A universal approach to the preparation of colloidal mesoporous platinum nanoparticles with controlled particle sizes in a wide range from 20 nm to 200 nm

2014 ◽  
Vol 16 (19) ◽  
pp. 8787-8790 ◽  
Author(s):  
Cuiling Li ◽  
Masataka Imura ◽  
Yusuke Yamauchi

We report a universal method for the preparation of mesoporous Pt nanoparticles with tunable particle sizes by changing the surfactant concentration.

2017 ◽  
Vol 54 (10) ◽  
pp. 1460-1471 ◽  
Author(s):  
Katherine A. Kwa ◽  
David W. Airey

This study uses a critical state soil mechanics perspective to understand the mechanics behind the liquefaction of metallic ores during transport by ship. These metallic ores are transported at relatively low densities and have variable gradings containing a wide range of particle sizes and fines contents. The effect of the fines content on the location of the critical state line (CSL) and the cyclic liquefaction behaviour of well-graded materials was investigated by performing saturated, standard drained and undrained monotonic and compression-only cyclic triaxial tests. Samples were prepared at four different gradings containing particle sizes from 9.5 mm to 2 μm with fines (<75 μm) contents of 18%, 28%, 40%, and 60%. In the e versus log[Formula: see text] plane, where e is void ratio and [Formula: see text] is mean effective stress, the CSLs shifted upwards approximately parallel to one another as the fines content was increased. Transitional soil behaviour was observed in samples containing 28%, 40%, and 60% fines. A sample’s cyclic resistance to liquefaction depended on a combination of its density and state parameter, which were both related to the fines content. Samples with the same densities were more resistant to cyclic failure if they contained higher fines contents. The state parameter provided a useful prediction for general behavioural trends of all fines contents studied.


2008 ◽  
Vol 591-593 ◽  
pp. 294-298
Author(s):  
Uilame Umbelino Gomes ◽  
L.A. Oliveira ◽  
S.R.S. Soares ◽  
M. Furukava ◽  
C.P. Souza

Sintered stainless steel has a wide range of applications mainly in the automotive industry. Properties such as wear resistance, density and hardness can be improved by addition of nanosized particles of refractory carbides. The present study compares the behavior of the sintering and hardness of stainless steel samples reinforced with NbC or TaC (particles size less than 20 nm) synthesized at UFRN. The main aim of this work was to identify the effect of the particle size and dispersion of different refractory carbides in the hardness and sintered microstructure. The samples were sintered in a vacuum furnace. The heating rate, sintering temperature and times were 20°C/min, 1290°C and 30, 60 min respectively. We have been able to produce compacts with a relative density among 95.0%. The hardness values obtained were 140 HV for the reinforced sample and 76 HV for the sample without reinforcement.


2017 ◽  
Vol 5 (37) ◽  
pp. 19857-19865 ◽  
Author(s):  
Kui Li ◽  
Zhao Jin ◽  
Junjie Ge ◽  
Changpeng Liu ◽  
Wei Xing

A robust architecture, consisting of Pt nanoparticles partially-embedded in carbon spheres with low loading, brings about outstanding electrocatalytic performance in DMFCs.


Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 225
Author(s):  
Pei-Ju Chen ◽  
Hsien-Yeh Chen ◽  
Wei-Bor Tsai

A facial, versatile, and universal method that breaks the substrate limits is desirable for antifouling treatment. Thin films of functional poly-p-xylylenes (PPX) that are deposited using chemical vapor deposition (CVD) provide a powerful platform for surface immobilization of molecules. In this study, we prepared an alkyne-functionalized PPX coating on which poly (sulfobetaine methacrylate-co-Az) could be conjugated via click chemistry. We found that the conjugated polymers were very stable and inhibited cell adhesion and protein adsorption effectively. The same conjugation strategy could also be applied to conjugate azide-containing poly (ethylene glycol) and poly (NIPAAm). The results indicate that our method provides a simple and robust tool for fabricating antifouling surfaces on a wide range of substrates using CVD technology of functionalized poly (p-xylylenes) for biosensor, diagnostics, immunoassay, and other biomaterial applications.


2021 ◽  
Vol 11 (3) ◽  
pp. 293-315
Author(s):  
D.Yu. VORONIN

The paper presents a research of the new legal regulation for such an institute in relation to a regional and equal court, as the referral of a case received in accordance with part 4 of Article 39 of the Arbitration Procedure Code of the Russian Federation to a court of general jurisdiction, which is in jurisdiction to hear a case as it is assigned by law. The absence of procedural legal regulation of this action, which is, in author’s opinion, has an obvious procedural nature, and researched practice general jurisdiction courts demonstrate the uncertainty in implementation of the considered reform. The author analyzes the new procedural institution on the basis of his own vision of a number of procedural norms, as well as scholar works and historical experience. In particular, the author reasoning that the courts are to issue special rulings on the referral of cases received from arbitration to the courts of general jurisdiction. Moreover, the author considers the mechanism for adopting such a judicial act. The article presents a wide range of practical examples of the implementation of considered provision, as well as the difference in the approaches of the appellate courts to assess these implementation practice. In conclusion, the article presents the proposals for further improvement of the regulation of considered issue. Most likely such an improvement will be impossible without the universal approach established by the Supreme Court of the Russian Federation. Such improvements should result in uniform judicial practice, as well as further developments of procedural legislation.


RSC Advances ◽  
2018 ◽  
Vol 8 (59) ◽  
pp. 33742-33747 ◽  
Author(s):  
Zhaohong Su ◽  
Chaorong Li ◽  
Yongbing Cheng ◽  
Qingwen Gui ◽  
Yuanfu Xiong ◽  
...  

Pt nanoparticles (PtNPs) well-dispersed on thiolated polyaniline (TPANI)-multiwalled carbon nanotubes (MWCNTs) were prepared for enhanced electrocatalytic oxidation of methanol in acidic media.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuliar Firdaus ◽  
Vincent M. Le Corre ◽  
Safakath Karuthedath ◽  
Wenlan Liu ◽  
Anastasia Markina ◽  
...  

Abstract The short exciton diffusion length associated with most classical organic semiconductors used in organic photovoltaics (5-20 nm) imposes severe limits on the maximum size of the donor and acceptor domains within the photoactive layer of the cell. Identifying materials that are able to transport excitons over longer distances can help advancing our understanding and lead to solar cells with higher efficiency. Here, we measure the exciton diffusion length in a wide range of nonfullerene acceptor molecules using two different experimental techniques based on photocurrent and ultrafast spectroscopy measurements. The acceptors exhibit balanced ambipolar charge transport and surprisingly long exciton diffusion lengths in the range of 20 to 47 nm. With the aid of quantum-chemical calculations, we are able to rationalize the exciton dynamics and draw basic chemical design rules, particularly on the importance of the end-group substituent on the crystal packing of nonfullerene acceptors.


2015 ◽  
Vol 3 (6) ◽  
pp. 2568-2571 ◽  
Author(s):  
Sanpei Zhang ◽  
Zhaoyin Wen ◽  
Kun Rui ◽  
Chen Shen ◽  
Yan Lu ◽  
...  

Graphene nanosheets loaded with highly dispersed platinum nanoparticles (Pt@GNSs) are prepared by a simple and effective hydrothermal method.


Author(s):  
George Okeke ◽  
Robert B. Hammond ◽  
S. Joseph Antony

Nanoparticles are nanometer sized metallic oxides which possess enhanced properties that are desirable to a wide range of industries. In this study, we investigate structural and surface properties of anatase TiO2 nanoparticles in vacuum and water environments using molecular dynamics simulations. The particle sizes ranged from 2 to 6 nm and simulations were performed at 300 K. Surface energy of the particles in vacuum was seen to be higher than that of the particles in water by about 100% for the smaller particles (i.e. 2 and 3nm) and about 60% for the larger particles (i.e. 4 to 6 nm). Surface energy of the particles in both environments, is seen to increase to a maximum (optimum value) as the particle size increases after which no further significant increase is observed. In vacuum, studies carried out at temperatures ranging from 300–2500 K showed a high dependence of surface energy on temperature. The estimated surface tension of water is seen to agree quite well with that of experiments.


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