Modification of graphene oxide and its effect on properties of natural rubber/graphene oxide nanocomposites

• Nghiem Thi Thuong,
• Le Dinh Quang,
• Vu Quoc Cuong,
• Cao Hong Ha,
• Nguyen Ba Lam and
• Seiichi Kawahara

Beilstein J. Nanotechnol. 2024, 15, 168–179, doi:10.3762/bjnano.15.16

• investigated by 29Si NMR, and it was found that the hydrolysis and condensation of VTES proceed more completely in basic conditions than in acidic conditions. The silica content of GO-VTES(b) was 43%, which is higher than that of GO-VTES(a) (8%). Morphology of silica was observed by SEM. The DPNR/GO-VTES

• conditions to determine the ideal condition to modify GO for grafting onto NR. The GO-VTES products were characterized using X-ray diffraction (XRD), contact angle, 29Si NMR, Fourier-transform infrared spectroscopy (FTIR), and morphology analysis. The GO-VTES was expected to improve the mechanical properties

• with the diffraction angle (2-theta) ranging from 5 to 80°. Solid-state 29Si NMR spectra were recorded with a JNM ECA-400 (JEOL, Japan) spectrometer operating at a magnetic field of 400 MHz. A suitable amount of rubber sample was inserted in an NMR tube and injected into an NMR system equipped with a

Synthesis of highly active ETS-10-based titanosilicate for heterogeneously catalyzed transesterification of triglycerides

• Muhammad A. Zaheer,
• David Poppitz,
• Khavar Feyzullayeva,
• Marianne Wenzel,
• Jörg Matysik,
• Radomir Ljupkovic,
• Aleksandra Zarubica,
• Alexander A. Karavaev,
• Andreas Pöppl,
• Roger Gläser and
• Muslim Dvoyashkin

Beilstein J. Nanotechnol. 2019, 10, 2039–2061, doi:10.3762/bjnano.10.200

• titanosilicate it was expected that the too small pores prohibit accommodation of triolein molecules. For P-ETS-10/60 this might result from the decreased surface hydrophobicity (as seen by the 29Si NMR and indirectly by the NH3-TPD), preventing efficient diffusion into the mesopores of the crystals. The

• “effective” basicity seen by the reactants might differ from the measured values. In addition to this, as is evident from the results of DTA and 29Si NMR, calcination leads to the partial surface dehydroxylation. This might improve the accessibility of mesopores for triolein via the increased surface

Layered double hydroxide/sepiolite hybrid nanoarchitectures for the controlled release of herbicides

• Ediana Paula Rebitski,
• Margarita Darder and
• Pilar Aranda

Beilstein J. Nanotechnol. 2019, 10, 1679–1690, doi:10.3762/bjnano.10.163

• techniques (XRD, FTIR and 29Si NMR spectroscopies, CHN analysis and SEM) that revealed interactions of LDH with the sepiolite fibers through the silanol groups present on the outer surface of sepiolite, together with the intercalation of MCPA in the LDH confirmed by the increase in the basal spacing from

• MCPA than the ion exchange reaction with the additional advantage of being less time-consuming. FTIR and 29Si NMR spectroscopic analysis corroborated that the LDH particles in the coprecipitated hybrid nanoarchitecture are chemically linked to the silanol groups that cover the silicate fibers

A novel polyhedral oligomeric silsesquioxane-modified layered double hydroxide: preparation, characterization and properties

• Xianwei Zhang,
• Zhongzhu Ma,
• Hong Fan,
• Carla Bittencourt,
• Jintao Wan and
• Philippe Dubois

Beilstein J. Nanotechnol. 2018, 9, 3053–3068, doi:10.3762/bjnano.9.284

• ]. Thereafter, the acylation reaction of OCPS with succinic anhydride was carried out to afford OCPS. The 1H NMR, 13C NMR and 29Si NMR spectra of OAPS and OCPS presented in Figure 2 and the MALDI-TOF-MS spectra, XRD patterns and FTIR spectra of OAPS and OCPS in Figure 3a–c reveal the well-defined structures

• ), 0.70 (m, SiCH2, 16H); 13C NMR (DMSO-d6) δ 41.03 (s, CH2N), 20.64 (s, SiCH2CH2), 8.46 (s, SiCH2); 13C NMR (D2O) δ 41.63 (d, CH2N), 20.55 (d, SiCH2CH2), 8.76 (m, SiCH2); 29Si NMR (DMSO-d6) δ −66.50 (s); MALDI-TOF-MS (DHB matrix, m/z): [M + H − 8HCl]+ calcd 881.29; found, 881.39 (100%); FTIR (KBr): υ(–NH3

• , CH2COOH, 16H), 2.30 (t, J = 6.5 Hz, C=OCH2, 16H), 1.43 (s, CH2CH2CH2, 16H), 0.59 (s, SiCH2, 16H); 13C NMR (DMSO-d6) δ 174.11 (s, COOH), 171.24 (s, NHCO), 41.20 (s, CH2CH2CH2), 30.18 (s, CH2NH), 29.33 (s, CH2COOH), 22.67(s, C=OCH2), 8.92 (s, SiCH2); 29Si NMR (DMSO-d6) δ −66.19 (s); MALDI-TOF-MS (DHB matrix

Tailoring bifunctional hybrid organic–inorganic nanoadsorbents by the choice of functional layer composition probed by adsorption of Cu²⁺ ions

• Veronika V. Tomina,
• Inna V. Melnyk,
• Yuriy L. Zub,
• Aivaras Kareiva,
• Miroslava Vaclavikova,
• Gulaim A. Seisenbaeva and
• Vadim G. Kessler

Beilstein J. Nanotechnol. 2017, 8, 334–347, doi:10.3762/bjnano.8.36

• /APTES molar ratio of 3:1, the surface layer did contain amino groups (1.56 mmol/g), but the particle size decreases to about 9 nm. When the order of components introduction was changed, the content of functional groups increased to 3.2 mmol/g. However, according to 29Si NMR spectroscopy, the content of

• contained water (DRIFT analysis in Supporting Information File 1). Solid-state CP/MAS NMR spectroscopy, especially 13C and 29Si NMR spectroscopy, has been widely used to study silica materials, it can provide information about hydrolysis and condensation processes. Clearly, hydrolysis and polycondensation

• and 2300. 29Si NMR spectra were recorded with 3 µs excitation pulses, a contact time of 2 ms, and 5 s recycling delay. The number of scans was between 640 and 1024. 13C and 29Si chemical shifts are referenced towards 4,4-dimethyl-4-silapentane-1-sulfonic acid (DSS). CHNS elemental analysis was

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

• sepiolite without access to the adsorbed species on the silicate [18][24]. Concerning the 29Si NMR spectra (Figure 9), the one of the ZnO/SiO2-SEP heterostructure is complex as it is composed of 29Si signals coming from silicon nuclei of sepiolite structure, from generated silica with different condensation

• degrees as well as from some other components involving more complex interactions, e.g., silica in interaction with ZnO and sepiolite. 29Si NMR spectra of pure sepiolite shows three characteristic signals at approximately −92.4, −95.0, and −98.6 ppm (Figure 9a) typical of Q3 signals attributed to Si atoms

• in different structural environments [25]. There is also a small Q2 signal at −85.7 ppm, which is related to the silanol groups located at the surface of the silicate [25]. The 29Si NMR spectrum of the ZnO/SiO2-SEP heterostructure is clearly different showing a strong decrease in the intensity of the

Electrostatic interplay: The interaction triangle of polyamines, silicic acid, and phosphate studied through turbidity measurements, silicomolybdic acid test, and ²⁹Si NMR spectroscopy

• Anne Jantschke,
• Katrin Spinde and
• Eike Brunner

Beilstein J. Nanotechnol. 2014, 5, 2026–2035, doi:10.3762/bjnano.5.211

• silica. Keywords: phosphate; self-assembly; silica–polyamine interactions; silicomolybdic acid test; 29Si NMR; turbidity measurements; Introduction Long-chain polyamines (LCPAs) were previously found biomolecules that are tightly associated to the biosilica of various diatom species [1][2][3][4][5

• studied in order to visualize the possible influence of hydrophobic interactions. For 29Si NMR spectroscopy aqueous solutions of isotope-labelled sodium [29Si] metasilicate as precursor compound were used. Different silica precursors, such as toxic TMOS (tetramethyl orthosilicate) or TEOS (tetraethyl

• oligomers/silica nanoparticles below the pKa of PAH. The resulting immobilization of higher silicic acid oligomers could indeed be observed by 29Si NMR spectroscopy previously [23]. The soluble silica (mono- and disilicic acid) is almost completely polycondensed into insoluble species (higher silica

Preparation of electrochemically active silicon nanotubes in highly ordered arrays

• Tobias Grünzel,
• Young Joo Lee,
• Karsten Kuepper and
• Julien Bachmann

Beilstein J. Nanotechnol. 2013, 4, 655–664, doi:10.3762/bjnano.4.73

• ' functional groups (Si(OR)4, R = Si or C) of siloxane compounds [23]. This is consistent with the identity of the material deposited by the ALD process into the porous samples as SiO2. After reduction with Li metal, the 29Si NMR signal at −108.4 ppm disappears. This indicates a quantitative conversion of SiO2

• . However, no signal attributable to a crystalline Si phase can be seen. One possible explanation for the absence of 29Si NMR signal is the highly amorphous character of Si formed by the reduction reaction. Indeed, extremely broad 29Si NMR signals, which are very sensitive to the sample handling conditions

• contaminants. The Si 2p peak position of 102.2 eV (Figure 6b) unambiguously excludes a significant presence of either crystalline Si (99.3 eV) or SiO2 (103.3 eV) [25], in agreement with the 29Si NMR data. The peak position is compatible with amorphous silicon, the Si 2p XPS line of which has been found at a

Synthesis and electrical characterization of intrinsic and in situ doped Si nanowires using a novel precursor

• Wolfgang Molnar,
• Alois Lugstein,
• Tomasz Wojcik,
• Peter Pongratz,
• Norbert Auner,
• Christian Bauch and
• Emmerich Bertagnolli

Beilstein J. Nanotechnol. 2012, 3, 564–569, doi:10.3762/bjnano.3.65

• /760 mmHg, 25 g), and Si3Cl8 (TB = 215 °C/760 mmHg, 16 g). Higher oligosilanes remained in the distillation residue and were not isolated. For characterization of the precursor compounds, Si2Cl6 and Si3Cl8 were identified by their characteristic 29Si NMR chemical shifts (Si2Cl6, δ = −6.4 ppm; Si3Cl8, δ