Particle surface characteristics of permanently charged poly(styrene-cationic comonomer) latices

1990 ◽  
Vol 26 (1) ◽  
pp. 35-39 ◽  
Author(s):  
W.M. Brouwer ◽  
M. van der Vegt ◽  
P. van Haeren
Keyword(s):  
Particle Surface ◽  
Surface Characteristics

Performance Impacts of Tailored Surface Geometry in Li-Ion Battery Cathodes

2013 ◽  
Author(s):  
George J. Nelson
Keyword(s):  
Surface Area ◽  
Solid Phase ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Analytical Models ◽  
Li Ion Battery ◽  
Fractal Structures ◽  
Surface Geometry ◽  
Trade Offs ◽  
Li Ion

Analytical models developed to investigate charge transfer in Li-ion battery cathodes reveal distinct transport regimes where performance may be limited by either microstructural surface characteristics or solid phase geometry. For several cathode materials, particularly those employing conductive additives, surface characteristics are expected to drive these performance limitations. For such electrodes gains in performance may be achieved by modifying surface geometry to increase surface area. However, added surface area may present a diminishing return if complex structures restrict access to electrochemically active interfaces. A series of parametric studies has been performed to better ascertain the merits of complex, tailored surfaces in Li-ion battery cathodes. The interaction between lithium transport and surface geometry is explored using a finite element model in which complex surfaces are simulated with fractal structures. Analysis of transport in these controlled structures permits assessment of scaling behavior related to surface complexity and provides insight into trade-offs in tailoring particle surface geometry.

scholarly journals Carbon and Neon Ion Bombardment Induced Smoothing and Surface Relaxation of Titania Nanotubes

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2458
Author(s):  
Astrid Kupferer ◽  
Michael Mensing ◽  
Jan Lehnert ◽  
Stephan Mändl ◽  
Stefan Mayr
Keyword(s):  
Mass Density ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Ion Bombardment ◽  
Surface Relaxation ◽  
Nanotube Arrays ◽  
Relaxation Effects ◽  
Titania Nanotube Arrays ◽  
Titania Nanotube ◽  
Neon Ion

Titania nanotube arrays with their enormous surface area are the subject of much attention in diverse fields of research. In the present work, we show that not only 60 keV and 150 keV ion bombardment of amorphous titania nanotube arrays yields defect creation within the tube walls, but it also changes the surface morphology: the surface relaxes and smoothens in accordance with a curvature-driven surface material’s transport mechanism, which is mediated by radiation-induced viscous flow or radiation-enhanced surface diffusion, while the nanotubes act as additional sinks for the particle surface currents. These effects occur independently of the ion species: both carbon and neon ion bombardments result in comparable surface relaxation responses initiated by an ion energy of 60 keV at a fluence of 1 × 1016 ions/cm2. Using atomic force microscopy and contact angle measurements, we thoroughly study the relaxation effects on the surface topography and surface free energy, respectively. Moreover, surface relaxation is accompanied by further amorphization in surface-near regions and a reduction in the mass density, as demonstrated by Raman spectroscopy and X-ray reflectivity. Since ion bombardment can be performed on global and local scales, it constitutes a versatile tool to achieve well-defined and tunable topographies and distinct surface characteristics. Hence, different types of nanotube arrays can be modified for various applications.

Mechanically Reinforcing Polyacrylate/Polyacrylamide Hydrogels through the Addition of Colloidal Particles

2009 ◽  
Vol 1190 ◽  
Author(s):  
Bryan A Baker ◽  
Rebecca Murff ◽  
Valeria T Milam
Keyword(s):  
Storage Modulus ◽  
Colloidal Particles ◽  
Volume Fraction ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Mechanical Stiffness ◽  
Polyacrylamide Hydrogels ◽  
Oscillatory Rheology ◽  
Polymer Volume ◽  
Hydrogel Particle

AbstractPolyacrylamide is a popular material for many bio-related applications ranging from electrophoretic separation to cellular supports. A limitation of polyacrylamide-based hydrogels, however, is their mechanical compliance. The current study examines the effect of colloidal particles as a reinforcing filler phase to enhance the mechanical stiffness of polyacrylamide-polyacrylate hydrogels. Measurements with oscillatory rheology show that for a fixed polymer volume fraction, the presence of colloidal particles with various surface modifications generally results in an increase of the shear storage modulus of the hydrogel-particle composite. Interestingly, this study indicated that no discernable trends can be linked between the values of the shear storage modulus and the particle surface characteristics.

The Significance of Soil Freezing for Stress Corrosion Cracking

1998 ◽  
Author(s):  
Peter J. Williams ◽  
Thomas L. White ◽  
J. Kenneth Torrance
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Freezing Point ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Corrosion Cracking ◽  
Soil Freezing ◽  
High Concentration ◽  
Frozen Ground ◽  
Freezing Soil

The microstructure of soils (the arrangement of pores and voids, aggregation and surface characteristics of particles) is substantially modified by freezing. Soils so modified differ, in a number of important properties, from soils not previously frozen. Furthermore, each time a soil is frozen there is a redistribution of particles, moisture and solutes. Corrosion of buried pipes is known to be related to the ground conditions. Accordingly the particular nature of frozen ground needs consideration in this respect. Studies of microstructure of samples of freezing, frozen and unfrozen soils, many obtained from a full-scale experimental study of the effects of freezing on a buried pipeline, have provided an explanation for measured changes in bulk geotechnical properties of the materials. The microstructure viewed by optical microscopy, reveals the soil structure as having a complex and striking dependence on freezing history. Scanning electron microscopy shows further details in clay rich soils. Freezing at temperatures occurring in nature normally does not convert all the soil water to ice. The effects of particle surface forces is to reduce the freezing point of the water nearest a mineral surface. The distribution of solutes is radically altered, with pockets of high concentration interconnected by a liquid phase of varying concentration. A variety of other effects, relating to chemical and mechanical properties of soils subjected to freezing, have been demonstrated or can be postulated. Some of these are important in corrosion phenomena. The stresses that have been shown to occur in a pipe as a result of frost heave in the freezing soil, will also tend to increase the possibility of stress corrosion cracking.

scholarly journals Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

2014 ◽  
Vol 5 ◽  
pp. 2403-2412 ◽  
Author(s):  
Cornelia Loos ◽  
Tatiana Syrovets ◽  
Anna Musyanovych ◽  
Volker Mailänder ◽  
Katharina Landfester ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Particle Surface ◽  
Volume Ratio ◽  
Superparamagnetic Iron Oxide ◽  
Surface Characteristics ◽  
Short Term ◽  
Polystyrene Nanoparticles ◽  
Cellular Environment ◽  
Wide Range ◽  
Surface Functionalizations

Nanoparticles of various shapes, sizes, and materials carrying different surface modifications have numerous technological and biomedical applications. Yet, the mechanisms by which nanoparticles interact with biological structures as well as their biological impact and hazards remain poorly investigated. Due to their large surface to volume ratio, nanoparticles usually exhibit properties that differ from those of bulk materials. Particularly, the surface chemistry of the nanoparticles is crucial for their durability and solubility in biological media as well as for their biocompatibility and biodistribution. Polystyrene does not degrade in the cellular environment and exhibits no short-term cytotoxicity. Because polystyrene nanoparticles can be easily synthesized in a wide range of sizes with distinct surface functionalizations, they are perfectly suited as model particles to study the effects of the particle surface characteristics on various biological parameters. Therefore, we have exploited polystyrene nanoparticles as a convenient platform to study bio–nano interactions. This review summarizes studies on positively and negatively charged polystyrene nanoparticles and compares them with clinically used superparamagnetic iron oxide nanoparticles.

Nanoparticle and Microparticle Flow in Porous and Fractured Media— An Experimental Study

SPE Journal ◽  
2012 ◽  
Vol 17 (04) ◽  
pp. 1160-1171 ◽  
Author(s):  
Mohammed Alaskar ◽  
Morgan Ames ◽  
Stephen Connor ◽  
Chong Liu ◽  
Yi Cui ◽  
...  
Keyword(s):  
Particle Size ◽  
Surface Charge ◽  
Preliminary Investigation ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Fractured Media ◽  
Fracture Aperture ◽  
Silica Microspheres ◽  
Particle Size Range ◽  
Ag Nanowires

Summary The goal of this research was to develop methods for acquiring reservoir pressure and temperature data near the wellbore and farther out into the formation and to correlate such information to fracture connectivity and geometry. Existing reservoir-characterization tools allow pressure and temperature to be measured only at the wellbore. The development of temperature- and pressuresensitive nanosensors will enable in-situ measurements within the reservoir. This paper provides the details of the experimental work performed in the process of developing temperature nanosensors. The study investigated the parameters involved in the mobility of nanoparticles through porous and fractured media. These parameters include particle size or size distribution, shape, and surface charge or affinity to rock materials. The principal findings of this study were that spherically shaped nanoparticles of a certain size and surface charge compatible with that expected in formation rock are most likely to be transported successfully, without being trapped because of physical straining, chemical, or electrostatic effects. We found that tin-bismuth (Sn-Bi) nanoparticles of 200 nm and smaller were transported through Berea sandstone. Larger particles were trapped at the inlet of the core, indicating that there was an optimum particle size range. We also found that the entrapment of silver (Ag) nanowires was primarily because of their shape. This conclusion was supported by the recovery of the spherical Ag nanoparticles with the same surface characteristics through the same porous media used during the Ag nanowires injection. The entrapment of hematite nanorice was attributed to its affinity to the porous matrix caused by surface charge. The hematite coated with surfactant (which modified its surface charge to one compatible with flow media) flowed through the glass beads, emphasizing the importance of particle surface charge. Preliminary investigation of the flow mechanism of nanoparticles through a naturally fractured greywacke core was conducted by injecting fluorescent silica microspheres. We found that silica microspheres of different sizes (smaller than the fracture opening) could be transported through the fracture. We demonstrated the possibility of using microspheres to estimate fracture aperture by injecting a polydisperse microsphere sample. It was observed that only spheres of 20 μm and smaller were transported. This result agreed reasonably well with the measurement of hydraulic fracture aperture (27 μm), as determined by the cubic law.

Particle Characteristics: A Key Factor in Effluent Treatment and Reuse

1999 ◽  
Vol 40 (4-5) ◽  
pp. 67-74 ◽  
Author(s):  
A. Adin
Keyword(s):  
Water Reuse ◽  
Particle Deposition ◽  
Treatment Process ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Effluent Treatment ◽  
Particle Characterization ◽  
Particle Characteristics ◽  
Key Factor ◽  
Improved Design

Particulate matter presents a major problem in advanced wastewater treatment and in water reuse operations. This paper illustrates and analyses the approach that particle characterization may serve as an important tool in understanding treatment process mechanisms for improved design and solving clogging problems in field systems. Particle size distribution and particle surface characteristics are defined, examples of their application to effluent chemical coagulation, to wastewater reservoir effluent characterization and to the prevention of particle deposition in reuse systems are described.

scholarly journals PRELIMINARY STUDY ON THE IMPACT OF POLYMER-LIPID TYPES AND RATIO TO POLYMERIC-LIPID HYBRID NANOPARTICLE

2021 ◽  
pp. 150-153
Author(s):  
OKTAVIA EKA PUSPITA ◽  
FERRI WIDODO ◽  
MONICA ANDIKA PUTRI ◽  
ISWA ROSSARIZA ◽  
AVIOLA FADHILLA ◽  
...  
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Lipid Nanoparticles ◽  
Polydispersity Index ◽  
Lipid Nanoparticle ◽  
Nanoprecipitation Method ◽  
One Step ◽  
The Impact

Objective: This study aims to determine the best lipid to polymer ratios in polymeric-lipid nanoparticles using various types and ratios of polymers and lipids. Method: Polymeric-lipid nanoparticle was prepared using the modified one-step nanoprecipitation method. This study used chitosan and Na alginate as polymers and lecithin and egg phosphatidylcholine as lipids. The lipid was crossed-combined with polymer in various ratios, i. e 12.5%, 25.0%, and 37.5%. On its preparation, Cinnamomum burmanii extract was loaded into the resulted polymeric-lipid nanoparticle as an active substance model. The results were assessed its particle surface characteristics including particle size, polydispersity index, and zeta potential. Results: Twelve formulas resulted from crossed-combination between the lipid and polymer were used in this study. Polymeric-lipid nanoparticles resulted from the combination of egg phosphatidylcholine/Na alginate has particle size, polydispersity index, and zeta potential of 380.07±3.52 nm, 0.66±002, and-30.6±1.15 mV, respectively. Conclusions: The best lipid to polymer ratio and type was observed in egg phosphatidylcholine: Na alginate. The particle surface characteristics were better compared to other combinations.

Polystyrene latex particle surface characteristics

1987 ◽  
Vol 24 (2-3) ◽  
pp. 195-208 ◽  
Author(s):  
Wilfried M. Brouwer ◽  
Rob L.J. Zsom
Keyword(s):  
Latex Particle ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Polystyrene Latex
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