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Steelmaking contributes 8% to the total CO2 emissions globally, primarily due to coal-based iron ore reduction. Clean hydrogen-based ironmaking has variable performance because the dominant gas-solid reduction mechanism is set by the defects and pores inside the mm- to nm-sized oxide particles that change significantly as the reaction progresses. While these governing dynamics are essential to establish continuous flow of iron and its ores through reactors, the direct link between agglomeration and chemistry is still contested due to missing measurements. In this work, we directly measure the connection between chemistry and agglomeration in the smallest iron oxides relevant to magnetite ores. Using synthesized spherical 10-nm magnetite particles reacting in H2, we resolve the formation and consumption of wüstite (Fe1-xO)-the step most commonly attributed to whiskering. Using X-ray diffraction, we resolve crystallographic anisotropy in the rate of the initial reaction. Complementary imaging demonstrated how the particles self-assemble, subsequently react, and grow into elongated whisker structures. Our insights into how morphologically uniform iron oxide particles react and agglomerate in H2 reduction enable future size-dependent models to effectively describe the multiscale aspects of iron ore reduction.

Producción Científica, The excellent catalytic properties of copper nanoparticles (CuNPs) for the degradation of the highly toxic and recalcitrant chlorpyrifos pesticide are widely known. However, CuNPs generally present low stability caused by their high sensitivity to oxidation, which leads to a change of the catalytic response over time. In the current work, the immobilization of CuNPs into a polycaprolactone (PCL) matrix via electrospinning was demonstrated to be a very effective method to retard air and solvent oxidation and to ensure constant catalytic activity in the long term. CuNPs were successfully anchored into PCL electrospun fibers in the form of Cu2O at different concentrations (from 1.25 wt % to 5 wt % with respect to the PCL), with no signs of loss by leaching out. The PCL mats loaded with 2.5 wt % Cu (PCL-2.5Cu) almost halved the initial concentration of pesticide (40 mg/L) after 96 h. This process was performed in two unprompted and continuous steps that consisted of adsorption, followed by degradation. Interestingly, the degradation process was independent of the light conditions (i.e., not photocatalytic), expanding the application environments (e.g., groundwaters). Moreover, the PCL-2.5Cu composite presents high reusability, retaining the high elimination capability for at least five cycles and eliminating a total of 100 mg/L of chlorpyrifos, without exhibiting any sign of morphological damages., Ministerio de Ciencia e Innovación (PID2021-127108OB-I00), Ministerio de Ciencia e Innovación (MCIN/AEI/ 10.13039/501100011033), EU NextGenerationEU/PRTR program (PLEC2021-007705), Ministerio de Ciencia, Innovación and Ministerio de Universidades - FEDER (RTI2018−098749−B-I00 and RTI2018−097367-A-I00), Junta de Castilla y León and EU-FEDER program (CLU-2019-04 and VA202P20)

A series of monometallic Ru, Pd, and bimetallic Ru–Pd catalysts loaded on CeO2 support have been prepared via mechanochemical and conventional incipient wetness impregnation methods and used in the partial oxidation of methane (POM) to obtain synthesis gas (H2 and CO). The influence of the preparation method, the order of addition of the metals, the Ru:Pd metal ratio, and the milling energy and time for samples prepared by the mechanochemical method, have been evaluated between 300 and 600 °C. The results revealed that bimetallic Ru–Pd/CeO2 catalysts outperform monometallic Ru–CeO2 and Pd–CeO2 for POM, both in terms of catalytic activity and stability. Additionally, the bimetallic Ru–Pd/CeO2 catalysts prepared by ball milling produced syngas at a much lower temperature compared to the conventional catalysts prepared by incipient wetness impregnation. Raman spectroscopy, temperature programmed reduction (H2–TPR), X–ray photoelectron spectroscopy (XPS) and high–resolution transmission electron microscopy (HRTEM) have been used to characterize the catalysts before and after reaction., Peer Reviewed, Postprint (published version)

X-ray is widely used in medical areas, typically for cancer treatment. Studies seek to enhance the X-ray effect using nanomaterials to increase energy deposition efficiency and a new discipline called X-ray nanochemistry was established based on these studies. While nanoparticles with high Z materials are proven to be able to deposit more X-ray energy to a system, nanoparticles are also found to be involved in the chemical reactions triggered by X-ray or biological response under radiation. These findings lead to discussions about other types of dose enhancement factors like chemical enhancement and biological enhancement are discussed. More studies were still needed to study the mechanisms and deconvolute these dose enhancement factors. The dissertation presents continuous work in the field of X-ray nanochemistry, focusing on type 2 physical enhancement and chemical enhancement. Direct quantification of type 2 physical enhancement (T2PE) was done by conjugating a 12-mer single-strand DNA onto surfaces of silica-coated gold nanoparticles (Au@SiO2). T2PE comes from energy deposited by secondary electrons emitted from nanoparticles in radiation which are low-energy electrons and will disappear a few nanometers from the surface of the nanoparticles. 3 reporters were linked to DNA strands respectively and the magnitude of T2PE was determined by comparing the number of reporters released from Au@SiO2 versus the same size of SiO2 when DNA strand breaks occurred. More than 9 times more reporters were released in the presence of 1wt% Au@SiO2. T2PE showed a much higher dose enhancement factor than T1PE and can help to develop X-ray-triggered releasing nanosystems by using single-strand DNA as linkers on the nanoparticle surface. An EPR study was performed using spin trap BMPO(5-tert-Butoxycarbonyl-5-methyl-1-pyrroline-N-oxide) to detect •OH produced by X-ray radiation in the presence of 3-nm THPC (Tetrakis(hydroxymethyl)phosphonium chloride) AuNPs. Similar amounts of •BMPO-O

Oregano essential oil was encapsulated in poly-¿-caprolactone nanoparticles by a nanoprecipitation method using glycerin as a moisturizer. Nanocapsule characterization was performed by measuring the particle size, colloidal stability and encapsulation efficiency using dynamic light scattering, UV–Vis spectrophotometry and scanning electron microscopy (SEM). The nanoparticles had a mean particle size of 235 nm with a monomodal distribution. In addition, a low polydispersity index was obtained, as well as a negative zeta potential of -36.3 mV and an encapsulation efficiency of 75.54%. Nanocapsules were applied to polyester textiles through bath exhaustion and foulard processing. Citric acid and a resin were applied as crosslinking agents to improve the nanocapsules’ adhesion to the fabric. The adsorption, desorption, moisture content and essential oil extraction were evaluated to determine the affinity between the nanocapsules and the polyester. The adsorption was higher when the citric acid and the resin were applied. When standard oregano nanocapsules were used, almost all of the impregnated nanoparticles were removed when washed with water. The moisture content was evaluated for treated and non-treated textiles. There was a significant increase in the moisture content of the treated polyester compared to the non-treated polyester, which indicates that the polyester hydrophilicity increased with an important absorption of the essential oil nanocapsules; this can improve fabric comfort and probably promote antibacterial properties, Postprint (published version)

CuO nanoparticles have demonstrated a significant effect on the formation kinetics of nitrosylcobalamin (CblNO) in the reaction between nitrocobalamin (CblNO) and ascorbic acid (Asc). Nanoparticles of CuO were modified by coating with a polydopamine layer (nCuO-pDP) and addition of functional ligands (o-(aminoethyl) polyethylene) (nCuO-pDP-polymer). It was demonstrated that the introduction of modifications improved the stability of the suspension and partially eliminated the aggregation of the nanoparticles. Kinetic measurements showed that the modified nanoparticles of CuO clearly accelerate the reaction between nitrocobalamin (CblNO) and ascorbic acid (Asc) under weakly acidic conditions. The presented research is part of the project ‘Air Pollution versus Autoimmunity: Role of multiphase aqueous Inorganic Chemistry’ that aims at studying the effect of inorganic compounds as a part of particulate matter (PM) on the processes that could affect the course of autoimmune diseases.

Producción Científica, To determine the effect of nanoclays and trapped air on the formation of rigid polyurethane foams, three different production procedures were used. To study the influence of mixing at atmospheric pressure, two approaches were carried out employing either an electric or a magnetic stirrer. The third approach was executed by mixing under vacuum conditions with magnetic stirring. The samples thus obtained were characterized, and the effect of trapped air into the reactive mixtures was evaluated by analyzing the cellular structures. Different levels of trapped air were achieved when employing each manufacturing method. A correlation between the trapped air and the increase in the nucleation density when nanoclays were added was found: the cell nucleation density increased by 1.54 and 1.25 times under atmospheric conditions with electric and magnetic stirring, respectively. Nevertheless, samples fabricated without the presence of air did not show any nucleating effect despite the nanoclay addition (ratio of 1.09). This result suggests that the inclusion of air into the components is key for improving nucleation and that this effect is more pronounced when the polyol viscosity increases due to nanoclay addition. This is the most important feature determining the nucleating effect and, therefore, the corresponding cell size decreases., Ministerio de Ciencia e Innovación and Ministerio de Universidades grant (FPU17/03299), Junta de Castilla y León (VA202P20), Ministerio de Ciencia e Innovación and Ministerio de Universidades (RTI2018-098749-B-I00).

Scalable synthetic strategies for high-quality and reproducible thermoelectric (TE) materials is an essential step for advancing the TE technology. We present here very rapid and effective methods for the synthesis of nanostructured bismuth telluride materials with promising TE performance. The methodology is based on an effective volume heating using microwaves, leading to highly crystalline nanostructured powders, in a reaction duration of two minutes. As the solvents, we demonstrate that water with a high dielectric constant is as good a solvent as ethylene glycol (EG) for the synthetic process, providing a greener reaction media. Crystal structure, crystallinity, morphology, microstructure and surface chemistry of these materials were evaluated using XRD, SEM/TEM, XPS and zeta potential characterization techniques. Nanostructured particles with hexagonal platelet morphology were observed in both systems. Surfaces show various degrees of oxidation, and signatures of the precursors used. Thermoelectric transport properties were evaluated using electrical conductivity, Seebeck coefficient and thermal conductivity measurements to estimate the TE figure-of-merit, ZT. Low thermal conductivity values were obtained, mainly due to the increased density of boundaries via materials nanostructuring. The estimated ZT values of 0.8-0.9 was reached in the 300-375 K temperature range for the hydrothermally synthesized sample, while 0.9-1 was reached in the 425-525 K temperature range for the polyol (EG) sample. Considering the energy and time efficiency of the synthetic processes developed in this work, these are rather promising ZT values paving the way for a wider impact of these strategic materials with a minimum environmental impact.

Postprint (published version)

Biopolymeric chitosan is considered a promising encapsulating agent for tex-tile applications due to its biocompatibility, lack of toxicity, antibacterial activ-ity, high availability, and low cost. After cellulose, it is nature's most importantorganic compound. Also, chitosan has unique chemical properties due to itscationic charge in solution. Microencapsulation technologies play an impor-tant role in protecting the trapped material and in the durability of the effect,controlling the release rate. The app lication of chitosan microcapsules in tex-tiles follows the current interest of industries in functionalization technologiesthat give different properties to products, such as aroma finish, insect repel-lency, antimicrobial activity, and thermal comfort. In this sense, methods ofcoacervation, ionic gelation, and LBL are presented for the production ofchitosan-based microcapsules and methods of textile finishing that incorporatethem are presented, bath exhaustion, filling, dry drying cure, spraying, immer-sion, and grafting chemical. Finally, current trends in the textile market areidentified and guidance on future developments, Postprint (author's final draft)

Los sistemas nanométricos se basan en el estudio de la materia a escalas de tamaño reducido, dando lugar al estudio de las propiedades fisicoquímicas únicas del sistema a estudiar. El auge de estudiar los aspectos a escala nanométrica ha llevado a un nuevo paradigma en áreas como la nanomedicina y perfumería, donde el hecho prioritario es el beneficio del paciente y la acción prolongada y homogénea de la dosis subministrada . En contraste, los sistemas nanométricos activados se basan en la respuesta de un estímulo interno (pH, presencia de encimas, luz, temperatura) mejorando la biodisponibilidad, proponiendo nuevos sistemas de liberación d ebido a su versatilidad química, consiguiendo ser funcionales en su superficie con moléculas que reconozcan selectivamente. Debido a su estructura y tamaño, los nanosistemas pueden contener una mayor cantidad de producto y permitiendo un mayor control de s u liberación. Los sistemas de nanoestructuras orgánicas e inorgánicas, donde se encuentran materiales poliméricos tales como nanoesferas, nanocápsulas, micelas, liposomas, etc. Han llevado al estudio de los campos anteriores, con tal de conseguir los obje tivos anteriormente mencionados. Debido a todo lo anteriormente antedicho, el objetivo principal del presente trabajo reside en el desarrollo de nanocápsulas de fragancia para la aplicación en sustratos textiles.

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While many crystals, both natural and artificial, grow isotropically, there are examples of crystals growing anisotropically. The aim of this theoretical study was to confirm the growth modes displayed by three different crystals, representing 3D, 2D and 1D structures. This was done by using energetic calculations with both molecular mechanics, with ReaxFF$_{ \textrm {SiO}}$ as the force field, and semi-empirical methods, with PM6 as the method. To start with, the 3D structure was represented by CaO, and both the ReaxFF$_{\textrm{SiO}}$ and PM6 results confirmed the isotropic growth mode of this rock salt structure. As for the 2D structure, nanoplatelets of calcium silicate hydrate (C-S-H), which make up the bulk phase in concrete, were investigated. These were modelled as C-S-H clusters with approximate cylinder shapes and adjustable chemical bonds and compositions. The ReaxFF$_{\textrm{SiO}}$ calculations showed that the energetic gain was higher when the radius was increased than when the height was increased. This was in agreement with the platelet shape of real C-S-H nanoparticles. However, the high computational costs of semi-empirical methods meant that the PM6 results did not represent a large enough cylinder size span to confirm the ReaxFF$_{ \textrm {SiO}}$ results. Lastly, the 1D structure was represented in the form of calcium oxalate monohydrate (COM), which may form elongated shapes such as raphides and styloids. Due to the ReaxFF$_{\textrm{SiO}}$ force field not being optimized for COM crystals, only PM6 calculations were performed. However, the computational demands of semi-empirical methods again limited the number of PM6 data points considerably. Therefore, it could not be concluded if the 1D growth mode was the most energetically favourable., Kristaller av olika former och storlekar finns överallt omkring oss. Medan de flesta kristaller föredrar att växa lika mycket i alla riktningar, som bordssalt (natriumklorid) och diamant, finns det kristaller som bara föredrar att växa i vissa specifika riktningar. Som exempel på det sistnämnda, s.k. anisotropisk tillväxt, finns det kristaller som växer endimensionellt och bildar nålliknande former eller de som bildar tvådimensionella plattor. Syftet med denna studie var just att undersöka varför olika kristaller växer på det sätt de gör. Att modellera hur kristaller växer är mycket svårt, och det finns många parametrar som antingen får kristaller att växa eller att falla sönder. Det finns analogier för de komplicerade parametrar som dikterar kristalltillväxt, exempelvis de komplexa biologiska och kemiska faktorer som styr hur träd växer, eller de ekonomiska och ingenjörsmässiga utmaningar som präglar bygget av skyskrapor. I denna studie valde vi att enbart skapa teoretiska modeller av olika kristaller, anta att de är stabila, och därefter beräkna den totala atomära interaktionsenergin för olika kristallstorlekar. Vi studerade tre olika kristaller, vilka växer som bulk, plättar och nålar; de kan anses representera kristaller som växer i 3D, 2D och 1D, respektive. Vi använde olika sätt för att modellera expansionen av dessa kristaller, i ett försök att förstå mekanismen bakom anisotropisk kristalltillväxt. Först och främst genomfördes beräkningar för kalciumoxid (3D tillväxt), en förening som väldigt mycket liknar bordssalt (natriumklorid). Kalciumoxid är ett mycket enkelt system växer lika mycket i alla riktningar, och beräkningarna bekräftade detta. Huvudfokus låg på betong (2D tillväxt) och tidigare studier har visat att de mikroskopiska betongpartiklarna bildar plättar. Det är den slumpmässiga och kaosartade strukturen hos de mikroskopiska betongpartiklarna som ger betong dess karaktäretiskt slitstarka karaktär. Som bekant är det just p.g.a. styrkan som betong åt

The structures and stabilities of hollow gold clusters are investigated by means of density functional theory (DFT) as topological duals of carbon fullerenes. Fullerenes can be constructed by taking a graphene sheet and wrapping it around a sphere, which requires the introduction of exactly 12 pentagons. In the dual case, a (111) face-centred cubic (fcc) gold sheet can be deformed in the same way, introducing 12 vertices of degree five, to create hollow gold nano-cages. This one-to-one relationship follows trivially from Euler’s polyhedral formula and there are as many golden dual fullerene isomers as there are carbon fullerenes. Photoelectron spectra of the clusters are simulated and compared to experimental results to investigate the possibility of detecting other dual fullerene isomers. The stability of the hollow gold cages is compared to compact structures and a clear energy convergence towards the (111) fcc sheet of gold is observed. The relationship between the Lennard-Jones (LJ) and sticky-hard-sphere (SHS) potential is investigated by means of geometry optimisations starting from the SHS clusters. It is shown that the number of non-isomorphic structures resulting from this procedure depends strongly on the exponents of the LJ potential. Not all LJ minima, that have been discovered in previous work, can be retrieved this way and the mapping from the SHS to the LJ structures is therefore non-injective and non-surjective. The number of missing structures is small and they correspond to energetically unfavourable minima on the energy landscape. The optimisations are also carried out for an extended Lennard-Jones potential derived from coupled-cluster calculations for the xenon dimer, and, although the shape of the potential is not too different from a regular (6,12)-LJ potential, the number of minima increases substantially. Gregory-Newton clusters, which are clusters where 12 spheres surround and touch a central sphere, are obtained from the complete set of SH

Structural DNA nanotechnology has been advanced in an extraordinary pace in the past three decades and increasingly more complex structures have been demonstrated in the field based on the three major categories of structural units: DNA branched junction, DNA origami and SSTs. Overall, they have been developed as very handy tools in bioengineering applications. One of the major challenges is to further scale up the self-assembly to build structures of expanded sizes and thus higher complexity. There are a number of ways to scale up DNA self-assembly, and the most direct one is to use a longer scaffold in origami approach; or in scaffold-free approach to increase the number of component species. However, it is not always convenient to obtain a long enough scaffold with satisfactory quality; and increasing number of component species can lead to an exponential drop in self-assembly yield. Hence, instead of one-pot self-assembly, higher-ordered structures can also be constructed in hierarchy from preformed structural units by either (i) sticky-end association, (ii) shape complementarity with blunt-end stacking, (iii) or the guidance from scaffold. Here, we demonstrated a new method, through the sticky-end association and toehold-mediated strand displacement, to form DNA nanostructures of higher order from the preformed SSTs. For bioengineering applications, DNA nanostructures must meet several essential criteria: (i) programmability, each component tile can be independently included, removed or modified. (ii) simplicity, the assembly and disassembly must be rather simple and easy-to-implement. (iii) reversibility, the assembly and disassembly must be switchable and inducible. Therefore, SSTs can be a promising solution. Here, we demonstrated the ability to reconfigure the preformed DNA nanostructures, through the toehold-mediated strand displacement, into complex 2D and 3D conformations in a switchable and inducible manner. We also created complex DNA nanostructures fo

The main aim of this Project is the synthesis and characterization of nanocelluloses from different sources: biotechnological, natural, and finally, chemical. To achieve this objective, it was necessary a previous theoretical introduction explaining the concepts related with cellulose and nanocellulose. In case of cellulose, it has been studied the chemical structure, the polymorphism and properties. In case of nanocellulose, it has been deeply studied its types, its different applications and the methodology to obtain nanocellulose from raw materials, reaction times and experimental procedure. With the aid of a bibliographic search, it is explained in a detailed way all the synthesis that were carried out in this project with its reagents, purification methods and additional processes such as sonication. The yield obtained in the biotechnological synthesis, the natural and finally the chemical synthesis was 4,33 g/L, 0,57% and 10%, respectively. It is important to stand out that, in the natural synthesis, it was not possible to carry out a measure of the dried raw material that is the reason why it has low yield. Thanks to spectroscopic analysis of the synthetized samples from laboratory, and the samples provided by Cellulose Lab and Borregaard, the nanocelluloses were compared and the peaks from IR in all cases were quite similar. In the case of XRD and SEM, the results confirm that there are samples that contain nanocellulose such as nata de coco and the chemical synthesis, obtaining CNF and CNC, respectively. Histograms were made from samples which were fibrous, to deeply study the size and how SEM pictures vary depending on samples. It was realized and economic study and an environmental impact study that causes the realization of this project. Finally, this project concludes both general and particular objectives were achieved by synthetizing and analyzing different samples of nanocellulose of different origins.

This paper seeks to express the chemical potential for proteins on a surface in terms of number surface densitiy. Generalized Van der Waals (GVdW) theory and Virial hard disk theory are explored and fitted to experimental data by varying the hard disk radius. Additionnally Metropolis Monte Carlo simulations are used to simulate the interactions between proteins. Simulations are done on freely rotating proteins with the center of mass constrained to a 2D plane and employing the Widom insertion method to calculate the chemical potential. The theory, derivation and discussion of GVdW, Virial and Widom insertion are examined in this paper. Finally an interactive tool is included, which dynamically plots GVdW potentials. This tool is available online, both as source code and as a public web interface., The surface of cells or the cell membrane contains proteins that are floating along the surface. How closely can you pack those proteins and how much energy would that cost? Proteins like to be spread out across the surface. The proteins are anchored to the cell membrane, but can move along the surface. In this way, they behave similarly to the particles in a gas, except that they can only move in two dimensions. One can indeed quite accurately model the proteins on a cell surface as a two-dimensional gas. Even the most basic theory of gases—which models molecules as hard marbles that bounce off each other when they get to close works quite well. Even though the shape, charges and other interactions of the molecules have been ignored, the hard marbles theory which only model the volume of the proteins correctly is able to make some decent rough predictions for the chemical potential, where the chemical potential is defined as the amount of energy it takes to add a single particle to the system. More than a century ago Dutch physicist Johannes van der Waals developed theories that describe the behavior of gases. The description of liquids and gases that he developed, is now called the “Van der Waals equation of state” and earned him the Nobel prize in physics in 1910. His theory is still relevant today and factors in two corrections to the ideal gas law: Firstly, molecules take up space, and their “excluded volume” limits the movability of the other molecules, which increases the pressure. Secondly, molecules attract each other, which lowers the pressure, which is expressed with a value called the “binding constant”. An alternative way to study the properties of a gas is to simulate it: put some virtual molecules in a virtual box and let the computer move and rotate them such that this virtual system is representative of a physical system. Then this virtual gas can be analyzed by several methods. For example, the chemical potential can be analyzed by via a sampling a

The aim of the investigation is to show the possibility of updating of the training program of the discipline «Chemistry» intended for training of engineers of chemical specialties of higher educational institutions on the basis of results of the last researches in the field of nanochemistry. The article is addressed to the scientists and teachers developing the specific fields of science, to students and graduate students who have decided to devote themselves to new perspective science of the 21st century.Methods. The analysis of the works concerning the combinational scattering method (Raman spectroscopy) is made. Exposure to the combinational scattering method and the method of infrared spectroscopy is necessary for the undergraduates who are engaged in synthesis of new nanomaterials on the basis of carbon while deciding of the obtained experimental data. The physical and chemical analysis was used in the research to study the properties and structure of shungite of the Zazhoginsky field – the unique natural mineral containing nanoparticles and the effective sorbent applied to purification of drinking water (emission spectral analysis with inductively coupled plasma, Raman spectroscopy and Infrared spectroscopy).Results and scientific novelty. When processing shungite with toluene, ochroleucous resinous substance was educed; this is an organic substance according to data of IR-spectroscopy. On the basis of the analysis of data of Ramanspectroscopy, the line about 2700 cm–1 is offered to consider as the indicator of crystallinity. A variety of physical and chemical and structural properties in connection on the basis of shungite allows us to speak about chemistry of fullerenes and nanochemistry as the new perspective direction of chemistry.Practical significance. Described data on Raman-spectroscopy will help undergraduates, young scientists and researchers to identify various modifications of carbon in the nanomaterials synthesized by them on the basis of carbon., Цель работы – показать на основе результатов последних исследований в области нанохимии возможности обновления учебной программы дисциплины «Химия», предназначенной для подготовки инженеров химических специальностей высших учебных заведений. Статья адресована научным работникам и преподавателям, развивающим конкретные области науки, студентам и аспирантам, которые решили посвятить себя новой перспективной науке XXI века.Методы и методология. Произведен анализ работ, касающихся метода комбинационного рассеяния (КР), знакомство с которым, равно как с методом ИК (инфракрасной) спектроскопии, при расшифровке полученных экспериментальных данных необходимо магистрантам, занимающимся синтезом новых наноматериалов на основе углерода. В исследовании свойств и состава шунгита Зажогинского месторождения – уникального природного минерала, содержащего наночистицы и являющегося эффективным сорбентом, применяющимся для очистки питьевой воды, использовался физико-химический анализ (эмиссионный спектральный анализ с индуктивно-связанной плазмой, КР- и ИК-спектроскопия). Результаты и научная новизна. При обработке шунгита толуолом было выделено желто-белое смолистое вещество, которое, согласно данным ИКспектроскопии, является органическим веществом. На основании анализа данных КР-спектроскопии линию около 2700 см–1 предложено рассматривать как индикатор упорядоченности структуры. Разнообразие физико-химических и структурных свойств в соединении на основе шунгита позволяет говорить о химии фуллеренов и нанохимии как о новом перспективном направлении химии.Практическая значимость. Описанные в работе сведения по КР-спектроскопии помогут магистрантам, молодым ученым и исследователям идентифицировать различные модификации углерода в синтезированных ими наноматериалах на основе углерода. Данные, полученные в ходе исследования, можно использовать для лабораторной работы «Определение нанокомпонентов, составляющих шунгит, современными физико-химическими методами», включив ее в тему «Углерод»

The optimization of a material functionality requires both the rational design and precise engineering of its structural and chemical parameters. In this work, we show how colloidal chemistry is an excellent synthetic choice for the synthesis of novel ternary nanostructured chalcogenides, containing exclusively noble metals, with tailored morphology and composition and with potential application in the energy conversion field. Specifically, the Ag–Au–Se system has been explored from a synthetic point of view, which leads to a set of Ag2Se-based hybrid and ternary nanoparticles including the room temperature synthesis of the rare ternary Ag3AuSe2 fischesserite phase. An in-depth structural and chemical characterization of all nanomaterials has been performed, which proofed especially useful for unravelling the reaction mechanism behind the formation of the ternary phase in solution. The work is complemented with the thermal and electric characterization of a ternary Ag–Au–Se nanocomposite with promising results: we found that the use of the ternary nanocomposite represents a clear improvement in terms of thermoelectric energy conversion as compared to a binary Ag–Se nanocomposite analogue., Peer Reviewed, Postprint (author's final draft)

Peer Reviewed, Postprint (published version)

This PhD Thesis addresses the tailored synthesis of metal/carbon hybrid nanomaterials from a novel “laser chemistry” approach, based on the idea that the composition and structure of the synthesized materials can be tuned by selecting the laser irradiation parameters and the chemical composition of the ablated coordination compounds. The work presented here is mainly focused on the synthesis of metal/carbon foams, which consist of metal nanoparticles embedded in nanocarbon matrices which comprise both graphitic nanostructures and amorphous carbon. By selecting the ablated ligands and laser parameters used (such as irradiance, and laser operation mode -continuous wave or pulsed mode-) this versatile “laser chemistry” method enables tailoring the metal loading, and nanoparticle size and composition, as well as the structure of the produced carbon matrices. Moreover, metal-free carbon foams have been also synthesized by this laser technique. This work also discusses on the physicochemical properties (textural-, magnetic-, and electrochemical properties), and processing of the produced nanostructured materials, as well as on the mechanisms involved in plasma- assisted high temperature assembly of carbon- and metal building blocks toward the growth of the synthesized nanomaterials. Alternatively to this “laser chemistry” method, a chemical route for the gold nanoparticle decoration of metal-free carbon foams and other carbon materials (including carbon nanotubes, graphene oxide, carbon black, ordered mesoporous carbon and nanodiamond) has been developed and the resulting gold/carbon nanohybrids provided a remarkable catalyst performance in hydroamination reactions. Finally, this GNP decoration process has been extended to bidimensional inorganic layered materials: tungsten (IV) sulfide and montmorillonite, a pillared clay.

This thesis is concerned with the structural and chemical control of two-dimensional (2D) supramolecular self-assemblies through judiciously manipulating bonding motifs at various intrinsic and external conditions. The self-selection and the self-recognition of the non-covalent interactions among organic and/or metallic building blocks govern the structural and chemical properties of the resultant self-assembled two-dimensional nanostructures, accompanying with the thermodynamic and kinetic process as well. In this thesis, we have investigated the supramolecular self-assembly achieved via coordination bonds assisted by transition metals and functional ligands on metal surfaces. The self-assembled nanostructures were studied by ultra-high vacuum scanning tunneling microscopy working at room temperatures. The structural transition processes were also inspected via the low energy electron diffraction. Further, artificial “quantum dots” represented by the cavities of the self-assembled networks were investigated. The modulation of surface electrons by these “quantum dots” was characterized by the local density of states detected by low-temperature scanning tunneling spectroscopy. The major contributions of this thesis are outlined as below: (1) Through modifying the chemical states of organic ligands, a unique coordination Kagome network structure was obtained for the first time by two distinct methods. TPyP (5, 10, 15, 20-tetra(4-pyridyl)porphyrin) species on Au(111) surfaces form the TPyP-Au coordination Kagome network achieved by a novel treatment that was suggested to modify the chemical state of the TPyP. In a condition that the TPyP coexists with Cu on a Au(111), Cu adatoms play two roles in the self-assembly – the coordination with pyridyl end-groups and the reaction with TPyP macrocycles, which control the chemical and structural phase of the self-assembly. Following a high temperature annealing, the same Kagome structure emerged from a precursor rhombus network

La creciente mejora de los productos y sistemas en los últimos años es consecuencia de la investigación y el desarrollo de nuevas técnicas que permiten la implementación de innovaciones tecnológicas en las escalas micrométricas y nanométricas, complementarias a las obtenidas por el diseño industrial. La microingeniería y nanoingeniería (MNI) constituyen un ámbito de conocimiento que permite desarrollar nuevos productos derivados del conocimiento de las propiedades y los procesos de estas escalas. En el presente trabajo se expone una visión del estado actual de esta tecnología, su aplicación en el ámbito de la química, ambiente inteligente, con mención a los riegos laborales que de su aplicación devienen., The increasing improvement of products and systems during these last years is a consequence of the research and development of new techniques that allow implementing technological innovations on micrometric and nanometric scales, complementary to those obtained through industrial design. Macro engineering and nano engineering (MNI) constitute a knowledge area that allows developing new products derived from knowing properties and processes about these scales. In this work it is exposed a view of the present condition of this technology, its application in chemistry, intelligent environment and mentioning work risks derived from its application.

Depuis les années quatre-vingt, la construction d’édifices supramoléculaires à base de complexes de coordination suscite un intérêt considérable dans la recherche de nouveaux nanomatériaux fonctionnels. L’utilisation de complexes métalliques permet non seulement l’obtention d’une multitude de supramolécules de géométrie et de dimensionnalité très variées, mais également l’introduction de processus remarquables au sein des entités nanométriques, comme par exemple le transfert d’énergie lumineuse, le transport d’électrons et la séparation photo-induite de charges. La recherche menée au cours de cette thèse s’est plus particulièrement focalisée sur l’étude de deux types d’édifices supramoléculaires polymétalliques de dimensions différentes, l’un tridimensionnel, construit au départ d’ions ruthénium (II), l’autre unidimensionnel, obtenu à partir d’ions cuivre (II) ou cuivre (I).Plus précisément, la première partie de ce travail a été consacrée à la synthèse d’un complexe hexanucléaire symétrique de Ru(II), à base de ligands pontants PHEHAT et TPAC, afin de développer de nouvelles antennes collectrices d’énergie lumineuse. Dans ce cadre, nos travaux se sont principalement concentrés sur la synthèse ainsi que sur l’étude électrochimique et photophysique de deux nouveaux composés précurseurs trinucléaires, le cis-{[(phen)2Ru(PHEHAT)]2Ru(CH3CN)2}6+ et le {[(phen)2Ru(PHEHAT)]2Ru(TPAC)}6+, pouvant également servir de bloc de construction pour l’élaboration d’entités de tailles encore plus importantes. Une analyse par spectrométrie de masse du produit obtenu par chélation de l’entité bis-CH3CN sur le composé trinucléaire à base de TPAC ne nous a pas permis de prouver la présence de l’entité hexanucléaire. La nature du composé identifié semble toutefois confirmer la formation de l’espèce souhaitée à un moment ou un autre. La seconde partie de notre travail a consisté à tester le TPAC ainsi que deux ligands dérivés du dipyrrométhène (m-DipyH et m-dpDipyH) comme agent, Doctorat en Sciences, info:eu-repo/semantics/nonPublished

We study the statistics of single electron transfers through quantum dot and single molecule junctions. For that purpose, we derive a path-integral formalism where the effects of the electrodes on the system are characterized by a Feynman-Vernon influence functional. This approach is more general than previous master equation formalisms based on perturbation theory or semiclassical stochastic path integrals. The path-integral is solved utilizing the hierarchical equations of motions approach. From the path-integral, quantum master- and rate equations are recovered. Based on the derived set of transport formalisms, we obtain generating functions that provide the full counting statistics of single electron transfers. From a trajectory approach, we derive transfer operators which are employed to calculate joint-probabilities of consecutive electron transfers. As a consequence, we introduce waiting time distributions to the field of electron transport. The derived theories are then applied to examine electron transfer statistics experiments utilizing quantum dots, single molecules and quantum dot Aharonov-Bohm interferometers. We find that the statistics is sensitive to the presence of quantum mechanical interference and the Aharonov-Bohm phase, when two parallel transport legs are present. It is observed that the fluctuation theorem is not violated by this form of interference. The transfer statistics provides detailed information on the electronic states of the system and transfer rates. This can be used for novel applications such as single electron counting spectroscopy, as we show in a model simulation of a single porphyrin molecule. We are able to investigate non-Markovian and cotunneling effects, since the path-integral allows to go beyond previous second-order system-electrode perturbation approaches.

In this study, anionic surfactant and silane modified hydrotalcites were synthesized through a soft chemical in-situ method. The resulting materials were characterized using X-ray diffraction (XRD), high-resolution thermogravimetric analysis (HRTG), Fourier Transform Infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and N2 adsorption-desorption. The Mg-Al hydrotalcite (LDH) and the only surfactant modified hydrotalcite (LDH-2) display similar XRD patterns while both surfactant and silane modified hydrotalcite (LDH-3) shows two distinct series of reflections, corresponding to hydrotalcite and smectite-like materials, respectively. The smectite-like materials shows a series of regular (001) reflections with d001=12.58 Å. Further supporting evidence was obtained from FTIR and TG, for example, the vibration at 1198 cm-1 corresponds to Si-O-Si stretching mode and the mass loss at ca. 861 oC to dehydroxylation. In LDH-2, the loaded surfactant are located in both the interlayer space and inter-particle pores with a “house of cards” structure as supported by FTIR, TG and N2 adsorption-desorption isotherms. Both electron microscopy (SEM and TEM) micrographs and N2 adsorption-desorption isotherms show that in-situ modification with surfactant and silane has a significant influence on the morphology and porous parameters of the resulting hydrotalcite materials.

Micro to nano sized GaOOH nanorods and particles were prepared under varying hydrothermal conditions without any surfactant and additive using gallium nitrate and sodium hydroxide as starting materials. The combination of X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Small Area Electron Diffraction (SAED) and Energy Dispersive X-ray analysis (EDX), Thermogravimetric analysis (TG) and FT-IR were employed to characterize the resulting gallium oxide hydroxide nanorods. Detailed results and the possible growth mechanism are presented.

Hydrotalcites of formula Mg6Al2(OH)16(PO4).4H2O formed by intercalation with the phosphate anion as a function of pH show variation in the d-spacing attributed to the size of the hydrated anion in the interlayer. The value changes from 11.91 Å for pH 9.3, to 7.88 Å at pH 12.5. No crystalline hydrotalcites with phosphate in the interlayer were formed at pH 9.3. Thermal decomposition identifies three steps namely dehydration, dehydroxylation and some loss of carbonate during the thermal treatment. The addition of a thermally activated ZnAl-HT to a phosphate solution resulted in the uptake of the phosphate and the reformation of the hydrotalcite. The technology has the potential for water purification through anion removal.

See also ADM202150. The original document contains color images.

Molecular simulation techniques are used to find the basal spacing of organoclay on the basis of the energy minimum, using the canonical NVT ensemble. Then, the interlayer structure and mobility of alkyl chains are explored based on the interlayer atomic density profiles. Besides the basic lateral-monolayer arrangement, lateral-bilayer accompanying with partial pseudo-trilayer and a transition structure between the two basic lateral models are observed. The later provides an excellent explanation about the reflection at 16 Å on XRD patterns in literature. The atomic density profiles reveal that nitrogen atoms show stronger layering behavior than carbon atoms do. Our simulation demonstrates that the molecular mobility of the confined alkyl chains decreases from lateral-monolayer to lateral-bilayer with the increase of the intercalated surfactant. This is in accordance with the suggestion deduced from experiments. Furthermore, our simulation indicates that the mobility of the alkyl chains strongly depends on the surfactant arrangement rather than the surfactant packing density.

This project has been aimed at: 1) identifying gas/solid reaction conditions for converting biologically-derived micro/nanotemplates into other oxides without a loss of the starting 3-D shape and fine features, and 2) evaluating the nanochemical/nanostructural evolution during such reactive conversion. The most significant accomplishments have been: 1) Development of an oxidation-reduction reaction process for converting biosilica-based micro/nanoassemblies into MgO nanoparticle structures with a preservation of the starting 3-D shape and fine features at temperatures as low as 700 deg C; 2) Development of a two-Step oxidation-reduction reaction process for converting biosilica-based micro/nanoassemblies into CaO nanoparticle structures with a preservation of the starting 3-D shape and fine features at temperatures as low as 1000 deg C; 3) Development of a two-step metathetic reaction process for converting biosilica-based micro/nanoassemblies into TiO2 nanoparticle structures with a preservation of the starting 3-D shape and fine features at temperatures as low as 350 deg C; 4) Identification of novel reaction paths accessed during conversion of biosilica structures into magnesia (via formation of forsterite as an intermediate product) and titania (via formation of the intermediate compound, titanium oxyfluoride); 5) Identification of peptides that promote room-temperature formation of germania nanoparticle networks., The original document contains color images. All DTIC reproductions will be in black and white. Prepared in cooperation with Ohio State University, Columbus, OH.

The orientation of HDTMA+ in the interlayer of organic pillared montmorillonites prepared at different concentrations of HDTMA+ have been studied using X-ray powder diffraction (XRD) and theoretical calculation. A series of arrangement models of HDTMA+ in the interlayer of montmorillonite have been proposed as lateral-monolayer (LM), lateral-bilayer (LB), pseudotrilayer (PT), paraffin-type-monolayer (PM), paraffin-type-bilayer (PB). With the increase of the concentration of HDTMA+, the arrangement model of HDTMA+ in the interlayer of montmorillonites changes as lateral-monolayer→lateral-bilayer→paraffin-type monolayer→pseudotrilayer→paraffin-type-bilayer and the packing density of HDTMA+ in the interlayer increases gradually. In the intermediate stages, different models may coexist.

The Sixth Conference on Molecular Reaction Dynamics in Condensed Matter was held Feb. 28 - Mar 3 at the Hotel La Casa del Camino in Laguna Beach, CA, sponsored by AFOSR and UC Irvine, and organized by D. Dlott and A. Apkarian. There were 39 attendees, including professors, graduate students, postdoctoral fellows, technical staff members from national laboratories and a representative from AFOSR. 34 talks were presented. There were 21 invited talks (50 minutes with discussion) and 9 contributed talks (25 minutes with discussion). Lively discussion continued until the wee hours. The conference website is: http://dlottgroup.scs.uiuc.edu/moldyn/. Symposia on the following topics were presented: (1) New frontiers; (2) Multidimensional spectroscopy; (3) Condensed phase dynamics; (4) Chemical reaction dynamics; and (5) Confined molecules: clusters and droplets., Sixth Symposium on Molecular Reaction Dynamics in Condensed Matter, held in Laguna Beach, CA, on 28 Feb-3 Mar 2001.

The Fifth Conference on Molecular Reaction Dynamics in Condensed Matter was held Feb. 10-13 at Newport Beach California, sponsored by AFOSR and ONR, and organized by D. Dlott and A. Apkarian. (Apkarian took over from Charles Wight of Utah). There were 42 attendees, including professors, graduate students, postdoctoral fellows, and technical staff members from national laboratories (LANL, PNL, NIH, etc.), 34 talks were presented. There were 21 invited talks (50 minutes with discussion) and 13 contributed talks (20 minutes with discussion). Lively discussion went on late into the morning. Symposia on the following topics were presented: 1. Nanochemistry 2. Condensed phase dynamics and chemical reactions 3. Vibrational relaxation.

This article reviews a relatively new method for preparing nanomaterials - membrane-based synthesis. This method entails the synthesis of the desired material within the pores of a nanoporous membrane. Because the membranes employed contain cylindrical pores of uniform diameter, monodisperse nanocylinders of the desired material, whose dimensions can be carefully controlled, are obtained. These nanocylinders may be either hollow (a tubule) or solid (a fibril or nanowire). We call this approach the 'template' method because the pores in the nanoporous membranes are used as templates for forming the desired material. This template method is a very general approach; it has been used to prepare nanotubules and fibrils of polymers, metals, semiconductors, carbons, and other materials.

Nanochemistry is an emerging subdiscipline of the chemical and materials sciences that deals with the development of methods for synthesizing nanoscopic particles of a desired material and with scientific investigations of the nanomaterial obtained. Nanomaterials have numerous possible commercial and technological applications including use in electronic, optical and mechanical devices, drug delivery and bioencapsulation. In addition this field poses an important fundamental philosophical question--how do the properties (e.g., electronic, optical, magnetic, etc.) of a nanoscopic particle of a material differ from the analogous properties for a macroscopic sample of the same material?

Nanochemistry is an emerging subdiscipline in the chemical and materials sciences that deals with the development of methods for synthesizing nanoscopic bits of a desired material and with chemical and other investigations of the nanomaterial obtained. My research group has been exploring a general method, called "template-synthesis," for preparing nanomaterials. This method entails synthesizing the desired material within the pores of a nanoporous membrane. The membranes employed have cylindrical pores of uniform diameter. In essence, we view each of these pores as a "nanobeaker" in which a piece of the desired material is synthesized. We have used this method to prepare nanostructures composed of electronically conductive polymers, metals, semiconductors, and other materials. In this Accounts article, I discuss my work on template synthesis of electronically conductive polymer nanostructures. I will show that these conductive polymer nanostructures have interesting and unusual electronic properties and that these nanostructures provide an opportunity for exploring how molecular and supermolecular structure affect conductivity in conductive polymers.

TiO2 nanoparticulates of well-defined size were synthesized using amino acid templates employing sol–gel method. Eight different amino acids were studied. The samples were characterized by various methods such as X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, Brunauer–Emmett–Teller surface area measurement, and transmission electron microscopy. Of the amino acids used, catalyst employing aspartic acid was found to have minimum particle size of 10.4 nm and maximum surface area of 95.3 m2/g. The catalytic activity of the prepared TiO2 samples was compared with Degussa-P25 catalyst for direct sunlight photodegradation of methylene blue and calmagite dyes. Catalyst prepared form branched amino acids, proline, valine, and aspartic acids, were found to give better results. Based on infrared spectroscopy studies, it is proposed that amino acids act as a surfactant by hydrogen bonding between the hydrogen of the ammonium ion and the surface hydroxyl group of the colloid. © 2017, Springer-Verlag GmbH Austria.