Correlated electronic systems, or materials in which electrons show cooperative effects rather than acting independently, are of interest not only for elucidating the origin of emergent behavior arising from simple components, but also due to the practical applications of the resulting physical phenomena. In this talk, I will first discuss how our development of new 'soft chemistry' methods for the preparation of meta- or kinetically-stable solids, when combined with modern pair distribution function techniques for determining local structure, is allowing us to finally begin to understand how correlated states, such as superconductivity, arise from local interactions of charge, orbital, and spin degrees of freedom. Specific examples will be drawn from our work on the nature of electronic mass enhancement in KNi2(S/Se)2, the origin of superconductivity in the ternary Bi-O-S system, and recent results on how chemistry can be used to discover new, and more versatile, 'topological materials.

Emergent quantum phenomena from new chemistry and new materials

This work presents the fate of carbamazepine (CBZ) and five of its metabolites in Barcelona's groundwater at a field scale under different redox conditions in connection with (1) the physicho-chemical properties of the target compounds, (2) the occurrence of common contaminants in urban groundwater of Barcelona and (3) the groundwater redox conditions. To this end, groundwater samples were collected in two distinct zones of Barcelona city: (1) Poble Sec and (2) Bes�s River Delta in May 2010. Overall, the highest concentrations and the largest number of detected target compounds were found in Bes�s River Delta, which is basically recharged by a river that receives large amounts of effluents from waste water treatments plants (WWTPs). Conversely, Poble Sec presented not only lower concentrations but also a smaller number of compounds. 27 Groundwater samples were collected during May 2010 and were analyzed by Liquid Chromatrography-tandem Mass Spectrometry (LC/MS-MS).The results of this study show that CBZ was more susceptible to be removed under the oxidizing conditions of Poble Sec aquifers than the reducing conditions of Bes�s River Delta. In the latter, the metabolites 2-hydroxycarbamazepine (2OH CBZ) and 3-hydroxycarbamazepine (3OH CBZ) and acridone (ACRON) were found to be highly persistent whilst 10,11-epoxy carbamazepine (CBZ-EP) did not. In Poble Sec, CBZ metabolites did not contribute to groundwater contamination because they were poorly detected. [Acknowledgements: This work was financially supported by SCARCE Consolide-Ingenio 2010 project (refCSD2009-00065) funded by the Ministry of Economy and Competitiviness of Spain.]

Occurrence and fate of carbamezapine and five metabolites in an urban aquifer under different redox conditions

Chlorinated polyvinyl chloride (CPVC) is a promising candidate for sprinkler piping systems in seismic areas. In spite of numerous advantages, the use of CPVC sprinkler piping in earthquake zones poses various concerns like chemical incompatibilities, environmental degradation and limited field data. In this study, the effect of simulated sunlight and ultraviolet (UVB) light on the chemical structure and physical properties of CPVC was studied. Exposures were conducted in the QSUN xenon test chamber and QUV accelerated weathering tester. CPVC tensile specimens were exposed for 1, 4, 8 and 12 weeks in both the QSUN and QUV chambers. Exposed CPVC samples were then analyzed by tensile testing apparatus, Fourier Transform � Infrared (FT-IR) spectroscopy and Differential Scanning Calorimetry (DSC). The results indicated early degradation of CPVC when exposed in the QSUN chamber. The tensile testing data showed apparent changes in elongation at break (70.40% reduction) after 8 weeks of exposure in the QSUN chamber (1344 hours of noon summer light). Figure below shows FT-IR spectrum of (a) unexposed control, (b) CPVC sample exposed for 4 weeks and (c) CPVC sample exposed for 8 weeks in the Q-Sun chamber. FT-IR analysis conducted on the surface of the exposed side indicated spectral changes (indicated by the blue arrows) in samples exposed in QSUN chamber as early as one week. For example, absorbance peak at 1718 cm-1 is not present in the unexposed control. 

Degradation of CPVC sprinkler piping material by simulated sunlight and UVB light

Perfluorinated alkyl substances (PFASs) comprise a large group of compounds that were manufactured for more than 60 years and were used for many industrial applications including stain repellents (such as Teflon), textile, paints, waxes, polishes, electronics, adhesives, and food packaging. Two of the most important PFCs are perfluorooctane sulphonate (PFOS) and perflorooctane acid (PFOA) and other perfluoro carboxylic acids (PFCAs) are resistant to degradation or/and can produce stable degradation products like fluorotelomers alcohols (PFTOHs), perfluorinated sulfonamides (PFASAs) and perfluorinated sulfonamide ethanols (PFASEs). Therefore, PFASs are ubiquitous environmental contaminants, which persist and may bioaccumulate through the food chain. The most important exposure pathways of perfluorinated compounds for humans are thought to be intake of drinking water, food and inhalation of dust. Because of their bioaccumulation and potential health concerns including toxicity, and their possible contribution to cancer promotion, non-governmental organizations, national and international authorities have addressed the PFASs problem by several pressure and legislative actions.PFASs are now included in different health programs in EEUU, Canada and Europe.  This communication will present the occurrence of 21 PFASS different type of matrices including drinking water and food from Spain, Saudi Arabia, Serbia and Brazil. The analytical techniques used for their analysis along different studies performed by our group will be presented. Finally, results of exposure and human bioaccumulation in Spain will be compared at global scale by comparison with results reported worldwide. Relations between occurrence levels and ambient factors, drinking water pollution and type of diet will be as well discussed.  [Acknowledgements: This work was supported by the Spanish Ministry of Economy and Competitiveness through the projects SCARCE (Consolider-Ingenio 2010 CSD2009-00065) and PRI-AIBSE-2011-1184 and by King Saud University grant number KSU-VPP-105.]

Fate and risk of perfluorinated alkyl substances in environmental and food samples across the world (Spain, Brazil, Saudi Arabia, and Serbia)

Solid state materials have wide-ranging applications from catalysts, sensors, and absorbents to platforms for the discovery of new exotic states of matter. Selective control of reactivity in the solid state is challenging, restricting the scope of accessible materials. Yet we know from organic chemistry and nanoscience that the ability to make non-thermodynamic products is critical in discovering new phenomena and providing useful functionality. In this talk, I will discuss our recent progress in precise control of reactivity in extended solids while maintaining well-defined structures and compositions. A focus is on the application of separate reagents to perform different steps in the chemical reaction pathway. The influence of ligand choice and metal cation binder on the reactivity and kinetics of oxidative deintercalation of KNi2(S/Se)2 and KCo2(S/Se)2 will be presented.

Selective reaction control in the solid state: Advances in oxidative deintercalation

Electrochemical impedance spectroscopy (EIS) is a sophisticated measurement technique for obtaining quantitative data on coated substrates. The U.S. Department of the Interior, Bureau of Reclamation (Reclamation) utilizes this method to evaluate coating systems, most notably for immersion and fluctuating immersion service conditions. Coatings serve a vital role in preventing corrosion and preserving Reclamation's capital infrastructure. Examples of ongoing coatings challenges include progressing environmental regulations which prohibit the use of trusted systems such as coal tar enamel. In addition, the Colorado River quagga mussel infestation necessitates the development of durable non-fouling coatings that prevent mussel adhesion. Structural features at Reclamation facilities are characteristically inaccessible and very expensive to re-coat. Therefore, it is most desirable to re-coat using systems which have very low degradation rates in immersion to obtain the longest achievable service life. EIS is one of the tools utilized by Reclamation to evaluate coatings and is particularly useful for those with no or minimal record of service. Steel coupons (3� x 6� x 0.125�) were prepared and coatings applied according to product manufacturer recommendations. The cured coatings were placed in immersion to simulate service conditions and removed regularly to measure dielectric properties by EIS. The data was used to evaluate two important questions:  (1) how does the coating perform as a barrier to water and ion migration, and (2) how do these barrier properties evolve over time, particularly as coating degradation proceeds? Therefore, the results are used to screen coating systems for both good corrosion resistance (high barrier properties) and weathering durability (properties are maintained for long time periods). Data from this experiment now exceeds 5 years.  The prediction or estimation of coating service lifetime using EIS data is also discussed.

Electrochemical impedance spectroscopy (EIS) for the evaluation of coating systems for immersion

246th National Meeting (2013)

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