Highly ordered mesoporous silica film nanocomposites containing gold nanoparticles for the catalytic reduction of 4-nitrophenol

• Mohamad Azani Jalani,
• Leny Yuliati,
• Siew Ling Lee and
• Hendrik O. Lintang

Beilstein J. Nanotechnol. 2019, 10, 1368–1379, doi:10.3762/bjnano.10.135

• from gold(III) chloride trihydrate (HAuCl4) solution have been used as a precursor for post-synthetic grafting upon mixing with mesoporous silica [20]. Another method is to utilize the co-condensation reaction by the mixing solution of HAuCl4 with surfactants and silica sources during the sol–gel

Scavenging of reactive oxygen species by phenolic compound-modified maghemite nanoparticles

• Małgorzata Świętek,
• Yi-Chin Lu,
• Rafał Konefał,
• Liliana P. Ferreira,
• M. Margarida Cruz,
• Yunn-Hwa Ma and
• Daniel Horák

Beilstein J. Nanotechnol. 2019, 10, 1073–1088, doi:10.3762/bjnano.10.108

• of chitosan increase with an increasing degree of deacetylation and a decreasing molecular weight [14][15]. Three strategies for incorporating phenolic compounds into chitosan have previously been described, including laccase- or tyrosinase-mediated enzymatic grafting, carbodiimide-activated

• conjugation via esterification or amidation, and free-radical grafting [16]. The aim of this work was to design and fabricate superparamagnetic iron oxide nanoparticles with antioxidant properties. Positively charged γ-Fe2O3 nanoparticles were synthesized through co-precipitation, and their surface was

• phenolic compounds resembled each other (Figure 1b). After free-radical grafting, new peaks appeared at 3.85, 3.98, 6.91 (only in CS-G), 8.85, and 9.19 ppm. Moreover, peaks at 1.78, 4.32, and 4.61 ppm changed their multiplicity and intensity. Peaks at 6.91, 8.85, and 9.19 ppm were ascribed to the 1H, 3OH

Enhanced inhibition of influenza virus infection by peptide–noble-metal nanoparticle conjugates

• Zaid K. Alghrair,
• David G. Fernig and
• Bahram Ebrahimi

Beilstein J. Nanotechnol. 2019, 10, 1038–1047, doi:10.3762/bjnano.10.104

• enhanced antiviral activity compared to the free peptides. The IC50 value of the FluPep-functionalised nanoparticles decreased as the grafting density of FluPep ligand increased from 0.03% to 5% (both mol/mol), with IC50 values down to about 10% of that of the corresponding free peptide. The data

• and such nanoparticles could be used in cell culture medium. Purification of functionalised gold nanoparticles When the peptide FluPep ligand was included in the ligand mix to functionalise the nanoparticles, its molar fraction in percent in relation to the matrix ligand should reflect its grafting

• of approximately two to eight plaques at 200 pM (Figure 4). As the grafting density of FluPep ligand was increased, so did the antiviral activity, to reach a maximum at 5% (mol/mol) FluPep (Figure 4). This is reflected by the decreased IC50 value, which shows a 4.5-fold greater potency of

Topochemical engineering of composite hybrid fibers using layered double hydroxides and abietic acid

• Liji Sobhana,
• Lokesh Kesavan,
• Jan Gustafsson and
• Pedro Fardim

Beilstein J. Nanotechnol. 2019, 10, 589–605, doi:10.3762/bjnano.10.60

• . The disintegrated pulp was dewatered by centrifugation to yield the free unbound cellulose fibers. These cellulose fibers were used for further grafting with LDH. Refining of the pulps and Schopper–Riegler analysis Refining of bleached and unbleached pulps was performed at a pulp concentration of 1.57

• well packed and stacked fibers that decrease the free path of water during filtration are obtained. Thus, refining increases water retention of the wet fiber mat during the Schopper–Riegler measurement, expressed as a higher value of the refining degree in °SR. Grafting of LDH on cellulose fibers The

• min under ambient conditions to allow for the grafting between LDH and AA. Then the handsheets were gently taken out and allowed to dry at room temperature. Characterization Optical microscopy analysis: An optical microscope Nikon Eclipse E200 combined with a Nikon DS-Fi2 digital camera was used to

One-step nonhydrolytic sol–gel synthesis of mesoporous TiO₂ phosphonate hybrid materials

• Yanhui Wang,
• P. Hubert Mutin and
• Johan G. Alauzun

Beilstein J. Nanotechnol. 2019, 10, 356–362, doi:10.3762/bjnano.10.35

• octylphosphonic acid with grafting densities of 1.4 and 4.1 P/nm2, respectively [37]. In our hybrid materials, the anatase particle size decreases with the P/Ti ratio, leading to an increase of the specific surface area of the crystallites. The density of grafting, estimated from the composition and from the

• diameter of the crystallites (assuming a spherical shape and a density of 3.8), increases with the P/Ti ratio from 1.5 P/nm2 for TiP0.02 to 2.9 P/nm2 for TiP0.1. These values suggest the formation of monolayers with low to moderate density (grafting densities of up to 4 to 5 P/nm2 have been reported for

Removal of toxic heavy metals from river water samples using a porous silica surface modified with a new β-ketoenolic host

• Said Tighadouini,
• Smaail Radi,
• Abderrahman Elidrissi,
• Khadija Haboubi,
• Maryse Bacquet,
• Stéphanie Degoutin,
• Mustapha Zaghrioui and
• Yann Garcia

Beilstein J. Nanotechnol. 2019, 10, 262–273, doi:10.3762/bjnano.10.25

• at several pressures [54] and is shown in Figure 4. A clear decrease is observed after grafting. This is obviously due to the obstruction of N2(g) access by organic moieties anchored onto the silica matrix, thus reducing its surface area [55]. The observed decrease of the initial specific surface

Targeting strategies for improving the efficacy of nanomedicine in oncology

• Gonzalo Villaverde and
• Alejandro Baeza

Beilstein J. Nanotechnol. 2019, 10, 168–181, doi:10.3762/bjnano.10.16

• strong affinity for NET. The replacement of the iodine by an amino group in MABG did not reduce the ability to bind to NET while it provided a reactive group that allowed for grafting this molecule to the surface of MSN employing a bifunctionalized polyethylene glycol (PEG) molecule as spacer between the

• circulation time of the particles caused by the presence of the PEG chains (Figure 2) [23]. The small size of these synthetic molecules allows for the grafting of multiple copies of them, or even combinations of two different molecules on the surface of the nanoparticles [24]. This fact can induce a

Colloidal chemistry with patchy silica nanoparticles

• Pierre-Etienne Rouet,
• Cyril Chomette,
• Laurent Adumeau,
• Etienne Duguet and
• Serge Ravaine

Beilstein J. Nanotechnol. 2018, 9, 2989–2998, doi:10.3762/bjnano.9.278

• carboxylic acid groups. The grafting efficiency was evidenced by zeta potential measurements and diffuse reflectance infrared Fourier-transform (DRIFT) spectroscopy. Figure 2b shows that after treatment of the silica surface by APTES, the so-aminated nanoparticles display a quite high zeta potential value of

• about 23 mV at pH 7.0. The isoelectric point (IEP) at pH 8.4 is close to the pKa value of the primary amine groups attesting to their efficient grafting and correct orientation on the silica surface. The carboxylated particles possess a zeta potential of about −43 mV at pH 7.0 and an isoelectric point

• shifted down to pH 3.8, attesting to the efficient grafting of the acid groups. Figure 2c shows that the IR spectrum of the aminated particles presents a characteristic band assigned to the C–C bond of the alkyl chain of APTES groups at 1473 cm−1, while the IR spectrum of the carboxylated particles

Layered calcium phenylphosphonate: a hybrid material for a new generation of nanofillers

• Kateřina Kopecká,
• Ludvík Beneš,
• Klára Melánová,
• Vítězslav Zima,
• Petr Knotek and
• Kateřina Zetková

Beilstein J. Nanotechnol. 2018, 9, 2906–2915, doi:10.3762/bjnano.9.269

• structure or by a surface modification [3][4] by grafting organophilic functional groups onto the clay surface, leading to the synthesis of hybrid organic–inorganic materials [5]. Layered metal organophosphonates are a class of materials which exhibit a hybrid character by their nature. They are generally

Accurate control of the covalent functionalization of single-walled carbon nanotubes for the electro-enzymatically controlled oxidation of biomolecules

• Naoual Allali,
• Veronika Urbanova,
• Mathieu Etienne,
• Xavier Devaux,
• Martine Mallet,
• Brigitte Vigolo,
• Jean-Joseph Adjizian,
• Chris P. Ewels,
• Sven Oberg,
• Alexander V. Soldatov,
• Edward McRae,
• Yves Fort,
• Manuel Dossot and
• Victor Mamane

Beilstein J. Nanotechnol. 2018, 9, 2750–2762, doi:10.3762/bjnano.9.257

• to increase the water solubility of f-SWCNTs and ii) the influence of metallic and/or carbonaceous impurities that may be present in the CNT sample. In this article, by using advanced and complementary analytical techniques, we fully confirm the covalent nature of the chemical grafting. In particular

• level of functionalization. It also reports an increase of the oxygen content after grafting FcETGn groups and this is particularly true for the HIPCO-HNO3-FcETG8 sample (entry 5). The change in the detailed C 1s spectrum if compared to that of the starting material is quite obvious, as shown in Figure

• to physisorbed molecules. TGA-MS experiments therefore confirm the covalent grafting of the ferrocene derivatives on the CNTs. Table 2 summarizes the global weight losses and the main departure peaks corresponding to the data plotted in Figure 6. Figure S2 (Supporting Information File 1) reports the

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

• the removal of toxic metal ions from wastewater. A carboxy group has two lone pairs of electrons on the oxygen, and hence it is required to form a chelate with a divalent metal. In this regard, Qiao et al. [101] synthesized a carboxylate-functionalized adsorbent by grafting maleic anhydride on primary

• flocculants are not only known for being biodegradable but also have a high specific surface area and have dimensions in the nanoscale regime [132]. Commonly, there are two categories of natural polymer based flocculants [133]. One of these categories involves the grafting of natural polymers to fabricate

• case, rod-shaped particles (commonly found in CNC) could deplete larger colloids than spherical particles [145]. Besides, the introduction of cationic pyridinium and imidazole functional groups through grafting provided an advantage to CNCs over common polymer flocculants in terms of flocculation

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• photovoltaic process and the correlation to the nanoscale morphology. A down-shift of the vacuum level of the TiO2 surface upon grafting was measured by Kelvin probe force microscopy (KPFM), evidencing the formation of a dipole at the TiO2/P3HT-COOH interface. Upon in situ illumination, a positive photovoltage

• composed of arrays of nanoscale columns, covalently sensitized with a P3HT-COOH monolayer to form hybrid bulk heterojunctions. The grafting of P3HT on the surface of TiO2, ensured by the COOH groups, was demonstrated to be beneficial for the photoconversion efficiency of the system [16][17][18]. The

• hemispherical protuberances. Regio-regular P3HT-COOH (5400 g/mol, which corresponds to about 30 monomer units, i.e., a total polymer chain length around 130 Å) was synthesized following a reported procedure [24]. A schematic description of the grafting protocol is given in Figure 1a–c. The polymer deposit was

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

• are grafting density, molar mass of grafted chains (brushes) and conformation of brushes. Grafting density strongly influences chain conformation. At a large grafting density, brushes cannot adopt a random coil conformation but instead adopt a stretched brush conformation and their length (h) is

• matrix polymer was almost twice as large as that of the brush [23]. Moll et al. obtained a similar state of dispersion only when the molar mass of the brush was almost four times larger than that of the matrix when using a significantly lower grafting density than Xu [25]. Clearly, sufficiently long

• suspension was composed of 37.8 wt % nanoparticles (NPs), 4.1 wt % ricinoleic acid and 58.1 wt % toluene. The grafting of the methacrylic units to the nanoparticle surface (NP-MMA) was achieved by esterification of the hydroxyl group from the ricinoleic acid with methacrylic anhydride (Scheme 1). A round

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

• positively charged, which adsorbed negatively charged Cr(VI) species effectively through electrostatic attraction. This facilitated the photocatalytic reduction of Cr(VI). In addition to this, the grafting of TiO2 onto RGO forms C–O–Ti bonds, which extends light absorption of TiO2 to longer wavelengths

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

• surface treatment. One approach is the functionalization of the surfaces with various ligands. For instance, grafting a thin molecular film with hydrophobic tail groups on a surface, formed by self-assembly process, prevents the formation of nano- or microdroplets of water on the treated sample, or

• the importance of the surface and quantity of grafting sites to form well-packed monolayers of self assembled monolayers (SAMs) on a surface (or NPs), which will ensure a proper mechanical behavior and aging of the system and reduce its destabilization along the time. In addition, long chains of more

Facile phase transfer of gold nanorods and nanospheres stabilized with block copolymers

• Yaroslav I. Derikov,
• Georgiy A. Shandryuk,
• Raisa V. Talroze,
• Alexander A. Ezhov and
• Yaroslav V. Kudryavtsev

Beilstein J. Nanotechnol. 2018, 9, 616–627, doi:10.3762/bjnano.9.58

• due to van der Waals interactions, so their stabilization requires the use of bulky surfactant molecules [24][25][26] or polymers with a strongly binding groups via grafting-to [27][28], grafting-from [4] and grafting-around [29] approaches, hyperbranched polymers [30] or polymers with a significant

• number of interacting pendant groups that provide nanoparticle “wrapping” [31][32][33]. Block copolymers can also be used for the stabilization of Au nanoparticles via grafting-to [34][35], grafting-from [36] and wrapping [29][37] strategies. Since nanoparticles can be driven by laser light [36], they

Single-step process to improve the mechanical properties of carbon nanotube yarn

• Maria Cecilia Evora,
• Xinyi Lu,
• Nitilaksha Hiremath,
• Nam-Goo Kang,
• Kunlun Hong,
• Roberto Uribe,
• Gajanan Bhat and
• Jimmy Mays

Beilstein J. Nanotechnol. 2018, 9, 545–554, doi:10.3762/bjnano.9.52

• ± 68.4 MPa) by more than 75% and the modulus (21.5 ± 0.6 GPa) by more than 144% as compared to untreated CNT yarn (strength 251 ± 26.5 MPa and modulus 8.8 ± 1.2 GPa). Keywords: carbon nanotube yarns; crosslinking; electron beam; grafting; Introduction Due to their exceptional mechanical, thermal, and

• ]. Ionizing radiation has a sufficiently high energy to break bonds and create free radicals that chemically react in several ways over a short period of time. The large penetrating power of high-energy radiation provides an opportunity to carry out grafting at different depths of the substrate and, also

• preliminary investigation was carried out with MWNTs as a loose powder grafted with AN. For this preliminary investigation, MWNTs as a loose powder were exposed to a direct radiation grafting technique in an aqueous solution of AN (20%, v/v in MeOH/H2O) and 4% of inhibitor Mohr’s salt ((NH4)2Fe(SO4)2·6H2O) at

L-Lysine-grafted graphene oxide as an effective adsorbent for the removal of methylene blue and metal ions

• Yan Yan,
• Jie Li,
• Fangbei Kong,
• Kuankuan Jia,
• Shiyu He and
• Baorong Wang

Beilstein J. Nanotechnol. 2017, 8, 2680–2688, doi:10.3762/bjnano.8.268

• ) used as an adsorbent for the removal of methyl orange and amaranth in 2017 [22]. The maximum adsorption capacities of PFGA for methyl orange and amaranth were as high as 3059.2 mg/g and 2043.7 mg/g, respectively. Herein, we inferred that grafting amino groups onto graphene might enhance the performance

• Table 3. Obviously, the adsorption performance of Lys-GO for MB and Cu2+ are much better than those of the other previously reported materials. The excellent adsorption performance of Lys-GO might be attributed to two factors: 1) Grafting L-lysine on the GO can improve the affinity for MB and Cu ions

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• carbon atoms in the alkyl chain were used as capping agents. Sheets of nanoparticles with short chains showed a conductivity (980.9 S/cm) that was ascribed to the shorter chain length and the lower grafting density, whereas sheets of particles functionalized with the longer thiocarboxylic acid were not

• the surface of metal nanoparticles lead to a different class of composites. Grafting or growing polymer chains from the metal surface can provide well-defined interfaces between polymer and particles that are favorable for charge transport [139][140]. Vijayakumar et al. stabilized gold nanoparticles

Identifying the nature of surface chemical modification for directed self-assembly of block copolymers

• Laura Evangelio,
• Federico Gramazio,
• Matteo Lorenzoni,
• Michaela Gorgoi,
• Francisco Miguel Espinosa,
• Ricardo García,
• Francesc Pérez-Murano and
• Jordi Fraxedas

Beilstein J. Nanotechnol. 2017, 8, 1972–1981, doi:10.3762/bjnano.8.198

• essentially hydroxylation of the surface. Thus, the combination between optimal process conditions for grafting the polymer brush layer and an adequate chemical functionalization by oxygen plasma exposure leads to the possibility to generate efficient chemical patterns for guiding the self-assembly of the BCP

Application of visible-light photosensitization to form alkyl-radical-derived thin films on gold

• Rashanique D. Quarels,
• Xianglin Zhai,
• Neepa Kuruppu,
• Jenny K. Hedlund,
• Ashley A. Ellsworth,
• Amy V. Walker,
• Jayne C. Garno and
• Justin R. Ragains

Beilstein J. Nanotechnol. 2017, 8, 1863–1877, doi:10.3762/bjnano.8.187

• lithography; photosensitization; TOF SIMS; Introduction The deposition of radical-derived organic thin films has emerged as an attractive alternative to the grafting of molecules such as thiols, chlorosilanes and alkoxysilanes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23

• ][24][25][26][27][28]. Carbon-centered radicals have proven to be versatile grafting species that can covalently bond to a number of surfaces including precious, coinage and industrial metals [1][2][3][4][5][6], hydrogen-terminated silicon [7][8], and indium tin oxide [9][10]. The resulting aryl- and

• polyphenylene multilayers. Other methods for aryl radical grafting include electrografting of diaryliodonium salts [15][16], and dimethoxybenzene- or [Ru(bpy)3]2+-photosensitized conversion of arenediazonium salts to aryl radicals in the presence of metal and polymer surfaces [17][18][19][20]. As such

Fluorination of vertically aligned carbon nanotubes: from CF₄ plasma chemistry to surface functionalization

• Claudia Struzzi,
• Mattia Scardamaglia,
• Jean-François Colomer,
• Alberto Verdini,
• Luca Floreano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2017, 8, 1723–1733, doi:10.3762/bjnano.8.173

• intensity of the peak around 10 eV and at 15 eV to the F 2p-like states and to the F–C 2s bonding orbitals, respectively [19][27]. The fluorine grafting drastically reduces also the density of states just below the Fermi level. A close view of this region is illustrated in the frame, where the dotted red

• , black curve) is strongly quenched because of the covalent fluorine grafting (blue curve), but its intensity is partially restored through thermal desorption (green curve). The states corresponding to the transition from C 1s to σ* are broaden due to the formation of C–F bond with σ symmetry [38

Surface functionalization of 3D-printed plastics via initiated chemical vapor deposition

• Christine Cheng and
• Malancha Gupta

Beilstein J. Nanotechnol. 2017, 8, 1629–1636, doi:10.3762/bjnano.8.162

• -printed materials for potential applications in tissue grafting, microfluidics, and electronics. Experimental 1H,1H,2H,2H-Perfluorodecyl acrylate (PFDA) (SynQuest Laboratories, 97%), 2-hydroxyethyl methacrylate (HEMA) (Aldrich, 97%), ethylene glycol diacrylate (EGDA) (Polysciences, Inc.), and tert-butyl

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

• to the strong interaction between the polymer and MWNCTs (including grafting) that reduced the mobility of the polymer chains. As a result, a substantial increase of both the storage and the loss moduli was achieved. At 60 °C, which is above the main transition region of the polymer, the in situ

• (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

• mechanical and thermal reinforcement was achieved due to the 3D network formation of the filler within the polymer matrix and creation of strong interactions (including grafting between the phases). Experimental Materials Multiwalled carbon nanotubes (MWCNTs, length = 5–10 µm; diameter = 10–20 nm) were

Preparation of thick silica coatings on carbon fibers with fine-structured silica nanotubes induced by a self-assembly process

• Benjamin Baumgärtner,
• Hendrik Möller,
• Thomas Neumann and
• Dirk Volkmer

Beilstein J. Nanotechnol. 2017, 8, 1145–1155, doi:10.3762/bjnano.8.116

• . Tetraethylenepentamine was chosen for covalent linkage to the fiber surface (Figure 1). The number of surface-exposed carboxylic acid groups was increased by wet-chemical oxidation with 65% nitric acid at 115 °C over a period of 90 min. Grafting the short-chain polyamine via amide functional groups was achieved by

• heating the previously oxidized carbon fibers at 180 °C in an excess of TEPA for 6 h. The possibility of a successful grafting by heating the fibers in an excess of TEPA was already demonstrated elsewhere [32]. In the present case, the presence of the polyamine at the carbon fiber surface was confirmed by

• XPS measurements (relative amounts: C 88.0%; N 4.0%; O 8.0% for oxidized fibers without TEPA grafting; C 75.5%; N 16.0%; O 8.5% for fibers with TEPA grafting) and quantified by a mass loss of 4.2% via thermogravimetric analysis by heating in nitrogen atmosphere. Silica deposition onto the as prepared