Publications by authors named "Ricard Garcia-Valls"

Nowadays, CO electroreduction is gaining special interest as achieving net zero CO emissions is not going to be enough to avoid or mitigate the negative effects of climate change. However, the cost of CO electroreduction is still very high because of the low efficiency of conversion (around 20%). Therefore, it is necessary to optimize the reaction conditions.

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The present work demonstrates the potential for improved CO capture capabilities of ionic liquids (ILs) by supporting them on a polysulfone polymeric matrix. CO is one of the main gases responsible for the greenhouse effect and is a focus of The European Commission, which committed to diminishing its emission to 55% by 2023. Various ILs based on combinations of 1-butyl-3-methyl- imidazolium cations and different anions (BMI·X) were synthesized and supported on a polysulfone porous membrane.

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Membrane electrode assemblies (MEAs) with palladium catalysts were successfully prepared by using a home-made manual pressing system with Nafion glue application that contributed to a decrease of additional energy consumption. The catalyst coated membranes were prepared with supported palladium on activated carbon (PdC) and unsupported palladium black (PdB) for comparison. The performance of passive, air breathing, functioning under ambient conditions and with low concentration (1 M) formate/formic acid fuel cell was evaluated.

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A molecular design approach was used to create asymmetrical visible light-triggered azo-derivatives that can be good candidates for polymer functionalization. The specific electron-donor substituted molecules were characterized and studied by means of NMR analyses and UV-visible spectroscopy, comparing the results with Time Dependent Density Functional (TD-DFT) calculations. A slow rate of isomerization (k = 1.

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The growing interest of oncologists in natural compounds such as polyphenols and flavonoids is encouraging the development of innovative and efficient carriers for the delivery of those drugs. This study examines carboxymethyl chitosan-based microcapsules created by spray drying as a method for delivering biologically active compounds isolated from the Cistus herb. Effects of sterilization and encapsulation on the polyphenol and flavonoid content of Cistus extract were investigated to optimize the production process.

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The current rapid advancement of numerous nanotechnology tools is being employed in treatment of many terminal diseases such as cancer. Nanocapsules (NCs) containing an anti-cancer drug offer a very promising alternative to conventional treatments, mostly due to their targeted delivery and precise action, and thereby they can be used in distinct applications: as biosensors or in medical imaging, allowing for cancer detection as well as agents/carriers in targeted drug delivery. The possibility of using different systems-inorganic nanoparticles, dendrimers, proteins, polymeric micelles, liposomes, carbon nanotubes (CNTs), quantum dots (QDs), biopolymeric nanoparticles and their combinations-offers multiple benefits to early cancer detection as well as controlled drug delivery to specific locations.

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We investigated the possibility of improving the performance of polysulfone (PSf) membranes to be used in carbon dioxide capture devices by blending PSf with a commercial polyethylene imine, Lupasol G20, previously modified with benzoyl chloride (mG20). Additive amount ranged between 2 and 20 wt %. Membranes based on these blends were prepared by phase inversion precipitation and exhibited different morphologies with respect to neat PSf.

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The aim of these studies is to evaluate the ambient CO capture abilities of the membrane contactor system in the same conditions as leafs, such as ambient temperature, pressure and low CO concentration, where the only driving force is the concentration gradient. The polysulfone membrane employed was made by a phase inversion process and characterized by ESEM micrographs which were used to determine the thickness, asymmetry and pore size. Besides, the porosity of the membrane was measured from the membrane and polysulfone density correlation and the hydrophobicity was analyzed by contact angle measurements.

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Background: This review aims to present the relevant background information and current research status in concentration of polyphenols using membrane technologies. The potential implementation of membrane separation to bioactive compounds like soluble phenolics from aqueous and organic solvent solutions is gaining increasing interest in the recent years. This review does not pretend to cover the abundant published literature on the subject, but to be representative for the observed tendencies in membrane processes applications for concentration of polyphenols derived from natural products.

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New very stable composites prepared by deposition of resorcinol-formaldehyde polymer (RF-) or carbon (C-) xerogels into walls of commercial porous tubular ceramics (TiO2-ZrO2 and alphaAl2O3-gammaAl203) were obtained by a sol-gel process followed by a drying and a pyrolytic (only for C-xerogel/ceramic composites) step. They were characterized by nitrogen adsorption-desorption, SEM and XRD, and tested for gas (H2, CH4, CO2 and CO) separation applications. Additional morpho-structural information about the open-interconnected ultramicropore structure of composites was found by gas permeation investigation.

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Textile detergent and softener industries have incorporated perfume microencapsulation technology to improve their products. Perfume encapsulation allows perfume protection until use and provides a long-lasting fragrance release. But, certain industrial microcapsules show low encapsulation capacity and low material stability.

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Novel composite asymmetrical membranes based on poly(vinyl alcohol)-co-ethylene (EVAL) as the host material and new polyethers that contain azobenzene moieties in the side chain were prepared by dry-cast phase inversion after dissolving the azo polymers in tetrahydrofuran and EVAL in dimethylsulfoxide and subsequently mixing the resulting solutions. By taking advantage of the proper temperature variation in the oven used for solvent evaporation, asymmetrical membranes that exhibited a dense, crystalline layer on the bottom and a porous, mainly amorphous layer on the top were obtained. Remarkable changes in the surface morphology and the contact angle with water were observed on the top surfaces of the composite membranes.

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