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Electromagnetic shielding materials in GHz range
(Wiley, 2018-07) González Sánchez, Marta; Pozuelo de Diego, Javier; Baselga Llidó, Juan; Ministerio de Economía y Competitividad (España)
The state-of-the art in the design and the manufacture methods of the different electromagnetic shielding materials has been reviewed. This topic has become a mainstream field of research because of the electromagnetic pollution generated by telecommunication technology development. The review is centred in absorbent materials and shows a general overview of how the absorption properties of such composites can be tailored through changes in geometry, composition, morphology, and the filler particles content. Although different types of materials are explained, the text is mainly focused on carbon materials such as graphene and carbon nanotubes. In this way, the importance of the dispersion of the conductive fillers in different polymer matrices is discussed. In addition, an extensive study on new complex architectures such as foam-based materials is presented. Finally, the combination of carbon fillers with other constituents such as metallic nanoparticles is mentioned. In all these studies, the efficiency of the composites as absorbent or reflective of electromagnetic radiation is discussed.
Modulating the electromagnetic shielding mechanisms by thermal treatment of high porosity graphene aerogels
(Elsevier, 2019-06-01) González Sánchez, Marta; Baselga Llidó, Juan; Pozuelo de Diego, Javier; Ministerio de Economía y Competitividad (España)
The possibility of modulating the electromagnetic shielding mechanisms of graphene aerogels by varying the reduction state of graphene oxide was evaluated. Highly porous graphene aerogels were prepared by a modified hydrothermal treatment. Reduction state was varied through a subsequent thermal treatment under Ar-2/H-2 atmosphere at different temperatures: 400, 600 and 1000 degrees C. Thermal treatments reduced the amount of oxygenated functional groups without altering pore morphology and pore size as revealed by XRD, XPS, Raman and SEM image analysis. The resulting aerogels presented thus a very low density, in the range 8.5-5.6 mg/cm(3) and a conductivity in the range 10-80 S/m. Electromagnetic characterization was performed in the range 8-18 GHz in terms of power analysis and shielding efficiency. All samples transmitted less than 5% of incident power although an increase of the reflection mechanism was observed as the thermal treatment temperature was increased.
Anticancer applications of nanostructured silica-based materials functionalized with titanocene derivatives: Induction of cell death mechanism through TNFR1 modulation
(MDPI, 2018-01-31) Gómez-Ruiz, S; García Peñas, Alberto; Prashar, S.; Rodríguez-Diéguez, A.; Ministerio de Economía y Competitividad (España)
A series of cytotoxic titanocene derivatives have been immobilized onto nanostructured silica-based materials using two different synthetic routes, namely, (i) a simple grafting protocol via protonolysis of the Ti-Cl bond; and (ii) a tethering method by elimination of ethanol using triethoxysilyl moieties of thiolato ligands attached to titanium. The resulting nanostructured systems have been characterized by different techniques such as XRD, XRF, DR-UV, BET, SEM, and TEM, observing the incorporation of the titanocene derivatives onto the nanostructured silica and slight changes in the textural features of the materials after functionalization with the metallodrugs. A complete biological study has been carried out using the synthesized materials exhibiting moderate cytotoxicity in vitro against three human hepatic carcinoma (HepG2, SK-Hep-1, Hep3B) and three human colon carcinomas (DLD-1, HT-29, COLO320) and very low cytotoxicity against normal cell lines. In addition, the cells' metabolic activity was modified by a 24-h exposure in a dose-dependent manner. Despite not having a significant effect on TNFalfa or the proinflammatory interleukin 1alfa secretion, the materials strongly modulated tumor necrosis factor (TNF) signaling, even at sub-cytotoxic concentrations. This is achieved mainly by upregulation of the TNFR1 receptor production, something which has not previously been observed for these systems.
Solution casting of cellulose acetate films: influence of surface substrate and humidity on wettability, morphology and optical properties
(Springer, 2023-01-09) Kramar, Ana; Rodriguez Ortega, Irene; Gonzalez Gaitano, Gustavo; González Benito, Francisco Javier; European Commission; Ministerio de Ciencia e Innovación (España); Universidad Carlos III de Madrid
Variations on the processing conditions of conventional methods for polymeric film preparation may allow tuning certain properties. In this work, different casting surfaces and humidity are presented as variables to consider for cellulose acetate (CA) film preparation using conventional solution casting method. Specifically, borosilicate glass, soda-lime glass and Teflon (PTFE) dishes have been used for casting and their influence on various properties on CA films assessed. The surfaces of glass dishes are smooth, while PTFE surface has a pattern constituted by concentric channels of micro dimensions (as seen by optical microscope), which is adopted by cast films upon drying. The resulting patterned films are translucent while films produced using smooth surfaces are transparent. The effect of the environment humidity (35%, 55% and 75% RH) in the properties of the CA films during the evaporation of solvent from solution has been evaluated. Higher humidity produces smoother surfaces and increased crystallinity as shown by XRD and DSC; however, the wettability of the films does not seem to be influenced by this variable. Due to the specific morphology of the patterned films, changes in material opacity upon wetting are detected, from translucent to transparent, while the removal of water from the surface restores the translucency. This micropatterning effect that causes different visual appearance of the material can find use as a humidity sensor in food packaging applications.
High ampacity carbon nanotube materials
(MDPI, 2019-03) Mokry López, Guillermo; Pozuelo de Diego, Javier; Villatela, Juan J.; Sanz Feito, Javier; Baselga Llidó, Juan; Ministerio de Economía y Competitividad (España)
Constant evolution of technology is leading to the improvement of electronical devices. Smaller, lighter, faster, are but a few of the properties that have been constantly improved, but these developments come hand in hand with negative downsides. In the case of miniaturization, this shortcoming is found in the inherent property of conducting materials-the limit of current density they can withstand before failure. This property, known as ampacity, is close to reaching its limits at the current scales of use, and the performances of some conductors such as gold or copper suffer severely from it. The need to find alternative conductors with higher ampacity is, therefore, an urgent need, but at the same time, one which requires simultaneous search for decreased density if it is to succeed in an ever-growing electronical world. The uses of these carbon nanotube-based materials, from airplane lightning strike protection systems to the microchip industry, will be evaluated, failure mechanisms at maximum current densities explained, limitations and difficulties in ampacity measurements with different size ranges evaluated, and future lines of research suggested. This review will therefore provide an in-depth view of the rare properties that make carbon nanotubes and their hybrids unique.
Influence of the characteristics of expandable graphite on the morphology, thermal properties, fire behaviour and compression performance of a rigid polyurethane foam
(MDPI, 2019-01) Acuña Domínguez, Pablo Alberto; Li, Zhi; Santiago Calvo, Mercedes; Villafane, Fernando; Rodríguez Pérez, Miguel Ángel; Wang, De-Yi; Ministerio de Economía y Competitividad (España)
Three types of expandable graphite (EG) differing in particle size and expansion volume, are compared as flame retardant additives to rigid polyurethane foams (RPUFs). In this paper we discuss microstructure, thermal stability, fire behavior, and compression performance. We find that ell size distributions were less homogeneous and cell size was reduced. Furthermore, thermal conductivity increased along with EG loading. Thermogravimetric analysis (TGA) showed that EG only increased residue yield differently. The results indicate that a higher expansion of EG increased the limiting oxygen index (LOI) value, whereas a bigger particle size EG improved the rating of the vertical burning test (UL94). Results from the cone calorimeter test showed that a bigger particle size EG effectively reduced peak of heat release rate (pHRR). Furthermore, a higher expansion, led to a decrease in smoke production (TSP). The combination of both characteristics gives extraordinary results. The physical-mechanical characterization of the EG/RPUF foams revealed that their compression performance decreased slightly, mostly due to the effect of a bigger size EG.
Effect of hydrophobic interactions on lower critical solution temperature for poly(N-isopropylacrylamide-co-dopamine methacrylamide) copolymers
(MDPI, 2019-06-04) García Peñas, Alberto; Sekhar Biswas, Chandra; Liang, Weijun; Wang, Yu; Yang, Pianpian; Stadler, Florian J.
For the preparation of thermoresponsive copolymers, for e.g., tissue engineering scaffolds or drug carriers, a precise control of the synthesis parameters to set the lower critical solution temperature (LCST) is required. However, the correlations between molecular parameters and LCST are partially unknown and, furthermore, LCST is defined as an exact temperature, which oversimplifies the real situation. Here, random N-isopropylacrylamide (NIPAM)/dopamine methacrylamide (DMA) copolymers were prepared under a systematical variation of molecular weight and comonomer amount and their LCST in water studied by calorimetry, turbidimetry, and rheology. Structural information was deduced from observed transitions clarifying the contributions of molecular weight, comonomer content, end-group effect or polymerization degree on LCST, which were then statistically modeled. This proved that the LCST can be predicted through molecular structure and conditions of the solutions. While the hydrophobic DMA lowers the LCST especially the onset, polymerization degree has an important but smaller influence over all the whole LCST range.
A new insight into the comonomer effect through NMR analysis in metallocene catalysed propene-co-1-nonene copolymers
(MDPI, 2019-08) Wu, Qiong; García Peñas, Alberto; Barranco García, Rosa; Cerrada, María Luisa; Benavente, Rosario; Pérez, Ernesto; Gómez Elvira, José Manuel; Ministerio de Economía y Competitividad (España); Agencia Estatal de Investigación (España)
The "comonomer effect" is an intriguing kinetic phenomenon in olefin copolymerization that still remains without a detailed explanation. It typically relates to the rate of enhancement undergone in ethylene and propene catalytic polymerization just by adding small fractions of an alpha-olefin. The difficulty lies in the fact that changes caused by the presence of the comonomer in reaction parameters are so conspicuous that it is really difficult to pin down which of them is the primary cause and which ones are side factors with marginal contribution to the phenomenon. Recent investigations point to the modification of the catalyst active sites as the main driving factor. In this work, the comonomer effect in the metallocene copolymerization of propene and 1-nonene is analysed and correlated to the comonomer role in the termination of the chain-growing process. The associated termination mechanisms involved furnish most of chain-free active sites, in which the selective interaction of the comonomer was proposed to trigger the insertion of monomers. A thorough characterisation of chain-end groups by means of the 1H NMR technique allows for detailing of specific transfer processes, ascribed to comonomer insertions, as well as evidencing the influence of the growing chain's microstructure over the different termination processes available.
Jet milling as an alternative processing technique for preparing polysulfone hard nanocomposites
(Hindawi, 2019-01-01) Llorente Muga, Amaia; Serrano Prieto, María Bernarda; Baselga Llidó, Juan; Gedler, Gabriel; Ozisik, Rahmi; Ministerio de Economía y Competitividad (España)
This work describes how a solid-state blending method such as jet milling can be used to successfully prepare polysulfone (PSU)/-alumina nanocomposites. For comparison purposes, conventional melt extrusion was used as well. Morphological analysis revealed how jet mill blending allows obtaining well-dispersed -alumina nanoparticles within a polysulfone matrix without any surface treatment, with an important decrease of particle size promoted by the breakup of agglomerates and aggregates due to the particle-particle impacts during processing, which was not observed in the extruded nanocomposites. DSC analysis demonstrated that jet-milling processing promoted T-g enhancements with alumina addition, while TGA experiments confirmed the increment of thermal stability of the nanocomposites prepared by jet milling when compared with the composites prepared by extrusion. The tensile tests showed that ductility remains at a high value for milled nanocomposites, which agreed with the fracture surface images revealing large plastic deformation as a function of the alumina content. This comparative study indicates that the dispersion of nanoparticles in PSU was more homogeneous, with smaller nanoparticles when preparing nanocomposites using jet milling, showing a strong correlation with the enhanced final properties of the nanocomposites.
Preparation, thermoresponsive behavior, and preliminary biological study of functionalized poly(N-isopropylacrylamide-co-dopamine methacrylamide) copolymers with an organotin(IV) compound
(Elsevier, 2021-02-01) García Peñas, Alberto; Wang, Yu; Mena Palomo, Irene; Lopez Collazo, Eduardo; Díaz García, Diana; Gomez Ruiz, Santiago; Stadler, Florian J.; Comunidad de Madrid; Ministerio de Ciencia, Innovación y Universidades (España)
Recent advances focused on smart polymers have demonstrated the numerous advantages regarding other structures because they can adapt the behavior depending on physicochemical properties. In this way, functionalized thermoresponsive polymers with organometallic complexes were profoundly analyzed. Consequently, novel catalytic systems or biomedical devices could be developed. This publication focuses on the facile preparation of poly(N-isopropylacrylamide-co-dopamine methacrylamide) copolymers functionalized with triphenyltin chloride by protonolysis through the -OH of catechol groups. The presence of hydrophobic organotin(IV) derivatives could modify the solubility, thermoresponsive behavior, and other properties regarding pure copolymers. Also, sensitive analysis of the microstructure could help to understand the changes associated with the lower critical solution temperature by rheology, UV-vis spectroscopy, and calorimetry. In addition, a preliminary biological study against MDA-MB-231 cancer cells and peripheral blood mononuclear cells showed that the functionalized copolymers could be a potential platform to be explored in the future in the fight against cancer.
Clickable polymer ligand-functionalized iron oxide nanocubes: A promising nanoplatform for 'local hot spots' magnetically triggered drug release
(ACS Publications, 2022-11-02) Mai, Binh T.; Conteh, John S.; Gavilán, Helena; Girolamo, Alessandro Di; Pellegrino, Teresa; European Commission
Exploiting the local heat on the surface of magnetic nanoparticles (MNPs) upon exposure to an alternating magnetic field (AMF) to cleave thermal labile bonds represents an interesting approach in the context of remotely triggered drug delivery. Here, taking advantages of a simple and scalable two-step ligand exchange reaction, we have prepared iron oxide nanocubes (IONCs) functionalized with a novel multifunctional polymer ligand having multiple catechol moieties, furfuryl pendants, and polyethylene glycol (PEG) side chains. Catechol groups ensure a strong binding of the polymer ligands to the IONCs surface, while the PEG chains provide good colloidal stability to the polymer-coated IONCs. More importantly, furfuryl pendants on the polymer enable to click the molecules of interest (either maleimide–fluorescein or maleimide–doxorubicin) via a thermal labile Diels–Alder adduct. The resulting IONCs functionalized with a fluorescein/doxorubicin-conjugated polymer ligand exhibit good colloidal stability in buffer saline and serum solution along with outstanding heating performance in aqueous solution or even in viscous media (81% glycerol/water) when exposed to the AMF of clinical use. The release of conjugated bioactive molecules such as fluorescein and doxorubicin could be boosted by applying AMF conditions of clinical use (16 kAm–1 and 110 kHz). It is remarkable that the magnetic hyperthermia-mediated release of the dye/drug falls in the concentration range 1.0–5.0 μM at an IONCs dose as low as 0.5 gFe/L and at no macroscopical temperature change. This local release effect makes this magnetic nanoplatform a potential tool for drug delivery with remote magnetic hyperthermia actuation and with a dose-independent action of MNPs.
Polyacrylonitrile-b-polystyrene block copolymer-derived hierarchical porous carbon materials for supercapacitor
(MDPI, 2022-12-01) Álvarez Gómez, Ainhoa; Yuan, Jiayin; Fernandez Blazquez, Juan P.; San Miguel Arnanz, Verónica; Serrano Prieto, María Bernarda; Ministerio de Ciencia e Innovación (España)
The use of block copolymers as a sacrificial template has been demonstrated to be a powerful method for obtaining porous carbons as electrode materials in energy storage devices. In this work, a block copolymer of polystyrene and polyacrylonitrile (PS−b−PAN) has been used as a precursor to produce fibers by electrospinning and powdered carbons, showing high carbon yield (~50%) due to a low sacrificial block content (fPS ≈ 0.16). Both materials have been compared structurally (in addition to comparing their electrochemical behavior). The porous carbon fibers showed superior pore formation capability and exhibited a hierarchical porous structure, with small and large mesopores and a relatively high surface area (~492 m2/g) with a considerable quantity of O/N surface content, which translates into outstanding electrochemical performance with excellent cycle stability (close to 100% capacitance retention after 10,000 cycles) and high capacitance value (254 F/g measured at 1 A/g).
Norbornene as key for a possible efficient chemical recycling in structures based on ethylene
(MDPI, 2022-11-02) Calles Valero, Antonio F.; García Peñas, Alberto; Cerrada, María L.; Gómez Elvira, José M.; Comunidad de Madrid; Ministerio de Ciencia e Innovación (España)
Different circular strategies attempt to increase the energy efficiency or reduce the accumulation of plastic in landfills through the development of circular polymers. Chemical recycling is essential to recover the initial monomers from plastic residues for obtaining new goods showing the same properties as those using virgin monomers from the initial feedstocks. This work addresses the preparation of poly(ethylene-co-norbornene) copolymers for a promising generation of materials for energy applications that could be treated by chemical recycling. The thermal and thermo-oxidative stability for these copolymers with norbornene is higher than for the neat PE, while their degradation exhibits an activation energy lower than that observed in PE, pointing out that chemical recycling would require a lower energy consumption.
Reactions of [60]fullerene with alkynes promoted by OH−
(Royal Society of Chemistry, 2022) Chang, Wei-Wei; He, Fa-Gui; García Peñas, Alberto; Shekh, Mehdihasan I.; Li, Zong-Jun
In the current work, the reactions of [60]fullerene with alkynes promoted by OH− (base) are addressed. The treatment of C60 with alkynes in the presence of TBAOH produces alkynylation products (R-C60–H) with high selectivity in o-DCB at 100 °C. Plausible reaction mechanisms were proposed. This work provides a convenient and environmental friendly method for the functionalization of fullerenes.
MXenes based nano-heterojunctions and composites for advanced photocatalytic environmental detoxification and energy conversion: A review
(Elsevier, 2022-03-01) Sharma, Sunil Kumar; Kumar, Amit; Sharma, Gaurav; Vo, Dai-Viet N.; García Peñas, Alberto; Moradi, Omid; Sillanpää, Mika
Extensive research is being done to develop multifunctional advanced new materials for high performance photocatalytic applications in the field of energy production and environmental detoxification, MXenes have emerged as promising materials for enhancing photocatalytic performance owing to their excellent mechanical properties, appropriate Fermi levels, and adjustability of chemical composition. Numerous experimental and theoretical research works implied that the dimensions of MXenes have a significant impact on their performance. For photocatalysis to thrive in the future, we must understand the current state of the art for MXene in different dimensions. Using MXene co-catalysts in widely used in photocatalytic applications such as CO2 reduction, hydrogen production and organic pollutant oxidation, this study focuses on the most recent developments in MXenes based materials, structural modifications, innovations in reaction and material engineering. It has been reported that using 5 mg of CdS–MoS2-MXene researchers were able to generate as high as 9679 μmol/g/h hydrogen under visible light. The MXenes based heterojunction photocatalyst Co3O4/MXene was utilized to degrade 95% bisphenol A micro-pollutant in just 7 min. Numerous novel materials, their preparations and performances have been discussed. Depending upon the nature of MXene-based materials, the synthesis techniques and photocatalytic mechanism of MXenes as co-catalyst are also summarized. Finally, some final thoughts and prospects for developing highly efficient MXene-based photocatalysts are provided which will indeed motivate researchers to design novel hybrid materials based on MXenes for sustainable solutions to energy and pollution issues.
Water-soluble and-insoluble polymers and biopolymers for biomedical, environmental, and biological applications [Editorial]
(MDPI, 2022-06-02) Stadler, Florian J.; García Peñas, Alberto
Gum acacia-crosslinked-poly(acrylamide) hydrogel supported C3N4/BiOI heterostructure for remediation of noxious crystal violet dye
(MDPI, 2022-04-01) Sharma, Gaurav; Kumar, Amit; Naushad, Mu.; Dhiman, Pooja; Thakur, Bharti; García Peñas, Alberto; Stadler, Florian J.
Herein, we report the designing of a C3N4/BiOI heterostructure that is supported on gum acacia-crosslinked-poly(acrylamide) hydrogel to fabricate a novel nanocomposite hydrogel. The potential application of the obtained nanocomposite hydrogel to remediate crystal violet dye (CVD) in an aqueous solution was explored. The structural and functional analysis of the nanocomposite hydrogel was performed by FTIR (Fourier transform infrared spectroscopy), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The different reaction parameters, such as CVD concentration, nanocomposite hydrogel dosage, and working pH, were optimized. The C3N4/BiOI heterostructure of the nanocomposite hydrogel depicts Z-scheme as the potential photocatalytic mechanism for the photodegradation of CVD. The degradation of CVD was also specified in terms of COD and HR-MS analysis was carried to demonstrate the major degradation pathways.
Fabrication and characterization of xanthan gum-cl-poly(acrylamide-co-alginic acid) hydrogel for adsorption of cadmium ions from aqueous medium
(MDPI, 2022-01) Sharma, Gaurav; Kumar, Amit; Ghfar, Ayman A.; García Peñas, Alberto; Naushad, Mu.; Stadler, Florian J.
The present research demonstrates the facile fabrication of xanthan gum-cl-poly(acrylamide-co-alginic acid) (XG-cl-poly(AAm-co-AA)) hydrogel by employing microwave-assisted copolymerization. Simultaneous copolymerization of acrylamide (AAm) and alginic acid (AA) onto xanthan gum (XG) was carried out. Different samples were fabricated by changing the concentrations of AAm and AA. A sample with maximum swelling percentage was chosen for adsorption experiments. The structural and functional characteristics of synthesized hydrogel were elucidated using diverse characterization tools. Adsorption performance of XG-cl-poly(AAm-co-AA) hydrogel was investigated for the removal of noxious cadmium (Cd(II)) ions using batch adsorption from the aqueous system, various reaction parameters optimized include pH, contact time, temperature, and concentration of Cd(II) ions and temperature. The maximum adsorption was achieved at optimal pH 7, contact time 180 min, temperature 35 °C and cadmium ion centration of 10 mg·L-1. The XG-cl-poly(AAm-co-AA) hydrogel unveiled a very high adsorption potential, and its adsorption capacities considered based on the Langmuir isotherm for Cd(II) ions was 125 mg·g-1 at 35 °C. The Cd(II) ions adsorption data fitted nicely to the Freundlich isotherm and pseudo-first-order model. The reusability investigation demonstrated that hydrogel retained its adsorption capacity even after several uses without significant loss.
Cure kinetics of samarium-doped Fe3O4/epoxy nanocomposites
(MDPI, 2022-01) Jouyandeh, Maryam; Ganjali, Mohammad Reza; Mehrpooya, Mehdi; Abida, Otman; Jabbour, Karam; Rabiee, Navid; Habibzadeh, Sajjad; Mashahdzadeh, Amin Hamed; García Peñas, Alberto; Stadler, Florian J.; Saeb, Mohammad Reza
To answer the question How does lanthanide doping in iron oxide affect cure kinetics of epoxy-based nanocomposites?, we synthesized samarium (Sm)-doped Fe3O4 nanoparticles electrochemically and characterized it using Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-Ray analysis (EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy analyses (XPS). The magnetic particles were uniformly dispersed in epoxy resin to increase the curability of the epoxy/amine system. The effect of the lanthanide dopant on the curing reaction of epoxy with amine was explored by analyzing differential scanning calorimetry (DSC) experimental data based on a model-free methodology. It was found that Sm3+ in the structure of Fe3O4 crystal participates in cross-linking epoxy by catalyzing the reaction between epoxide rings and amine groups of curing agents. In addition, the etherification reaction of active OH groups on the surface of nanoparticles reacts with epoxy rings, which prolong the reaction time at the late stage of reaction where diffusion is the dominant mechanism.
Antibacterial capability of MXene (Ti3C2Tx) to produce PLA active contact surfaces for food packaging applications
(MDPI, 2022-11) Santos Arocha, Xiomara; Álvarez Robledo, Marcos; Videira-Quintela, Diogo; Mediero, Aranzazu; Rodriguez, Juana; Guillén, Francisco; Pozuelo de Diego, Javier; Martín Cádiz, Olga; Ministerio de Ciencia e Innovación (España)
The globalization of the market and the increase of the global population that requires a higher demand of food products superimposes a big challenge to ensure food safety. In this sense, a common strategy to extend the shelf life and save life of food products is by avoiding bacterial contamination. For this, the development of antibacterial contact surfaces is an urgent need to fulfil the above-mentioned strategy. In this work, the role of MXene (Ti3C2Tx) in providing antibacterial contact surfaces was studied through the creation of composite films from polylactic acid (PLA), as the chosen polymeric matrix. The developed PLA/MXene films maintained the thermal and mechanical properties of PLA and also presented the attractive antibacterial properties of MXene. The composites behaviour against two representative foodborne bacteria was studied: Listeria mono-cytogenes and Salmonella enterica (representing Gram-positive and Gram-negative bacteria, respectively). The composites prevented bacterial growth, and in the case of Listeria only 0.5 wt.% of MXene was necessary to reach 99.9999% bactericidal activity (six log reductions), while against Salmonella, 5 wt.% was necessary to achieve 99.999% bactericidal activity (five log reductions). Cy-totoxicity tests with fHDF/TER166 cell line showed that none of the obtained materials were cytotoxic. These results make MXene particles promising candidates for their use as additives into a polymeric matrix, useful to fabricate antibacterial contact surfaces that could prove useful for the food packaging industry.

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