247 research outputs found

    From old to new inorganic materials for advanced applications: The paradigmatic example of the sepiolite clay mineral

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    This review article focuses on sepiolite fibrous clay mineral, which has been selected here as an example of an ancient inorganic natural material that is currently receiving much attention as excellent candidate for advanced materials and applications. Sepiolite clay is an abundant hydrated magnesium silicate whose crystal structure determines the presence of nanoporous cavities as well as large surface and rheological properties of great interest for the further design of functional materials. The present work introduces and discusses the relationship between aspects of this clay, in terms of its structural and morphological organization, and its physicochemical characteristics from which emerging applications arise. One of the sections is devoted to describe current industrial applications of commercially available sepiolite-based materials. As sepiolite can be considered a nanomaterial by itself, approaches including its controlled chemical and physical modifications intended to develop new advanced inorganic and hybrid nanostructured materials provided with pre-designed functionalities. Among them, polymer nanocomposites that include bionanocomposites and carbon-sepiolite nanomaterials, materials for adsorption of pollutants, functionalization with magnetic nanoparticles, active phase of sensors and DNA support for gene transfer are some of the examples that we refer to in the present review articleThis research was partially funded by AEI (Spain), FEDER (EU), the European Union’s Horizon research and innovation program under the Marie Skłodowska-Curie Action, which grant numbers are MAT2015- 71117-R, PID2019-105479RB-I00 and GA 101064359, respectivel

    Espumas rígidas de tipo composite basadas en biopolímeros combinados con arcillas fibrosas y su método de preparación

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    Espumas rígidas de tipo composite basadas en biopolímeros combinados con arcillas fibrosas y su método de preparación. La presente invención se refiere a espumas rígidas de tipo composite que comprenden una matriz biopolimérica y partículas de silicatos pertenecientes a la familia de las arcillas fibrosas (sepiolita y palygorskita). La invención también se refiere al procedimiento de preparación de estos materiales, en el que la etapa de secado mediante liofilización o secado supercrítico es fundamental para obtener materiales de alta porosidad, así como a su uso en aplicaciones diversas tales como aislamiento acústico y térmico, material de embalaje, soporte de sólidos con propiedades eléctricas, magnéticas y ópticas, así como de fármacos y especies biológicas.Peer reviewedConsejo Superior de Investigaciones Científicas (España

    Nanoarchitectures Based on Layered Titanosilicates Supported on Glass Fibers: Application to Hydrogen Storage

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    This work reports on the synthesis of nanosheets of layered titanosilicate JDF-L1 supported on commercial E-type glass fibers with the aim of developing novel nanoarchitectures useful as robust and easy to handle hydrogen adsorbents. The preparation of those materials is carried out by hydrothermal reaction from the corresponding gel precursor in the presence of the glass support. Because of the basic character of the synthesis media, silica from the silicate-based glass fibers can be involved in the reaction, cementing its associated titanosilicate and giving rise to strong linkages on the support with the result of very stable heterostructures. The nanoarchitectures built up by this approach promote the growth and disposition of the titanosilicate nanosheets as a house-of-cards radially distributed around the fiber axis. Such an open arrangement represents suitable geometry for potential uses in adsorption and catalytic applications where the active surface has to be available. The content of the titanosilicate crystalline phase in the system represents about 12 wt %, and this percentage of the adsorbent fraction can achieve, at 298 K and 20 MPa, 0.14 wt % hydrogen adsorption with respect to the total mass of the system. Following postsynthesis treatments, small amounts of Pd (<0.1 wt %) have been incorporated into the resulting nanoarchitectures in order to improve their hydrogen adsorption capacity. In this way, Pd-layered titanosilicate supported on glass fibers has been tested as a hydrogen adsorbent at diverse pressures and temperatures, giving rise to values around 0.46 wt % at 298 K and 20 MPa. A mechanism of hydrogen spillover involving the titanosilicate framework and the Pd nanoparticules has been proposed to explain the high increase in the hydrogen uptake capacity after the incorporation of Pd into the nanoarchitecture.We thank the CICYT (Spain, projects MAT2009-09960 and MAT2012-31759), Obra Social la Caixa, Aragon Government (GA-LC-019/2011), ESF, Generalitat Valenciana, and FEDER (PROMETEO/2009/047) for financial support. J.P.-C. is grateful for a Ph.D. grant (FPI, BES-2010-038410) from the Spanish Ministerio de Ciencia e Innovación

    Functional biohybrid materials based on halloysite, sepiolite and cellulose nanofibers for health applications

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    Multicomponent nanopaper from the assembly of nanotubular halloysite, microfibrous sepiolite and cellulose nanofibers was developed for diverse functional applications such as slow release of antibacterial model drugs loaded into halloysite lumen

    Fibrous clays based bionanocomposites

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    Chitosan-smectite biointerfaces vs. Alkylammonium-clay interfaces in adsorption process

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    Two series of chitosan-clay nanocomposites were synthesized using commercial (CLOISITE® Na+ ) and Na+ -enriched Serbian clay from seldom investigated locality Mečji Do. The samples were characterized by X-ray diffraction and intercalation of chitosan into bilayer structures was confirmed for particular chitosan/clay ratio in both series of chitosan-clay naonocomposites. Reactivity of chitosan-smectite biointerfaces vs. alkylammonium-clay interfaces in adsorption process was compared using textile dye Reactive Black 5 (RB5) as adsorbate. Chitosan-clay naonocomposites had similar adsorption uptake, being more than three times higher than adsorption uptake of commercial alkylammonium-clay CLOISITE® 30B.The Langmuir adsorption model was found to be appropriate for all investigated adsorbents

    Magnetic Chitosan Bionanocomposite Films as a Versatile Platform for Biomedical Hyperthermia

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    Responsive magnetic nanomaterials offer significant advantages for innovative therapies, for instance, in cancer treatments that exploit on-demand delivery on alternating magnetic field (AMF) stimulus. In this work, biocompatible magnetic bionanocomposite films are fabricated from chitosan by film casting with incorporation of magnetite nanoparticles (MNPs) produced by facile one pot synthesis. The influence of synthesis conditions and MNP concentration on the films’ heating efficiency and heat dissipation are evaluated through spatio-temporal mapping of the surface temperature changes by video-thermography. The cast films have a thickness below 100 µm, and upon exposure to AMF (663 kHz, 12.8 kA m−1), induce exceptionally strong heating, reaching a maximum temperature increase of 82 °C within 270 s irradiation. Further, it is demonstrated that the films can serve as substrates that supply heat for multiple hyperthermia scenarios, including: i) non-contact automated heating of cell culture medium, ii) heating of gelatine-based hydrogels of different shapes, and iii) killing of cancerous melanoma cells. The films are versatile components for non-contact stimulus with translational potential in multiple biomedical applications. © 2023 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.This work was developed within the scope of the projects CICECO– Aveiro Institute of Materials UIDB/50011/2020, UIDP/50011/2020 &LA/P/0006/2020, CESAM -UIDP/50017/2020, and UIDB/50017/2020 andLA/P/0094/2020 and M-ERA-NET2/0021/2016 – BIOFOODPACK – Bio-composite Packaging for Active Preservation of Food. A.B. is thankfulto FCT for grant SFRH/BD/148856/2019. C.N. is grateful to the Por-tuguese national funds (OE) through FCT IP in the scope of the frame-work contract foreseen in the numbers 4, 5, and 6 of the Article 23of the Decree-Law 57/2016 of August 29 changed by Law 57/2017 ofJuly 19. J.K.W., D.W., and D.F.B. acknowledge support from the ScienceFoundation Ireland (16/IA/4584). E.R.-H. acknowledges financial supportfrom the MCIN/AEI/10.13039/501100011033 (Spain, project PID2019-105479RB-I00). M.M.C. and L.P.F. acknowledge FCT for Centre grantsUIDB/04046/2020 and UIDP/04046/2020 to BioISI. Part of the work in this article is based on the mobility exchange program of COST ActionCA18132, supported by COST (European Cooperation in Science and Tech-nology). FCT is also acknowledged for the research contract under Scien-tific Employment Stimulus to H.O. (CEECIND/04050/2017).Open access funding provided by IReLSupporting InformationPeer reviewe

    Las arcillas en sociedad: reconstruyendo el pasado y modelando el futuro. La Sociedad Española de Arcillas (SEA)

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    Se hace referencia a la historia de la Sociedad Española de Arcillas (SEA), una de las Sociedades científicas más veteranas de España, a la ciencia en torno a la que se proyecta, y a las perspectivas y objetivos que acompañan a la misma. El comienzo de esta sociedad científica se sitúa en 1959 con la fundación del grupo español de Minerales de la Arcilla (GEMA), que dio lugar a la SEA en 1971, la cual va camino de cumplir 64 años

    Graphene derivatives in biopolymer-based composites for food packaging applications

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    This review aims to showcase the current use of graphene derivatives, graphene-based nanomaterials in particular, in biopolymer-based composites for food packaging applications. A brief introduction regarding the valuable attributes of available and emergent bioplastic materials is made so that their contributions to the packaging field can be understood. Furthermore, their drawbacks are also disclosed to highlight the benefits that graphene derivatives can bring to bio-based formulations, from physicochemical to mechanical, barrier, and functional properties as antioxidant activity or electrical conductivity. The reported improvements in biopolymer-based composites carried out by graphene derivatives in the last three years are discussed, pointing to their potential for innovative food packaging applications such as electrically conductive food packaging
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