Organometallic synthesis of water-soluble ruthenium nanoparticles in the presence of sulfonated diphosphines and cyclodextrins

2014 ◽  
Vol 1675 ◽  
pp. 219-225
Author(s):  
Miguel Guerrero ◽  
Nguyet Trang Thanh Chau ◽  
Alain Roucoux ◽  
Audrey Nowicki-Denicourt ◽  
Eric Monflier ◽  
...  
Keyword(s):  
Size Distribution ◽  
Surface Properties ◽  
High Stability ◽  
Catalytic Properties ◽  
Water Soluble ◽  
Narrow Size Distribution ◽  
Ruthenium Nanoparticles ◽  
Organometallic Synthesis ◽  
Protective Agents

ABSTRACTThe organometallic approach was successfully applied to synthesize water-soluble ruthenium nanoparticles displaying interesting catalytic properties in hydrogenation of unsaturated model-substrates. Nanocatalyst synthesis was performed by hydrogenation of the complex [Ru(COD)(COT)] in the presence of sulfonated diphosphines and cyclodextrins as protective agents providing very small ruthenium nanoparticles (ca. 1.2-1.5 nm) with narrow size distribution and high stability. Catalysis results in water evidenced a control of the surface properties of these novel ruthenium nanocatalysts at a supramolecular level.

scholarly journals Novel dendron-stabilized gold nanoparticles with high stability and narrow size distribution

2001 ◽  
pp. 667-668 ◽  
Author(s):  
Min-Kyu Kim ◽  
You-Moon Jeon ◽  
Woo Sung Jeon ◽  
Hee-Joon Kim ◽  
Kimoon Kim ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Size Distribution ◽  
High Stability ◽  
Narrow Size Distribution

scholarly journals A new purification technique to obtain specific size distribution of giant lipid vesicles using dual filtration

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254930
Author(s):  
Mohammad Abu Sayem Karal ◽  
Tawfika Nasrin ◽  
Marzuk Ahmed ◽  
Md. Kabir Ahamed ◽  
Shareef Ahammed ◽  
...  
Keyword(s):  
Size Distribution ◽  
Fluorescent Probe ◽  
Lognormal Distribution ◽  
Lipid Vesicles ◽  
Water Soluble ◽  
Size Distributions ◽  
Narrow Size Distribution ◽  
Purification Technique ◽  
Polycarbonate Membranes ◽  
Filtration Technique

A new purification technique is developed for obtaining distribution of giant unilamellar vesicles (GUVs) within a specific range of sizes using dual filtration. The GUVs were prepared using well known natural swelling method. For filtration, different combinations of polycarbonate membranes were implemented in filter holders. In our experiment, the combinations of membranes were selected with corresponding pore sizes–(i) 12 and 10 μm, (ii) 12 and 8 μm, and (iii) 10 and 8 μm. By these filtration arrangements, obtained GUVs size distribution were in the ranges of 6−26 μm, 5–38 μm and 5–30 μm, respectively. In comparison, the size distribution range was much higher for single filtration technique, for example, 6−59 μm GUVs found for a membrane with 12 μm pores. Using this technique, the water-soluble fluorescent probe, calcein, can be removed from the suspension of GUVs successfully. The size distributions were analyzed with lognormal distribution. The skewness became smaller (narrow size distribution) when a dual filtration was used instead of single filtration. The mode of the size distribution obtained in dual filtration was also smaller to that of single filtration. By continuing this process of purification for a second time, the GUVs size distribution became even narrower. After using an extra filtration with dual filtration, two different size distributions of GUVs were obtained at a time. This experimental observation suggests that different size specific distributions of GUVs can be obtained easily, even if GUVs are prepared by different other methods.

Amphiphilic architectures based on fullerene and calixarene platforms: From buckysomes to shape-persistent micelles

2008 ◽  
Vol 80 (3) ◽  
pp. 571-587 ◽  
Author(s):  
Andreas Hirsch
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Transfer ◽  
Size Distribution ◽  
Photoinduced Electron Transfer ◽  
Building Blocks ◽  
Water Soluble ◽  
Narrow Size Distribution ◽  
Transmission Electron ◽  
Supramolecular Aggregation

The supramolecular aggregation properties of new prototypes of artificial amphiphiles consisting of fullerene or calixarene building blocks serving as platforms for the connection of hydrophobic and dendritic hydrophilic groups are reported. Very water-soluble monoadducts of C60 carrying a defined number of negative charges at a given pH were hybridized with cationic porphyrins including cyctochrome C and investigated with respect to photoinduced electron transfer. Fullerene adducts with dendritic deprotected sugar addends self-assemble to supramolecular sugar balls in water with a narrow size distribution of the micelles of around 4 nm. Various examples of cone- or T-shaped amphiphiles involving calixarene and fullerene cores self-organize to the first examples of shape-persistent micelles whose supramolecular arrangement in water has been determined with unprecedented precision based on the analysis of cryo-transmission electron microscopy (TEM) investigations.

scholarly journals Design and Synthesis of Functional Silsesquioxane-Based Hybrids by Hydrolytic Condensation of Bulky Triethoxysilanes

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Hideharu Mori
Keyword(s):  
Size Distribution ◽  
Water Soluble ◽  
Metal Alkoxides ◽  
Narrow Size Distribution ◽  
Stimuli Responsive ◽  
Design And Synthesis ◽  
One Step ◽  
The Subject ◽  
Characteristic Features ◽  
The One

This paper presents a short overview of recent advances in the design and synthesis of organic-inorganic hybrids using silsesquioxane-based nanoparticles having nanometer size, relatively narrow size distribution, high functionalities, and various characteristic features, mainly focusing on our recent researches related to the subject. A highlight of this paper is the water-soluble silsesquioxane-based nanoparticles, including hydroxyl-functionalized and cationic silsesquioxanes, which were synthesized via the one-step condensation of the bulky triethoxysilane precursors. The design and synthesis of R-SiO1.5/SiO2and R-SiO1.5/TiO2hybrids by hydrolytic cocondensation of a triethoxysilane precursor and metal alkoxides are briefly introduced. This paper also deals with recent results in stimuli-responsive hybrids based on the water-soluble silsesquioxane nanoparticles and fluorinated and amphiphilic silsesquioxane hybrids.

Formation of Submicron Scale Particles of Narrow Size Distribution from a Water-Soluble Dendrimer with Links to Porphyrins and a Fullerene

2006 ◽  
Vol 39 (4) ◽  
pp. 1607-1613 ◽  
Author(s):  
Toru Arai ◽  
Junya Ogawa ◽  
Emiko Mouri ◽  
Mohammed P. I. Bhuiyan ◽  
Norikazu Nishino
Keyword(s):  
Size Distribution ◽  
Water Soluble ◽  
Narrow Size Distribution ◽  
Submicron Scale

Macrostructure and microphysics of Saturn's E-ring

1984 ◽  
Vol 75 ◽  
pp. 607-613 ◽  
Author(s):  
Kevin D. Pang ◽  
Charles C. Voge ◽  
Jack W. Rhoads
Keyword(s):  
Size Distribution ◽  
Spherical Shape ◽  
Mie Scattering ◽  
Narrow Size Distribution ◽  
Electrostatic Levitation ◽  
Volcanic Origin ◽  
Micron Diameter

Abstract.All observed optical and infrared properties of Saturn's E-ring can be explained in terms of Mie scattering by a narrow size distribution of ice spheres of 2 - 2.5 micron diameter. The spherical shape of the ring particles and their narrow size distribution imply a molten (possibly volcanic) origin on Enceladus. The E-ring consists of many layers, possibly stratified by electrostatic levitation.

scholarly journals Size-Segregated Atmospheric Humic-Like Substances (HULIS) in Shanghai: Abundance, Seasonal Variation, and Source Identification

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 526
Author(s):  
Tianming Sun ◽  
Rui Li ◽  
Ya Meng ◽  
Yu Han ◽  
Hanyun Cheng ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Size Distribution ◽  
Principal Component ◽  
Water Soluble ◽  
Atmospheric Particulate Matter ◽  
Biomass Combustion ◽  
Vehicle Exhaust ◽  
Total Suspended Particulates ◽  
Condensation Mode ◽  
Water Soluble Organic Carbon

Humic-like substances (HULIS) are of great interest due to their optical and chemical characteristics. In this study, a total of 180 samples of atmospheric particulate matter (PM) of different sizes were collected from summer 2018 to spring 2019, in order to analyze the size distribution, to investigate the seasonal variation and then to identify the key sources of HULIS. The annual mean concentration of HULIS in the total suspended particulates reached 5.12 ± 1.42 μg/m3. The HULIS concentration was extremely higher in winter (8.35 ± 2.06 μg/m3) than in autumn (4.88 ± 0.95 μg/m3), in summer (3.62 ± 1.68 μg/m3) and in spring (3.36 ± 0.99 μg/m3). The average annual ratio of water-soluble organic carbon (WSOC) to OC and the ratio of HULIS to WSOC reached 0.546 ± 0.092 and 0.56 ± 0.06, respectively. Throughout the whole year, the size distributions of WSOC and HULIS-C were relatively smooth. The peaks of WSOC appeared at 1.8~3.2 μm and 0.56~1.0 μm, while the peaks of HULIS-C were located at 3.2~5.6 μm, 1.0~1.8 μm and 0.18~0.32 μm. The distribution of the HULIS particle mode was similar in spring, summer and autumn, while there was a lower proportion of the coarse mode and a higher proportion of the condensation mode in winter. By using the comprehensive analysis of principal component analysis (PCA), air mass backward trajectories (AMBTs) and fire point maps, key sources of WSOC and HULIS in Shanghai were identified as biomass combustion (48.42%), coal combustion (17.49%), secondary formation (16.07%) and vehicle exhaust (5.37%). The remaining part might be contributed by crustal dust sources, marine sources and/or other possible sources. This study provides new insight into the characteristics and size distribution of HULIS in Shanghai, thereby providing a practical base for further modeling.

scholarly journals Nanoformulation and Evaluation of Oral Berberine-Loaded Liposomes

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2591
Author(s):  
Thuan Thi Duong ◽  
Antti Isomäki ◽  
Urve Paaver ◽  
Ivo Laidmäe ◽  
Arvo Tõnisoo ◽  
...  
Keyword(s):  
Thin Film ◽  
Drug Release ◽  
Size Distribution ◽  
Water Soluble ◽  
Release Behavior ◽  
Uniform Size ◽  
Ethanol Injection ◽  
Drug Release Behavior ◽  
Poorly Water Soluble

Berberine (BBR) is a poorly water-soluble quaternary isoquinoline alkaloid of plant origin with potential uses in the drug therapy of hypercholesterolemia. To tackle the limitations associated with the oral therapeutic use of BBR (such as a first-pass metabolism and poor absorption), BBR-loaded liposomes were fabricated by ethanol-injection and thin-film hydration methods. The size and size distribution, polydispersity index (PDI), solid-state properties, entrapment efficiency (EE) and in vitro drug release of liposomes were investigated. The BBR-loaded liposomes prepared by ethanol-injection and thin-film hydration methods presented an average liposome size ranging from 50 nm to 244 nm and from 111 nm to 449 nm, respectively. The PDI values for the liposomes were less than 0.3, suggesting a narrow size distribution. The EE of liposomes ranged from 56% to 92%. Poorly water-soluble BBR was found to accumulate in the bi-layered phospholipid membrane of the liposomes prepared by the thin-film hydration method. The BBR-loaded liposomes generated by both nanofabrication methods presented extended drug release behavior in vitro. In conclusion, both ethanol-injection and thin-film hydration nanofabrication methods are feasible for generating BBR-loaded oral liposomes with a uniform size, high EE and modified drug release behavior in vitro.

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