Persona: Ruiz-Bermejo, Marta
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Centro de Astrobiologia
El Centro de Astrobiología (CAB) es un centro mixto de investigación en astrobiología, dependiente tanto del Instituto Nacional de Técnica Aeroespacial (INTA) como del Consejo Superior de Investigaciones Científicas (CSIC).
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Publicación Acceso Abierto An XPS study of HCN-derived films on pyrite surfaces: a prebiotic chemistry standpoint towards the development of protective coatings(Royal Society of Chemistry, 2021-06-06) Pérez Fernández, Cristina; Ruiz-Bermejo, Marta; Gálvez Martínez, Santos; Mateo Marti, Eva; Agencia Estatal de Investigación (AEI); 0000-0002-8059-1335; 0000-0003-4709-4676; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737Traditionally, the effect of mineral surfaces on increasing molecular complexity has been considered a major issue in studies about the origin of life. In contrast, herein, the effects of organic films derived from cyanide over an important prebiotic mineral, pyrite, are considered. An XPS spectroscopy study was carried out to understand the surface chemistry of the HCN-derived polymer/pyrite system. As a result, the simulation of a plausible prebiotic alkaline hydrothermal environment led to the identification of an NH4CN-based film with protective corrosion properties that immediately prevented the oxidation of the highly reactive pyrite surface. In addition, the effect of coating with antioxidant properties was preserved over a relatively long time, and the polymeric film was very stable under ambient conditions. These results increase the great potential of HCN polymers for development as a cheap and easily produced new class of multifunctional polymeric materials that also show promising and attractive insights into prebiotic chemistry.Publicación Restringido Modelling the kinetics and structural property evolution of a versatile reaction: aqueous HCN polymerization(Royal Society of Chemistry (RSC), 2018-05-29) Fernández, Amparo; Ruiz-Bermejo, Marta; de la fuente, Jose Luis; Ministerio de Economía y Competitividad (MINECO); Instituto Nacional de Técnica Aeroespacial (INTA)The kinetics of the reaction of the synthesis of HCN polymers in aqueous medium at high temperatures have been analysed to ascertain a suitable model for this material, for which it was recently demonstrated that prebiotic chemistry may now be adapted in the development of a new generation of high performance coatings and adhesives with biomedical applications. These experimental conditions were chosen for the simplicity of the reagents, being particularly convenient in regard to potential industrial scale-up of coating technology, where these polymers have revealed an interesting field of application. The kinetics of the precipitation polymerization of HCN in water were studied under isothermal conditions at four different temperatures between 75 °C and 90 °C throughout gravimetric measurements. The use of the Kamal–Sourour autocatalytic kinetic model was proposed, properly describing the overall formation process of this insoluble HCN polymer. All of the kinetic parameters, including reaction orders, kinetic constants and activation energy, were determined for the cross-linking polymerization reaction under study, and a relevant autocatalysis effect was observed. An isoconversion method was also used to analyse the variation of the global activation energy with conversion; and characterization by means of elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) was carried out. This study demonstrates the autocatalytic, robust and straightforward character of this heterogeneous aqueous HCN polymerization, and to the best of our knowledge, this report describes the first time that a systematic and extended kinetic analysis has been conducted to obtain a more comprehensive and deeper understanding of this complex reaction, which is of great interest to the origin of life and, currently, to materials science.Publicación Acceso Abierto Tuning the Morphology in the Nanoscale of NH4CN Polymers Synthesized by Microwave Radiation: A Comparative Study(Multidisciplinary Digital Publishing Institute (MDPI), 2021-12-24) Pérez Fernández, Cristina; Valles González, M. P.; González Toril, Elena; Mateo Marti, Eva; de la fuente, Jose Luis; Ruiz-Bermejo, Marta; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Ciencia e Innovación (MICINN); Agencia Estatal de Investigación (AEI); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737A systematic study is presented to explore the NH4CN polymerization induced by microwave (MW) radiation, keeping in mind the recent growing interest in these polymers in material science. Thus, a first approach through two series, varying the reaction times and the temperatures between 130 and 205 °C, was conducted. As a relevant outcome, using particular reaction conditions, polymer conversions similar to those obtained by means of conventional thermal methods were achieved, with the advantage of a very significant reduction of the reaction times. The structural properties of the end products were evaluated using compositional data, spectroscopic measurements, simultaneous thermal analysis (STA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). As a result, based on the principal component analysis (PCA) from the main experimental results collected, practically only the crystallographic features and the morphologies in the nanoscale were affected by the MW-driven polymerization conditions with respect to those obtained by classical syntheses. Therefore, MW radiation allows us to tune the morphology, size and shape of the particles from the bidimensional C=N networks which are characteristic of the NH4CN polymers by an easy, fast, low-cost and green-solvent production. These new insights make these macromolecular systems attractive for exploration in current soft-matter science.Publicación Acceso Abierto Kinetic Study of the Effective Thermal Polymerization of a Prebiotic Monomer: Aminomalononitrile(Multidisciplinary Digital Publishing Institute, 2023-01-17) Hortelano, C.; Ruiz-Bermejo, Marta; de la fuente, Jose Luis; Agencia Estatal de Investigación (AEI); Ministerio de Ciencia e Innovación (MICINN)Publicación Restringido Air effect on both polymerization kinetics and thermal degradation properties of novel HCN polymers based on diaminomaleonitrile(Elsevier, 2022-12) Hortelano, C.; Ruiz-Bermejo, Marta; de la fuente, Jose Luis; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Ciencia, Innovación y Universidades (MICIN); Agencia Estatal de Investigación (AEI); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737The impact of air on the bulk polymerization kinetics of diaminomaleonitrile (DAMN), tetramer of HCN, and thermal degradation properties of this resulting conjugated C=N polymeric system is investigated under different temperature regimes and environments. This study shows the effect of exposure to air and oxygen, time, temperature, and evolved gases during DAMN polymerization reactions, which can be suitably monitored by differential scanning calorimetry (DSC) through both dynamic and isothermal measurements. Thus, low heating rates and isothermal scans at 150-170 °C allow us to describe the solid-state polymerization (SSP) of DAMN, and those experiments at 190, 195 and 200 °C and higher heating runs define its melt polymerization (MP) behaviour. Both processes are highly efficient, possibly due to the self-acceleration nature of their kinetics, which is consistent with a three-step Šesták-Berggren (SB) model. The oxygen effect was analysed to determine their tolerance to this variable and confirm the nonradical nature of the mechanism under study. In addition, a detailed thermal characterization by simultaneous DSC/thermogravimetry coupled to mass spectrometry (TG-MS) of these singular polymeric systems obtained under air atmosphere has been completed, and the improvement of the thermal stability of those samples prepared by an SSP at lower temperature was confirmed. The present work offers lower-cost and simpler synthetic methods to obtain this novel class of promising multifunctional polymeric materials through highly efficient and very fast processes.Publicación Restringido HCN-derived polymers from thermally induced polymerization of diaminomaleonitrile: A non-enzymatic peroxide sensor based on prebiotic chemistry(Elsevier, 2021-11-24) Ruiz-Bermejo, Marta; García Armada, Pilar; Mateo Marti, Eva; de la fuente, Jose Luis; Ministerio de Ciencia e Innovación (MICINN); Instituto Nacional de Técnica Aeroespacial (INTA); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737HCN-derived polymers have recently attracted considerable attention due to their promising applications as multifunctional materials. This study, inspired by plausible early Earth geochemical conditions, describes a strategy to synthesize them from the self-initiated thermal bulk polymerization of the HCN tetramer, diaminomaleonitrile (DAMN), with outstanding sensing properties. These conjugated polymers were obtained through noncatalysed and simple isothermal reactions at 170 °C in the solid-state, and experiments at 190 °C permitted polymerization in the melt. Both processes are highly efficient, allowing quantitative yields of the end products. The conductivity properties of both polymers have been explored to show their high potential, especially DAMN polymers synthesized in melt, as nonenzymatic peroxide sensors. To better understand the differences found between the two series, structural characterisation was carried out using compositional data, Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) and X-ray photoelectron (XPS) spectroscopies, and X-ray diffraction (XRD) measurements. The interpretation of the structural data suggests that a two-dimensional (2-D) macrostructure based on N-heterocyclics is predominant regardless of the state of monomer aggregation during the course of polymerization, but preferably formed in the melt. The morphological and thermal stability properties of the polymers based on DAMN were also evaluated. Finally, the most likely mechanisms based on the dehydrocyanation and deamination reactions that take place during the polymerization reaction are proposed. This study demonstrates the robust and straightforward character of these thermally activated polymerizations, which are of interest to chemical evolution research and to current materials and surface science.Publicación Restringido Solid-state polymerization of diaminomaleonitrile: Toward a new generation of conjugated functional materials(Elsevier BV, 2021-05-03) Hortelano, C.; Ruiz-Bermejo, Marta; de la fuente, Jose Luis; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737The solid-state polymerization (SSP) of organic molecules to form two-dimensional (2D) materials remains a challenge, especially when these reactions are performed in one pot using a single reagent. As will be shown, the SSP of the HCN tetramer diaminomaleonitrile (DAMN) may be an excellent example of these reactions. Dynamic experiments by differential scanning calorimetry (DSC) allow the analysis of the thermally initiated bulk polymerization of DAMN. Under nonisothermal measurements at low heating rates, a multiple-step polymerization reaction takes place. The SSP of DAMN is highly efficient, possibly due to the autocatalytic nature of its kinetics, which are consistent with the two-parameter Šesták-Berggren (SB) model and describe the three stages found in its complicated mechanism, confirmed also from an analysis of the variation in the apparent activation energy with the conversion degree. Relevant mechanistic aspects, such as the dehydrocyanation and deamination processes during SSP, are extracted by thermogravimetry-mass spectrometry (TG-MS). Moreover, some structural and morphological properties of these materials are characterized by Fourier-transform infrared (FTIR) spectroscopy and microscopy. All this information allows us to propose hypothetical pathways for the production of a complex conjugated system, predominantly constituted by a 2D macrostructure based on imidazole rings. This work opens up new possibilities for the synthesis of functional poly(heterocycle) systems, expanding our view of a plausible prebiotic chemical reaction space and providing the foundation for systematic studies of the structure-property relationships of novel HCN-derived polymers, which are currently of great interest in the fields of materials and surface science.Publicación Restringido Temperature effect on aqueous NH4CN polymerization: Relationship between kinetic behaviour and structural properties(Elsevier BV, 2020-06-05) Mas, I.; de la fuente, Jose Luis; Ruiz-Bermejo, Marta; Agencia Estatal de Investigación (AEI); De la Fuente, J. L. [https://orcid.org/0000-0002-1855-0153]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737Herein, a kinetic analysis for aqueous NH4CN polymerizations is presented, which is consistent with an autocatalytic model when polymerizations are performed at relatively high temperatures, 80–90 °C. Further experiments at lower polymerization temperatures, approximately 50 °C, have demonstrated that this relevant prebiotic reaction follows nth-order kinetics rather than an autocatalytic mechanism. In addition, the sol fractions of these precipitation polymerizations have been evaluated by UV–Vis measurements, which also show a mechanistic shift with the reaction temperature. This change in the kinetic behaviour led to the proposal of a simple empirical methodology to describe both chemical- and diffusion-controlled regions. Despite the simplicity of the approach based on the Hill equation, fundamental kinetic parameters, such as the activation energy, can be determined in the diffusion-free zone. These results motivated a systematic structural characterization study of the respective insoluble polymers by means of elemental analysis, FT-IR and NMR spectroscopies and XRD. All these kinetic and structural analyses confirmed that the temperature has a significant effect on the polymerization kinetic of the system, on the macrostructural features and properties of the HCN-based polymers, and presumably also on the polymerization pathways. These data increase our knowledge about the chemistry of this particular family of HCN polymers, which is currently of interest both in the field of materials science and in prebiotic chemistry and astrobiology.Publicación Acceso Abierto Environmental parameters, and not phylogeny, determine the composition of extracellular polymeric substances in microbial mats from extreme environments(Elsevier, 2019-02-10) Blanco, Yolanda; Rivas, Luis Alfonso; González Toril, Elena; Ruiz-Bermejo, Marta; Moreno Paz, Mercedes; Parro, Víctor; Palacín, Arantxa; Aguilera, Á.; Puente Sánchez, Fernando; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI)The ability to establish biofilms is a key trait for microorganisms growing in extreme environments. The extracellular polymeric substances (EPS) present in biofilms provide not only surface attachment, but also protection against all kinds of environmental stressors, including desiccation, salinity, temperature or heavy metal pollution. The acquisition of suitable biofilm characteristics might thus be an important process mediating the adaptation of microorganisms to novel environmental conditions. In this work we have characterized the EPS of 20 phylogenetically diverse biofilms collected in situ from five contrasting extreme environments, including two geothermal areas (Copahue, Argentina; Seltun, Iceland), two cold areas (Pastoruri glacier, Peru; Byers Peninsula, Antarctica) and one extremely acidic river (Río Tinto, Spain). Biofilms were subjected to biochemical characterization, glycan profiling and immunoprofiling with an antibody microarray. Our results showed that environmental conditions strongly influence biofilm characteristics, with microorganisms from the same environment achieving similar EPS compositions regardless of the phylogeny of their main species. The concentration of some monosaccharides in the EPS could be related to environmental conditions such as temperature or heavy metal toxicity, suggesting that in some cases stress resistance can be mediated by specific sugars. Overall, our results highlight the existence of conserved EPS compositional patterns for each extreme environment, which could in turn be exploited to engineer ecological adaptations in genetically modified microorganisms.Publicación Acceso Abierto Multivariate Analysis Applied to Microwave-Driven Cyanide Polymerization: A Statistical View of a Complex System(Multidisciplinary Digital Publishing Institute (MDPI), 2023-01-12) Pérez Fernández, Cristina; González Toril, Elena; Mateo Marti, Eva; Ruiz-Bermejo, Marta; Ministerio de Ciencia e Innovación (MICINN)For the first time, chemometrics was applied to the recently reported microwave-driven cyanide polymerization. Fast, easy, robust, low-cost, and green-solvent processes are characteristic of these types of reactions. These economic and environmental benefits, originally inspired by the constraints imposed by plausible prebiotic synthetic conditions, have taken advantage of the development of a new generation of HCN-derived multifunctional materials. HCN-derived polymers present tunable properties by temperature and reaction time. However, the apparently random behavior observed in the evolution of cyanide polymerizations, assisted by microwave radiation over time at different temperatures, leads us to study this highly complex system using multivariate analytical tools to have a proper view of the system. Two components are sufficient to explain between 84 and 98% of the total variance in the data in all principal component analyses. In addition, two components explain more than 91% of the total variance in the data in the case of principal component analysis for categorical data. These consistent statistical results indicate that microwave-driven polymerization is a more robust process than conventional thermal syntheses but also that plausible prebiotic chemistry in alkaline subaerial environments could be more complex than in the aerial part of these systems, presenting a clear example of the “messy chemistry” approach of interest in the research about the origins of life. In addition, the methodology discussed herein could be useful for the data analysis of extraterrestrial samples and for the design of soft materials, in a feedback view between prebiotic chemistry and materials science.
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