Nano-assembling and optical properties of sub-100 nm raspberry-like nanoparticles

2018 ◽  
Vol 82 (2) ◽  
pp. 20401
Author(s):  
Chouaib Daoudi ◽  
Mahmoud Ould Metidji ◽  
Mohamed Remram ◽  
Anne-Marie Jurdyc ◽  
Matteo Martini ◽  
...  
Keyword(s):  
Optical Properties ◽  
Self Assembly ◽  
Hot Spots ◽  
Silica Particles ◽  
Assembly Method ◽  
Dispersed Particles ◽  
Transmission Electron ◽  
Scattering Measurements ◽  
Monodisperse Silica ◽  
The Stability

The optical properties of sub-100 nm raspberry-like nano-systems composed of highly monodisperse silica particles and large gold nanoparticles (GNPs) is studied experimentally. The nanoparticles (NPs) were prepared by a self-assembly method, and the pH of each solution was determined by measuring the ζ-potential to ensure the stability of the nano-systems. Dynamic light scattering measurements show a narrow size distribution of NPs, and fairly dispersed particles in solution. The obtained nanoraspberries was also studied by transmission electron microscopy, which shows that the GNPs closely packed on the surface of silica particles. This effect induced a broadening and a shift of the absorption band to higher wavelengths, with an increase in GNPs density. It was also observed that the reduced size of silica particles resulted in a shortening of the inter-particles distance, which has favoured the generation of many hot spots in the gaps between GNPs. The tenability of obtained plasmon bands may have benefits in SERS probe, photocatalysis and fluorescence-based bioimaging.

Fabrication and characterization of mesoporous borosilicate glasses with different boron contents

2007 ◽  
Vol 22 (7) ◽  
pp. 1834-1838 ◽  
Author(s):  
Tongping Xiu ◽  
Qian Liu ◽  
Jiacheng Wang
Keyword(s):  
Boric Acid ◽  
Self Assembly ◽  
Sol Gel ◽  
Sorption Isotherms ◽  
Mesoporous Structure ◽  
Borosilicate Glasses ◽  
Whole Process ◽  
Transmission Electron ◽  
Evaporation Induced Self Assembly ◽  
The Stability

A series of wormhole-like mesoporous borosilicate glasses (MBSGs) with different compositions has been prepared by a combination of surfactant templating, sol-gel methods, and evaporation-induced self-assembly processes. Small-angle x-ray diffraction, high-resolution transmission electron microscopy, and N2 sorption isotherms analysis showed that all the MBSGs prepared possess the mesoporous structure. However, the stability of the mesoporous structure is strongly affected by the boron contents. When boron content was increased, boric acid was found in the final product, and the mesoporous structure was partially degraded. The formation and loss of boric acid through the whole process may account for the partial collapse of the mesostructure.

Preparation and Chromatic Properties of Encapsulated Carbon Black Pigment via Layer-by-Layer Self-Assembly Method

2015 ◽  
Vol 1104 ◽  
pp. 15-20 ◽  
Author(s):  
Xiao Jun Zhang ◽  
Ting Chen ◽  
Wei Hui Jiang ◽  
Jian Min Liu ◽  
Tong Qing Zhou
Keyword(s):  
Carbon Black ◽  
Self Assembly ◽  
Black Pigment ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Assembly Method ◽  
Transmission Electron ◽  
Color System ◽  
Chromatic Properties ◽  
Cie Color System

Encapsulated carbon black pigment was prepared by layer-by-layer self-assembly method. The RX8002 carbon black particles were well coated by a SiO2 layer, which makes it has good connection with ZrSiO4 layer. Meanwhile, dense ZrSiO4 layer was coated on the C@SiO2 particles surface to prevent the corrosive effects of glaze. The structure and morphology of samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The chromatic value of the pigments was measured by the CIE color system. The results show that the carbon black particles can be well coated by SiO2 and ZrSiO4 layer. When the TEOS/H2O ratio is 0.002 and the ZrSiO4/C ratio is 0.71, the chromatic value of the encapsulated carbon black pigment is 42.55, and the pigment has a good stability in glaze.

Electrorheological Properties of Carbon Nanotube/Polyelectrolyte Composite Silica Nanoparticles by Layer-by-Layer Self-Assembly

2008 ◽  
Vol 8 (8) ◽  
pp. 3895-3899
Author(s):  
Byung-Soo Kim ◽  
Bumsu Kim ◽  
Kyung-Do Suh
Keyword(s):  
Electric Fields ◽  
Self Assembly ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Oxidation ◽  
Composite Particles ◽  
Layer By Layer ◽  
Assembly Method ◽  
Transmission Electron ◽  
Zeta Potential Analysis ◽  
Electrorheological Properties

Multiwall carbon nanotubes (MCNTs)/silica (SiO2) composite particles were prepared by layer-by-layer (LbL) self-assembly method using polyelectrolytes and functionalized MCNTs (fMCNTs). The fMCNTs prepared by chemical oxidation method were incorporated on the outermost layer of polyelectrolyte-coated SiO2 particles. The amount of fMCNTs was varied by LbL self assembly. In the process the number of fMCNT layers on SiO2 particles could be controlled. The fMCNT-coated SiO2 particles were characterized by zeta-potential analysis, transmission electron microscopy (TEM), and optical microscopy (OM). In addition, the electrorheological (ER) properties of multilayers containing fMCNTs on silica particles were investigated under controlled electric fields. The ER properties of the composite particles were influenced by the amount of fMCNTs in multilayers.

Morphology Controlled Nanostructure of Zinc Porphyrin

2013 ◽  
Vol 562-565 ◽  
pp. 1314-1318
Author(s):  
Jun Jie Li ◽  
Chang Jun Hou ◽  
Zhi Fei Li ◽  
Huan Bao Fa ◽  
Mei Yang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Fluorescence Spectroscopy ◽  
Aqueous Solutions ◽  
Self Assembly ◽  
Cationic Surfactants ◽  
Zinc Porphyrin ◽  
Assembly Method ◽  
Fluorescent Spectra ◽  
Anionic And Cationic Surfactants ◽  
Surfactant Assisted

We have shown that various Zinc porphyrin-based nanostructures can be easily synthesized by a surfactant-assisted self-assembly method, where nonionic, anionic and cationic surfactants are employed. It was found that tuning the type of surfactant offered an alternative to promote the formation of Zinc porphyrin nanostructure with different morphologies in aqueous solutions. As-prepared nano-scale self-assemblies, including disc-shaped, ellipsoid, square and quadrangular pyramidal nanoparticles, were investigated in solution via UV/vis, fluorescence spectroscopy and SEM microscopy. The different UV/vis as well as fluorescent spectra between nano-porphyrin and its monomer further conformed that the nano-crystallization of porphyrin would result in novel optical properties differing from the single subunits.

Preparation, Characterization, and Photocatalytic Performance of Bismuth and Boron Co-Doped Mesporous TiO2 by EISA Method

2014 ◽  
Vol 953-954 ◽  
pp. 1003-1007
Author(s):  
Yu Xiu Zhang ◽  
Li Yang ◽  
Dai Mei Chen ◽  
Shuang Deng ◽  
Ying Jie Shi
Keyword(s):  
Visible Light ◽  
Self Assembly ◽  
Photocatalytic Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Assembly Method ◽  
Transmission Electron ◽  
Evaporation Induced Self Assembly ◽  
Crystallite Sizes ◽  
Mesoporous Structures

Abstract. The large-pore mesoporous Bi-B-TiO2 nanoparticles with the different Bi/Ti rations were prepared by EISA(evaporation-induced self-assembly) method. The prepared catalysts were characterized by X-ray diffraction, transmission electron microscopy, N2 absorption-desorption, ultraviolet visible light spectroscopy and photoluminescence spectroscopy technologies. The results revealed that all the samples are large aperture mesoporous structures. The crystallite sizes were in the range7-11nm, as confirmed by the results obtained from TEM images. The photodecomposition experiments showed that the photodegradation activity of Bi-B-doped TiO2 was higher than that of undoped TiO2 in degradation of 2, 4–dichlorophenol under visible light irradiation.

scholarly journals Hybrid Perovskite/Polymer Materials: Preparation and Physicochemical Properties

2021 ◽  
Vol 5 (11) ◽  
pp. 304
Author(s):  
Martha Kafetzi ◽  
Stergios Pispas ◽  
George Mousdis
Keyword(s):  
Optical Properties ◽  
Temporal Stability ◽  
Random Copolymer ◽  
Polymer Materials ◽  
Hybrid Particles ◽  
Hybrid Films ◽  
Photoluminescence Decay ◽  
Hybrid Perovskite ◽  
Transmission Electron ◽  
The Stability

The aim of this work is to investigate the preparation, the optical properties, and the stability over time of a colloidal organic–inorganic hybrid perovskite (CH3NH3PbBr3)/random copolymer P(MMA-co- DMAEMA) system. Different ratios of perovskite to copolymer were used to study its effect on stability and properties. The optical properties were investigated by UV-Vis and fluorescence spectroscopy. Dynamic light scattering was used to determine the size, and the size polydispersity of the colloidal hybrid particles; while morphology was investigated by transmission electron microscopy. Photoluminescence decay studies revealed the interaction of the random copolymer with the perovskite. Finally, thin-films were prepared, to investigate the optical properties of the samples in the absence of the solvent. High temporal stability of the optical properties of thin hybrid films was observed under certain conditions.

scholarly journals Cobalt Element Effect of Ternary Mesoporous Cerium Lanthanum Solid Solution for the Catalytic Conversion of Methanol and CO2 into Dimethyl Carbonate

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 270
Author(s):  
Xu Li ◽  
Hua Shi ◽  
Yunhan Gu ◽  
Qingyan Cheng ◽  
Yanji Wang
Keyword(s):  
Solid Solution ◽  
Oxygen Vacancy ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Dimethyl Carbonate ◽  
Catalytic Performance ◽  
X Ray ◽  
Assembly Method ◽  
Transmission Electron ◽  
Adsorption Desorption

A citric acid ligand assisted self-assembly method is used for the synthesis of ternary mesoporous cerium lanthanum solid solution doped with metal elements (Co, Zr, Mg). Their textural property was characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption, X-ray photoelectron spectroscopy and TPD techniques, and so on. The results of catalytic testing for synthesis of dimethyl carbonate (DMC) from CH3OH and CO2 indicated that the DMC yield reached 316 mmol/g on Ce-La-Co solid solution when the reaction temperature was 413 K and the reaction pressure was 8.0 MPa. It was found that Co had synergistic effect with La and Ce, doping of Co on the mesoporous Ce-La solid solution was helpful to increase the surface area of the catalyst, promote CO2 adsorption and activation, and improve the redox performance of solid solution catalyst. The conversion of Co2+ to Co3+ resulted in the continuous redox cycle between Ce4+ and Ce3+, and the oxygen vacancy content of the catalyst was increased. Studies have shown that the catalytic performance of Ce-La-Co solid solution is positively correlated with oxygen vacancy content. On this basis, the reaction mechanism of DMC synthesis from CO2 and CH3OH on the catalyst was speculated.

scholarly journals Amphiphilic Nucleobase-Containing Polypeptide Copolymers—Synthesis and Self-Assembly

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1357
Author(s):  
Michel Nguyen ◽  
Khalid Ferji ◽  
Sébastien Lecommandoux ◽  
Colin Bonduelle
Keyword(s):  
Self Assembly ◽  
Ring Opening ◽  
Building Blocks ◽  
Ring Opening Polymerization ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Transmission Electron ◽  
Scattering Measurements ◽  
Thymidine Monophosphate ◽  
The Impact

Nucleobase-containing polymers are an emerging class of building blocks for the self-assembly of nanoobjects with promising applications in nanomedicine and biology. Here we present a macromolecular engineering approach to design nucleobase-containing polypeptide polymers incorporating thymine that further self-assemble in nanomaterials. Diblock and triblock copolypeptide polymers were prepared using sequential ring-opening polymerization of γ-Benzyl-l-glutamate N-carboxyanhydride (BLG-NCA) and γ-Propargyl-l-glutamate N-carboxyanhydride (PLG-NCA), followed by an efficient copper(I)-catalyzed azide alkyne cycloaddition (CuAAc) functionalization with thymidine monophosphate. Resulting amphiphilic copolymers were able to spontaneously form nanoobjects in aqueous solutions avoiding a pre-solubilization step with an organic solvent. Upon self-assembly, light scattering measurements and transmission electron microscopy (TEM) revealed the impact of the architecture (diblock versus triblock) on the morphology of the resulted nanoassemblies. Interestingly, the nucleobase-containing nanoobjects displayed free thymine units in the shell that were found available for further DNA-binding.

Synthesis, Structural and Photoelectrical Properties of Self-Assembled Gold-Poly(3,4-Ethylenedioxythiophene) Nanowires and Nanocables

2013 ◽  
Vol 650 ◽  
pp. 200-205
Author(s):  
Bin Sun ◽  
Yun Ze Long ◽  
Meng Meng Li ◽  
Xiu Jie Hu ◽  
Ying Qun Qi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Composite Films ◽  
Xenon Lamp ◽  
Multifunctional Composites ◽  
Photoelectrical Properties ◽  
Selected Area Electron Diffraction ◽  
Assembly Method ◽  
Transmission Electron ◽  
Potential Applications ◽  
Coaxial Nanocables

Gold-poly (3,4-ethylenedioxythiophene) (Au-PEDOT) nanowires with Au nanoparticles embedded in the polymer matrix and polyvinylpyrrolidone (PVP) modified Au-PEDOT coaxial nanocables with a core-shell structure have been synthesized by a new and facile self-assembly method. The morphology and structure features of the composites were characterized by transmission electron microscopy, selected-area electron diffraction, and energy-dispersive x-ray spectrometry. The room-temperature electrical conductivity of the casted composite films was about 0.21 S/cm. Photoresponse of the films were also investigated with respect to wide potential applications of the multifunctional composites. Clear photocurrent switching characteristic during switching on/off of a xenon lamp was observed.

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