Metal Nanoparticles with clean surface: the importance and progress

2021 ◽  
pp. 100927
Author(s):  
Houkang Pu ◽  
Huizhen Dai ◽  
Te Zhang ◽  
Kaiyu Dong ◽  
Yingying Wang ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Clean Surface

scholarly journals A Simple and Fast Method to Synthesize Cubic Iridium Nanoparticles with Clean Surface Free from Surfactants

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 76 ◽  
Author(s):  
Rongrong Zhang ◽  
Xuan Liu ◽  
Litong Shi ◽  
Xin Jin ◽  
Yanchao Dong ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Metal Nanoparticles ◽  
Reducing Agent ◽  
Fast Method ◽  
Clean Surface ◽  
Free Surfaces ◽  
Iridium Nanoparticles ◽  
Cu Foil

Cubic Iridium nanoparticles without any surfactants on the surface have been synthesized successfully in this work. The process of synthesis was quite simple by just injecting one drop of 400 µL solution containing Iridium precursor onto Cu foil (1 cm × 1 cm), and through galvanic reaction between the Ir precursor and Cu foil, the cubic Iridium nanoparticle could be obtained quite quickly (<30 s). The Cu foil played the roles of both reducing agent and substrate. This method could also be employed to synthesize cubic nanoparticles of other Pt-group metals such as Rh. By employing this method, cubic metal nanoparticles with surfactant-free surfaces could be produced economically and efficiently, and as a result, a realistic relationship between structure and catalytic activity could be established.

Surface reactions observed by photoemission electron microscopy (PEEM)

1992 ◽  
Vol 50 (1) ◽  
pp. 286-287
Author(s):  
H.H. Rotermund
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Work Function ◽  
Chemical Reactions ◽  
Reaction Diffusion ◽  
Dynamic Processes ◽  
Clean Surface ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

Rem Study of Current Effect on the Structure of Clean Si(111) Surface

1990 ◽  
Vol 48 (1) ◽  
pp. 306-307
Author(s):  
A. Yamanaka ◽  
H. Ohse ◽  
K. Yagi
Keyword(s):  
The Other ◽  
Current Direction ◽  
Clean Surface ◽  
Current Effect ◽  
Atomic Steps ◽  
Step Bunching ◽  
Terrace Width ◽  
Step Down ◽  
A Current

Recently current effects on clean and metal adsorbate surfaces have attracted much attention not only because of interesting phenomena but also because of practically importance in treatingclean and metal adsorbate surfaces [1-6]. In the former case, metals deposited migrate on the deposit depending on the current direction and a patch of the deposit expands on the clean surface [1]. The migration is closely related to the adsorbate structures and substrate structures including their anisotropy [2,7]. In the latter case, configurations of surface atomic steps depends on the current direction. In the case of Si(001) surface equally spaced array of monatom high steps along the [110] direction produces the 2x1 and 1x2 terraces. However, a relative terrace width of the two domain depends on the current direction; a step-up current widen terraces on which dimers are parallel to the current, while a step-down current widen the other terraces [3]. On (111) surface, a step-down current produces step bunching at temperatures between 1250-1350°C, while a step-up current produces step bunching at temperatures between 1050-1250°C [5].In the present paper, our REM observations on a current induced step bunching, started independently, are described.Our results are summarized as follows.(1) Above around 1000°C a step-up current induces step bunching. The phenomenon reverses around 1200 C; a step-down current induces step bunching. The observations agree with the previous reports [5].

Determination of the Size Distribution of Dissolved Organics in Effluents

1973 ◽  
Vol 8 (1) ◽  
pp. 1-15 ◽  
Author(s):  
L.A. Addie ◽  
K.L. Murphy ◽  
J.L. Robertson
Keyword(s):  
Size Distribution ◽  
Biological Treatment ◽  
Oxygen Demand ◽  
Molecular Size ◽  
Monitoring Systems ◽  
Clean Surface ◽  
Sephadex Column ◽  
Dissolved Organics ◽  
Molecular Size Distribution

Abstract The importance of removing the small amounts of residual organics is increasing as the sources of clean surface water decrease. Knowledge of the nature of these soluble residual organics will be needed in order to assess the type of treatment required for their removal. Residual organics in three different biological treatment plants were analyzed and compared. An attempt was made to characterize these organics by a molecular size distribution on a Sephadex column monitored by differential ultraviolet and refractive index detectors. The organic carbon and chemical oxygen demand of the fractions collected from the column was also determined. An investigation of some of the problems inherent in the monitoring systems was conducted.

Trends in Nanotechnology for in vivo Cancer Diagnosis: Products and Patents

2020 ◽  
Vol 26 (18) ◽  
pp. 2167-2181
Author(s):  
Tatielle do Nascimento ◽  
Melanie Tavares ◽  
Mariana S.S.B. Monteiro ◽  
Ralph Santos-Oliveira ◽  
Adriane R. Todeschini ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Quantum Dots ◽  
Magnetic Resonance ◽  
Metal Nanoparticles ◽  
Cancer Diagnosis ◽  
Imaging Techniques ◽  
Tumor Detection ◽  
Abnormal Growth ◽  
Pharmaceutical Nanotechnology

Background: Cancer is a set of diseases formed by abnormal growth of cells leading to the formation of the tumor. The diagnosis can be made through symptoms’ evaluation or imaging tests, however, the techniques are limited and the tumor detection may be late. Thus, pharmaceutical nanotechnology has emerged to optimize the cancer diagnosis through nanostructured contrast agent’s development. Objective: This review aims to identify commercialized nanomedicines and patents for cancer diagnosis. Methods: The databases used for scientific articles research were Pubmed, Science Direct, Scielo and Lilacs. Research on companies’ websites and articles for the recognition of commercial nanomedicines was performed. The Derwent tool was applied for patent research. Results: This article aimed to research on nanosystems based on nanoparticles, dendrimers, liposomes, composites and quantum dots, associated to imaging techniques. Commercialized products based on metal and composite nanoparticles, associated with magnetic resonance and computed tomography, have been observed. The research conducted through Derwent tool displayed a small number of patents using nanotechnology for cancer diagnosis. Among these patents, the most significant number was related to the use of systems based on metal nanoparticles, composites and quantum dots. Conclusion: Although few systems are found in the market and patented, nanotechnology appears as a promising field for the development of new nanosystems in order to optimize and accelerate the cancer diagnosis.

Review on Methodologies Used in the Synthesis of Metal Nanoparticles: Significance of Phytosynthesis Using Plant Extract as an Emerging Tool

2020 ◽  
Vol 26 (40) ◽  
pp. 5188-5204
Author(s):  
Uzair Nagra ◽  
Maryam Shabbir ◽  
Muhammad Zaman ◽  
Asif Mahmood ◽  
Kashif Barkat
Keyword(s):  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Plant Extracts ◽  
Biomedical Applications ◽  
Noble Metals ◽  
Cost Effective ◽  
Green Technology ◽  
Critical Parameters ◽  
Nanosized Particles ◽  
Preparation Methods

Nanosized particles, with a size of less than 100 nm, have a wide variety of applications in various fields of nanotechnology and biotechnology, especially in the pharmaceutical industry. Metal nanoparticles [MNPs] have been synthesized by different chemical and physical procedures. Still, the biological approach or green synthesis [phytosynthesis] is considered as a preferred method due to eco-friendliness, nontoxicity, and cost-effective production. Various plants and plant extracts have been used for the green synthesis of MNPs, including biofabrication of noble metals, metal oxides, and bimetallic combinations. Biomolecules and metabolites present in plant extracts cause the reduction of metal ions into nanosized particles by one-step preparation methods. MNPs have remarkable attractiveness in biomedical applications for their use as potential antioxidant, anticancer and antibacterial agents. The present review offers a comprehensive aspect of MNPs production via top-to-bottom and bottom-to-top approach with considerable emphasis on green technology and their possible biomedical applications. The critical parameters governing the MNPs formation by plant-based synthesis are also highlighted in this review.

Preparation and Application of Non-spherical Metal Nanoparticles: Reality and Perspective

2017 ◽  
Vol 21 (23) ◽  
Author(s):  
Cristina Lucena-Serrano ◽  
Rafael Contreras-Caceres ◽  
Maria Sanchez-Molina ◽  
Miguel Angel Casado-Rodriguez ◽  
Jean Manuel Cloarec ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Spherical Metal Nanoparticles
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