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Producción Científica, The structural characterization is an essential task in the study of porous materials. To achieve reliable results, it requires to evaluate images with hundreds of pores. Current methods require large time amounts and are subjected to human errors and subjectivity. A completely automatic tool would not only speed up the process but also enhance its reliability and reproducibility. Therefore, the main objective of this article is the study of a deep-learning-based technique for the structural characterization of porous materials, through the use of a convolutional neural network. Several fine-tuned Mask R–CNN models are evaluated using different training configurations in four separate datasets each composed of numerous SEM images of diverse polymeric porous materials: closed-pore extruded polystyrene (XPS), polyurethane (PU), and poly(methyl methacrylate) (PMMA), and open-pore PU. Results prove the tool capable of providing very accurate results, equivalent to those achieved by time-consuming manual methods, in a matter of seconds., MCIN/AEI/10.13039/501100011033 and the EU NextGenerationEU/PRTR program (PLEC2021-007705), Junta de Castilla y León y el programa EU-FEDER (CLU-2019-04)

Producción Científica, Glucose oxidase (GOX) and catalase (CAT) were co-immobilized in silica–calcium–alginate hydrogels to degrade must glucose. The effect of the enzyme dose (1.2–2.4 U/mL), the initial must pH (3.6–4.0), and the incubation temperature (10–20 °C) on the glucose consumption, gluconic acid concentration, pH, and color intensity of Verdejo must was studied by using a Box–Behnken experimental design and comparing free and co-immobilized enzymes. A reduction of up to 37.3 g/L of glucose was observed in co-immobilized enzyme-treated must, corresponding to a decrease in its potential alcohol strength of 2.0% vol. (v/v), while achieving a slight decrease in its pH (between 0.28 and 0.60). This slight acidification was due to a significant reduction in the estimated gluconic acid found in the must (up to 73.7%), likely due to its accumulation inside the capsules. Regarding the operational stability of immobilized enzymes, a gradual reduction in glucose consumption was observed over eight consecutive cycles. Finally, co-immobilized enzymes showed enhanced efficiency over a reaction period of 48 h, with an 87.1% higher ratio of glucose consumed per enzyme dose in the second 24 h period compared with free enzymes. These findings provide valuable insights into the performance of GOX–CAT co-immobilized to produce reduced-alcohol wines, mitigating excessive must acidification.

Producción Científica, A new set of microporous organic polymers (POPs) containing diphosphine derivatives synthesized by knitting via Friedel–Crafts has been attained. These amorphous three-dimensional materials have been prepared by utilizing diphosphines, 1,3,5-triphenylbenzene, and biphenyl as nucleophile aromatic groups, dimethoxymethane as the electrophilic linker, and FeCl3 as a promoting catalyst. These polymer networks display moderate thermal stability and high microporosity, boasting BET surface areas above 760 m2/g. They are capable of coordinating with palladium acetate, using the phosphine derivative as an anchoring center, and have proven to be highly efficient catalysts in Suzuki–Miyaura coupling reactions involving bromo- and chloroarenes under environmentally friendly (using water and ethanol as solvents) and aerobic conditions. These supported catalysts have achieved excellent turnover numbers (TON) and turnover frequencies (TOF), while maintaining good recyclability without significant loss of activity or Pd leaching after five consecutive reaction cycles., Agencia Estatal de Investigación (AEI), Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea (EU) - (Projects: PID2019-109403RBC22, PID2019-109403RB-C21 y PID2020- 118547GB-I00), Junta de Castilla y León - (grant VA224P20)

Producción Científica, The relationships between gas permeability and free volume fraction, intersegmental distance, and glass transition temperature, are investigated. They are analyzed for He, CO2, O2, CH4, and N2 gases and for five similar polyimides with a wide range of permeabilities, from very low to extremely high ones. It has been established here that there is an exponential relationship between permeability and the free volume fraction, and between permeability and the most probable intersegmental distance as measured by WAXS; in both cases, with an exponential coefficient that depends on the kinetic gas diameter as a quadratic polynomial and with a preexponential positive constant. Moreover, it has been proven that the intersegmental distance increases linearly with the free volume fraction. Finally, it has been established that the free volume fraction increases with the glass transition temperature for the polymers tested, and that they depend on each other in an approximate linear way., Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 y Unión Europea NextGenerationEU/PRTR - (Project TED2021-131170A-I00), Unión Europea NextGenerationEU - (project MIG-202111071), Junta de Castilla y León y Unión Euopea (UE)-Fondo Europeo de Desarrollo Regional (FEDER) - (programs CL-EI-2021-07 and UIC082))

Producción Científica, Mixed matrix membranes (MMMs) provide the opportunity to test new porous materials in challenging applications. A series of low-cost porous organic polymer (POPs) networks, possessing tunable porosity and high CO2 uptake, has been obtained by aromatic electrophilic substitution reactions of biphenyl, 9,10-dihydro-9,10-dimethyl-9,10-ethanoanthracene (DMDHA), triptycene and 1,3,5-triphenylbenzene (135TPB) with dimethoxymethane (DMM). These materials have been characterized by FTIR, 13C NMR, WAXD, TGA, SEM, and CO2 uptake. Finally, different loadings of these POPs have been introduced into Matrimid, Pebax, and chitosan:polyvinyl alcohol blends as polymeric matrices to prepare MMMs. The CO2/CH4 separation performance of these MMMs has been evaluated by single and mixed gas permeation experiments at 4 bar and room temperature. The effect of the porosity of the porous fillers on the membrane separation behavior and the compatibility between them and the different polymer matrices on membrane design and fabrication has been studied by Maxwell model equations as a function of the gas permeability of the pure polymers, porosity, and loading of the fillers in the MMMs. Although the gas transport properties showed an increasing deviation from ideal Maxwell equation prediction with increasing porosity of the POP fillers and increasing hydrophilicity of the polymer matrices, the behavior of biopolymer-based CS:PVA MMMs approached that of Pebax-based MMMs, giving scope to not only new filler materials but also sustainable polymer choices to find a place in membrane technology., Generalitat Valenciana y Universidad de Cantabria - (grant PRO-81), Agencia Estatal de Investigación (AEI), Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea (EU) - (Projects: PID2019-109403RBC22 y PID2019-109403RB-C21)

Producción Científica, In the present work, the effectiveness of four non-halogenated flame retardants (FR) (aluminium trihydroxide (ATH), magnesium hydroxide (MDH), Sepiolite (SEP) and a mix of metallic oxides and hydroxides (PAVAL)) in blends with recycled acrylonitrile-butadiene-styrene (rABS) was studied in order to develop a more environmentally friendly flame-retardant composite alternative. The mechanical and thermo-mechanical properties of the obtained composites as well as their flame-retardant mechanism were evaluated by UL-94 and cone calorimetric tests. As expected, these particles modified the mechanical performance of the rABS, increasing its stiffness at the expense of reducing its toughness and impact behavior. Regarding the fire behavior, the experimentation showed that there is an important synergy between the chemical mechanism provided by MDH (decomposition into oxides and water) and the physical mechanism provided by SEP (oxygen barrier), which means that mixed composites (rABS/MDH/SEP) can be obtained with a flame behavior superior to that of the composites studied with only one type of FR. In order to find a balance between mechanical properties, composites with different amounts of SEP and MDH were evaluated. The results showed that composites with the composition rABS/MDH/SEP: 70/15/15 wt.% increase the time to ignition (TTI) by 75% and the resulting mass after ignition by more than 600%. Furthermore, they decrease the heat release rate (HRR) by 62.9%, the total smoke production (TSP) by 19.04% and the total heat release rate (THHR) by 13.77% compared to unadditivated rABS; without compromising the mechanical behavior of the original material. These results are promising and potentially represent a greener alternative for the manufacture of flame-retardant composites., European Union’s Horizon 2020 - (project Creator 820477), Ministerio de Ciencia, Innovación y Universidades, Centro para el Desarrollo Tecnológico y la Innovación (CDTI) - (grant CER-20211009), Ministerio de Economía y Competitividad - (project PTQ2020-010968), Ministerio de Economía y Competitividad - (project PTQ2021-011628)

Producción Científica, The mixtures 2-propanol or 2-butanol + n-alkanone, or + acetophenone, or + linear monoether, or + cyclic ether, or + linear organic carbonate, or + propylene carbonate have been investigated using thermodynamic data, and in terms of the Flory theory, and the Kirkwood-Buff integrals. The data considered are: excess molar enthalpies (), volumes, entropies, and the temperature dependence of. The enthalpy of the 2-alkanol-solvent interactions have been determined, and the different contributions to discussed. It is shown that values of the 2-alkanol (fixed) + n-alkanone, or + linear carbonate mixtures change in the same manner that for n-alkanone, or linear carbonate + n-alkane (fixed) systems. In contrast, values of 2-alkanol (fixed) + linear monoether or + n-alkane mixtures change similarly. This set of results suggests that solvent–solvent interactions are determinant in systems with n-alkanone or linear carbonate, while interactions between alcohol molecules are determinant in mixtures with linear monoethers. According to the Flory model, orientational effects in systems with a given 2-alkanol become weaker in the sequence: linear monoether > linear organic carbonate > n-alkanone, and are stronger in solutions with a cyclic monoether than in those with cyclic diethers, and in systems with acetophenone or propylene carbonate than in the mixtures with the corresponding linear solvents. Results obtained from the Kirkwood-Buff integrals are consistent with these findings. The application of Flory model reveals that orientational effects are similar in systems with 1- or 2-alkanols, with the exception of solutions with linear monoethers, where such effects are stronger in mixtures containing 1-alkanols. For the examined systems, the formalism of the Kirkwood-Buff integrals makes no meaningful distinction between solutions with 1-alkanols or 2-alkanols.

Producción Científica, In recent years, a number of microbial enzymes capable of degrading plastics have been identified. Biocatalytic depolymerization mediated by enzymes has emerged as a potentially more efficient and environmentally friendly alternative to the currently employed methods for plastic treatment and recycling. However, the functional and systematic study of depolymerase enzymes with respect to the degradation of a series of plastic polymers in a single work has not been widely addressed at present. In this study, the ability of a set of enzymes (esterase, arylesterase and cutinase) to degrade commercial biodegradable polymers (PBS, PBAT, PHB, PHBH, PHBV, PCL, PLA and PLA/PCL) and the effect of pre-treatment methods on their degradation rate was assessed. The degradation products were identified and quantified by HPLC and LC-HRMS analysis. Out of the three enzymes, Fusarium solani cutinase (FsCut) showed the highest activity on grinded PBAT, PBS and PCL after 7 days of incubation. FsCut was engineered and heterologous expressed in Escherichia coli, which conferred the bacterium the capability of degrading solid discs of PBAT and to grow in PBS as the sole carbon source of the medium., Société des Produits Nestlé S.A, Junta de Castilla y León y Fondo Europeo de Desarrollo Regional (FEDER) - (grant CL-EI-2021-07 and UIC 315)

Producción Científica, An optimized synthesis of the monomer 2,2′3,3′-biphenyltetracarboxylic dianhydride, iBPDA, was performed to obtain high molecular weight polymers. This monomer has a contorted structure that produces a non-linear shape, hindering the packing of the polymer chain. Aromatic polyimides of high molecular weight were obtained by reaction with the commercial diamine 2,2-bis(4-aminophenyl) hexafluoropropane, 6FpDA, which is a very common monomer in gas separation applications. This diamine has hexafluoroisopropylidine groups which introduce rigidity in the chains, hindering efficient packing. The thermal treatment of the polymers processed as dense membranes had two targets: on the one hand, to achieve the complete elimination of the solvent used, which could remain occluded in the polymeric matrix, and on the other hand to ensure the complete cycloimidization of the polymer. A thermal treatment exceeding the glass transition temperature was performed to ensure the maximum degree of imidization at 350 °C. The good mechanical properties of these materials allow for their use in high-pressure gas purification applications. Moreover, models of the polymers exhibited an Arrhenius-like behavior characteristic of secondary relaxations, normally associated with local motions of the molecular chain. The gas productivity of these membranes was high., Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación (AEI) - (projects PID2019- 109403RB-C21 and PID2019-109403RB-C22), Junta de Castilla y León y Fondo Europeo de Desarrollo Regional (FEDER) - (grant CLU2017-09, UIC082 and VA088G19)

Producción Científica, In this work, the potential of Methylocystis hirsuta to simultaneously use methane and volatile fatty acids mixtures for triggering PHBV accumulation was assessed for the first time batchwise. Biotic controls carried out with CH4 alone confirmed the inability of Methylocystis hirsuta to produce PHBV and achieved 71.2 ± 7 g m−3d−1 of PHB. Pure valeric acid and two synthetic mixtures simulating VFAs effluents from the anaerobic digestion of food waste at 35 °C (M1) and 55 °C (M2) were supplied to promote 3-HV inclusion. Results showed that pure valeric acid supported the highest polymer yields of 105.8 ± 9 g m−3d−1 (3-HB:3-HV=70:30). M1 mixtures led to a maximum of 103 ± 4 g m−3d−1 of PHBV (3-HB:3-HV=85:15), while M2 mixtures, which did not include valeric acid, showed no PHV synthesis. This suggested that the synthesis of PHBV from VFAs effluents depends on the composition of the mixtures, which can be tuned during the anaerobic digestion process., Junta de Castilla y León - EU-FEDER [CL-EI-2021-07 y UIC 315], Ministerio de Desarrollo Económico, “Fondo per la Crescita Sostenibile- “Agrifood” PON I&C 2014-2020” (F/200125/01-03/X45)

Producción Científica, A new procedure to enhance the performance of polymer-based electrochemical sensors is proposed in this work. Polycaprolactone (PCL) electrospun fiber mats with tunable fiber morphology are functionalized with a conductive polymer (PEDOT:PSS) by a facile dip-coting process, providing them the necessary electrical conductivity to work as sensors. The modification of the fiber morphology is achieved by an enhanced gas dissolution foaming procedure, an environmentally friendly procedure that employs CO2 as blowing agent and takes advantage of recent advances that allowed extending such procedure to polymeric microfibers. Thus, the enhanced gas dissolution foaming approach was employed both before and after the coating of the fiber mats with PEDOT:PSS, producing in both cases hollow fibers with enhanced surface porosity and area, as well as increased diameter regarding the initial solid PCL fibers. The addition of PEDOT:PSS, both in solid and foamed PCL fibers, allows their use as sensors, as proved by cyclic voltammetry in a KCl solution, as well as calibrated with catechol solutions. Remarkable influence of the foaming procedure on the performance of the sensors have been found, proving by a detailed characterization that the foaming procedure applied after the PEDOT:PSS coating provides an enhanced sensoring response (i.e., increased signal, optimal linearity, decreased LOD) due to their superior surface area and optimal PEDOT:PSS distribution along the fiber mats, not only covering the external surface of the fibers but infusing into the inner regions., Ministerio de Ciencia e Innovación (PID2021-127108OB-I00 y subvención FPI: PRE2019-088820), MCIN/AEI /10.13039/501100011033 - EU NextGenerationEU/ PRTR (PLEC2021-007705), Ministerio de Ciencia e Innovación y Ministerio de Universidades -FEDER “Una manera de hacer Europa” (UE) (RTI2018 - 098749-B-I00 y RTI2018 - 097367-A-I00), Junta de Castilla y León y EU-FEDER (CLU-2019-04, VA275P18 y VA202P20), MINECO-FEDER Plan Nacional (PID2021-122365OB-100), Junta de Castilla y León- FEDER (VA202P20, CLU-2019-04)

Producción Científica, A set of linear polymers were synthesized utilizing an electrophilic aromatic substitution reaction (SEAr) between biphenyl and ketone containing electron-withdrawing groups (isatin, IS; N-methylisatin, MeIS; and 4,5-diazafluoren-9-one, DF). Optimization of the polycondensation reaction was made to obtain high molecular weight products when using DF, which has not previously been used for linear polymer synthesis. Due to the absence of chemically labile units, these polymers exhibited excellent chemical and thermal stability. Linear SEAr polymers were blended with porous polymer networks derived from IS and MeIS, and both neat/mixed materials were tested as membranes for gas separation. The gas separation properties of both pristine polymers and mixed matrix membranes were good, showing some polymer membrane CO2 permeability values higher than 200 barrer.

Producción Científica, In this work, CO2 adsorption at 273.15 K and N2 adsorption at 77 K of mixed matrix membranes has been studied, as a method to directly determine their fractional free volume (FFV). These membranes consist of a continuous phase of copoly(o-hydroxyamide)s (HPA) or copoly(o-hydroxyamide-amide)s (PAA) and a relatively highly porous polymer network filler (PPN1). Both the pure copolymers and the mixed matrix membranes (MMMs) have been analyzed before and after a thermal rearrangement (TR) process. The CO2 adsorption results have allowed characterizing the pore size distribution of the studied membranes in the 3–15 Å range, by using the Non-Local Density Functional Theory (NLDFT). Whereas the N2 adsorption has allowed determining the pore size distributions in the range between 20 and 250 Å. The experimental determination of the pore volume and the density allows the direct calculation of the membranes’ free volume fractions, which were in good agreement with the most usual FFV evaluation methods. In addition, part of the pore volume detected by N2 adsorption was associated with defects and poor integration of the membrane components. This correction has allowed us to make a new evaluation of the density of these materials., Gobierno de España (AEI) proyects (PID2019-109403RB-C21/AEI/10.13039/501100011033 y PID2019-109403RB-C22/AEI/10.13039/501100011033), Junta de Castilla y León - EU-FEDER (CL-EI-2021-07, UIC082)

Producción Científica, Polyurethane foams with a hybrid structure between closed cell and open cell were fabricated and fully characterized. Sound absorption measurements were carried out in order to assess their acoustic performance at different frequency ranges. The cellular structure of these systems was studied in detail by defining some novel structural parameters that characterize the cell wall openings such as the average surface of holes (Sh), the number of holes (h), and the area percentage thereof (%HCW). Therefore, these parameters allow to analyze quantitatively the effect of different structural factors on the acoustic absorption performance. It has been found that the parameters under study have a remarkable influence on the normalized acoustic absorption coefficient at different frequency ranges. In particular, it has been demonstrated that increasing the surface of the holes and the percentage of holes in the cell walls allows increasing the acoustic absorption of these types of foams, a promising statement for developing highly efficient acoustic insulators. Additionally, we could determine that a suitable minimum value of hole surface to reach the highest sound dissipation for these samples exists., Ministerio de Ciencia, Innovación y Universidades - (grant FPU17/03299), Junta de Castilla y León - (Grant VA202P20), Ministerio de Ciencia, Innovación y Universidades - (project RTI2018-098749-B-I00), Junta de Castilla y León, Ente Público Regional de la Energía de Castilla y León - (EREN_2019_L4_UVA)

Producción Científica, Copoly(o-hydroxyamide)s (HPA) and copoly(o-hydroxyamide-amide)s (PAA) have been synthesized to be used as continuous phases in mixed matrix membranes (MMMs). These polymeric matrices were blended with different loads (15 and 30 wt.%) of a relatively highly microporous porous polymer network (PPN). SEM images of the manufactured MMMs exhibited good compatibility between the two phases for all the membranes studied, and their mechanical properties have been shown to be good enough even after thermal treatment. The WAX results show that the addition of PPN as a filler up to 30% does not substantially change the intersegmental distance and the polymer packing. It seems that, for all the membranes studied, the free volume that determines gas transport is in the high end of the possible range. This means that gas flow occurs mainly between the microvoids in the polymer matrix around the filler. In general, both HPA- and PAA-based MMMs exhibited a notable improvement in gas permeability, due to the presence of PPN, for all gases tested, with an almost constant selectivity. In summary, although the thermal stability of the PAA is limited by the thermal stability of the polyamide side chain, their mechanical properties were better. The permeability was higher for the PAA membranes before their thermal rearrangement, and these values increased after the addition of moderate amounts of PPN., Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 - (projects PID2019- 109403RB-C21 and PID2019-109403RB-C22), Junta de Castilla y León y Fondo Europeo de Desarrollo Regional (FEDER) - (grant CLU2017-09, CL-EI-2021-07, UIC082)

Producción Científica, Over the past decade, polymeric membranes have been widely investigated for a variety of industrial gas separation applications. In today’s competitive and ever-changing environment, membrane gas separation is now widely accepted as an economic process to produce moderate purity stream gases. [Texto extraído del artículo de Bibiana Comesaña Gándara].

Producción Científica, A set of thermally rearranged mixed matrix membranes (TR-MMMs) was manufactured and tested for gas separation. These membranes were obtained through the thermal treatment of a precursor MMM with a microporous polymer network and an o-hydroxypolyamide,(HPA) created through a reaction of 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (APAF) and 5′-terbutil-m-terfenilo-3,3″-dicarboxylic acid dichloride (tBTmCl). This HPA was blended with different percentages of a porous polymer network (PPN) filler, which produced gas separation MMMs with enhanced gas permeability but with decreased selectivity. The thermal treatment of these MMMs gave membranes with excellent gas separation properties that did not show the selectivity decreasing trend. It was observed that the use of the PPN load brought about a small decrease in the initial mass losses, which were lower for increasing PPN loads. Regarding the glass transition temperature, it was observed that the use of the filler translated to a slightly lower Tg value. When these MMMs and TR-MMMs were compared with the analogous materials created from the isomeric 5′-terbutil-m-terfenilo-4,4″-dicarboxylic acid dichloride (tBTpCl), the permeability was lower for that of tBTmCl, compared with the one from tBTpCl, although selectivity was quite similar. This fact could be attributed to a lower rigidity as roughly confirmed by the segmental length of the polymer chain as studied by WAXS. A model for FFV calculation was proposed and its predictions compared with those evaluated from density measurements assuming a matrix-filler interaction or ideal independence. It turns out that permeability as a function of FFV for TR-MMMs follows an interaction trend, while those not thermally treated follow the non-interaction trend until relatively high PPN loads were reached., Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación - (projects PID2019- 109403RB-C21/AEI/10.13039/501100011033 and PID2019-109403RB-C22/AEI/10.13039/501100011033), Junta de Castilla y León, Unión Europea y Fondo Europeo de Desarrollo Regional (FEDER) - (project CLU2017-09, UIC082)

Producción Científica, This article presents, for the first time, the results of applying the rheological technique to measure the molecular weights (Mw) and their distributions (MwD) of highly hierarchical biomolecules, such as non-hydrolyzed collagen gels. Due to the high viscosity of the studied gels, the effect of the concentrations on the rheological tests was investigated. In addition, because these materials are highly sensitive to denaturation and degradation under mechanical stress and temperatures close to 40 °C, when frequency sweeps were applied, a mathematical adjustment of the data by machine learning techniques (artificial intelligence tools) was designed and implemented. Using the proposed method, collagen fibers of Mw close to 600 kDa were identified. To validate the proposed method, lower Mw species were obtained and characterized by both the proposed rheological method and traditional measurement techniques, such as chromatography and electrophoresis. The results of the tests confirmed the validity of the proposed method. It is a simple technique for obtaining more microstructural information on these biomolecules and, in turn, facilitating the design of new structural biomaterials with greater added value., Instituto para la Competitividad Empresarial de Castilla y León (ICE), PROYECTOS I + D CENTROS TECNOLÓGICOS - (project CCTT3/20/VA/0006), Universidad de Valladolid - Postdoctoral Contract CONVOCATORIA 2020 (K.C.N.C)

Producción Científica, A set of aromatic copolyimides was obtained by reaction of 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), and mixtures of the diamines 1,4-bis(4-amino-2-trifluoromethylphenoxy)-2,5-di-tert-butylbenzene (CF3TBAPB) and 3,5-diamino benzoic acid (DABA). These polymers were characterized and compared with the homopolymer derived from 6FDA and CF3TBAPB. All copolyimides showed high molecular weight values and good mechanical properties. The presence of carboxylic groups in these copolymers allowed their chemical crosslinking by reaction with 1,4-butanediol. Glass transition temperatures (Tg) were higher than 260 °C, showing the non-crosslinked copolyimides had the highest Tg values. Degradation temperature of crosslinked copolyimides was lower than their corresponding non-crosslinked ones. Mechanical properties of all polymers were good, and thus, copolyimide (precursor, and crosslinked ones) films could be tested as gas separation membranes. It was observed that CO2 permeability values were around 100 barrer. Finally, the plasticization resistance of the crosslinked material having a large number of carboxylic groups was excellent., Gobierno de España (Agencia Estatal de Investigación), Unión Europea y Fondo Europeo de Desarrollo Regional (FEDER) - (Projects PID2019-109403RB-C22, PID2019-109403RB-C21 and PID2020- 118547GB-I00), Junta de Castilla y León - (Project VA224P20)

Producción Científica, A new set of catalytic materials having a pyrrolidine moiety confined in microporous organic polymer networks (POPs) has been attained. These catalytic polymers have been prepared by a straightforward synthesis starting from microporous polymer networks made from isatin (or a mixture of isatin and trifluoroacetophenone) and 1,3,5-triphenylbenzene. The polymers efficiently catalyzed the formation of nitrones under very mild and sustainable conditions using green solvents through an iminium ion activation mechanism. The reactions are scalable, and polymers are easily recycled. Special attention has been paid to understanding all the factors that could affect the efficiency of the confined catalysts. The electronic and conformational characteristics of the pyrrolidine moiety attached to the porous polymers, as well as other features that could affect the transport through the network, such as molecular volume and shape of reactants and products, and even hydrophilic or hydrophobic properties, have been systematically evaluated. In addition, the heterogeneous polymers are also useful in Cdouble bondC bond formation through both iminium ion and enamine activation., Gobierno de España (Agencia Estatal de Investigación) - (Projects CTQ2016-78779-R, PID2019-109403RB-C22, RTI2018-096328-B-I00, CTQ2017-89217-P and PID2020-118547GBI00), Junta de Castilla y León, Unión Europea y Fondo Europeo de Desarrollo Regional (FEDER) - (Project VA224P20))

Producción Científica, Mixed matrix membranes (MMMs), derived from three aromatic polyimides (PIs), and an affordable porous organic polymer (POP) having basic bipyridine moieties were prepared. Matrimid and two fluorinated polyimides, which were derived from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride and 2,2′-bis(4-aminophenyl)hexafluoropropane (6F6F) or 2,4,6-trimethyl-m-phenylenediamine (6FTMPD), were employed as polymer matrixes. The used POP was a highly microporous material (surface area of 805 m2 g−1) with excellent thermal and chemical stability. The MMMs showed good compatibility between the PIs and POP, high thermal stabilities and glass transition temperatures superior to those of the neat PI membranes, and good mechanical properties. The addition of POP to the matrix led to an increase in the gas diffusivity and, thus, in permeability, which was associated with an increase in the fractional free volume of MMMs. The increase in permeability was higher for the less permeable matrix. For example, at 30 wt.% of POP, the permeability to CO2 and CH4 of the MMMs increased by 4- and 7-fold for Matrimid and 3- and 4-fold for 6FTMPD. The highest CH4 permeability led to a decrease in CO2/CH4 selectivity. The CO2/N2 separation performance was interesting, as the selectivity remained practically constant. Finally, the POP showed no molecular sieving effect towards the C2H4/C2H6 and C3H6/C3H8 gas pairs, but the permeability increased by about 4-fold and the selectivity was close to that of the matrix. In addition, because the POP can form metal ion bipyridine complexes, modified POP-based MMMs could be employed for olefin/paraffin separations., Gobierno de España (Agencia Estatal de Investigación) - (Projects PID2019- 109403RB-C21, PID2019-109403RB-C22, and PID2020-118547GB-I00), Junta de Castilla y León, Unión Europea y Fondo Europeo de Desarrollo Regional (FEDER) - (Projects CLU2017-09, UIC082, VA088G19 and VA224P20)

Producción Científica, A new approach to produce nanocellular polymers combining small cell sizes with low relative densities is presented herein. This production method, based on gas dissolution foaming, consists of performing a double saturation and foaming cycle. Thus, nanocellular polymethylmethacrylate (PMMA) has been produced through a first saturation at different saturation conditions (6, 10, and 20 MPa and −32 °C), at constant foaming conditions (60 °C for 1 min). Then, the nanocellular PMMAs obtained from the previous step were again saturated at different saturation conditions, 10 MPa 24 °C, 31 MPa 24 °C, 35 MPa 22 °C, and 6 MPa −15 °C and foamed at different temperatures (40, 80 and 100 °C) for 1 min. This new approach allows the cells created in the first saturation and foaming cycle to further grow in the second cycle. This fact permits producing nanocellular polymethylmethacrylate sheets combining, for the first time in the literature, cell sizes of 24 nm with relative densities of 0.3., Junta de Castilla y León (Project VA202P20), Ministerio de Ciencia, Innovación y Universidades - (Projects RTI2018-098749-B-I00 and PTQ2019-010560) )

The present thesis focuses on the development of new experimental techniques to study the process-structure-properties relationship in polymeric foams. To achieve this objective rigid polyurethane (RPU) foams were studied. Methodologies have been developed to investigate the synthesis of RPU foams from complementary rheological, physicochemical and structural points of view. To validate the potential of the methods, the effect of different catalyst and blowing agent concentrations on the synthesis of these foams has been systematically studied. As a result of this research, new methods of characterisation of the synthesis process have been obtained at laboratory level, these are based on Dynamic Mechanical Analysis (DMA), Shear Rheology, as well as X-ray tomography and X-ray radioscopy. Furthermore, the development and application of these techniques has allowed to understand the effect of micrometric Silica Aerogel particles on the synthesis, cellular structure and thermal insulation properties of RPU foams reinforced with these particles. The joint evaluation of the reaction kinetics, polymer matrix development and cell structure of RPU foams has identified new ways for the future improvement and optimisation of RPU-Aerogel composite materials with great potential to replace traditional thermal insulators. The present thesis is part of the research activities carried out in the CellMat Laboratory of the Department of Condensed Matter Physics of the University of Valladolid and has been supervised by Prof. Dr. Miguel Ángel Rodríguez-Pérez, director of this laboratory and professor at the University of Valladolid. This thesis has been written as a compendium of eight publications, five of which have already been published in international journals. In addition, this thesis meets the requirements to be accredited with an International Mention., La presente tesis se centra en el desarrollo de nuevas técnicas experimentales para estudiar la relación proceso-estructura-propiedades en las espumas poliméricas. Para alcanzar este objetivo se estudiaron principalmente espumas de poliuretano rígido (RPU). Se han desarrollado metodologías que permiten investigar la síntesis de las espumas de RPU desde puntos de vista complementarios, reológico, fisicoquímicos y estructural. Para validar el potencial de los métodos se ha estudiado de forma sistemática el efecto de distintas concentraciones de catalizador y agente espumante en la síntesis de estas espumas. Como resultado de esta investigación se han podido obtener nuevos métodos de caracterización a nivel de laboratorio del proceso de síntesis, basados en Análisis Mecánico Dinámico (DMA), Reología de Cizalla, así como tomografía y radioscopía de rayos X. Además, el desarrollo y aplicación de estas técnicas ha permitido comprender el efecto de partículas micrométricas de Aerogel de Silice en la síntesis, estructura celular y propiedades de aislamiento térmico de espumas de RPU reforzadas con dichas partículas. La evaluación conjunta de las cinética de reacción, desarrollo de la matriz polimérica y de la estructura celular de las espumas de RPU ha permitido identificar vías para la mejora y optimización futura de materiales compuestos de RPU-Aerogel con gran potencial para sustituir a los aislantes térmicos tradicionales. La presente tesis es parte de las actividades de investigación desarrolladas en el Laboratorio CellMat del Departamento de Física de la Materia Condensada de la Universidad de Valladolid y ha sido supervisada por el Prof. Dr. Miguel Ángel Rodríguez-Pérez, director de este laboratorio y catedrático de la Universidad de Valladolid. Esta tesis se ha escrito como compendio de ocho publicaciones, cinco de las cuales ya han sido publicadas en revistas internacionales. Además, esta tesis reúne los requerimientos para ser acreditada con Mención Internacional., Escuela de Doctorado, Doctorado en Física

Producción Científica, Blends of poly(methyl methacrylate) (PMMA) and a triblock copolymer poly(methyl methacrylate)-b-poly(butyl acrylate)-b-poly(methyl methacrylate) (MAM) have been obtained following both out-of-equilibrium (extrusion) and near-equilibrium (solvent casting) production routes. The self-assembly capability and the achievable nanostructures of these blends are analyzed by transmission electron microscopy (TEM) regarding their production route and potential for the achievement of nanocellular foams by CO2 gas dissolution foaming. The influence of the initial nanostructure of the solids on the obtained cellular structure of bulk and film samples is determined by high-resolution scanning electron microscopy (HRSEM) for diverse foaming conditions (saturation pressure, saturation temperature, and post-foaming stage), taking into account the required use of a foaming mold to achieve foams from films. Moreover, the influence of the nanostructuration on the presence of solid outer layers, typical of the selected foaming process, is addressed. Finally, consideration of a qualitative model and the obtained results in terms of nanostructuration, cellular structure, and foaming behavior, allow proposing a detailed cell nucleation, growth, and stabilization scheme for these materials, providing the first direct evidence of the cell nucleation happening inside the poly(butyl acrylate) phase in the PMMA/MAM blends., Ministerio de Asuntos Económicos y Transformación Digital - FEDER (RTI2018-098749-B-I00, RTI2018-097367-A-I00 and PRE2019-088820), Junta de Castilla y León (VA275P18), Strategic Program (CLU-2019-04)

Este trabajo consiste en un estudio para la optimización de la bioproducción de proteínas recombinantes de tipo elastina. Para este cometido se han realizado ensayos en un fermentador de 0,5L con 2 cepas de Escherichia Coli productoras diferentes estudiando la respuesta de éstas ante la adición de oxígeno. El polímero producido fue la construcción (EISilk)2 que presenta un rendimiento muy bajo en las condiciones de trabajo habituales obteniéndose con la nueva cepa SE1 un rendimiento de hasta un 402,8% con respecto a las condiciones anteriores de producción con la cepa BL21 y sin oxígeno añadido. Con esta mejora se realizó una evaluación económica obteniendo que con las nuevas condiciones los costes de producción se reducían un 71,9% con respecto a las condiciones iniciales., Departamento de Química Analítica, Grado en Ingeniería Química

En los últimos años se han desarrollado tecnologías de fabricación aditiva que permiten el procesado de piezas en tiempos cortos con elevada personalización. Sin embargo, el estudio del comportamiento mecánico de estas piezas es complejo y difícil de predecir, lo que limita su uso para la fabricación de piezas funcionales. Por esta razón, en el presente proyecto se desarrollará una metodología que permita predecir el comportamiento mecánico de las piezas procesadas mediante fabricación aditiva con tecnología FDM. Se construirá un modelo, apoyado en herramientas de cálculo por elementos finitos, capaz de simular el comportamiento mecánico de materiales poliméricos termoplásticos con anisotropía, tanto en la zona elástica como en la plástica, válido para cualquier geometría y estado de carga. Para alimentar este modelo de simulación se realizará una caracterización mecánica mediante ensayos experimentales de piezas fabricadas por FDM, que permita modelar de manera rigurosa el material procesado mediante esta tecnología, Departamento de Física de la Materia Condensada, Cristalografía y Mineralogía, Grado en Ingeniería Mecánica

El objetivo del proyecto es crear un objeto impreso en 3D mediante FDM (Modelado por Deposición Fundida) con una parte suave y una parte dura combinando sus propiedades y el diseño del objeto. Diseñar un filamento de material blando con buena compatibilidad con un termoplástico, poli (ácido láctico) (PLA) usando diferentes (co)polímeros comerciales para el proceso de extrusión e impresión y por último elegir un método para evaluar la adhesión del filamento diseñado con el filamento de PLA. En este informe se estudia la extrusión y la posibilidad de impresión de diferentes TPE (elastómeros termoplásticos). Primero, se incluye un fondo bibliográfico que presenta el estudio. En segundo lugar, se recopila una lista de los materiales y métodos utilizados para este estudio. Y finalmente, se presentan los resultados obtenidos en este estudio, así como las perspectivas de conclusión., Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Grado en Ingeniería Química

Hoy en día, una gran mayoría de lo que nos rodea se ha fabricado a partir de polímeros obtenidos mediante la reacción de polimerización de pequeñas repetitivas subunidades (monómeros). Los monómeros más empleados en la industria son los alquenos ligeros. Sin embargo, su método de obtención da lugar a algunas impurezas (alquinos y alcadienos) que provocan la contaminación del catalizador. El objetivo de este estudio ha sido encontrar un catalizador adecuado para la hidrogenación selectiva del 1,3-butadieno ya que este proceso es una alternativa para conseguir purificar las corrientes de alquenos. Para ello, se han llevado a cabo dos métodos de preparación: “Chemical Reduction” y “Deposition-precipitation with urea”. Además, distintas técnicas de caracterización tales como XRD, XRF, TEM-EDX, TPR, BET.. se han utilizado para conocer la estructura, composición y morfología de los materiales. Por último, los catalizadores basados en hierro fueron sometidos a análisis catalíticos en la reacción de hidrogenación selectiva de 1,3-butadieno con el fin de comprobar su actividad catalítica, selectividad y estabilidad. El material que presentó mejor comportamiento fue Fe-Zn 1:5/TiO2., Departamento de Organización de Empresas y Comercialización e Investigación de Mercados, Máster en Ingeniería Industrial

Over the years material science has pursued to mimicking the properties and features inherent to natural proteins. One of these proteins that offer biocompatibility, elasticity and thermosensitive behavior that leads to self-assembled processes is the elastin. From (VPGXG) repeated motifs a variety of Elastin-like recombinamers (ELRs) inspired in natural elastin have been developed. The aim of this thesis is to demonstrate the versatile properties of ELRs in order to create a variety of ELRs able to form nanocomplexes and be applied for biomedical purposes as gene or even drug delivery. The present work has addressed the whole process of design, production, purification, characterization and direct application of the novel ELRs. For that, the utilization of genetic engineering, microbiology, physico-chemical together with in vitro and in vivo techniques has been performed. Initially, the design of ELRs through recombinant techniques and focused on gene delivery applications was achieved. A collection of hydrophilic ELRs rich in lysine and histidine amino acids was obtained. In addition, the incorporation of new functionalities by means of penetratin CPP and LAEL peptides was accomplished. Chemical modifications led to the generation of novel ELRs provided of buffering capacity and cell specificity by means of imidazole groups and anti-MUC1 aptamer incorporations. Indeed, the suitability of a self-assembled ELR diblock (ELRBC) modified with Arg8 CPP at C-t for pH sensitive drug delivery was accomplished. This work explored the cell uptake and accumulation of ELR nanoparticles into acidic vesicles in order to evaluate the incorporation of Arg8 peptide to the ELRBC as the best alternative for carrying the drug. In addition, macropinocytosis as cellular entrance pathway was confirmed by the role of heparin sulfate proteglycan (HSPG) and p21 activated kinase 1 (PAK1) molecules. In addition, the evaluation of ELRs with the biofunctional domains penetratin, LAEL and imidaz, Departamento de Bioquímica y Biología Molecular y Fisiología, Doctorado en Investigación Biomédica

Esta tesis se basa en producir carbonatos de polipropileno en reacciones de copolimerización utilizando dos tipos diferentes de catalizadores heterogéneos: Glutarato de zinc (ZnGA) y catalizadores Double Metal Cyanide (DMC). Se ha hecho un estudio completo de ambos catalizadores además de la caracterización de los policarbonatos obtenidos en las reacciones. Uno de los aspectos más interesantes de este estudio es el uso del dióxido de carbono (CO2), no sólo como medio de presurización de la reacción sino también como fuente de alimentación de carbonos (C1). El dióxido de carbono es una de las principales fuentes que causan el efecto invernadero. De cara a atacar y solucionar este problema, el CO2 (subproducto de numerosos procesos industriales) ha sido capturado, almacenado y utilizado (e insertado) en reacciones de copolimerización. Estas reacciones, las cuales son llevadas a cabo en condiciones subcríticas y en modo batch, se denominan reacciones de copolimerización puesto que implican la utilización de dos monómeros como reactivos: óxido de propileno y dióxido de carbono., Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Doctorado en Ingeniería Química y Ambiental

La tecnología de membranas para separación de gases ha experimentado un gran desarrollo gracias al descubrimiento de nuevos materiales con capacidades mejoradas de permeación y separación. Esta Tesis se basa en una de las familias de polímeros sintéticos que despiertan en la actualidad el mayor interés desde el putno de vista científico y práctico, los denominados polímeros TR. Los polímeros TR se obtiene mediante transposición térmica a partir de poliimdias orto-funcionalizadas, la cual origina cambios conformacionales y de composición química que favorecen una modifiación importante del volumen libre y de su distribución, lo que se traduce en permeabilidades próximas o superiores a 1000 Barrers según los casos. En este trabajo, se ha incidido fundamentalmente en los aspectos de preparación y evaluación de nuevos polímeros TR, y en el estudio pormenorizado de los mecanismos que gobiernan la transposición y conducen a los materiales finales mediante un tratamiento térmico extremo., Instituto Universitario Centro de Innovación en Química y Materiales Avanzados (Cinquima)

La presente tésis se centra en las espumas poliolefínicas (polietileno y polipropileno) con el objetivo fundamental de mejorar sus propiedades físicas. Durante su desarrollo se presentan dos rutas de producción nuevas para la fabricación de espumas estructurales y para la fabricación de espumas no reticuladas de polipropileno con excelentes propiedades mecánicas. Se presta especial atención a las propiedades barreras a gases las cuales se mejoran mediante la incorporación de nanoarcillas. Las propiedades mecánicas también se mejoran con la incorporación de diversos tipos de nanoarcillas y nanotubos de carbono. Como métodos de espumado se emplea disolución de gas en estado sólido, espumado libre, moldeo a compresión mejorado y stages molding. Finalmente se estudia en detalle la interacción de la espumación con la exfoliación de las nanoarcillas mediante difracción por dispersión de energía empleando radiación sincrotrón, Departamento de Física de la Materia Condensada, Cristalografía y Minerealogía