scholarly journals Ultra-Small Fatty Acid-Stabilized Magnetite Nanocolloids Synthesized byIn SituHydrolytic Precipitation

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Kheireddine El-Boubbou ◽  
Rabih O. Al-Kaysi ◽  
Muhanna K. Al-Muhanna ◽  
Hassan M. Bahhari ◽  
Abdulaziz I. Al-Romaeh ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Targeted Delivery ◽  
Large Scale ◽  
Colloidal Stability ◽  
Elevated Temperatures ◽  
Metal Oxide Nanoparticles ◽  
Cost Effective ◽  
Water Soluble ◽  
Great Promise ◽  
One Pot

Simple, fast, large-scale, and cost-effective preparation of uniform controlled magnetic nanoparticles remains a major hurdle on the way towards magnetically targeted applications at realistic technical conditions. Herein, we present a unique one-pot approach that relies on simple basic hydrolyticin situcoprecipitation of inexpensive metal salts (Fe2+and Fe3+) compartmentalized by stabilizing fatty acids and aided by the presence of alkylamines. The synthesis was performed at relatively low temperatures (~80°C) without the use of high-boiling point solvents and elevated temperatures. This method allowed for the production of ultra-small, colloidal, and hydrophobically stabilized magnetite metal oxide nanoparticles readily dispersed in organic solvents. The results reveal that the obtained magnetite nanoparticles exhibit narrow size distributions, good monodispersities, high saturation magnetizations, and excellent colloidal stabilities. When the [fatty acid] : [Fe] ratio was varied, control over nanoparticle diameters within the range of 2–10 nm was achieved. The amount of fatty acid and alkylamine used during the reaction proved critical in governing morphology, dispersity, uniformity, and colloidal stability. Upon exchange with water-soluble polymers, the ultra-small sized particles become biologically relevant, with great promise for theranostic applications as imaging and magnetically targeted delivery vehicles.

One-Pot Synthesis of Water Soluble, Extremely Small-Sized Superparamagnetic Magnetite Nanoparticles

2012 ◽  
Vol 531 ◽  
pp. 219-222
Author(s):  
Li Hua Shen ◽  
Ting Shang ◽  
Jun Zhou ◽  
Dong Wang ◽  
Yu Han ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Room Temperature ◽  
Colloidal Stability ◽  
Aqueous Media ◽  
Mri Contrast Agents ◽  
Water Soluble ◽  
Potential Candidate ◽  
One Pot ◽  
Mri Contrast

Extremely small-sized superparamagnetic magnetite nanoparticles of 3Cit). The resulting Cit-coated magnetite nanoparticles exhibited long-term colloidal stability in aqueous media without any surface modification. Regarding the magnetic properties, the nanoparticles were superparamagnetic at room temperature, and might be the potential candidate for MRI contrast agents.

scholarly journals Variable Porous Electrode Compression for Redox Flow Battery Systems

Batteries ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 53 ◽  
Author(s):  
Nicholas Gurieff ◽  
Victoria Timchenko ◽  
Chris Menictas
Keyword(s):  
Large Scale ◽  
Effective Means ◽  
Porous Electrode ◽  
Cost Effective ◽  
Electrical Energy ◽  
Limiting Current ◽  
Great Promise ◽  
Full Potential ◽  
Uniform Compression ◽  
Novel Concept

Vanadium redox flow batteries (VRFBs) offer great promise as a safe, cost effective means of storing electrical energy on a large scale and will certainly have a part to play in the global transition to renewable energy. To unlock the full potential of VRFB systems, however, it is necessary to improve their power density. Unconventional stack design shows encouraging possibilities as a means to that end. Presented here is the novel concept of variable porous electrode compression, which simulations have shown to deliver a one third increase in minimum limiting current density together with a lower pressure drop when compared to standard uniform compression cell designs.

scholarly journals PVB/PEG-Based Feedstocks for Injection Molding of Alumina Microreactor Components

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1219 ◽  
Author(s):  
Anna Julia Medesi ◽  
Dorit Nötzel ◽  
Thomas Hanemann
Keyword(s):  
Injection Molding ◽  
Large Scale ◽  
Metal Oxide Nanoparticles ◽  
Reaction Medium ◽  
Cost Effective ◽  
Polyvinyl Butyral ◽  
Shear Stresses ◽  
Scale Production ◽  
Ceramic Injection Molding ◽  
Functional Components

The ceramic injection molding (CIM) process is a cost-effective powder-based near net shape manufacturing process for large-scale production of complex-shaped ceramic functional components. This paper presents the rheological analysis of environmentally friendly CIM feedstock formulations based on the binder components polyvinyl butyral (PVB) and polyethylene gycol (PEG). The prepared PVB/PEG-based alumina molding compounds were investigated with respect to their PVB:PEG ratios as well as to their powder filling degrees in the range between 50 and 64 vol.%. Corresponding viscosities and shear stresses were determined for increasing shear rates to show the effects of increased PEG content and solid loadings on them. Two single reactor components were injection molded and subsequently joined in their green state for fabrication of an alumina microreactor. The intended purpose of the alumina microreactors is their potential application as wear-resistant and hydrothermal stable multifunctional devices (µ-mixer, µ-reactor, µ-analyzer) for continuous hydrothermal synthesis (CHTS) of metal oxide nanoparticles in supercritical water (sc-H2O) as the reaction medium.

Evaluation of Boron Nitride Coated Nextel 312TM Fiber/BlackglasTM Composites Using an Environmental SEM

1998 ◽  
Vol 4 (S2) ◽  
pp. 282-283
Author(s):  
Richard L. Schalek ◽  
John Helmuth ◽  
Lawrence T. Drzal
Keyword(s):  
Boron Nitride ◽  
Large Scale ◽  
Elevated Temperatures ◽  
Fiber Surface ◽  
Ceramic Matrix Composites ◽  
Cost Effective ◽  
Ceramic Matrix ◽  
Silicon Oxycarbide ◽  
Ceramic Fiber ◽  
Matrix Composites

The most critical technical issue preventing large scale application of ceramic matrix composites is the cost-effective application of stable interface coatings on continuous ceramic fibers. Currently, an alumina-silica ceramic fiber containing up to 14 wt. % boria (Nextel 312TM) is composited at elevated temperatures to form a boron nitride (BN) coating on the fiber surface. This BN coating serves as a compliant layer facilitating crack deflection and producing a non-catastrophic failure mode. Continued development of these ceramic matrix composites requires a more complete understanding of the mechanistic paths involved in composite densification. The objective of this work is to investigate and more clearly describe the role of the BN coating and its relation to composite processing and properties of the densified Nextel 312TM fiber/BlackglasTM (silicon oxycarbide) composites.Three composites consisting of as-received fibers (coated with an organic sizing), desized fibers (sizing removed by heating), and boron nitride coated fibers were fabricated using BlackglasTM preceramic polymer 489C B-stage resin.

scholarly journals Mechanisms of Spontaneous Curvature Inversion in Compressed Graphene Ripples for Energy Harvesting Applications via Molecular Dynamics Simulations

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 516
Author(s):  
James M. Mangum ◽  
Ferdinand Harerimana ◽  
Millicent N. Gikunda ◽  
Paul M. Thibado
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Energy Barrier ◽  
Large Scale ◽  
Elevated Temperatures ◽  
Outer Edge ◽  
Great Promise ◽  
Central Position ◽  
Spontaneous Curvature ◽  
Dynamics Simulations

Electrically conductive, highly flexible graphene membranes hold great promise for harvesting energy from ambient vibrations. For this study, we built numerous three-dimensional graphene ripples, with each featuring a different amount of compression, and performed molecular dynamics simulations at elevated temperatures. These ripples have a convex cosine shape, then spontaneously invert their curvature to concave. The average time between inversion events increases with compression. We use this to determine how the energy barrier height depends on strain. A typical convex-to-concave curvature inversion process begins when the ripple’s maximum shifts sideways from the normal central position toward the fixed outer edge. The ripple’s maximum does not simply move downward toward its concave position. When the ripple’s maximum moves toward the outer edge, the opposite side of the ripple is pulled inward and downward, and it passes through the fixed outer edge first. The ripple’s maximum then quickly flips to the opposite side via snap-through buckling. This trajectory, along with local bond flexing, significantly lowers the energy barrier for inversion. The large-scale coherent movement of ripple atoms during curvature inversion is unique to two-dimensional materials. We demonstrate how this motion can induce an electrical current in a nearby circuit.

scholarly journals The Large-Scale Synthesis of Vinyl-Functionalized Silicon Quantum Dot and Its Application in Miniemulsion Polymerization

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xuan-Dung Mai ◽  
Quang-Bac Hoang
Keyword(s):  
Large Scale ◽  
Miniemulsion Polymerization ◽  
Water Soluble ◽  
Molar Ratio ◽  
Biological Applications ◽  
Photoluminescence Properties ◽  
Polystyrene Nanoparticles ◽  
One Pot ◽  
Two Photon ◽  
Silicon Quantum Dot

Stable luminescence, size-tunability, and biocompatibility encourage the deployment of Cd-free NPs into diverse biological applications. Here we report one-pot synthesis of blue-emitting and polymerizable silicon quantum dots (Si QDs) from which water-soluble Si QDs embedded polystyrene nanoparticles (SiQD@PS NPs) were prepared using a miniemulsion polymerization approach. The hydrodynamic size of NPs was controlled by KOH to oleic acid molar ratio. Studies on the photoluminescence properties of SiQD@PS NPs in different conditions reveal that they exhibit two-photon luminescence property and high stability against pH and UV exposure. These NPs add new size regime to the Si QDs based luminescent makers for bioimaging and therapy applications.

Growth Mechanism and Characterization of Zinc Oxide Spheres

2012 ◽  
Vol 534 ◽  
pp. 169-172
Author(s):  
Shuang Xu
Keyword(s):  
Zinc Oxide ◽  
Hydrothermal Method ◽  
Growth Mechanism ◽  
Large Scale ◽  
Water Soluble ◽  
Experimental Results ◽  
Soluble Polymer ◽  
One Pot ◽  
Water Soluble Polymer

Novel uniform-sized, ZnO mesocrystal spheres have been synthesized on a large scale using a facile one-pot hydrothermal method in the presence of the water-soluble polymer poly. Sphere crystallinity was characterized by XRD and SEM. On the basis of the experimental results, we proposed a possible mechanism to elucidate the formation of ZnO spheres.

scholarly journals A DNA-Small Molecule Conjugate Modulates the Complexity of Multicomponent Supramolecular Polymerization in Biorelevant Environments

2020 ◽  
Author(s):  
Mykhailo Vybornyi ◽  
Sjors Wijnands ◽  
Byoung-jin Jeon ◽  
Omar Saleh ◽  
E.W. (Bert) Meijer
Keyword(s):  
Elevated Temperatures ◽  
Pure Water ◽  
Physical And Mechanical Properties ◽  
Water Soluble ◽  
Great Promise ◽  
Type I ◽  
Temperature Window ◽  
Elongation Phase ◽  
First Time ◽  
Supramolecular Polymerization

Aqueous multicomponent supramolecular systems hold great promise for designing synthetic biomaterials with tailored properties. Inspired by this notion, we explore the consequences of modulating the assembly behaviour of supramolecular polymers based on benzene-1,3,5-trixaboxamide (BTA) derivatives by the corresponding BTA-DNA conjugate. Our data demonstrate the divergence of the assembly mechanisms upon shifting from pure water to buffered solutions (pH=7) upon introducing the DNA conjugate. To follow the morphologic transitions, we developed a correlative spectroscopic-microscopic method suitable for the analyses of thermally controlled supramolecular copolymerization in aqueous systems. Using this approach, the structural origins of the cooperative transitions in water-soluble BTA systems were confirmed for the first time. Thus, at the macroscale, the elongation into micrometer-long supramolecular fibers occurs from globular aggregates, which exist at elevated temperatures. The acquired experimental data support the assumption expressed in the previous computational reports that nanoscale BTA ordering within the globules precedes the elongation phase. Furthermore, depending on the content of the DNA modulator, the globules derive two forms of supramolecular fibers, type I and type II, respectively. The latter type is stable within a short temperature window, transforming into the former one upon further cooling. Finally, the supramolecular copolymers were transformed in functional hydrogels via a DNA crosslinking strategy. Physical and mechanical properties of the hydrogels were assessed by microrheology.

scholarly journals Designing Self-Sustainable Icephobic Layer by Introducing a Lubricating Un-Freezable Water Hydrogel from Sodium Polyacrylate on the Polyolefin Surface

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1126
Author(s):  
Junqi Shi ◽  
Chongjian Cao ◽  
Lu Zhang ◽  
Yiwu Quan ◽  
Qingjun Wang ◽  
...  
Keyword(s):  
Cost Effective ◽  
Great Promise ◽  
Sodium Polyacrylate ◽  
One Pot ◽  
Practical Applications ◽  
Freezable Water ◽  
Lubricating Layer ◽  
Cost Effective Method ◽  
Long Time ◽  
Ice Adhesion

A convenient, environment-friendly, and cost-effective method to keep anti-icing for a long time was highly desirable. Slippery lubricant layers were regarded to be effective and promising for anti-icing on different surfaces, but the drought-out of lubricants and the possible detriments to the environment were inevitable. By combining super-high molecular weight sodium polyacrylate (H-PAAS) with polyolefin through a one-pot method, a self-sustainable lubricating layer with extremely low ice adhesion of un-freezable water hydrogel was achieved at subzero conditions. The lubricant hydrogel layer could auto-spread and cover the surface of polyolefin after encountering supercooled water, frost, or ice. Due to the reduction of storage modulus in the interface, the ice adhesion of the specimen surfaces was far below 20 kPa, varying from 5.13 kPa to 18.95 kPa. Furthermore, the surfaces could preserve the fairly low adhesion after icing/de-icing cycles for over 15 times and thus exhibited sustainable durability. More importantly, this method could be introducing to various polymers and is of great promise for practical applications.

One-pot controllable synthesis of CoFe2O4solid, hollow and multi-shell hollow nanospheres as superior anode materials for lithium ion batteries

2017 ◽  
Vol 5 (41) ◽  
pp. 21994-22003 ◽  
Author(s):  
Yun Qi ◽  
Bingqiu Liu ◽  
Lingyu Zhang ◽  
Yuqiu Huo ◽  
Lu Li ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Materials ◽  
Large Scale ◽  
Lithium Ion ◽  
Cost Effective ◽  
Hollow Nanospheres ◽  
Controllable Synthesis ◽  
One Pot ◽  
Cost Effective Method ◽  
First Time

CFO-SNSs, CFO-HNSs and MS-CFO-HNSs are controllably fabricated for the first time by a straightforward and cost-effective method on a large scale as superior anode materials for lithium ion batteries.

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