Combining vegetable oils and bioactive compounds via inverse vulcanization for antioxidant and antimicrobial materials

8 Páginas.-- 6 FigurasThe current great concern about plastic pollution opens up opportunities for the production of more sustainable polymers. Inverse vulcanization has emerged as a novel procedure to obtain inorganic-organic hybrid polymeric materials. Sulfur is attained as a by-product of oil refining production and makes inverse vulcanization a sustainable process due to a large amount of sulfur without a useful life. In previous studies, vegetable oils were used as a comonomer with sulfur to form copolymers based on sustainable raw material. Nevertheless, compounds from agro-wastes, could be a third comonomer that improves new copolymers bio-applications. In this study, a new series of copolymers with castor oil as vegetable oil and sulfur was formulated by adding a third compound bearing double bonds or heteroatoms. A study was conducted to assess the antimicrobial capacity and antioxidant activity of the copolymers obtained to demonstrate the benefits of adding a new comonomer to improve their bioactivity.The authors are grateful to the Regional Government of Andalusia, Junta de Andalucía, Consejería de Economía y Conocimiento and University of Huelva (Project UHU-1257728).Peer reviewe

Actas de las V Jornadas ScienCity 2022. Fomento de la Cultura Científica, Tecnológica y de Innovación en Ciudades Inteligentes

ScienCity es una actividad que viene siendo continuada desde 2018 con el objetivo de dar a conocer los conocimientos y tecnologías emergentes siendo investigados en las universidades, informar de experiencias, servicios e iniciativas puestas ya en marcha por instituciones y empresas, llegar hasta decisores políticos que podrían crear sinergias, incentivar la creación de ideas y posibilidades de desarrollo conjuntas, implicar y provocar la participación ciudadana, así como gestar una red internacional multidisciplinar de investigadores que garantice la continuación de futuras ediciones. En 2022 se recibieron un total de 48 trabajos repartidos en 25 ponencias y 24 pósteres pertenecientes a 98 autores de 14 instituciones distintas de España, Portugal, Polonia y Países Bajos.Fundación Española para la Ciencia y la Tecnología-Ministerio de Ciencia, Innovación y Universidades; Consejería de la Presidencia, Administración Pública e Interior de la Junta de Andalucía; Estrategia de Política de Investigación y Transferencia de la Universidad de Huelva; Cátedra de Innovación Social de Aguas de Huelva; Cátedra de la Provincia; Grupo de investigación TEP-192 de Control y Robótica; Centro de Investigación en Tecnología, Energía y Sostenibilidad (CITES

El agua dulce en la agenda de seguridad internacional de comienzos del siglo XXI

This article analyses, both theoretically and empirically, the impact of fresh water on the international security agenda at the beginning of the 21st century. First, we discuss to what extent -and how- fresh water becomes a spark for conflicts within countries. Second, we review the characteristics of a number of conflicts over water control occurred during the past century. Third, we examine the last wave of water-related conflicts, from 2001 to 2007, pointing the most recent trends and highlighting the territories with more tensions and disputes. Finally, a series of conclusions are given.El presente artículo ofrece una aproximación teórica y empírica al papel que está desempeñando y puede desempeñar en el futuro el agua dulce en la agenda de seguridad internacional de comienzos del siglo XXI. En primer lugar se aborda el potencial conflictual de este recurso natural y se establece la gama de roles que puede desempeñar en los conflictos. En segundo lugar se describen y analizan brevemente aquellos conflictos interestatales registrados en el último siglo que tuvieron como causa única o compartida el control per se del agua dulce. En tercer lugar se analizan los conflictos interestatales en torno a este recurso natural ya en el siglo XXI, concretamente en el período 2001-2007, y se ofrece una visión general de la posible evolución de los principales conflictos existentes, así como del potencial surgimiento, por regiones, de conflictos interestatales en torno al agua dulce. Por ultimo se aportan algunas consideraciones finales

Bio and waste-based binders with hybrid rubberized-thermoplastic characteristics for roofing

Non-bituminous binders with sustainable characteristics have been developed as potential roofing materials. A vegetable colophony rosin ester, waste cooking oil, waste crumb rubber and a blend of recycled high-density polyethylene (HDPE) and polypropylene (PP) have been used for binder formulations. Rheological, calorimetric and technological characterizations have been performed to assess the compatibility among binder components and optimal compositions. Additionally, thermal conductivity, heat capacity and solar radiation tests have been performed on selected non-bituminous and bitumen-based binders. Solar radiation experimental set-up has been simulated by Computational Fluid Dynamics (CFD) in order to get a deeper insight into heat transmission mechanisms involved. A binder formulation composed of 40 wt% maleic-modified rosin ester, 32 wt% waste oil, 20 wt% crumb rubber and 8 wt% recycled HDPE/PP blend has shown suitable mechanical properties and solar behaviour for roofing materials. The use of recycled thermoplastics and elastomers imparts material with a hybrid character, showing enhanced flexibility and softening points, respectively, at low and high in-service temperatures. Its solar behaviour is comparable to that of the modified bitumen, with a similar heat absorption from Sun (about 30 %) but lower heat storage capacity at ambient temperature

Promising Chalcogenide Hybrid Copolymers for Sustainable Applications as Bio-lubricants and Metal Adsorbents

9 Páginas.-- 4 Tablas.--5 FigurasInverse vulcanization has emerged as a reaction to achieve hybrid inorganic-organic polymeric materials, which allows us to use the high amount of sulfur produced during refining crude oil as a raw material. In this study, a gamut of copolymers has been formulated using a quantitative atom economy, that is, elemental sulfur and castor oil (CO), as can be seen from the appearance of gels to crystalline copolymers. The physical and chemical characterization has been carried out using techniques such as Fourier transform infrared spectroscopy, NMR, differential scanning calorimetry, and thermogravimetric analysis. Furthermore, two types of copolymers have been selected to test their capabilities in different applications. Copolymers with S ratios higher than 30% have been tested for water remediation, with high removal rates for metals such as lead and cadmium. Although copolymers with a percentage of up to 10% sulfur have been tested as bio-based lubricants, showing improvements in terms of viscosities compared to the initial vegetable oil.The authors thank financial support from Junta de Andalucía, Consejería de Economía y Conocimiento, and University of Huelva (P.O. Feder UHU-1257728).Peer reviewe

Competitive and synergistic effects of metal adsorption in water remediation processes mediated by hybrid copolymers

11 Páginas.-- 6 Figuras.-- 1 TablaCopolymers based on vegetable oils and sulfur have recently been developed using the inverse vulcanization technique for water remediation. This study aimed to create a copolymer with heteroatoms, such as nitrogen, to improve adsorption efficiency and examine the competition and synergy between heavy metals in the adsorption process. FTIR, 1H NMR, solid 13C NMR, zeta potential, nitrogen adsorption, Elemental analysis, TEM, and SEM were used to characterize the copolymers synthesized. Once metal adsorption was optimized using the synthesized copolymers, a comparative adsorption study was conducted for the removal of individual heavy metals, Cd2+, Pb2+, Zn2+, Mn2+, and Cu2+ (100 mg/L), using two copolymers, S/CO:80/20 and S/CO/TAA:80/14/6. The copolymers exhibited a higher affinity for soft metals, such as Cd2+, Pb2+, and Cu2+, when they are individually and in a mixture. After 1 h, the S/CO:80/20 copolymer removed 47%, 40%, and 13% of these metals. While with the S/CO/TAA:80/14/6 copolymer removal increased to 10%, 24%, and 53%, respectively respect to S/CO:80/20 copolymer. The introduction of heteroatoms in the copolymers improved their removal efficiency, particularly for heavy metals like Pb2+. Overall, this study demonstrates a promising approach for sustainable water remediation using copolymers.The authors are grateful to the Regional Government of Andalusia, Junta de Andalucía, Consejería de Economía y Conocimiento (Project UHU-1257728).Peer reviewe

End-performance evaluation of thiourea-modified bituminous binders through viscous flow and linear viscoelasticy testing

Straight-run bitumens are no longer suitable in new asphalt mixtures. Consequently, the use of modified bitumens has become more important. In order to both improve binders mechanical properties and prevent it from phase separation whilst stored at high temperature, the paving industry is currently developing new modification routes based on reactive agents. This work studies the use of thiourea, which has proven to efficiently broaden the temperature interval over which the binder demonstrates an adequate performance. On the one hand, viscous flow and dynamic shear tests indicate an enhancement in the high in-service temperature strength, along with a reduced thermal susceptibility. On the other hand, results of dynamic flexural tests reveal a significant decrease in the binder glass transition temperature. Finally, the use of master curves and a further frequency/temperature conversion are proposed, in order to attain a suitable viscoelastic characterisation of bituminous binders at low temperatures.This work is part of a research project sponsored by Junta de Andalucia-CEIC (TEP6689) and also by "Ministerio de Educacion" through its Research Mobility Programme (Partal's grant Ref. PR2010-0593) and through the Cuadri's F.P.U. research grant (AP2008-01419). Authors gratefully acknowledge their finncial support.This work is part of a research project sponsored by Junta de Andalucia-CEIC (TEP6689) and also by “Ministerio de Educacion” through its Research Mobility Programme (Partal’s grant Ref. PR2010-0593) and through the Cuadri’s F.P.U. research grant (AP2008-01419). Authors gratefully acknowledge their financial support