Abstract:Earthicle was conceived as an astromimetic particle mimicking the stratified structure of Earth. Although earthicle can come in various compositional and structural forms, its seminal version consisted of a spherical nanoparticle with an iron core, a silica shell, and a carbon crust. This study provides a historical review of composite, core/shell particles composed of four different combinations of phases present in this original version of the earthicle, three of which are biphasic and one of which is tripha… Show more
“…A variety of important relationships intersecting natural phenomena and human engineered systems can be found within the field of colloid and emulsion science. For example, the flow of contaminants such as lead, mercury, and chromium in natural water sources occurs through colloidal transport processes. − Emulsions and microemulsions impact crude oil spills on natural water sources, − guiding engineers to develop methods to separate oil from water after these disasters occur. − New insights on the formation of particles, as disparate as atmospheric aerosols that begin as microlayer droplets at sea surface and mesoporous opal nanoparticles in shales from the Marcellus Formation, have been gained by making comparisons to microemulsion systems created in laboratories. , A critical intersection of natural phenomena and human engineering, reverse micellar water-in-oil (w/o) microemulsions, has been used in the creation of multilayered nanoparticles called earthicles, created specifically to mimic the structure and composition of the earth’s layers at a much smaller scale. − Thus, with colloidal chemistry reaching into so many aspects of earth and environmental science and engineering, continually deepening our understanding of the structure and stability of colloidal systems has an equally far-reaching impact on our ability to predict natural phenomena and chemical behaviors in complex environments.…”
Colloidal
systems, including micellar and reverse micellar mixtures,
are essential for a variety of natural transport processes, such as
the flow of organic and inorganic contaminants in lakes, rivers, and
underground fissures. Thus, an understanding of their structure and
stability is important for prediction of their behavior in complex
environments. Previous experiments have shown that the solvodynamic
diameters (D) of reverse micelles contract linearly
with increased concentrations of salts such as NaBH4, FeSO4, Mg(NO3)2, CuCl2, Al(NO3)3, Fe(NO3)3, and Y(NO3)3. It has also been previously determined that
reverse micelle size is a function of cation valency, through the
Debye screening length (κ–1), and of anion
hydrated radius. Here, we present a new theoretical model for the
aqueous reverse micelle core substructure in water/AOT/isooctane colloidal
systems with added salts. Our model is based on electrical double
layer (EDL) theory and assumes ions are evenly distributed within
the reverse micelle water core. We further analyze reverse micelle
size with respect to ion hydration, reverse micelle water dynamics,
and ion distribution, to propose a mechanism for reverse micelle contraction
and determine the cause of system instability at the critical destabilization
concentration for each salt. We find that destabilization occurs when
the interfacial core water and waters needed for complete ion hydration
exceed the water contained within the reverse micelle at its stable
size. This establishes ion hydration capacity a likely primary mechanism
for reverse micelle destabilization.
“…A variety of important relationships intersecting natural phenomena and human engineered systems can be found within the field of colloid and emulsion science. For example, the flow of contaminants such as lead, mercury, and chromium in natural water sources occurs through colloidal transport processes. − Emulsions and microemulsions impact crude oil spills on natural water sources, − guiding engineers to develop methods to separate oil from water after these disasters occur. − New insights on the formation of particles, as disparate as atmospheric aerosols that begin as microlayer droplets at sea surface and mesoporous opal nanoparticles in shales from the Marcellus Formation, have been gained by making comparisons to microemulsion systems created in laboratories. , A critical intersection of natural phenomena and human engineering, reverse micellar water-in-oil (w/o) microemulsions, has been used in the creation of multilayered nanoparticles called earthicles, created specifically to mimic the structure and composition of the earth’s layers at a much smaller scale. − Thus, with colloidal chemistry reaching into so many aspects of earth and environmental science and engineering, continually deepening our understanding of the structure and stability of colloidal systems has an equally far-reaching impact on our ability to predict natural phenomena and chemical behaviors in complex environments.…”
Colloidal
systems, including micellar and reverse micellar mixtures,
are essential for a variety of natural transport processes, such as
the flow of organic and inorganic contaminants in lakes, rivers, and
underground fissures. Thus, an understanding of their structure and
stability is important for prediction of their behavior in complex
environments. Previous experiments have shown that the solvodynamic
diameters (D) of reverse micelles contract linearly
with increased concentrations of salts such as NaBH4, FeSO4, Mg(NO3)2, CuCl2, Al(NO3)3, Fe(NO3)3, and Y(NO3)3. It has also been previously determined that
reverse micelle size is a function of cation valency, through the
Debye screening length (κ–1), and of anion
hydrated radius. Here, we present a new theoretical model for the
aqueous reverse micelle core substructure in water/AOT/isooctane colloidal
systems with added salts. Our model is based on electrical double
layer (EDL) theory and assumes ions are evenly distributed within
the reverse micelle water core. We further analyze reverse micelle
size with respect to ion hydration, reverse micelle water dynamics,
and ion distribution, to propose a mechanism for reverse micelle contraction
and determine the cause of system instability at the critical destabilization
concentration for each salt. We find that destabilization occurs when
the interfacial core water and waters needed for complete ion hydration
exceed the water contained within the reverse micelle at its stable
size. This establishes ion hydration capacity a likely primary mechanism
for reverse micelle destabilization.
“…Also due to poor chemical permeability, silica can prevent the destruction of MNPs in different chemical environments. Moreover, the abundant silanol groups on the silica surface provide suitable conditions for different types of modification 10 , 25 – 28 . Some of recently developed magnetic nanostructures with silica shells are Fe 3 O 4 @BOS@SB/In 29 , Fe 3 O 4 @SiO 2 @PMO 30 , Re–SiO 2 –Fe 3 O 4 31 , Mag@Ti-NOS 32 , Fe 3 O 4 @RF@void@PMO(IL)/Cu 33 , Fe 3 O 4 @SiO 2 @propyl‐ANDSA 34 and Fe 3 O 4 @Au@mSiO 2 -dsDNA/DOX 35 .…”
In this paper, the synthesis, characterization and catalytic application of a novel magnetic silica-supported Ag2CO3 (MS/Ag2CO3) with core–shell structure are developed. The MS/Ag2CO3 nanocomposite was prepared through chemical modification of magnetic MS nanoparticles with AgNO3 under alkaline conditions. The structure, chemical composition and magnetic properties of MS/Ag2CO3 were investigated by using VSM, PXRD, FT-IR, EDX and SEM techniques. The MS/Ag2CO3 nanocomposite was used as an effective catalyst for the Knoevenagel condensation under solvent-free conditions at 60 °C in an ultrasonic bath. The recovery and leaching tests were performed to study the nature of the MS/Ag2CO3 catalyst under applied conditions.
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