Surface engineering of linearly fused Au13 units by diphosphine and Cd doping

2021 ◽  
Author(s):  
Tianrong Li ◽  
Qinzhen Li ◽  
Sha Yang ◽  
Liyun Xu ◽  
Jinsong Chai ◽  
...  
Keyword(s):  
Surface Engineering ◽  
Critical Role ◽  
Volume Ratio ◽  
Cd Doping

Large surface‐to‐volume ratio is one of the most intriguing characters of nanoclusters, which endow the surface a critical role in the demonstrating the nanoclusters’ novel properties and applications. In this...

scholarly journals Ultrafiltration Method for Plasma Protein Binding Studies and Its Limitations

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 382
Author(s):  
Camelia-Maria Toma ◽  
Silvia Imre ◽  
Camil-Eugen Vari ◽  
Daniela-Lucia Muntean ◽  
Amelia Tero-Vescan
Keyword(s):  
Protein Binding ◽  
Plasma Protein Binding ◽  
Plasma Protein ◽  
Specific Binding ◽  
Critical Role ◽  
Volume Ratio ◽  
Binding Studies ◽  
Experimental Conditions ◽  
Key Aspects

Plasma protein binding plays a critical role in drug therapy, being a key part in the characterization of any compound. Among other methods, this process is largely studied by ultrafiltration based on its advantages. However, the method also has some limitations that could negatively influence the experimental results. The aim of this study was to underline key aspects regarding the limitations of the ultrafiltration method, and the potential ways to overcome them. The main limitations are given by the non-specific binding of the substances, the effect of the volume ratio obtained, and the need of a rigorous control of the experimental conditions, especially pH and temperature. This review presents a variety of methods that can hypothetically reduce the limitations, and concludes that ultrafiltration remains a reliable method for the study of protein binding. However, the methodology of the study should be carefully chosen.

scholarly journals Batch Syngas Fermentation by Clostridium carboxidivorans for Production of Acids and Alcohols

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1075
Author(s):  
Fabiana Lanzillo ◽  
Giacomo Ruggiero ◽  
Francesca Raganati ◽  
Maria Elena Russo ◽  
Antonio Marzocchella
Keyword(s):  
Critical Role ◽  
Volume Ratio ◽  
Liquid Volume ◽  
Syngas Fermentation ◽  
Co Concentration ◽  
Depletion Rate ◽  
Growth Differences ◽  
Gas Volume ◽  
Clostridium Carboxidivorans ◽  
Kinetics Of

Syngas (CO, CO2, and H2) has attracted special attention due to the double benefit of syngas fermentation for carbon sequestration (pollution reduction), while generating energy. Syngas can be either produced by gasification of biomasses or as a by-product of industrial processes. Only few microorganisms, mainly clostridia, were identified as capable of using syngas as a substrate to produce medium chain acids, or alcohols (such as butyric acid, butanol, hexanoic acid, and hexanol). Since CO plays a critical role in the availability of reducing equivalents and carbon conversion, this work assessed the effects of constant CO partial pressure (PCO), ranging from 0.5 to 2.5 atm, on cell growth, acid production, and solvent production, using Clostridium carboxidivorans. Moreover, this work focused on the effect of the liquid to gas volume ratio (VL/VG) on fermentation performances; in particular, two VL/VG were considered (0.28 and 0.92). The main results included—(a) PCO affected the growth kinetics of the microorganism; indeed, C. carboxidivorans growth rate was characterized by CO inhibition within the investigated range of CO concentration, and the optimal PCO was 1.1 atm (corresponding to a dissolved CO concentration of about 25 mg/L) for both VL/VG used; (b) growth differences were observed when the gas-to-liquid volume ratio changed; mass transport phenomena did not control the CO uptake for VL/VG = 0.28; on the contrary, the experimental CO depletion rate was about equal to the transport rate in the case of VL/VG = 0.92.

Slurry Erosion of High Velocity Oxy-fuel Thermal Sprayed Coatings

1997 ◽  
Author(s):  
B. Arsenault ◽  
J.-G. Legoux ◽  
H. Hawthorne
Keyword(s):  
High Velocity ◽  
Surface Engineering ◽  
National Research Council ◽  
Volume Ratio ◽  
Jet Impingement ◽  
Slurry Erosion ◽  
Hvof Coatings ◽  
Carbide Coatings ◽  
Coating Microstructure ◽  
Technology Group

Abstract Improvement of the high velocity oxy-fuel deposition (HVOF) process in the last decade has enhanced the microstructure of coatings in order to better perform against wear and corrosion. Indeed cermet and metal HVOF coatings are reliable and have excellent performance under slurry erosion and provide therefore an alternative to the use of high-priced material. This paper presents the results of a study undertaken within the core research program of the National Research Council of Canada technology group in surface engineering, "SURFTEC", in which the performance of ten HVOF erosion-resistant coatings was evaluated. Ten different types of HVOF coatings were studied including: six grades of WC with either Co or a Ni based matrix, one grade of Cr3C2 in a Ni-Cr matrix, and three grade of metallic alloy: Ni alloy, Co alloy and a SS 316- L. The performance of coatings was evaluated with respect to: the volume ratio and composition of metallic binder in carbide coatings, type of carbide, coating microstructure, impinging angle and the size of the erodent particles. All coatings were produced using the HVOF JP-5000 system controlled by the Hawcs-ll controller. Slurry erosion tests were conducted with a jet impingement rig with a 10 %w/w alumina particle/water slurry. The volume loss of material under various slurry erosion conditions was related to the coating properties and microstructure. Results indicate that the behavior of HVOF sprayed materials is dependent on the erodent particle size, to the erosion impinging angle to some extent and to the corrosion resistance of the cermet matrix.

Critical role of metal ions in surface engineering toward brightly luminescent and stable cesium lead bromide perovskite quantum dots

Nanoscale ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 2602-2607 ◽  
Author(s):  
Congyang Zhang ◽  
Bo Wang ◽  
Qun Wan ◽  
Long Kong ◽  
Weilin Zheng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Metal Ions ◽  
Surface Engineering ◽  
Critical Role ◽  
Stable Cesium ◽  
Photoluminescence Quantum Yield ◽  
Lead Bromide ◽  
Perovskite Quantum Dots ◽  
Engineering Strategy

A facile metal ions-assistant ligand surface engineering strategy to synchronously boost photoluminescence quantum yield and stability of CsPbBr3 PQDs.

Hydrocarbon-Phase Behaviors in Shale Nanopore/Fracture Model: Multiscale, Multicomponent, and Multiphase

SPE Journal ◽  
2019 ◽  
Vol 24 (06) ◽  
pp. 2526-2540 ◽  
Author(s):  
Yinuo Zhao ◽  
Zhehui Jin
Keyword(s):  
Oil Recovery ◽  
Density Functional ◽  
Critical Role ◽  
Volume Ratio ◽  
Phase Region ◽  
Bulk Phase ◽  
Two Phase ◽  
Well Productivity ◽  
Pressure Drops ◽  
Shale Reservoirs

Summary Hydrocarbon recovery from shale subformations has greatly contributed to the global energy supply and has been constantly reshaping the energy sector. Oil production from shale is a complex process in which multicomponent–fluid mixtures experience multiphase transitions in multiscale volumes (i.e., nanoscale pores are connected to fractures/macropores). Understanding such complicated phenomena plays a critical role in the estimation of ultimate oil recovery, well productivity, and reserves estimation, and ultimately in policy making. In this work, we use density–functional theory (DFT) to explicitly consider fluid/surface interactions, inhomogeneous–density distributions in nanopores, volume partitioning in nanopores, and connected macropores/natural fractures to study the complex multiphase transitions of multicomponent fluids in multiscale volumes. We found that vapor–like and liquid–like phases can coexist in nanopores when pressure is between the bubblepoint and dewpoint pressures of nanoconfined fluids, both of which are much lower than those of the originally injected hydrocarbon mixtures. As the volume ratio of the bulk at the initial condition to pores decreases, both the bubblepoint and the dewpoint in nanopores increase and the pore two–phase region expands. Within the pore two–phase region, both C1 and C3 are released from the nanopores to the bulk phase as pressure declines. Meanwhile, both liquid and vapor phases become denser as pressure drops. By further decreasing pressure below the dewpoint of confined fluids, C3 in the nanopore can be recovered. Throughout the process, the bulk–phase composition varies, which is in line with the field observation. Collectively, this work captures the coupled complexity of multicomponent and multiphase fluids in multiscale geometries that is inherent to shale reservoirs and provides a theoretical foundation for reservoir simulation, which is significant for the accurate prediction of well productivity and ultimate oil recovery in shale reservoirs.

Surfaces and Interfaces of Nanoscale Silicon Materials

2013 ◽  
Vol 1550 ◽  
Author(s):  
Sean R. Wagner ◽  
Pengpeng Zhang
Keyword(s):  
Electrical Transport ◽  
Rational Design ◽  
Critical Role ◽  
Volume Ratio ◽  
Molecular Structures ◽  
Prototype System ◽  
Electrical Transport Properties ◽  
Surface And Interface ◽  
Surfaces And Interfaces ◽  
Si Nanostructures

AbstractSurfaces and interfaces play a critical role in determining properties and functions of nanomaterials, in many cases dominating bulk properties, owing to the large surface- and interface-area-to-volume ratio. Using Si nanomembranes, a well-controlled two-dimensional single-crystalline semiconductor, as a prototype system, we discuss how surfaces and interfaces influence electrical transport properties at the nanoscale. We show that electronic conduction in Si nanomembranes is not determined by bulk dopants but by the interplay of surface and interface electronic structures with the “bulk” band structure of the thin Si membrane. Additionally, we describe our recent experimental results on the control of highly ordered molecular structures on Si surfaces, which is of intense interest for the integration of ordered organic thin films in silicon-based electronics. This could also potentially lead to the rational design of Si nanostructures with controlled properties through regulation of the surface chemistry.

scholarly journals Formation of a Bacteriostatic Surface on ZrNb Alloy via Anodization in a Solution Containing Cu Nanoparticles

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3913 ◽  
Author(s):  
Viktoriia Korniienko ◽  
Oleksandr Oleshko ◽  
Yevheniia Husak ◽  
Volodymyr Deineka ◽  
Viktoriia Holubnycha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Engineering ◽  
Critical Role ◽  
Antibacterial Properties ◽  
Cell Toxicity ◽  
Cu Nanoparticles ◽  
Implant Surface ◽  
Promising Alternative ◽  
X Ray ◽  
Bacteria Adhesion

High strength, excellent corrosion resistance, high biocompatibility, osseointegration ability, and low bacteria adhesion are critical properties of metal implants. Additionally, the implant surface plays a critical role as the cell and bacteria host, and the development of a simultaneously antibacterial and biocompatible implant is still a crucial challenge. Copper nanoparticles (CuNPs) could be a promising alternative to silver in antibacterial surface engineering due to low cell toxicity. In our study, we assessed the biocompatibility and antibacterial properties of a PEO (plasma electrolytic oxidation) coating incorporated with CuNPs (Cu nanoparticles). The structural and chemical parameters of the CuNP and PEO coating were studied with TEM/SEM (Transmission Electron Microscopy/Scanning Electron Microscopy), EDX (Energy-Dispersive X-ray Dpectroscopy), and XRD (X-ray Diffraction) methods. Cell toxicity and bacteria adhesion tests were used to prove the surface safety and antibacterial properties. We can conclude that PEO on a ZrNb alloy in Ca–P solution with CuNPs formed a stable ceramic layer incorporated with Cu nanoparticles. The new surface provided better osteoblast adhesion in all time-points compared with the nontreated metal and showed medium grade antibacterial activities. PEO at 450 V provided better antibacterial properties that are recommended for further investigation.

ARSENIC REMEDIATION USING SURFACE FUNCTIONALIZED ULTRAFINE NANOPARTICLES

2011 ◽  
Vol 10 (04n05) ◽  
pp. 1167-1171
Author(s):  
R. GOSWAMI ◽  
P. DEB ◽  
R. THAKUR ◽  
K. P. SARMA ◽  
A. BASUMALLICK
Keyword(s):  
Surface Engineering ◽  
High Efficiency ◽  
Arsenic Removal ◽  
Volume Ratio ◽  
Freundlich Isotherm ◽  
Spectroscopic Studies ◽  
Electron Microscopic ◽  
Adsorption Sites ◽  
Equilibrium Data ◽  
Adsorption Equilibrium Data

Ultrafine nanoparticles owing to their increased surface to volume ratio, coupled with the ability to tune their surface properties through molecular modification have made them ideal for their detection and remediation of broad range of environmental contaminants. Arsenic contamination has become a worldwide epidemic and remediation of this problem needs the development of technology with improved materials and systems with high efficiency. In the present study, we have demonstrated a simple and efficient method using surface functionalized ultrafine iron oxide nanoparticles for absolute removal of arsenic from arsenic treated water with low contact time period and low adsorbent dose. The efficiency of arsenic removal has been drastically improved by considering nanoparticles of size 10 nm and subsequent surface engineering of the nanoparticles resulting more adsorption sites being exposed to arsenic. The mechanism for adsorption was identified through electron microscopic and spectroscopic studies. The adsorption equilibrium data were well fitted to Freundlich isotherm.

Construction of a new Au27Cd1(SAdm)14(DPPF)Cl nanocluster by surface engineering and insight of its structure-property correlation

2021 ◽  
Author(s):  
Liyun Xu ◽  
Qinzhen Li ◽  
Tianrong Li ◽  
Jinsong Chai ◽  
Sha Yang ◽  
...  
Keyword(s):  
Surface Engineering ◽  
Volume Ratio ◽  
Structure Property ◽  
Work Surface ◽  
Property Correlation

Large surface-to-volume ratio is one of the most intriguing natures of nanoclusters, which endows the nanoclusters novel properties and applications. In this work, surface engineering with functional DPPF ligand and...

Slurry and Dry Erosion of High Velocity Oxy-Fuel Thermal Sprayed Coatings

1998 ◽  
Author(s):  
B. Arsenault ◽  
J.G. Legoux ◽  
J.P. Immarigeon ◽  
V.R. Parameswaran ◽  
H. Hawthorne
Keyword(s):  
High Velocity ◽  
Surface Engineering ◽  
Alumina Particle ◽  
National Research Council ◽  
Volume Ratio ◽  
Slurry Erosion ◽  
Hvof Coatings ◽  
Carbide Coatings ◽  
Coating Microstructure ◽  
Technology Group

Abstract Improvement of the high velocity oxy-fuel deposition (HVOF) process in the last decade has lead to coatings with significant improved microstructures for better protection against wear and corrosion. HVOF coatings of cermet and metallic materials provide protection against erosion and are therefore good alternatives to the use of high-priced material. This paper presents the results of a study undertaken within the core research program of the National Research Council of Canada technology group in surface engineering, "SURFTEC", in which the performance of ten HVOF erosion-resistant coatings were evaluated under both dry and slurry erosion. Ten different types of HVOF coatings were studied including: six grades of WC with either Co or a Ni based matrix, one grade of Cr3C2 in a Ni-Cr matrix, and three grades of metallic alloy: Ni alloy, Co alloy and a SS 316-L. Coatings performance was evaluated with respect to the volume ratio and composition of metallic binder in carbide coatings, type of carbide, coating microstructure, impinging angle and the size of the erodent particles. All coatings were produced using the HVOF IP5000 system controlled by the Hawcs-II controller. Slurry jet erosion tests were conducted using a 10 %w/w alumina particle/water slurry. Two alumina particle sizes, 320 and 80 grit (nominal grain diameters 35 urn and 200 urn, respectively) were used. The nominal impact velocity of the slurry was 15 m/s and the nozzle-specimen distance 100 mm. Dry erosion tests were conducted using 50 urn diameter alumina particles projected onto coated flat test coupons through a carbide nozzle of diameter 1.14mm with a particle velocity of 84 m/s at a feed rate of2±1 g/min. let impingement angles of 90° and 20° were used for both dry and slurry erosion tests. The volume loss of material under various erosion conditions was related to the coating properties and microstructure. Results indicate that the coating behavior is dependent on the erodent particle size, the erosion impinging angle to some extent and for slurry erosion, to the corrosion resistance of the cermet matrix.

Sign in / Sign up

Export Citation Format

Share Document