K. Kadirov,
• Vladimir F. Mironov,
• Lucia Ya. Zakharova,
• Shamil K. Latypov and
• Oleg G. Sinyashin

Beilstein J. Nanotechnol. 2017, 8, 313–324, doi:10.3762/bjnano.8.34

• 700 nm were formed. For long-chain dialkylated isoindigo derivatives, micellar aggregates of 100 to 200 nm were observed. Using micellar surfactant water-soluble forms of monosubstituted 1-hexadecylisoindigo as well as 1,1′-dimethylisoindigo were prepared for the first time. The formation of mixed

• micellar structures of different types in micellar anionic surfactant solutions (sodium dodecyl sulfate) was determined. These findings are of practical importance and are of potential interest for the design of drug delivery systems and new nanomaterials. Keywords: drug delivery systems; dyes; isoindigo

• solubility, stability, and bioavailability [73][74][75]. Importantly, amphiphilic molecules and drugs can form mixed assemblies that would result in changing in the micellization process [66]. In addition, the amphiphilic nature of surfactant micelles can serve as a tentative model of biomembranes [74][76

Photo-ignition process of multiwall carbon nanotubes and ferrocene by continuous wave Xe lamp illumination

• Paolo Visconti,
• Patrizio Primiceri,
• Daniele Longo,
• Luciano Strafella,
• Paolo Carlucci,
• Mauro Lomascolo,
• Arianna Cretì and
• Giuseppe Mele

Beilstein J. Nanotechnol. 2017, 8, 134–144, doi:10.3762/bjnano.8.14

• /ferrocene mixture in toluene, before the treatment (c), after ten minutes of sonication and other ten minutes of magnetic stirring (d) and after another sonication for ten minutes (e). MWCNT/ferrocene mixture after adding SDS surfactant. Absorption spectra of MWCNT/ferrocene soon after sonication and

Sensitive detection of hydrocarbon gases using electrochemically Pd-modified ZnO chemiresistors

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Gennaro Cassano,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2017, 8, 82–90, doi:10.3762/bjnano.8.9

• amount of palladium deposited on ZnO was about 1.0 atom %. The TOAB surfactant was almost completely removed from the Pd surface after annealing. In Figure 3, the SEM images of pristine and Pd-functionalized ZnO NRs after thermal annealing at 550 °C are reported. Pristine and functionalized ZnO reveal a

Structural and tribometric characterization of biomimetically inspired synthetic "insect adhesives"

• Matthias W. Speidel,
• Malte Kleemeier,
• Andreas Hartwig,
• Klaus Rischka,
• Angelika Ellermann,
• Rolf Daniels and
• Oliver Betz

Beilstein J. Nanotechnol. 2017, 8, 45–63, doi:10.3762/bjnano.8.6

• (C30) representing hydrocarbons of defined structure and length within the range of C23–C49 as established in the biological role models. Albumin and gelatin were substitutes for proteinogenic amino acids, with the surfactant Span 80 (Sorbitane monooleate) being used as a combined replacement for fatty

• , standard deviation (Supporting Information File 1, Table S1)) showed a positive statistical correlation to the chemical compounds Vaseline, glycerine and SDS (sodium dodecyl sulfate), occurring mostly within the first generation of emulsions. The non-ionic surfactant Span 80 and the ionic surfactant AOT

• , microcrystalline wax, poly(vinyl alcohol) (only at the highest sliding speed of 500 µm s−1), glycerine, gelatin and sodium dodecyl sulphate (SDS) showed a positive significant relationship with friction. In addition, friction was also negatively affected by the non-ionic surfactant Span 80 at an almost significant

From iron coordination compounds to metal oxide nanoparticles

• Mihail Iacob,
• Carmen Racles,
• Codrin Tugui,
• George Stiubianu,
• Adrian Bele,
• Liviu Sacarescu,
• Daniel Timpu and
• Maria Cazacu

Beilstein J. Nanotechnol. 2016, 7, 2074–2087, doi:10.3762/bjnano.7.198

•  3d). The core–shell morphology is visible in Figure 3c, with an inorganic core covered by the surfactant. Nanoparticle samples (NPT4) were obtained starting from a FeAc2 ([Fe3O(CH3COO)6(H2O)3]NO3∙4H2O) cluster. TEM observations (Figure 4) revealed particles in the form of spheres with hair-like

• NPT1b. Both samples were redispersed in hexane and ethanol and then centrifuged to remove excess surfactant. NPT2–NPT4 nanoparticles were prepared using a procedure similar to that described for NPT1a, but using the reagents amounts, reaction time and temperature indicated in Table 1. Preparation of

• precipitated with ethanol and were then centrifuged. To remove excess surfactant, the washing procedure with ethanol and centrifugation were repeated three times. Dry thermal decomposition (calcination) (NPC series). Samples NPC1, NPC2 and NPC3 were prepared by heating of FeAc2, FeCrF and FePAZ, respectively

Effect of Anderson localization on light emission from gold nanoparticle aggregates

• Mohamed H. Abdellatif,
• Marco Salerno,
• Gaser N. Abdelrasoul,
• Ioannis Liakos,
• Alice Scarpellini,
• Sergio Marras and
• Alberto Diaspro

Beilstein J. Nanotechnol. 2016, 7, 2013–2022, doi:10.3762/bjnano.7.192

• shows a peak at ≈521 nm which is much sharper (FWHM ≈40 nm) than both cases of quartz and glass substrate. This confirms that the surfactant in the colloidal solution prevents the AuNPs from aggregating [8]. The theoretical simulation of the absorption of the spherical AuNPs is finally shown in Figure

Intercalation and structural aspects of macroRAFT agents into MgAl layered double hydroxides

• Dessislava Kostadinova,
• Ana Cenacchi Pereira,
• Muriel Lansalot,
• Franck D’Agosto,
• Elodie Bourgeat-Lami,
• Fabrice Leroux,
• Christine Taviot-Guého,
• Sylvian Cadars and
• Vanessa Prevot

Beilstein J. Nanotechnol. 2016, 7, 2000–2012, doi:10.3762/bjnano.7.191

• fabricating polymer nanocomposites [20][21][22][23]. To favor the dispersion of LDH platelets into polymers, hybrid surfactant (usually dodecyl sulphate)-intercalated LDH were prepared and incorporated into polymer matrices such as polyethylene [24], polypropylene [25], poly(methyl methacrylate) [26

• ], elastomers [27], epoxy polymers [28], poly(ε-caprolactone) [29], polyesters [30], polyurethane [31] and polyimide [21]. Alternatively, Leroux et al. described the preparation of a hybrid LDH phase intercalated by an anionic polymerizable surfactant acting further as an anchor that compatibilizes the

• inorganic LDH with the polymer matrix during the polymerization [32]. Water soluble macromolecules such as poly(vinyl alcohol), poly(acrylic acid) (PAA), poly(styrene sulfonate) were also intercalated into the layered structure to avoid the use of surfactant molecules which can alter nanocomposite

A dioxaborine cyanine dye as a photoluminescence probe for sensing carbon nanotubes

• Mohammed Al Araimi,
• Petro Lutsyk,
• Anatoly Verbitsky,
• Yuri Piryatinski,
• Mykola Shandura and
• Aleksey Rozhin

Beilstein J. Nanotechnol. 2016, 7, 1991–1999, doi:10.3762/bjnano.7.190

• the PL detection towards the nanotube diameters. The energy diagram shown at the right-hand side of Figure 2a represents a two-component system consisting of the anionic surfactant SDBS and the SWNTs in water, where the anionic surfactant forms micelles around the nanotubes having typical exciton

• between the surfactant (at premicellar and micellar concentrations) and the dye. Referring to our previous studies on the interaction of SDBS and astraphloxin (a polymethine dye with cyanines at both terminal groups) resulting in the aggregation of the dye. There is no such behaviour in the case of DOB

• -719. In addition, we have studied the three-component system of DOB-719, SDBS, and SWNTs, where an extra amount of surfactant was added (see Supporting Information File 1, Figures S3–S5) to obtain a concentration of SDBS above the critical micellar concentration of 0.15 mg/mL [22]. The three-component

Organoclay hybrid materials as precursors of porous ZnO/silica-clay heterostructures for photocatalytic applications

• Marwa Akkari,
• Pilar Aranda,
• Abdessalem Ben Haj Amara and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2016, 7, 1971–1982, doi:10.3762/bjnano.7.188

• tetraethoxysilane (TEOS) and tetramethoxysilane (TMOS) although this methodology may involve the use of other alkoxysilanes as well as diverse metal alkoxides [14]. The influence of the surfactant incorporated into the organoclay on the characteristics of the obtained materials has been pointed out recently [15][16

• ]. The methodology has been also applied to organoclays derived from fibrous clays (e.g., sepiolite) in which the presence of the surfactant at the external surface results in the formation of silica NP of diverse characteristics depending on the nature of both, silane precursor and surfactant present at

• and sepiolite fibrous clay, in which SiO2-clay organoheterostructures are used for further assembling ZnO NP. In this way, heterostructures in which the surfactant is still present are formed from TMOS and organoclays derived from two types of silicates (smectites and sepiolite) and then the formed