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Your search keyword '"Amenitsch, Heinz"' showing total 144 results
Start Over Author "Amenitsch, Heinz" Publisher american chemical society
144 results on '"Amenitsch, Heinz"'

7. Strongly Confined CsPbBr3 Quantum Dots as Quantum Emitters and Building Blocks for Rhombic Superlattices.

Author

Boehme, Simon C., Bodnarchuk, Maryna I., Burian, Max, Bertolotti, Federica, Cherniukh, Ihor, Bernasconi, Caterina, Zhu, Chenglian, Erni, Rolf, Amenitsch, Heinz, Naumenko, Denys, Andrusiv, Hordii, Semkiv, Nazar, John, Rohit Abraham, Baldwin, Alan, Galkowski, Krzysztof, Masciocchi, Norberto, Stranks, Samuel D., Rainò, Gabriele, Guagliardi, Antonietta, and Kovalenko, Maksym V.

Published
2023
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10. Monodisperse Long-Chain Sulfobetaine-Capped CsPbBr₃ Nanocrystals and Their Superfluorescent Assemblies

Author

Krieg, Franziska, Sercel, Peter C., Burian, Max, Andrusiv, Hordii, Bodnarchuk, Maryna I., Stöferle, Thilo, Mahrt, Rainer F., Naumenko, Denys, Amenitsch, Heinz, Rainò, Gabriele, and Kovalenko, Maksym V.

Abstract

Ligand-capped nanocrystals (NCs) of lead halide perovskites, foremost fully inorganic CsPbX₃ NCs, are the latest generation of colloidal semiconductor quantum dots. They offer a set of compelling characteristics—large absorption cross section, as well as narrow, fast, and efficient photoluminescence with long exciton coherence times—rendering them attractive for applications in light-emitting devices and quantum optics. Monodisperse and shape-uniform, broadly size-tunable, scalable, and robust NC samples are paramount for unveiling their basic photophysics, as well as for putting them into use. Thus far, no synthesis method fulfilling all these requirements has been reported. For instance, long-chain zwitterionic ligands impart the most durable surface coating, but at the expense of reduced size uniformity of the as-synthesized colloid. In this work, we demonstrate that size-selective precipitation of CsPbBr₃ NCs coated with a long-chain sulfobetaine ligand, namely, 3-(N,N-dimethyloctadecylammonio)-propanesulfonate, yields monodisperse and sizable fractions (>100 mg inorganic mass) with the mean NC size adjustable in the range between 3.5 and 16 nm and emission peak wavelength between 479 and 518 nm. We find that all NCs exhibit an oblate cuboidal shape with the aspect ratio of 1.2 × 1.2 × 1. We present a theoretical model (effective mass/k·p) that accounts for the anisotropic NC shape and describes the size dependence of the first and second excitonic transition in absorption spectra and explains room-temperature exciton lifetimes. We also show that uniform zwitterion-capped NCs readily form long-range ordered superlattices upon solvent evaporation. In comparison to more conventional ligand systems (oleic acid and oleylamine), supercrystals of zwitterion-capped NCs exhibit larger domain sizes and lower mosaicity. Both kinds of supercrystals exhibit superfluorescence at cryogenic temperatures—accelerated collective emission arising from the coherent coupling of the emitting dipoles.

Published
2021

12. Structural Diversity in Multicomponent Nanocrystal Superlattices Comprising Lead Halide Perovskite Nanocubes.

Author

Cherniukh, Ihor, Sekh, Taras V., Rainò, Gabriele, Ashton, Olivia J., Burian, Max, Travesset, Alex, Athanasiou, Modestos, Manoli, Andreas, John, Rohit Abraham, Svyrydenko, Mariia, Morad, Viktoriia, Shynkarenko, Yevhen, Montanarella, Federico, Naumenko, Denys, Amenitsch, Heinz, Itskos, Grigorios, Mahrt, Rainer F., Stöferle, Thilo, Erni, Rolf, and Kovalenko, Maksym V.

Published
2022
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13. Humidity Response of Cellulose Thin Films.

Author

Reishofer, David, Resel, Roland, Sattelkow, Jürgen, Fischer, Wolfgang J., Niegelhell, Katrin, Mohan, Tamilselvan, Kleinschek, Karin Stana, Amenitsch, Heinz, Plank, Harald, Tammelin, Tekla, Kontturi, Eero, and Spirk, Stefan

Published
2022
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16. Growth kinetics of ZnO nanocrystals: A few surprises

Author

Viswanatha, Ranjani, Amenitsch. Heinz, and Sarma, D.D.

Subjects
Zinc oxide -- Chemical properties, Zinc oxide -- Structure, Nanotechnology -- Research, Chemical synthesis -- Research, Chemistry
Abstract

The extensive state-of-the-art experiments over a wide range of synthesis parameters are used to study the qualitatively different growth kinetics for ZnO nanocrystals, as compared to the kinetics of all other semiconducting nanocrystals. The results show that the formation of an effective passivating layer around the growing nanocrystals inhibits the reaction, instead of facilitating it, hence giving all the different results and observations.

Published
2007

17. Silica orthorhombic mesostructured films with low refractive index and high thermal stability

Author

Falcaro, Paolo, Grosso, David, Amenitsch, Heinz, Innocenzi, Plinio, Kawasaki, M., and Koinuma, H.

Subjects
Evaporation -- Observations, Silica -- Research, Silica -- Thermal properties, Chemistry, Physical and theoretical -- Research, Chemicals, plastics and rubber industries
Abstract

Silica mesoporous films with an orthorhombic mesostructure are synthesized via Evaporation Induced Self-Assembling (EISA). An optimized thermal treatment applied to the silica mesostructured films enhanced the thermal stability of the organized phase up to 950 degree C and a progressive thermal treatment with different increasing steps of 100 degree C, allowed controlling the condensation and the thermal dehydroxylation of the silica walls.

Published
2004

18. Pressure effects on columnar lyotropics: anisotropic compressibilities in guanosine monophosphate four-stranded helices

Author

Ausili, Pamela, Pisani, Michela, Finet, Stephanie, Amenitsch, Heinz, Ferrero, Claudio, and Mariani, Paolo

Subjects
Chemistry, Physical and theoretical -- Observations, Cyclic guanylic acid -- Atomic properties, Cyclic guanylic acid -- Research, Chemicals, plastics and rubber industries
Abstract

A high-pressure X-ray diffraction analysis of the structural properties of GMP helices in the hexagonal phase in the presence and absence of KCl is discussed. The reported experimental data might be helpful in using theoretical approaches in further analysis at different force/extension regimes.

Published
2004

19. Opsonin-Deficient Nucleoproteic Corona Endows UnPEGylated Liposomes with Stealth Properties In Vivo.

Author

Giulimondi, Francesca, Vulpis, Elisabetta, Digiacomo, Luca, Giuli, Maria Valeria, Mancusi, Angelica, Capriotti, Anna Laura, Laganà, Aldo, Cerrato, Andrea, Zenezini Chiozzi, Riccardo, Nicoletti, Carmine, Amenitsch, Heinz, Cardarelli, Francesco, Masuelli, Laura, Bei, Roberto, Screpanti, Isabella, Pozzi, Daniela, Zingoni, Alessandra, Checquolo, Saula, and Caracciolo, Giulio

Published
2022
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20. Metal Sulfide Thin Films with Tunable Nanoporosity for Photocatalytic Applications.

Author

Vakalopoulou, Efthymia, Rath, Thomas, Kräuter, Marianne, Torvisco, Ana, Fischer, Roland C., Kunert, Birgit, Resel, Roland, Schröttner, Hartmuth, Coclite, Anna Maria, Amenitsch, Heinz, and Trimmel, Gregor

Abstract

Metal xanthates are widely used as single-source precursors for the formation of metal sulfide thin films. In this study, we explore the length of the alkyl ligand as an efficient tool to control the formation and the nanoporosity of zinc sulfide thin films. The presented approach allows us to prepare highly porous thin metal sulfide films with potential applications in photocatalysis, whereby the nanoporosity is significantly enhanced with an increasing number of carbons in the alkyl chain of the metal xanthate precursors. To gain knowledge about the mechanisms leading to the changes in the nanoporosity, the thermal conversion process toward the porous films is studied in detail by time-resolved simultaneous grazing incidence small- and wide-angle X-ray scattering measurements using synchrotron radiation and thermogravimetric analysis. Thereby, we found that the structural changes during the early stages of the conversion process, which are distinctly influenced by the decomposition temperature of the metal xanthates, different growth regimes of the nanocrystals, and a mesophase formation, governed by the properties of the decomposition products of the metal xanthates, are mainly responsible for the changes of the structural properties and the nanoporosity of the final ZnS films. [ABSTRACT FROM AUTHOR]

Published
2022
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21. Short-chain alcohols

Author

Argen, Patrik, Linden, Mika, Rosenholm, Jarl B., Schwarzenbacher, Robert, Kriechbaum, Manfred, Amenitsch, Heinz, Laggner, Peter, Balnchard, Juliette, and Schuth, Ferdi

Subjects
Alcohols -- Research, Butanol -- Research, Silicates -- Research, Surface active agents -- Research, Chemicals, plastics and rubber industries
Abstract

In situ synchrotron small angle X-ray scattering was used to study the formation of hexagonal and lamellar surfactant-silicate mesophases at room temperature with emphasis on the effect of butanol and hexanol on cosurfactant concentration and chain length. The addition of either HeOh or BuOH was found to lower curvature structures, with the HeOH having a more pronounced effect. Moreover, the one, two or three coexisting phases that were observed depended on the reaction composition.

Published
1999

28. Accessing ultrashort reaction times in particle formation with SAXS experiments: ZnS precipitation on the microsecond time scale

Author

Schmidt, Wolfgang, Bussian, Patrick, Linden, Mika, Amenitsch, Heinz, Agren, Patrik, Tiemann, Michael, and Schuth, Ferdi

Subjects
Diffusion processes -- Analysis, Hydrogen sulfide -- Chemical properties, Hydrogen sulfide -- Structure, Jets -- Design and construction, Jets -- Usage, Zinc compounds -- Chemical properties, Zinc compounds -- Structure, Chemistry
Abstract

A liquid jet flow cell was designed to understand the mechanism underlying the zinc sulfide particle formation on the time scales down to [10.sup.-5] s. The highly rapid growth of zinc sulfide particles is controlled by the diffusion of the hydrogen sulfide into the liquid jet.

Published
2010

29. Universality of DNA adsorption behavior on the cationic membranes of nanolipoplexes

Author

Caracciolo, Giulio, Pozzi, Daniela, Amici, Augusto, and Amenitsch, Heinz

Subjects
Adsorption -- Analysis, DNA -- Structure, DNA -- Chemical properties, DNA -- Electric properties, DNA-ligand interactions -- Analysis, Drug delivery systems -- Research, Drugs -- Vehicles, Drugs -- Research, Chemicals, plastics and rubber industries
Published
2010

31. Observation of a rectangular DNA superlattice in the liquid-crystalline phase of cationic lipid/DNA complexes

Author

Caracciolo, Giulio, Pozzi, Daniela, Caminiti, Ruggero, Mancini, Giovanna, Luciani, Paola, and Amenitsch, Heinz

Subjects
DNA -- Research, Lipid membranes -- Structure, Lipid membranes -- Chemical properties, X-rays -- Diffraction, X-rays -- Usage, Chemistry
Abstract

The observation of the transbilayer correlation in the DNA ordering in the liquid-crystalline lipid phase is presented.

Published
2007

32. Two-dimensional lipid mixing entropy regulates the formation of multicomponent lipoplexes

Author

Caracciolo, Giulio, Pozzi, Daniela, Caminiti, Ruggero, and Amenitsch, Heinz

Subjects
Entropy (Physics) -- Analysis, Lipoproteins -- Thermal properties, Proteolipids -- Thermal properties, Liposomes -- Usage, X-rays -- Diffraction, X-rays -- Observations, Chemicals, plastics and rubber industries
Abstract

An investigation of the mechanism of formation of multicomponent lipoplexes is presented by means of synchrotron Small-Angle X-ray diffraction (SAXD). The equilibrium structure of multicomponent lipoplexes is found to be unique and did not depend on the number and kind of populations composing lipid dispersion but only on the lipid species involved and on their relative molar ratio.

Published
2006

33. Detailed in situ XRD and calorimetric study of the formation of silicate/mixed surfactant mesophases under alkaline conditions. Influence of surfactant chain length and synthesis temperature

Author

Beurroies, Isabelle, Agren, Patrik, Buchel, Gunter, Rosenholm, Jarl B., Amenitsch, Heinz, Denoyel, Renaud, and Linden, Mika

Subjects
Silicon compounds -- Spectra, Silicon compounds -- Chemical properties, Chemical synthesis -- Analysis, X-rays -- Diffraction, X-rays -- Analysis, Chemicals, plastics and rubber industries
Abstract

The formation of mesoscopically ordered silica/surfactant composites under alkaline synthesis conditions are analyzed by using time-resolved in situ small-angle X-ray diffraction with synchrotron radiation. The two-step mechanism is confirmed by a microcalorimetric study where the heat evolved during the hydrolysis-condensation reactions is followed as a function of time.

Published
2006

34. Highly ordered 'defect-free' self-assembled hybrid films with a tetragonal mesostructure

Author

Falcaro, Paolo, Kidchob, Tongjit, Malfatti, Luca, Costacurta, Stefano, Innocenzi, Plinio, Nucara, Alessandro, Mattei, Giovanni, Piccinini, Massimo, Amenitsch, Heinz, Guidi, Cestelli, Marcelli, Agusto, and Cestelli, Mariangela

Subjects
Silicon compounds -- Chemical properties, Hydrolysis -- Research, Dielectric films -- Research, Thin films -- Research, Chemistry
Abstract

Hybrid mesostructured films prepared by cohydrolysis are synthesized along with self-assembly of an optimized methyltriethoxysilane- tetraethyl orthosilicate (MTES-TEOS) mixture with the purpose to reach a large order in the pore organization without 'point defects' are synthesized. It used these films to introduce a rigorous methodology, based on TEM and SAXS analysis followed by a computer simulation, to identify phases in these mesoporous films.

Published
2005

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