Realizing the Full Potential of Insertion Anodes for Mg-Ion Batteries Through the Nanostructuring of Sn

Magnesium is of great interest as a replacement for lithium in next-generation ion-transfer batteries but Mg-metal anodes currently face critical challenges related to the formation of passivating layers during Mg-plating/stripping and anode–electrolyte–cathode incompatibilities.− Alternative anode materials have the potential to greatly extend the spectrum of suitable electrolyte chemistries, but must be systematically tailored for effective Mg²⁺ storage. Using analytical (scanning) transmission electron microscopy ((S)­TEM) and ab initio modeling, we have investigated Mg²⁺ insertion and extraction mechanisms and transformation processes in β-SnSb nanoparticles (NPs), a promising Mg-alloying anode material. During the first several charge–discharge cycles (conditioning), the β-SnSb particles irreversibly transform into a porous network of pure-Sn and Sb-rich subparticles, as Mg ions replace Sn atoms in the SnSb lattice. After electrochemical conditioning, small Sn particles/grains (<33 ± 20 nm) exhibit highly reversible Mg-storage, while the Sb-rich domains suffer substantial Mg trapping and contribute little to the system performance. This result strongly indicates that pure Sn can act as a high-capacity Mg-insertion anode as theoretically predicted, but that its performance is strongly size-dependent, and stable nanoscale Sn morphologies (<40 nm) are needed for superior, reversible Mg-storage and fast system kinetics

"Painopeiton kaveriksi" : Painopeitto kehitysvammaisen rentoutumiseen toimintaterapiassa

Tämä on toiminnallinen opinnäytetyö, jonka tarkoituksena oli valmistaa painopeitto sekä löytää perusteet painopeiton käytön hyödyllisyyteen kehitysvammaiselle. Lisäksi painopeiton valmistamisesta tuotettiin kuvallinen vaiheittain etenevä ohjeistus. Painopeiton valmistus toteutettiin etelä-pohjanmaalla sijaitsevan Lehtimäen erityiskansanopiston toimintaterapiaan. Lehtimäen erityiskansanopisto on erityistä tukea ja ohjausta tarvitsevien henkilöiden oppilaitos. Tässä opinnäytetyössä tuodaan esille rentoutuminen osana ihmiselle merkityksellistä toimintaa, jonka viitekehyksenä on käytetty Kanadalaisen toiminnallisuuden ja sitoutumisen mallia, Canadian Model of Occupational Performance and Engagement, (CMOP-E). Rentoutumista mahdollistaa taktiiliset- ja proprioseptiviset aistimukset, jotka perustellaan sensorisen integraation teorian kautta. Painopeiton avulla kehitysvammaiselle voidaan tarjota taktilisia- ja proprioseptiivisia aistimuksia.The purpose of this functional thesis was to manufacture a weighted blanket and to find a basis for its usefulness for a mentally disabled patient. In addition, step by step visual instructions for the making of a weighted blanket were produced. The weighted blanket was made for the occupational therapy conducted at the Lehtimäki Special Folk High School located in Southern Ostrobothnia. The Lehtimäki Special Folk High School is an institution which caters for individuals in need of special support and guidance. This thesis raises relaxation as an important aspect of a person’s activities. Its theoretical basis originates from the Canadian Model of Occupational Performance and Engagement, (CMOP-E). Relaxation allows tactile and proprioceptive sensations which are justified by using the sensory integration theory. With the help of a weighted blanket, a mentally disabled person can be offered tactile and proprioceptive sensations

Analysis of existing approaches at the bank's competitiveness

Викладений аналіз найпоширеніших сучасних підходів до аналітичного оцінювання конкурентоспроможності банку.The article analyzes the most common approaches of building the model of the bank's competitiveness

Direct <i>in Situ</i> Observation of Nanoparticle Synthesis in a Liquid Crystal Surfactant Template

Controlled and reproducible synthesis of tailored materials is essential in many fields of nanoscience. In order to control synthesis, there must be a fundamental understanding of nanostructure evolution on the length scale of its features. Growth mechanisms are usually inferred from methods such as (scanning) transmission electron microscopy ((S)TEM), where nanostructures are characterized after growth is complete. Such <i>post mortem</i> analysis techniques cannot provide the information essential to optimize the synthesis process, because they cannot measure nanostructure development as it proceeds in real time. This is especially true in the complex rheological fluids used in preparation of nanoporous materials. Here we show direct <i>in situ</i> observations of synthesis in a highly viscous lyotropic liquid crystal template on the nanoscale using a fluid stage in the STEM. The nanoparticles nucleate and grow to ∼5 nm particles, at which point growth continues through the formation of connections with other nanoparticles around the micelles to form clusters. Upon reaching a critical size (>10–15 nm), the clusters become highly mobile in the template, displacing and trapping micelles within the growing structure to form spherical, porous nanoparticles. The final products match those synthesized in the lab <i>ex situ</i>. This ability to directly observe synthesis on the nanoscale in rheological fluids, such as concentrated aqueous surfactants, provides an unprecedented understanding of the fundamental steps of nanomaterial synthesis. This in turn allows for the synthesis of next-generation materials that can strongly impact important technologies such as organic photovoltaics, energy storage devices, catalysis, and biomedical devices

Direct <i>in Situ</i> Observation of Nanoparticle Synthesis in a Liquid Crystal Surfactant Template

Controlled and reproducible synthesis of tailored materials is essential in many fields of nanoscience. In order to control synthesis, there must be a fundamental understanding of nanostructure evolution on the length scale of its features. Growth mechanisms are usually inferred from methods such as (scanning) transmission electron microscopy ((S)TEM), where nanostructures are characterized after growth is complete. Such <i>post mortem</i> analysis techniques cannot provide the information essential to optimize the synthesis process, because they cannot measure nanostructure development as it proceeds in real time. This is especially true in the complex rheological fluids used in preparation of nanoporous materials. Here we show direct <i>in situ</i> observations of synthesis in a highly viscous lyotropic liquid crystal template on the nanoscale using a fluid stage in the STEM. The nanoparticles nucleate and grow to ∼5 nm particles, at which point growth continues through the formation of connections with other nanoparticles around the micelles to form clusters. Upon reaching a critical size (>10–15 nm), the clusters become highly mobile in the template, displacing and trapping micelles within the growing structure to form spherical, porous nanoparticles. The final products match those synthesized in the lab <i>ex situ</i>. This ability to directly observe synthesis on the nanoscale in rheological fluids, such as concentrated aqueous surfactants, provides an unprecedented understanding of the fundamental steps of nanomaterial synthesis. This in turn allows for the synthesis of next-generation materials that can strongly impact important technologies such as organic photovoltaics, energy storage devices, catalysis, and biomedical devices

Direct <i>in Situ</i> Observation of Nanoparticle Synthesis in a Liquid Crystal Surfactant Template

Controlled and reproducible synthesis of tailored materials is essential in many fields of nanoscience. In order to control synthesis, there must be a fundamental understanding of nanostructure evolution on the length scale of its features. Growth mechanisms are usually inferred from methods such as (scanning) transmission electron microscopy ((S)TEM), where nanostructures are characterized after growth is complete. Such <i>post mortem</i> analysis techniques cannot provide the information essential to optimize the synthesis process, because they cannot measure nanostructure development as it proceeds in real time. This is especially true in the complex rheological fluids used in preparation of nanoporous materials. Here we show direct <i>in situ</i> observations of synthesis in a highly viscous lyotropic liquid crystal template on the nanoscale using a fluid stage in the STEM. The nanoparticles nucleate and grow to ∼5 nm particles, at which point growth continues through the formation of connections with other nanoparticles around the micelles to form clusters. Upon reaching a critical size (>10–15 nm), the clusters become highly mobile in the template, displacing and trapping micelles within the growing structure to form spherical, porous nanoparticles. The final products match those synthesized in the lab <i>ex situ</i>. This ability to directly observe synthesis on the nanoscale in rheological fluids, such as concentrated aqueous surfactants, provides an unprecedented understanding of the fundamental steps of nanomaterial synthesis. This in turn allows for the synthesis of next-generation materials that can strongly impact important technologies such as organic photovoltaics, energy storage devices, catalysis, and biomedical devices

Direct <i>in Situ</i> Observation of Nanoparticle Synthesis in a Liquid Crystal Surfactant Template

Controlled and reproducible synthesis of tailored materials is essential in many fields of nanoscience. In order to control synthesis, there must be a fundamental understanding of nanostructure evolution on the length scale of its features. Growth mechanisms are usually inferred from methods such as (scanning) transmission electron microscopy ((S)TEM), where nanostructures are characterized after growth is complete. Such <i>post mortem</i> analysis techniques cannot provide the information essential to optimize the synthesis process, because they cannot measure nanostructure development as it proceeds in real time. This is especially true in the complex rheological fluids used in preparation of nanoporous materials. Here we show direct <i>in situ</i> observations of synthesis in a highly viscous lyotropic liquid crystal template on the nanoscale using a fluid stage in the STEM. The nanoparticles nucleate and grow to ∼5 nm particles, at which point growth continues through the formation of connections with other nanoparticles around the micelles to form clusters. Upon reaching a critical size (>10–15 nm), the clusters become highly mobile in the template, displacing and trapping micelles within the growing structure to form spherical, porous nanoparticles. The final products match those synthesized in the lab <i>ex situ</i>. This ability to directly observe synthesis on the nanoscale in rheological fluids, such as concentrated aqueous surfactants, provides an unprecedented understanding of the fundamental steps of nanomaterial synthesis. This in turn allows for the synthesis of next-generation materials that can strongly impact important technologies such as organic photovoltaics, energy storage devices, catalysis, and biomedical devices

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div

Tunable, Metal-Loaded Polydopamine Nanoparticles Analyzed by Magnetometry

We report the preparation and study of Mn­(III)-, Fe­(III)-, Co­(II)-, Ni­(II)-, Cu­(II)-, Zn­(II)-, and Ga­(III)-loaded polydopamine nanoparticles (PDA-NPs) via autoxidation polymerization of metal–dopamine complexes in the presence of free dopamine. An analysis of the doping range and parameters that influence final particle morphology is presented. In addition, magnetometry provides a probe of the general electronic structure and electronic interactions for Mn­(III)-, Ni­(II)-, and Co­(II)-loaded PDA-NPs. PDA-NPs doped with Mn­(III) are found to have high spin, low anisotropy, and weak magnetic coupling and are therefore predicted to have superior relaxivity behavior compared to previously studied Fe­(III)-loaded PDA-NPs. Comparison of Mn­(III)- and Fe­(III)-loaded PDA-NP relaxivity confirms the predictive ability of the magnetometry measurements

In Situ Observation of Directed Nanoparticle Aggregation During the Synthesis of Ordered Nanoporous Metal in Soft Templates

The prevalent approach to developing new nanomaterials is a trial-and-error process of iteratively altering synthesis procedures and then characterizing the resulting nanostructures. This is fundamentally limited in that the growth processes that occur during synthesis can be inferred only from the final synthetic structure. Directly observing real-time nanomaterial growth provides unprecedented insight into the relationship between synthesis conditions and product evolution and facilitates a mechanistic approach to nanomaterial development. Here, we use in situ liquid-stage scanning transmission electron microscopy to observe the growth of mesoporous palladium in a solvated block copolymer (BCP) template under various synthesis conditions, and we ultimately determined a refined synthesis procedure that yields extended structures with ordered pores. We found that after sufficient drying time of the casting solvent (tetrahydrofuran, THF), the BCP assembles into a rigid, cylindrical micelle array with a high degree of short-range order but poor long-range order. Upon slowing the THF evaporation rate using a solvent-vapor anneal step, the long-range order was greatly improved. The electron beam induces nucleation of small particles in the aqueous phase around the micelles. The small particles then flocculate and grow into denser structures that surround, but do not overgrow, the micelles, forming an ordered mesoporous structure. The microscope observations revealed that pore disorder can be addressed prior to metal reduction and is not invariably induced by the Pd growth process itself, allowing for more rapid optimization of the synthetic method