Ald processes development for hybrid nanodevices-like nanostructures

194 p.The development of new and innovative atomic structures displaying multifunctional properties goes together with progress in advanced processes which enable atomic level control. One leading deposition technique is Atomic layer deposition (ALD), which has emerged as a powerful tool for bond-specific functionalization and the growth of stoichiometric films over wafer scale and high area uniformity. ALD offers a wide range of functionalization routes by means of four processes such as vapor phase metalation (VPM), multiple pulsed vapor-phase infiltration (MPI), ALD and molecular layer deposition (MLD). As an example of VPM on soft molecules, Zn metalation on Enterobactin (H6EB) and FeEnterobactin (FeH3EB) were studied experimentally and theoretically. Thus, we showed that the VPM process could become a route to functionalize soft organic molecules with potential applications in the pharmaceutical field. Extending Zn metalation-VPM growth to hybrid nanostructures, in this case ML-(NH4)V7O16. nanostructured square and Mw-H2Ti3O7 nanotubes. Zn metalation-VPM process provides a way to functionalize soft nanostructured materials in order to change their crystal structure and thereby their magnetic and optical properties, without affect their morphology. The use of DEZn/H2O in MPI, promotes the nucleation of ZnO nanoparticles around the nanotube (cactus-like) affecting the morphology and surface properties. It was found that the electronic energy gap decreases with increasing Zn content, making the (ZnO)Ti3O7 nanoparticle/nanotube nanocomposites potentially useful as photoanode for dye-sensitized solar cells (DSCs) and sensors. The ALD growth of uniform MxOy thin films where M stands for V, Mn, Sn or Zn was undertaken. The preliminary results show successful deposition of ¿-MnO2, ¿-V2O5, SnxOy and ZnO stoichiometric films, uniform over large areas. This points towards the possible growth of these oxides which can be considered as energy materials. Finally, the growth of alucone thin films (AlO-T and AlO-A, T: terephthalate and A: adipate) by ALD and MLD was explored. Stoichiometric thin films with large area uniformity were obtained in both cases. The use of bifunctional monomers (aromatic and aliphatic carboxylate) in the growth of AlO-T and AlO-A thin films leads to a lamellar phase and to an amorphous one, respectively. The structure of AlO-T is obtained by optimizing four models and correlating experimental data with DFT calculations. The analysis of the electronic band gap using frontier orbital (HOMO-LUMO), alongside the uniform LiPF6 distribution through the AlO-T, point to future studies of AlO-T for anode and electrolyte nanomembranes with potential applications in carboxylates-based energy storage concepts. Thus, in this thesis we have shown the versatility of ALD processes to realize novel thin films and pursue various functionalization strategies

Ald processes development for hybrid nanodevices-like nanostructures

194 p.The development of new and innovative atomic structures displaying multifunctional properties goes together with progress in advanced processes which enable atomic level control. One leading deposition technique is Atomic layer deposition (ALD), which has emerged as a powerful tool for bond-specific functionalization and the growth of stoichiometric films over wafer scale and high area uniformity. ALD offers a wide range of functionalization routes by means of four processes such as vapor phase metalation (VPM), multiple pulsed vapor-phase infiltration (MPI), ALD and molecular layer deposition (MLD). As an example of VPM on soft molecules, Zn metalation on Enterobactin (H6EB) and FeEnterobactin (FeH3EB) were studied experimentally and theoretically. Thus, we showed that the VPM process could become a route to functionalize soft organic molecules with potential applications in the pharmaceutical field. Extending Zn metalation-VPM growth to hybrid nanostructures, in this case ML-(NH4)V7O16. nanostructured square and Mw-H2Ti3O7 nanotubes. Zn metalation-VPM process provides a way to functionalize soft nanostructured materials in order to change their crystal structure and thereby their magnetic and optical properties, without affect their morphology. The use of DEZn/H2O in MPI, promotes the nucleation of ZnO nanoparticles around the nanotube (cactus-like) affecting the morphology and surface properties. It was found that the electronic energy gap decreases with increasing Zn content, making the (ZnO)Ti3O7 nanoparticle/nanotube nanocomposites potentially useful as photoanode for dye-sensitized solar cells (DSCs) and sensors. The ALD growth of uniform MxOy thin films where M stands for V, Mn, Sn or Zn was undertaken. The preliminary results show successful deposition of ¿-MnO2, ¿-V2O5, SnxOy and ZnO stoichiometric films, uniform over large areas. This points towards the possible growth of these oxides which can be considered as energy materials. Finally, the growth of alucone thin films (AlO-T and AlO-A, T: terephthalate and A: adipate) by ALD and MLD was explored. Stoichiometric thin films with large area uniformity were obtained in both cases. The use of bifunctional monomers (aromatic and aliphatic carboxylate) in the growth of AlO-T and AlO-A thin films leads to a lamellar phase and to an amorphous one, respectively. The structure of AlO-T is obtained by optimizing four models and correlating experimental data with DFT calculations. The analysis of the electronic band gap using frontier orbital (HOMO-LUMO), alongside the uniform LiPF6 distribution through the AlO-T, point to future studies of AlO-T for anode and electrolyte nanomembranes with potential applications in carboxylates-based energy storage concepts. Thus, in this thesis we have shown the versatility of ALD processes to realize novel thin films and pursue various functionalization strategies

Ald processes development for hybrid nanodevices-like nanostructures

194 p.The development of new and innovative atomic structures displaying multifunctional properties goes together with progress in advanced processes which enable atomic level control. One leading deposition technique is Atomic layer deposition (ALD), which has emerged as a powerful tool for bond-specific functionalization and the growth of stoichiometric films over wafer scale and high area uniformity. ALD offers a wide range of functionalization routes by means of four processes such as vapor phase metalation (VPM), multiple pulsed vapor-phase infiltration (MPI), ALD and molecular layer deposition (MLD). As an example of VPM on soft molecules, Zn metalation on Enterobactin (H6EB) and FeEnterobactin (FeH3EB) were studied experimentally and theoretically. Thus, we showed that the VPM process could become a route to functionalize soft organic molecules with potential applications in the pharmaceutical field. Extending Zn metalation-VPM growth to hybrid nanostructures, in this case ML-(NH4)V7O16. nanostructured square and Mw-H2Ti3O7 nanotubes. Zn metalation-VPM process provides a way to functionalize soft nanostructured materials in order to change their crystal structure and thereby their magnetic and optical properties, without affect their morphology. The use of DEZn/H2O in MPI, promotes the nucleation of ZnO nanoparticles around the nanotube (cactus-like) affecting the morphology and surface properties. It was found that the electronic energy gap decreases with increasing Zn content, making the (ZnO)Ti3O7 nanoparticle/nanotube nanocomposites potentially useful as photoanode for dye-sensitized solar cells (DSCs) and sensors. The ALD growth of uniform MxOy thin films where M stands for V, Mn, Sn or Zn was undertaken. The preliminary results show successful deposition of ¿-MnO2, ¿-V2O5, SnxOy and ZnO stoichiometric films, uniform over large areas. This points towards the possible growth of these oxides which can be considered as energy materials. Finally, the growth of alucone thin films (AlO-T and AlO-A, T: terephthalate and A: adipate) by ALD and MLD was explored. Stoichiometric thin films with large area uniformity were obtained in both cases. The use of bifunctional monomers (aromatic and aliphatic carboxylate) in the growth of AlO-T and AlO-A thin films leads to a lamellar phase and to an amorphous one, respectively. The structure of AlO-T is obtained by optimizing four models and correlating experimental data with DFT calculations. The analysis of the electronic band gap using frontier orbital (HOMO-LUMO), alongside the uniform LiPF6 distribution through the AlO-T, point to future studies of AlO-T for anode and electrolyte nanomembranes with potential applications in carboxylates-based energy storage concepts. Thus, in this thesis we have shown the versatility of ALD processes to realize novel thin films and pursue various functionalization strategies

Ald processes development for hybrid nanodevices-like nanostructures

Doctoral programme in physics of nanostructures and advanced materials.The development of new and innovative atomic structures displaying multifunctional properties goes together with progress in advanced processes which enable atomic level control. One leading deposition technique is Atomic layer deposition (ALD), which has emerged as a powerful tool for bond-specific functionalization and the growth of stoichiometric films over wafer scale and high area uniformity. ALD offers a wide range of functionalization routes by means of four processes such as vapor phase metalation (VPM), multiple pulsed vapor-phase infiltration (MPI), ALD and molecular layer deposition (MLD). As an example of VPM on soft molecules, Zn metalation on Enterobactin (H6EB) and FeEnterobactin (FeH3EB) were studied experimentally and theoretically. Thus, we showed that the VPM process could become a route to functionalize soft organic molecules with potential applications in the pharmaceutical field. Extending Zn metalation-VPM growth to hybrid nanostructures, in this case ML-(NH4)V7O16. nanostructured square and Mw-H2Ti3O7 nanotubes. Zn metalation-VPM process provides a way to functionalize soft nanostructured materials in order to change their crystal structure and thereby their magnetic and optical properties, without affect their morphology. The use of DEZn/H2O in MPI, promotes the nucleation of ZnO nanoparticles around the nanotube (cactus-like) affecting the morphology and surface properties. It was found that the electronic energy gap decreases with increasing Zn content, making the (ZnO)Ti3O7 nanoparticle/nanotube nanocomposites potentially useful as photoanode for dye-sensitized solar cells (DSCs) and sensors. The ALD growth of uniform MxOy thin films where M stands for V, Mn, Sn or Zn was undertaken. The preliminary results show successful deposition of ¿-MnO2, ¿-V2O5, SnxOy and ZnO stoichiometric films, uniform over large areas. This points towards the possible growth of these oxides which can be considered as energy materials. Finally, the growth of alucone thin films (AlO-T and AlO-A, T: terephthalate and A: adipate) by ALD and MLD was explored. Stoichiometric thin films with large area uniformity were obtained in both cases. The use of bifunctional monomers (aromatic and aliphatic carboxylate) in the growth of AlO-T and AlO-A thin films leads to a lamellar phase and to an amorphous one, respectively. The structure of AlO-T is obtained by optimizing four models and correlating experimental data with DFT calculations. The analysis of the electronic band gap using frontier orbital (HOMO-LUMO), alongside the uniform LiPF6 distribution through the AlO-T, point to future studies of AlO-T for anode and electrolyte nanomembranes with potential applications in carboxylates-based energy storage concepts. Thus, in this thesis we have shown the versatility of ALD processes to realize novel thin films and pursue various functionalization strategies.Peer reviewe

Phosphate Favors the Biosynthesis of CdS Quantum Dots in Acidithiobacillus thiooxidans ATCC 19703 by Improving Metal Uptake and Tolerance

Recently, we reported the production of Cadmium sulfide (CdS) fluorescent semiconductor nanoparticles (quantum dots, QDs) by acidophilic bacteria of the Acidithiobacillus genus. Here, we report that the addition of inorganic phosphate to Acidithiobacillus thiooxidans ATCC 19703 cultures favors the biosynthesis of CdS QDs at acidic conditions (pH 3.5). The effect of pH, phosphate and cadmium concentrations on QDs biosynthesis was studied by using Response Surface Methodology (RSM), a multivariate technique for analytical optimization scarcely used in microbiological studies to date. To address how phosphate affects intracellular biosynthesis of CdS QDs, the effect of inorganic phosphate on bacterial cadmium-uptake was evaluated. By measuring intracellular levels of cadmium we determined that phosphate influences the capacity of cells to incorporate this metal. A relation between cadmium tolerance and phosphate concentrations was also determined, suggesting that phosphate participates in the adaptation of bacteria to toxic levels of this metal. In addition, QDs-biosynthesis was also favored by the degradation of intracellular polyphosphates. Altogether, our results indicate that phosphate contributes to A. thiooxidans CdS QDs biosynthesis by influencing cadmium uptake and cadmium tolerance. These QDs may also be acting as a nucleation point for QDs formation at acidic pH. This is the first study reporting the effect of phosphates on QDs biosynthesis and describes a new cadmium-response pathway present in A. thiooxidans and most probably in other bacterial species

The issue of micro and nanoplastics on the American coasts of the Pacific Ocean

Este trabajo aborda la problemática representada por los micro y nanoplásticos (MP y NP, respectivamente) en las costas americanas del Océano Pacífico, desde la perspectiva de la Red Micro y Nano Allpa Pacha. Esta red está conformada por científicos de Chile, Perú, Costa Rica, Colombia, Ecuador, Panamá y México, quienes, preocupados por el impacto en el ambiente y su repercusión en la salud, decidieron establecer colaboraciones científicas internacionales para la geolocalización, monitoreo y caracterización de MP y NP presentes en las costas del Océano Pacífico en el continente americano. Se espera aportar datos basados en evidencias científicas y armonizados, que impacten en la enseñanza y en la planificación de medidas de control y regulación de estos contaminantes en nuestros países. En este trabajo se incluyen algunos aspectos de polímeros y plásticos, definiciones de MP’s y NP’s, y sus diversos impactos, la problemática de la toma de muestras, caracterización adecuada, entre otros. Unas de las conclusiones permitieron determinar que hay muchas características de los NP’s y MP’s sin investigar como la interacción con otros productos químicos, el impacto de la morfología en la biodisponibilidad, la formación de adherencias y liberación de las mismas durante su contacto con los compartimentos ambien- tales, la dependencia de su composición con su comportamiento y destino, entre otras. Asimismo, se determinó que todo aporte a la mitigación del problema de estos materiales debe incluir la concientización, la prevención y la reducción, mediante un enfoque integral de educación y capacitación, y considerando todos los actores de la sociedad, responsables de la problemática generada, bajo un enfoque de evidencia científica. Finalmente, se determinó que el tema aún está en su fase inicial, y la información es reiterativa y auto referenciadaThis work addresses the micro and nanoplastics (MP and NP, respectively) on the American coasts of the Pacific Ocean from the perspective of the Micro & Nano Allpa Pacha Network. This network is made up of scientists from Chile, Perú, Costa Rica, Colombia, Ecuador, Panama, and Mexico, who, concerned about the impact on the environment and its repercussions on health, decided to establish international scientific collaborations for the geolocation, monitoring, and characterization of MP and NP present on the coasts of the Pacific Ocean in the American continent. It is expected to provide data based on harmonized scientific evidence, which will impact the teaching and planning of control and regulation measures for these pollutants in our countries. This work includes some aspects of polymers and plastics, definitions of MP’s and NP’s and their various impacts, the problem of taking samples, adequate characterization, among others. One of the conclusions determined that are many characteristics of NP’s and MP’s without investigating, such as interaction with other chemical products, the impact of morphology on bioavailability, formation of adhesions and their release during their contact with environmental compartments, the dependence of its composition with its behavior and destiny, among others. Likewise, it was determined that any contribution to mitigating the problem of these materials must include awareness, prevention, and reduction through a comprehensive approach to education and training and considering all actors in society responsible for the problem generated under a scientific evidence approach. Finally, it was determined that the issue is still in its initial phase, and the information is repetitive and self-reference

Table1.docx

<p>Recently, we reported the production of Cadmium sulfide (CdS) fluorescent semiconductor nanoparticles (quantum dots, QDs) by acidophilic bacteria of the Acidithiobacillus genus. Here, we report that the addition of inorganic phosphate to Acidithiobacillus thiooxidans ATCC 19703 cultures favors the biosynthesis of CdS QDs at acidic conditions (pH 3.5). The effect of pH, phosphate and cadmium concentrations on QDs biosynthesis was studied by using Response Surface Methodology (RSM), a multivariate technique for analytical optimization scarcely used in microbiological studies to date. To address how phosphate affects intracellular biosynthesis of CdS QDs, the effect of inorganic phosphate on bacterial cadmium-uptake was evaluated. By measuring intracellular levels of cadmium we determined that phosphate influences the capacity of cells to incorporate this metal. A relation between cadmium tolerance and phosphate concentrations was also determined, suggesting that phosphate participates in the adaptation of bacteria to toxic levels of this metal. In addition, QDs-biosynthesis was also favored by the degradation of intracellular polyphosphates. Altogether, our results indicate that phosphate contributes to A. thiooxidans CdS QDs biosynthesis by influencing cadmium uptake and cadmium tolerance. These QDs may also be acting as a nucleation point for QDs formation at acidic pH. This is the first study reporting the effect of phosphates on QDs biosynthesis and describes a new cadmium-response pathway present in A. thiooxidans and most probably in other bacterial species.</p