Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

• Keiko Kojima,
• Nodoka Kosugi,
• Hirokuni Jintoku,
• Kazufumi Kobashi and
• Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

• . Keywords: aqueous dispersion; bar-coating; carbon nanotube; coffee-ring effect; liquid crystal; Introduction Carbon nanotubes (CNTs) are cylindrical carbon structures with high electrical conductivity and tensile strength in the direction of the tube, anticipated as durable and highly conductive fibers

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• in water of 0.03 wt % (upper), 0.30 wt % (middle) and 1.0 wt % (lower) at different times since preparation. A is the aqueous dispersion of particles, B is after addition of oil but before emulsification. Optical microscopy images of cyclohexane-in-water emulsions of Figure 4 after one month for

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• -bromoacetophenone (1a) and styrene (2a). In our previous reports [46][47][48], it was exposed that a PVP-Pd NPs aqueous dispersion exhibited a high stability, and for that reason, the Pd NPs cannot be separated by a physical technique. Any attempt to separate the nanocatalyst from reaction media by centrifugation

• the galvanostatic electrolysis. After completion of the reaction the aqueous dispersion of Pd NPs was placed in a 25 mL volumetric flask to be used as catalyst solution for Mizoroki–Heck coupling reaction without further purification. Average dimensions and shapes of Pd NPs were determined by

Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

• Tamás Zoltán Agócs,
• István Puskás,
• Erzsébet Varga,
• Mónika Molnár and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2016, 12, 2873–2882, doi:10.3762/bjoc.12.286

• provided by Evonik [41]. However, in aqueous dispersion prepared in our laboratory, these nanocrystallites form – still relatively small – aggregates having a mean size of 50–60 nm (Figure 3 and Figure 4, red curves). The particle size distribution of nanoTiO2 in the absence of destabilizing ions is

A self-assembled cyclodextrin nanocarrier for photoreactive squaraine

• Ulrike Kauscher and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248

• solution in a round bottom flask. Hydration and extrusion with a Liposofast extruder and membranes with 100 nm pore size yield bilayer vesicles of an approximate size of 100 nm. CDVs were decorated with AdSq by simple addition of the AdSq to the aqueous dispersion of the CDVs. Interestingly, the

• investigated the photochemistry of AdSq on CDV. To this end, AdSq was added to an aqueous dispersion of CDV exactly as described above. The solution was irradiated for 600 s and absorption spectra were taken at various time points. As shown before in the acetonitrile solution, also AdSq immobilized on CDV

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• method. The CD nanogel was labeled with fluorescein isothiocyanate (FITC) in the aqueous phase before emulsification. A Pickering emulsion was prepared by mixing the aqueous dispersion containing FITC labeled-CD nanogels (0.1 wt %) with n-dodecane (Φoil = 0.1) and subsequent shaking for 1 min. After

• water was changed twice daily. Then the aqueous dispersion was lyophilized for three days to yield a white powder as a urethane-crosslinked DM-β-CD polymer. The CD nanogel was prepared by the redispersion of the powder in distilled water with the aid of ultrasonication and stored in a refrigerator until

• temperature for 24 h. The resulting solution was purified by dialysis for three days using a dialysis membrane (molecular weight cut-off of 10 kDa) to remove free FITC. The aqueous dispersion was lyophilized for three days to yield a powder. Finally, the FITC-labeled CD/PDI polymer was dissolved in water. The

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• in an aqueous dispersion of a Pt-TiO2 catalyst, an interesting self-reaction occurred. Ohtani and co-workers isolated modest yields of secondary amines 13 that were formed via C–N coupling (Scheme 4, top) [48]. Terminal diamines reacted by ring closure resulting in cyclic amines 14; pyrrolidine was

Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test

• Gerald Jarre,
• Steffen Heyer,
• Elisabeth Memmel,
• Thomas Meinhardt and
• Anke Krueger

Beilstein J. Org. Chem. 2014, 10, 2729–2737, doi:10.3762/bjoc.10.288

• ), 810 (w), 677 (m) cm−1; TGA (% weight loss): 150–540 °C: 4.2% (C8H10N2S2); surface loading: 0.23 mmol g−1 (calculated from sulfur content in EA), 0.21 mmol g−1 (calculated from nitrogen content in EA), 0.21 mmol g−1 (calculated from TGA); zetapotential: +34.2 mV (measured in aqueous dispersion

• demonstrated in a control experiment); surface loading: 0.21 mmol g−1 (calculated from sulfur content in EA), 0.23 mmol g−1 (calculated from nitrogen content in EA), 0.21 mmol g−1 (calculated from corrected TGA data); zetapotential: +19.8 mV (measured in aqueous dispersion). Synthesis of 11: 20 mg of the

• mmol g−1 (calculated from corrected TGA); zetapotential: +12.2 mV (measured in aqueous dispersion). FTIR-spectra of annealed nanodiamond 2 (a), nitrile 4 (b) and amine 5 (c). As can be seen from the disappearance of the CN signal after the reduction of 4 the nitrile is fully converted into the

Cyanoethylation of the glucans dextran and pullulan: Substitution pattern and formation of nanostructures and entrapment of magnetic nanoparticles

• Kathrin Fiege,
• Heinrich Lünsdorf,
• Sevil Atarijabarzadeh and
• Petra Mischnick

Beilstein J. Org. Chem. 2012, 8, 551–566, doi:10.3762/bjoc.8.63

• glc; the numbers assign the substituted positions, e.g., 234 = 2,3,4-tri-O-cyanoethyl glc; H1 heterogeneity parameter for the standard deviation as defined in Table 2. TEM micrograph of iron oxide nanoparticles prepared from an aqueous dispersion. SEM micrographs of CEP-3 with iron oxide nanoparticles

Hybrid biofunctional nanostructures as stimuli-responsive catalytic systems

• Gernot U. Marten,
• Thorsten Gelbrich and
• Annette M. Schmidt

Beilstein J. Org. Chem. 2010, 6, 922–931, doi:10.3762/bjoc.6.98

• ). The hydrodynamic diameter of the core–shell nano-objects in aqueous dispersion can be detected by dynamic light scattering (DLS). A significant increase of the hydrodynamic diameter can be observed (Table 1), compared to electrostatic stabilized particles, and to CTS functionalized particles with a