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Diseño de Nanomateriales y Microestructuras

Broad objectives:
New procedures to improve the control of the micro- and nanostructure of materials, Microstructural and chemical characterization in the nanoscale to understand the behaviour of materials
Specific objectives:
Development of nanostructured and nanocomposite coatings for mechanical, tribological and protective applications. Simulation of mechanical properties on nanostructured materials and correlation with the microstructural characterization and the experiment
Specific advantages
Very well positioned in the magnetron sputtering technology for deposition of nanostructured coatings for mechanical, tribological and protective applications, Very well positioned in the physical and chemical approach synthesis methodologies of nanostructured materials like sol-gel, colloidal synthesis and gas phase condensation, A multidisciplinary approach combining chemists, physicist and materials engineers. Experimental approach complemented by the incorporation of simulation and modelling. Strong simulation capabilities for mechanical properties of nanostructured materials, Strong experience in high resolution microscopies: Atomic force, transmission and scanning electron microscopies. Understanding of nanomaterials processes by controlling and determining the microstructure. Multitechnique approach (XPS, XAS, TEM/EELS, XRD), Line with strong participation in European projects

Boron carbide and titanium nitride-based nanostructured ceramics for structural applications



Research head: Diego Gómez García / Arturo Domínguez Rodríguez
Period: 01-01-2016 / 31-12-2019
Financial source: Ministerio de Economía y Competitividad
Code: MAT2015-71411-R
Research group: Francisco L. Cumbreras Hernández, Felipe Gutíerrez Mora, Ana Morales Rodríguez

Abstract[+]

Boron carbide and titanium nitride are among the most promising ceramic materials nowadays. In the first case, this is due to the outstandng mechanical properties (it is the third hardest material in nature) and its high resistance to chemical attack. In the case of Titanium nitride, its remarkable optical properties and electrical conductivity makes this a potential material for electronic devices. In both cases, sintering is a challenging issue due to the low diffusitivity. In this project, sintering of these materials by spark plasma sintering will be studied and the conditions for nanostructuration will be determined. Preliminary results show that average grain sizes as low as 100 nm can be achieved. In a second stage, plasticity will be studied. A previous model developed by the authors show that twinning is a key ingredient as a driving force of plasticity of boron carbide. The case of titanium nitride is mostly exciting because the stacking fault energy is the lowest ever known and it can make twinnin very favoured. The comparison between these two systems can be a clue about the basic mechanism for hardening in these ceramic materials.


Development of supported catalysts on porous structures for hydrogen generation and catalytic combustion applications in the framework of renewable energies



Research head: Asunción Fernández Camacho
Period: 01-01-2016 / 31-12-2018
Financial source: Ministerio de Economía y Competitividad
Code: CTQ2015-65918-R
Research group: Asunción Fernández, Mª Carmen Jiménez de Haro, Vanda Godinho, Gisela Arzac, Dirk Hufschmidt, Rocio García

Abstract[+]

The depletion of fossil fuels (in a short and long term) and the global warming derived from greenhouse effect are consequences of the extensive use of these fuels. In this context, hydrogen appears as an attractive, clean and abundant energy carrier in the context of a wider use of clean and removable energies. For the implementation of the “hydrogen economy” many technological challenges regarding hydrogen production (free from CO2), transport, storage (in a safe manner) and combustion (to produce heat or electricity) should be met first. New research will be conducted in this project on the basis of our previous results regarding the study of complex hydrides for hydrogen storage and the development of catalysts and processes for hydrogen generation and use in portable applications. In particular, new catalysts will be developed on porous structures such as polymeric, metallic and ceramic membranes and/or foams with high actual interest.  Catalysts will we developed and studied for hydrogen generation and combustion reactions according to the following research lines:

1) Development of new materials (catalysts and supports) with a high added value of the complete system catalyst + support. Porous Ni and SiC foams together with PTFE membranes will be selected as supports for the studies. The main objective is to design new catalysts on technologically interesting supports such as separating membranes, electrolytes, electrodes and/or hydrogen combustors. These new catalysts will be developed following the objective of reducing the amount of noble metals by combining or replacing with another non-noble metals (e.g. Pt-Cu and Ni-Fe) and/or with metalloids (e.g carbides, borides, etc). Wet impregnation methods will be used and special emphasis will be put on the use of the PVD methodology (magnetron sputtering) recently employed in our laboratory for the fabrication of Co thin films with very good results. The latter methodology opens a highly interesting research field because permits to tune microstructure and composition (i.e. Co, Co-B, Co-C) on demand.

2) Characterization of the prepared materials from a microstructural and chemical point of view. Modern nanoscopies will play a key role in the characterization, comprehension and further improvement of these highly nanostructured catalysts.

3) Catalytic studies on the prepared materials will be carried out in three catalytic tests: i) the hydrogen generation through hydrolysis reactions, ii) the photocatalytic water splitting, and iii) the catalytic hydrogen combustion. These reactions are of high interest in the context of the hydrogen economy.

--The interaction of these three research lines as proposed in this project will permit to achieve basic knowledge on the rational design of nanocatalysts supported on porous materials. Structure-composition-activity relationships will be established through catalytic and photo-catalytic studies in combination with characterization techniques based on high resolution analytical TEM and additional spectroscopic techniques.


High temperature energy application coatings



Research head: Juan Carlos Sánchez López
Period: 01-01-2016 / 31-12-2018
Financial source: Ministerio de Economía y Competitividad
Code: MAT2015-65539-P
Research group: Iñigo Braceras Izaguirre (INASMET), Teresa Cristina Rojas Ruiz, Maria Belinda Sigüenza Carballo

Abstract[+]

The protection of surfaces from thermal, wear and oxidation phenomena has reached a substantial progress by developing new materials and coatings with improved properties as extreme hardness, low friction and wear rates, increased thermal and oxidation resistance. These improvements suppose a huge energy-saving and cost reduction due to the increased life-time of mechanical components without needs of replacement as well as a reduction in the environmental impact. This field of research has a deep impact in a large variety of industrial sectors (energy, machining tools, automotive, aeronautic, metallurgy, etc.). The challenge for most of these surface functionalization procedures is to get a strict control of the micro and nanostructure of the surface and interfaces that make possible the advent of new properties and applications that nanotechnology concept offers.

In this project, tailored nanostructured coatings for protection of components submitted to high temperature and aggressive environments are prepared seeking for an improved performance. This goal will be explored for three different applications that would contribute to an energy efficiency, renewable energies and solutions to decrease environmental impact. Based on the Cr-Al-N system, different coatings will be prepared by reactive magnetron sputtering technology changing chemical composition (metal content, incorporation of dopants like Y or Si); microstructure; phase distribution; architecture (multilayer/ nanocomposite) or more complex structures (tandem, multilayer gradient) on appropriated substrates depending on the foreseen application: a) oxidation resistance at high temperature (up to 1000ºC) for tool components; b) thermal stable solar selective absorber coating for mid (300-500ºC) and high temperature (>600ºC); c) corrosion resistant coating for supercritical turbine components (650ºC and 100% steam atmosphere).

The investigation of the oxidation mechanisms, phase transformations, structural modifications, etc. will be object of a careful study directly over the defined substrates for these applications to get fundamental knowledge on the degradation phenomena and protective effects. The establishment of the relationships between the initial properties and observed functional performance will enable the better understanding of the protection mechanisms and the optimization of such nanostructured coating systems for the selected application.

 

Keywords: Coating, high-temperature, oxidation-resistant, corrosion, nanostructured, energy, solar absorber, multilayer


Processing and microsctructural, mechanical and electrical characterization of ceramic-graphene composites



Research head: Angela Gallardo López (UEI) / Rosalía Poyato Galán
Period: 01-01-2016 / 31-12-2018
Financial source: Ministerio de Economía y Competitividad
Code: MAT2015-67889-P
Research group: Antonio Muñoz Bernabé, Felipe Gutiérrez Mora, Ana Morales Rodríguez

Abstract[+]

Nowadays, interesting prospects are proposed for ceramic-graphene composites, in application fields such as catalysis, energy storage and conversion, environment protection and biotechnology. A great effort is still required to answer open questions. Issues such as shear resistance of the ceramic-graphene interface essential to obtain an effective load transfer to the graphene sheets-, distribution of graphene in the ceramic matrix -to maximize the reinforcement mechanisms and electrical conductivity- and the high temperature mechanical
properties in these composites need special attention.
A systematic study of ceramic matrix graphene composites, including processing and microstructural, mechanical and electrical characterization is proposed in this project, with the aim of improving the comprehension of mechanisms controlling these properties when adding graphene nanostructures to a ceramic matrix.
Both alumina and yttria tetragonal zirconia (3YTZP) graphene composites will be processed by means of colloidal techniques. Special attention will be devoted to the dispersion of graphene in the ceramic matrix which is not a straightforward aspect, but is key to improve mechanical and functional properties. Sintering will be carried out by spark plasma sintering, SPS. Conditions will be optimized in order to obtain fully dense composites with nanometric grain size. Microstructural analysis will be performed by X ray diffraction, Raman spectroscopy, scanning and transmission electronmicroscopy (SEM and TEM). The present crystallographic phases, grain size and distribution of graphene nanostructures will be evaluated. In order to design advanced materials, it is necessary to study the relationship between microstructure and mechanical or electrical properties. Room temperature mechanical properties (hardness, fracture toughness and flexural resistance) will be characterized by indentation and bending tests at macro and microscopic scales. At high temperature, the plastic behavior of these ceramic-graphene composites will be assessed by creep tests under controlled atmosphere. Tribological behavior of the composites will also be studied to evaluate their resistance to wear. The electrical response will be assessed in a wide range of temperatures by means of complex impedance spectroscopy or by direct current conductivity measurements in the composites with lower resistivity. This is a most interesting property since it can be strongly increased when incorporating graphene to these ceramic systems. 


Application of advanced electron microscopy techniques to the characterization of nanostructured coatings for clean energy applications



Research head: Ana María Beltrán Custodio
Period: 01-03-2015 / 28-02-2017
Financial source: Junta de Andalucía
Code: TAHUB-050. Programa Talent HUB
Research group:

Abstract[+]

This project is focus on the hydrogen generation and storage with the aim of producing hydrogen for clean and sustainable energies. It happens due to an exothermic reaction where a catalyst is required to do so safety. Catalysts based on noble metals are good candidates for this purpose such as, cobalt, cupper… Here, the complete catalysts systems and different supports are studied. They have been grown by magnetron sputtering technology. The structure and composition are studied, up to nano-scale, by advanced scanning-transmission electron microscopy techniques, (S)TEM, such as high-resolution (HRTEM), high-angle annular dark field (HAADF), energy dispersive X‑Ray (EDX), electron energy loss spectroscopy (EELS), for chemical analysis. Furthermore, the use of the three-dimensional characterization technique electron-tomography provides a full understanding of the analysed material. The combination of structural and compositional analytical microscope techniques, in both STEM and TEM mode, allows a full nano-characterization of the systems. The (S)TEM analyses are the essential tool to determine the relationship among the microstructure, the growth conditions and the final behaviour and properties of the systems which will help to improve them and, therefore, to contribute to the production of clean energy.

This project has four main strategic objectives:

1. Nano-materials for sustainable energy applications. Materials for the production, use and storage of Hydrogen.
2. Development of sputtering technology for the fabrication of nanostructures (thin films, coatings and controlled microstructure multilayers).
3. Development of the potential capabilities of the Laboratory for Nanoscopies and Spectroscopies (LANE).
4. Use of advanced structural and analytical techniques for the nano-analysis of new nanomaterials.


Development of processes for the catalytic combustion of hydrogen and study of the integration in devices for portable applications



Research head: Asunción Fernández Camacho
Period: 16-05-2014 / 15-05-2016
Financial source: Junta de Andalucía
Code: P12-TEp-862
Research group: Julián Martínez, Gisela Arzac, Dirk Hufschmidt, Joaquín Ramírez, M.Carmen Vera, Vanda Godinho, Lionel Cervera, T.Cristina Rojas, Olga Montes, Mariana Paladini, Jaime Caballero-Hernández

Abstract[+]

Hydrogen is an attractive candidate as a vector for storage and transport of energy in the context of an increased use of renewable and clean energies. The production and use of energy based on hydrogen technology is particularly important for small-scale portable (and potentially scalable for stationary) applications. In this project the process of catalytic (controlled) combustion of hydrogen will be investigated in the various aspects that could lead to a final integrated configuration with a H2 generation system for portable applications. For that the project will take advantage of the synergy of integrating two researcher groups from the PAI: i) The TEP217 group, specialists in storage and generation of hydrogen based on metal hydrides, complex hydrides and hydride composites reactive systems; and in the use of catalysts and additives to control and improve the kinetics of these processes. ii) The FQM342, specialist group for the fabrication of porous ceramics of high interest as catalyst supports for harsh combustion environments. Further collaboration is completed with the participation of the company Abengoa Hidrógeno SA that will be involved as sub-contractor as specialist in systems for the production and storage of hydrogen.
In particular we will work on this project in the following lines:
1.- Development of catalysts and supports for catalytic combustion. Typically porous biomorphic silicon carbide ceramics and classic noble metal catalysts, as well as new low cost catalysts to be developed in the project.
2.- Development of reactors needed for the study of the catalytic combustion. Typically hydrogen flows from a few ml/min to the scale of a H2 generator already available in the range 0.5 to 1.5 L/min.
3.- Coupling the catalytic combustion system with a portable hydrogen generation systems that we have developed in previous projects.
4.- Application of the sputtering technology in an exploratory manner in this project to deposit the catalyst materials for the H2 catalytic combustion on porous substrates.
5.- Microstructural and chemical characterization of the supports and catalysts in the nanoscale to follow the procedures of synthesis and evolution in operation.

 


Development of novel materials and processes for the generation and use of hydrogen mainly in portable applications



Research head: Asunción Fernández Camacho
Period: 01-01-2013 / 31-12-2015
Financial source: Ministerio de Economía y Competitividad
Code: CTQ2012-32519
Research group: Gisela Arzac, Jaime Caballero, Lionel Cervera, Vanda Fortio, Carlos Negrete, Dirk Hufschmidt, Cristina Rojas Ruiz, Roland Schierholz

Abstract[+]

Hydrogen as a vector of transport and storage of energy is a very attractive candidate in the context of increased use of renewable and clean energies. This project will address the study of the different processes that lead to the final configuration of an integrated systems for hydrogen generation and use mainly in portable applications (and potentially scalable for stationary applications). In particular, work will be carried out in this project in the following lines:
a) Research on new lightweight compounds for use in hydrogen generation processes on a small scale by chemical routes (hydrolysis). Typically hydrolysis reactions of borohydrides (i.e. NaBH4) and compounds like ammonia borane, hydrazine borane or hydrazine. This line includes the development of catalysts at the nanoscale using wet chemical methods for their synthesis: Metal-metalloid nanostructures (i.e. Co-B, Co-B-P and similar ones) and bimetallic catalysts (including or not metalloid) of low cost which potentiate synergistic effects (i.e. CoRu, NiPt or Co-Ru-B). The topic also includes the development of portable reactors for these processes and the development of new substrates and monoliths, studies of adherence and durability of the catalyst.
b) Research on new host-guest systems containing hydrogen for reversible storage (loading / unloading). Mainly porous supports (host) like the so called "nanoscaffolds" (based on C or BN) infiltrated with borohydrides materials (guest) (i.e. titanium borohydride) typically used for reversible hydrogen storage. These new materials must present improved charging and de-charging kinetics.
c) Studies of coupling a hydrogen generator system with a low cost fuel cell. Typically a continuous reactor for the hydrolysis of NaBH4 with Co-B catalyst for providing H2 at constant flow rate conditions to directly feed a PEM fuel cell of 60 W.
d) Fundamental studies for the development of catalysts and supports for the controlled combustion of hydrogen. It's a new line in the research group based on wet chemical preparation of noble metal nanoparticle catalysts on commercial porous ceramic supports (i.e. SiC). The line also includes the design of a reactor for laboratory-scale study of heat production by controlled combustion of hydrogen.
e) Development of sputtering technology ("magnetron sputtering") for the preparation of catalysts and nano-structures on various substrates for use in the processes developed in the previous sections. The group has extensive experience in this technology to be applied in novel ways in this project leading to a great versatility regarding nanostructure, composition and addition of additives to improve catalytic activity, durability and selectivity of catalysts.
f) Microstructural and chemical characterization of new materials and catalysts developed in the project. We are dealing typically with materials of controlled nanostructure where modern nanoscopic techniques will play a key role in the custom manufacturing of these materials

 


Development of nanostructured protective coatings for extreme environmental conditions (NANOPROTEXT)



Research head: Juan Carlos Sánchez López
Period: 01-01-2012 / 31-12-2014
Financial source: Ministerio de Ciencia e Innovación
Code: MAT2011-29074-C02-01
Research group: T. Cristina Rojas Ruiz; Francisco Javier Pérez Trujillo;Maria del Pilar Hierro de Bengoa;Germán Alcalá Penades; Maria Sonia Mato Díaz; Marta Brizuela; Pablo Corengia; José Luis Viviente; Alberto García;Daniel González

Abstract[+]

In many industrial operations, the machines or tool components in contact are submitted to severe conditions of load, friction, temperature or variable atmosphere. The research efforts are directed towards the development of new multiphase coatings capable to increase their performance by protection of the surface against wear and oxidation that cause failure mechanisms. By appropriate control of the size and distribution of phases, chemical composition and microstructure in the nanometric regime it is possible to obtain multifunctionality as low friction, hardness and thermal stability. To achieve excel in this purpose it is necessary to correlate the macroscopic properties of these coated surfaces (mechanical, tribological, oxidation resistance) with these basic phenomena.

In this project, three types of nanostructured coatings will be prepared using a magnetron sputtering process for protection in running operations under extreme or singular conditions (pressure, temperature, oxidant atmospheres, vacuum, etc.). The chosen systems are constituted by crystals of hard materials (nitrides or carbides) in combination with a second element or phase that improves the practical performance. Thus, nanocomposite coatings consisting of WC nanocrystals dispersed in an amorphous dichalcogenide phase (WS2 or WSe2) are proposed as solid lubricant coatings to run under high vacuum conditions useful for spatial applications or inert environments. In the second case, Y or Zr will be tested as dopant elements in CrAlN coatings with the aim of increasing the corrosion and oxidation resistance and tribological behaviour useful for many industrial fields (machining tools, metallurgy, aeronautic, automotive, etc…). Finally, hard and transparent nanocomposite coatings based on the Al-Si-N system are suggested as protective coatings for optical systems.

In all cases, the project comprises their synthesis, chemical and structural characterization, and validation in tribological and oxidation under extreme condition tests that simulate the final operation conditions. In the case of the hard and transparent coatings, their optical properties will be also analysed. The establishment of the relationships between microstructure and measured properties will be an essential objective, since it enables the better understanding of the action mechanisms, and thus, the optimisation of such nanostructured multifunctional systems for an improved technological benefit.

 


Fatty hydroxyacids molecular interactions as model for biomimetic polyester design



Research head: José Jesús Benítez Jiménez
Period: 01-01-2012 / 31-12-2014
Financial source: Ministerio de Ciencia e Innovación
Code: CTQ2011-24299
Research group: Alejandro Heredia Guerrero, Miguel Angel San Mibuel Barrera, Jaime Oviedo López, Miguel Salmerón Batalle

Abstract[+]

The objective of this Project is to study and characterize the specific interactions between fatty carboxylic acids molecules arising from selective  hydroxylation of the alkyl chain. To address this issue, molecular self-assembled systems showing a low interaction with an atomically flat support are proposed as models. The use of low binding energy supports is to ensure the packing structure to be mainly driven by the molecule to molecule interactions rather than the molecule to substrate adsorption. These self-assembled systems will be characterized by scanning probe microscopies  such as AFM and STM and infrared spectroscopy. Results will be complemented with molecular dynamics atomistic simulations. Basic information  obtained from self-assembled models will be used to design the in-vitro chemical synthesis of cutin mimetic polyesters. Cutin is a non toxic, fully  biodegradable barrier biopolymer present at the skin of fruits, leaves and non lignified stems of higher plants. Physical (mechanical, water  permeability, ionic transport, etc…) and chemical (ester yield, controlled chemical degradation rate, etc…) properties of synthetic polyesters will be determined. Material features will be related with both, the main structure arising from the ester bonds formation and the secondary network resulting from hydrogen bonding between spare non reacted hydroxyl groups. Structure-function patterns will be used to redesign the synthesis route to obtain polymeric esters with tailored properties. To achieve this goal, both the primary and secondary structural networks will be manipulated. In the first  case non hydroxylated molecules will be used to prevent ester bonding propagation. To modify hydrogen bonding crosslinking, additives with selected  hydroxylation (primary or secondary) will be employed. The final motivation of this research is to explore the applicability of such mimetic polyester as substitutes for the highly contaminant hydrocarbon based plastics.


Advanced laboratory for the nano-analysis of novel functional materials (AL-NANOFUNC)



Research head: María Asunción Fernández Camacho
Period: 01-10-2011 / 30-03-2015
Financial source: Unión Europea
Code: REGPOT-CT-2011-285895
Research group: T. Cristina Rojas, M.Carmen Jiménez, Gisela Arzac, Olga Montes, Inmaculada Rosa, Rafael Alvarez, Vanda Godinho, Juan Carlos Sánchez-López, Hernán Míguez, Agustín R. González-Elipe, Manuel Ocaña, M. Jesús Sayagués, Lionel Cervera, Roland Schierholz, Salah Rouillon, Lucia Castillo, Rocío García, Carlos García-Negrete, Jaime Caballero

Abstract[+]

The AL-NANOFUNC project has been designed to install and fully develop at the Materials Science Institute of Seville (ICMS, CSIC-Univ.Seville, Spain) an advanced laboratory for the Nano-analysis of novel functional materials. Advanced Nanoscopy facilities, based on latest generation electron microscopy equipments, will be devoted to breakthrough research in specific topics of high interest: i) Nanomaterials for sustainable energy applications; ii) protective and multifunctional thin film and nanostructured coatings; iii) nanostructured photonic materials and sensors. To take the ICMS laboratories to a leading position that is competitive in a world-wide scenario, the AL-NANOFUNC project is contemplated to up-grade the actual research potential in several directions: i) improve equipment capabilities regarding the Analytical High Resolution Electron Microscopy facilities; ii) improve the impact and excellence of basic research through hiring of experienced researchers and transnational exchange with the reference centers in Europe; iii) develop and improve the innovation potential of the ICMS’s research by opening the new facilities to companies and stakeholders; iv) organize workshops and conferences, dissemination and take-up activities to improve research visibility. Close collaborations with reference centers and companies in Liège (Belgium), Graz (Austria), Jülich (Germany), Oxford (England), Cambridge (England), Dübendorf (Switzerland) and Rabat (Morocco), as well as with laboratories at Andalucian Universities, are foreseen in this project. Five companies in Andalusia will also collaborate in close synergies to promote the long-term strategic lines of interest for the region in the natural and artificial stone products and solar and renowable energy sectors.


Nanostructured films for operating under vacuum



Research head: Juan Carlos Sánchez López
Period: 01-10-2011 / 31-12-2011
Financial source: Ministerio de Ciencia e Innovación
Code: MAT2010-21597-C02-01
Research group: T. Cristina Rojas Ruiz, Santiago Domínguez Meister

Abstract[+]

In this project, nanostructured coatings will be prepared using a magnetron sputtering process for lubrication of mechanical components used in aerospace applications. These materials must provide wear protection and low friction when operating in ambient air or vacuum environment. The chosen systems to obtain this compromise are constituted by WC nanocrystals dispersed in an amorphous dichalchogenide phase (WS2 or WSe2). These solid lubricant coatings are proposed to enhance the wear resistance, mechanical strength and oxidation resistance in comparison to their conventional MoS2 or DLC coatings for this kind of applications.


Development of carbon-based composites for biomedical applications



Research head: Juan Carlos Sánchez López
Period: 15-03-2011 / 15-03-2014
Financial source: Junta de Andalucía
Code: P10-TEP 06782
Research group: T. Cristina Rojas, Carlos López Cartes, David Abad, Vanda Godinho, Santiago Domínguez, Inmaculada Rosa

Abstract[+]

This project pursues the development of carbon-based coatings including the tailored synthesis, characterization, evaluation in wear tests and biocompatibility study for the application in artificial implants. The control of the carbon chemical bonding (sp2/sp3) and the chemical composition, including metals as (Ag, Ti) or other elements (B, N, O) will enable to tune the mechanical and tribological properties (hardness, friction and wear resistance) with the aim of improving the final performance. To achieve this goal, the use of magnetron sputtering technique is envisaged to deposit advanced coatings under different synthesis conditions. Next, these carbon composites will be evaluated comparatively in friction and wear tests that simulate the conditions that these materials will face in the final application. In this way, it will be possible to establish the correlation between the observed behavior and chemical and structural characteristics of the prepared layers in cell adhesion tests, cytotoxicity and antibacterial activity. This complete characterization will provide an excellent overview of the possibilities of technological transfer of these advanced materials to the biomedicine.


Functionalized for hypethermia applications and evaluation of ecotoxicity



Research head: Asunción Fernández Camacho
Period: 03-02-2010 / 02-02-2013
Financial source: Junta de Andalucía
Code: P09-FQM-4554
Research group: J. Blasco, M. Hampel, Carlos López, L.M. Lubián, I. Moreno, Miguel Angel Muñoz, David Philippon, T. Cristina Rojas, Inmaculada Rosa, Carlos García-Negrete

Abstract[+]

This Excellence project is taking profit of the previous experience of the group TEP-217 in the development and characterization of functionalized biocompatible nanoparticles and potentially trying to advance in four directions. a) Continue with the development of nanoparticle based mainly on Au, Ag and magnetic oxides with different functionalizations and microstructure. b) To deepen the physical-chemical interaction with electromagnetic fields (in a wide range of frequencies from kHz to GHz) to produce local heating. Currently, various mechanisms have been proposed (Eddy current, hysteresis, relaxation of magnetic moments and Brownian motion) without enough data yet existing to understand and interpret the experimental results. c) Establish a multidisciplinary collaboration with the group RNM-306, a specialist in ecotoxicity testing, to improve the knowledge of the environmental impact of nanoparticles (mainly gold and silver) in marine ecosystems, which are the ultimate sink for a good part of nanomaterials currently produced. d) Conduct preliminary studies of the toxicity of nanoparticles as a function of applied magnetic field. In any project dedicated to nanotechnology is extremely valuable to introduce studies to determine the toxicological and environmental impact of new materials being developed at present. A key objective of this project is the training of research personnel through the implementation of one doctoral thesis at the Institute of Materials Science of Seville.


Role of additives in the reactive hydride composite systems for hydrogen storage



Research head: Asunción Fernández Camacho
Period: 01/01/2010 - 31/12/2012
Financial source: Ministerio de Educación y Ciencia
Code: CTQ2009-13440
Research group: Carlos López, Cristina Rojas Ruiz, Gisela Arzac, Dirk Hufschmidt, Raimondo Ceccini, Emilie Deprez

Abstract[+]

Due to the expected short-medium term exhaustion of fossil fuels and due to clime changes produced by the green house effect, it is necessary to reconsider a new global energy policy. Hydrogen, as a vector for energy storage and transport, is an attractive candidate for a clean handling of energy. In the present project it is proposed the study of the so called reactive hydride composite systems (RHC) for hydrogen storage. These systems are based in the coupling of a single metal hydride (i.e. MgH2) with a complex hydride (typically a borohydride compound, i.e LiBH4) to give a reversible reaction that is producing or consuming hydrogen. The system can so be used as a hydrogen storage material according to following reaction: MgH2+2LiBH4 ↔ MgB2+LiH+4H2 (11.4 wt% hydrogen storage capacity). The reaction is improving the heat transfer handling, as compared to pure MgH2, by reducing heat release during the charging process. To improve the kinetic aspects (reduction of operation temperatures and times) it has been proposed the use of catalysts a/o additives. The main objective of the project is to understand the role of these additives to improve the hydrogen sorption kinetics. In particular commercial Ti-Isopropoxide (TiO4C12H28) , TiO2 and VCl3 have been selected as additives for this study. Also other catalysts like Co3B, Ni3B or RuCo will be prepared in our laboratory and also tested. The systems will be prepared and activated by high energy ball milling of the two hy-dride materials milled together with or without the additives (5-10 mol%). Kinetic studies will be carried out by gravimetric and volumetric hydrogen sorption measurements (hydrogen desorption or adsorption vs. time at constant T) and differential scanning calorymetry (DSC) analysis. An exhaustive microstructural and chemical analysis of the systems at the different step (as prepared, desorbed and re-absorbed) will be undertaken by following techniques: X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) coupled to EDX (energy dispersive X-Ray) and EELS (Electron Energy Loss Spectroscopy) analysis, X-Ray Photoelectrton Spectroscopy (XPS) and X-Ray absorption Spectroscopy (XAS). The comparative study of the samples, with and without additives, and the correlation between the kinetic studies and the microstructural and chemical analysis, should clarify the mechanisms of the kinetic improvements produced by the additives. These mechanisms are today far from being understood. On basis of the acquired knowledge we expect to significantly improve the systems with respect to hydrogen storage applications.


The coupling of grain boundary dynamics and impurity segregation in nanostructured polycrystals: application to yttria tetragonal zirconia polycrystal (YTZP)



Research head: Diego Gómez García
Period: 01/01/2010 – 31/12/2012
Financial source: Ministerio de Educación y Ciencia
Code: MAT2009-14351-C02-01
Research group: Francisco Luis Cumbrera Hernández (USE), Arturo Domínguez Rodríguez (USE), Robert Luis González Romero (becario AECID)

Abstract[+]

This project aims to study, by computer simulation at different length scales, the mi-crostructural evolution of a polycrystal at elevated temperature and under an applied mechanical stress field, with an emphasis on nanometric systems. For this study it is essential to know the law of mobility of the grain boundaries as a function of the temperature and the local stresses. When impurities are present, this law depends critically upon the concentration of segregated chemical species at these boundaries and upon their evolution during the dynamic regime (i.e., during deformation). As segregation itself is altered by the movement of the grain boundary, the two phenomena are coupled. The study of segregation will be carried out by Molecular Dynamics (MD) simulations; MD will also be used to characterize the mobility of a single grain boundary containing impurities. These data will be used as input in a mesoscopic model, which will allow the study of the dynamics of an ensemble of nanometric grains and, consequently, plasticity in this model polycrystalline system. The final objective of this project is to determine the law of evolution of the centers of mass of the grains in order to get, via a statistical treatment, the constitutive law for plasticity in a nanometric polycrystal. This macroscopic law will then be compared with experimental results in nanometric YTZPa system in which the research team has wide experience in recent years.


Structure, packing and tribology of Fatty Self-assembled monolayers of Alkylamines



Research head: José Jesús Benítez Jiménez
Period: 01-01-2009 / 31-12-2011
Financial source: Ministerio de Ciencia y Tecnología
Code: CTQ2008-00188
Research group: Miguel Salmerón, Eduardo Garzón Garzón, Pedro J. Sánchez Soto, J. Alejandro Heredia Guerrero

Abstract[+]

The aim of this research project is to study the contribution of molecular scale events to the tribological properties of self-assembled monolayers of alkyl molecules. The amount of topographic and frictional AFM data available on typical self-assembled systems such as thiols on gold and silanes on mica is very extensive. Here, we propose alkylamines on mica as a new self-assembled system. The reason is that the weaker interaction between the amino end group and mica, if compared with S-gold and silane-mica, leads to a less effective molecular packing. The ability to control the quality of molecular packing by tunning the preparation conditions is a good model to test the contribution of defects to friction. Molecular resolution using contact AFM is not possible on alkylamine self-assembled monolayers, so there is a lack of structural information on this system. The new methodology described in this project proposes the use of Scanning Polarization Force Microscopy (SPFM) to address this issue based on the high polarization signal contrast between mica and self-assembled layers. Furthermore, the high sensitivity of SPFM to the presence of water molecules filling vacancies, can be used to evaluate the quality of the molecular packing by monitoring the screening effect exerted by the self-assembled layer. Consequently, the study of both, the frictional and the SPFM properties of self-assembled monolayers of alquilamines, are complementary to describe the contribution of defects to friction.


Study of the viability of carbonation process through wollastonite-like composites for CO2 capture and re-use industrial processes



Research head: Luis Esquivias Fedriani
Period: 01/01/2009 – 31/12/2011
Financial source: Ministerio de Educación y Ciencia
Code: CIT-44000-209-1
Research group: Alberto Santos Sánchez, Víctor Morales Flórez, Cristián Cárdenas Escudero, Laura Pereda Briones

Abstract[+]

The Wollastonite Project deals the current challenge of reducing the industrial carbon dioxide emissions. Its main goal consists in developing a system able to capture huge amounts of CO2 and other green-house gasses (GHG) from localized sources, typically, thermal plants and cement factories, so the designed technology could be scaled-up at an industrial level. On the one hand, the economic and technological viability of the carbon dioxide capturing processes based on composites of calcium and silica, typically wollastonite, will be assessed, and on the other hand, the required technical features of an scaled-up industrial process able to capture CO2 from industrial plants will be researched. Given that the by-product of carbon mineral capture processes based on calcium sili-cates can be a valuable mineral, namely calcium carbonate, a valuable environmental safe compound and thermodynamically stable, it can be re-used as raw material from some indus-trial processes, depending on its morphology, purity or grain size. Therefore, the possible applications of the carbon mineral capture by-product will be researched, assessing on each process the energetic and economical ratio costs/profits. This applications will allow the design of an integral industrial process, able to reduce GHG emissions and subsequently able to re-use the by-product in an industrial process.


Study of the viability of carbonation process through wollastonite-like composites for CO2 capture and re-use industrial processes



Research head: Luis Esquivias Fedriani
Period: 01/01/2009 – 31/12/2011
Financial source: Ministerio de Educación y Ciencia
Code: CIT-44000-209-1
Research group: Alberto Santos Sánchez, Víctor Morales Flórez, Cristián Cárdenas Escudero, Laura Pereda Briones

Abstract[+]

The Wollastonite Project deals the current challenge of reducing the industrial carbon dioxide emissions. Its main goal consists in developing a system able to capture huge amounts of CO2 and other green-house gasses (GHG) from localized sources, typically, thermal plants and cement factories, so the designed technology could be scaled-up at an industrial level. On the one hand, the economic and technological viability of the carbon dioxide capturing processes based on composites of calcium and silica, typically wollastonite, will be assessed, and on the other hand, the required technical features of an scaled-up industrial process able to capture CO2 from industrial plants will be researched. Given that the by-product of carbon mineral capture processes based on calcium sili-cates can be a valuable mineral, namely calcium carbonate, a valuable environmental safe compound and thermodynamically stable, it can be re-used as raw material from some indus-trial processes, depending on its morphology, purity or grain size. Therefore, the possible applications of the carbon mineral capture by-product will be researched, assessing on each process the energetic and economical ratio costs/profits. This applications will allow the design of an integral industrial process, able to reduce GHG emissions and subsequently able to re-use the by-product in an industrial process.


Creating and disseminating novel nano-mechanical characterization techniques and standars (NANOINDENT)



Research head: Asunción Fernández Camacho
Period: 01-09-2008 / 31-08-2011
Financial source: Unión Europea
Code: NMP3-CA-2008-218659
Research group: Godinho, V., Philippon, D.

Abstract[+]

Our project aims to gather, improve, catalogue and present characterisation tech-niques, methods and equipment for nanomechanical testing. European-wide activities coordinated by a new virtual centre will improve existing nanoindentation metrology to reveal structure-properties relationship at the nano-scale. These methods are the only tools to characterise nanocomposite, nanolayer and interface mechanical behaviours in the nanometre range. This work will also lay down a solid base for subsequent efforts for defining and preparing new standards to support measurement technology in the field of nanomaterials characterisation. Steps include development of the classical and the dynamic nanoindentation method and its application to new fields, application of modified nano-indenters to new fields as scratching and wear measurement, firm and uniform determination of instrumental parameters and defining new standard samples for the new applications. The virtual centre will disseminate information based on a new “Nanocharacterisation database” built on two definite levels: on a broader level partners will inventory and process all novel nanocharacterisation techniques and, in narrower terms, they will concentrate on nanomechanical characterisation. This will be achieved through the synchronisation of efforts set around a core of round robins but the database will include data of other channels as parallel research work and literature recherché.


Multifunctional nanostructured coatings for mechanical and tribological applications (NANOMETRIB)



Research head: Juan Carlos Sánchez López
Period: 01-10-2007 / 30-09-2011
Financial source: Ministerio de Ciencia e Innovación
Code: MAT2007-66881-C02-01
Research group: Asunción Fernández Camacho, Cristina Fernández, Miguel Angel Muñoz-Márquez, Said El Mrabet, Vanda Godinho, M. David Abad

Abstract[+]

In this In the field of mechanical and tribological applications, the investigations are oriented towards the development of new systems capable to increase the performance of industrial operations, machines or tools by increasing the hardness and diminution of the friction and wear rate of materials under contact or increasing the oxidation resistance. These improvements suppose an energy-saving and cost reduction due to increase of tool life-time without needs of reparation as well as a reduction in the employment of lubricant emulsions with oils and greases. This project goal is to develop bew multifunctional nanostructured sys-tems by the Magnetron Sputtering PVD technique for mechanical and tribological applications where an adequate balance among the above-mentioned properties as friction, hardness and thermal stability are searched. The combination of multiple functions into a materials increase noticeably the material added value. To achieve this general objective, different coatings will be prepared by confinement of size and distribution of phases, chemical composition and microstructure in the nanometric regime. The chosen systems are constituted by crystals of hard materials (nitrides, carbides and borides of transition metals: Cr, Ti, W) that can be surrounded by a second phase that acts as lubricant based on C or dichalcogenides of W and doped with certain metals to increase their thermal resistance (V or Nb). In all cases, the project comprises their synthesis, chemical and structural characterization, and their practical validation in tribological tests of friction and wear. The establishment of the relationships between microstructure and measured properties will be an essential objective, since it enables the better understanding of the action mechanisms, and thus, the optimisation of such nanostructured multifunctional systems for an improved technological benefit.


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