Papers by elisa calabrese
CELEHIS : Revista del Centro de Letras Hispanoamericanas, Dec 19, 2020
Me propongo aquí considerar la novela Río de las congojas("). pues permite reflexionar en to... more Me propongo aquí considerar la novela Río de las congojas("). pues permite reflexionar en torno de cuestiones que atraviesan el tema a que se ha dedicado esta publicación. Por una parte, porque se remite a un período escasamente transitado por la novela histórica argentina, es decir el perrodo colonial. Por otra, porque ello conlleva plantear algunas consideraciones respecto de las características del género en el momento en que fuera publicada, es decir el año 1981 y los procedimientos que el texto pone en juego.
The development of hydrophobic composite coatings is of great interest for several applications i... more The development of hydrophobic composite coatings is of great interest for several applications in the aerospace industry. Functionalized microparticles can be obtained from waste fabrics and employed as fillers to prepare sustainable hydrophobic epoxy-based coatings. Following a waste-to-wealth approach, a novel hydrophobic epoxy-based composite including hemp microparticles (HMPs) functionalized with waterglass solution, 3aminopropyl triethoxysilane, polypropylene-graft-maleic anhydride, and either hexadecyltrimethoxysilane or 1H,1H,2H,2H-perfluorooctyltriethoxysilane is presented. The resulting epoxy coatings based on hydrophobic HMPs were cast on aeronautical carbon fiber-reinforced panels to improve their anti-icing performance. Wettability and anti-icing behavior of the prepared composites were investigated at 25°C and −30°C (complete icing time), respectively. Samples cast with the composite coating can achieve up to 30°C higher water contact angle and doubled icing time than aeronautical panels treated with unfilled epoxy resin. A low content (2 wt %) of tailored HMPs causes an increase of ∼26% in the glass transition temperature of the coatings compared to pristine resin, confirming the good interaction between the hemp filler and epoxy matrix at the interphase. Finally, atomic force microscopy reveals that the HMPs can induce the formation of a hierarchical structure on the surface of casted panels. This rough morphology, combined with the silane activity, allows the preparation of aeronautical substrates with enhanced hydrophobicity, anti-icing capability, and thermal stability.
Macromolecular Materials and Engineering
The present invention relates to catalysts which must be stable in an interactive environment, su... more The present invention relates to catalysts which must be stable in an interactive environment, such as an epoxy mixture hardened at high temperature and/or with hardeners such as aromatic primary amines, in particular catalysts for self-healing resins comprising of vessels containing healing agents
Polymer, 2021
Abstract Fully biodegradable self-healing nanocomposites were prepared by mixing carbon nanotubes... more Abstract Fully biodegradable self-healing nanocomposites were prepared by mixing carbon nanotubes (CNTs)-based carboxyl methyl cellulose (CMC), produced by chemical modification of cellulose, with a commercial biodegradable highly amorphous vinyl alcohol polymer (HAVOH) containing murexide salt. Damaged specimens were allowed to cure by simply touching the cutting sections in a controlled temperature and humidity environment (30 °C and 80%) for a period of 48 h. The healing efficiency of the samples, evaluated by the recovery of the “Storage Modulus” determined by dynamic-mechanical analysis (DMA) of healed samples, manifests a temperature-dependence behaviour. For temperatures above 50 °C, an almost complete recovery (100%) was observed for the sample of HAVOH containing a solubilized murexide salt. The presence of CNTs-based CMC imparts improved mechanical properties. Maximum values for healing efficiency were observed between 30 and 80 °C.
Composites Part B: Engineering, 2021
Abstract Lightweight electro-thermal flexible heaters are attracting great attention for the cons... more Abstract Lightweight electro-thermal flexible heaters are attracting great attention for the considerable applicative potentialities. Some causes, including cost, material availability, complex manufacturing process, absence of biodegradability/recyclability, or low heating efficiency are preventing their widespread application. Herein, an expanded graphite-based polymeric film similar to buckypaper prepared by a very simple green process is proposed as an intermediate layer of a flexible electro-thermal multilayer film heater. The multilayer is also designed to be used on human skin and with any type of food. For low applied voltages, from 3 V to 8 V, a temperature ranging between 26 and 100 °C can be set, reaching a heating rate of 84 °C/min for the maximum applied voltage. A simple simulation of the heating data can help to plan the heating for specific applications. The ease of the production steps together with the absence of pollutants during the preparation process makes the designed device useable on a large scale and for a large variety of applications where values of temperature equal to or below 130 °C are required.
Materials Today: Proceedings, 2020
The use of aeronautical thermosetting resins in the field of structural materials is still limite... more The use of aeronautical thermosetting resins in the field of structural materials is still limited because of several drawbacks, such as the absence of electrical and thermal conductivity and the poor impact damage resistance. An important contribution for increasing the composite application in this field can be given by implementing a strategy of autonomous damage-repair and other specific functions integrated into the material structure. This work proposes a successful strategy based on the design of supramolecular self-healing systems. It is aimed at developing self-healing, load-bearing structures with all functionalities integrated into a single material able to fulfill important industrial requirements.
Revolutionizing Aircraft Materials and Processes, 2020
Thermosetting composites in aircraft structures are typically based on high-performance reinforci... more Thermosetting composites in aircraft structures are typically based on high-performance reinforcing materials, such as carbon fibre, held together by polymer resins, such as epoxies, which undergo an irreversible curing reaction to form the desired structural components. Compared to conventional metallic materials used in aerostructures, thermosetting composites offer superior specific strength and stiffness, along with improved corrosion and fatigue resistance. This can lead to significant gains in performance and fuel efficiency, along with reduced maintenance requirements. Consequently, these materials continue to gain favour in aircraft construction. The drive towards lower production costs, partly facilitated through the development of larger integrated structural components at higher production rates, is leading to new innovations in manufacturing. Advances in liquid resin infusion methodologies are helping to produce such large structural components more economically, while the development of automated fibre placement technologies is enhancing production quality and minimising conventional labour costs. However, a lack of maturity and experience in the analysis, design, manufacture, and maintenance of composite aerostructures continue to necessitate the need for greater research. For example, improvements in non-destructive inspection and adhesively bonded repairs are required to make composite maintenance more efficient and reliable. Further weight savings and performance benefits could also be achieved by integrating essential systems within composite structures, imbuing them with ‘multifunctionality’. Composite waste is another significant issue, given the projected increase in demand for these materials. In particular, thermoset composite recycling is expected to be a key technology requirement.
Composites Part B: Engineering, 2019
The development of high performance self-healing composites is still at an early stage due to the... more The development of high performance self-healing composites is still at an early stage due to the difficulty to integrate self-healing mechanisms in their structure by applying current manufacturing processes. Here, the authors propose structural self-healing resins based on dynamic hydrogen bonds capable to overcome many current industrial limitations. Hydrogen bonding moieties, such as barbiturate and thymine, able to act as reversible healing-elements by their simultaneous donor and acceptor character, can be covalently linked to multi-wall carbon nanotubes (MWCNTs) to generate self-healing nanocomposites. The so functionalized MWCNTs, embedded in a rubber-toughened epoxy formulation, lead to reversible MWCNTs-bridges through the matrix due to strong attractive interactions between the rubber phase, finely dispersed in the matrix, and MWCNT walls. Healing efficiencies have been assessed for the nanocharged epoxy formulation loaded with 0.5% wt/wt of MWCNTs decorated with barbituric acid and thymine groups. For both functional groups, healing efficiencies higher than 50% have been found. Dynamic mechanical analysis (DMA) evidences an enhancement in epoxy chains movements due to micro/nano domains of the rubber phase enabling self-healing behavior by recovering the critical fracture load. Results from this study may promote the wide development of safe and costefficient self-healing composites in aeronautical, automotive, civil engineering and wind power industries.
International Journal of Structural Integrity, 2018
PurposeThe purpose of this paper is to highlight the relevant role of the stereochemistry of two ... more PurposeThe purpose of this paper is to highlight the relevant role of the stereochemistry of two Ruthenium catalysts on the self-healing efficiency of aeronautical resins.Design/methodology/approachHere, a very detailed evaluation on the stereochemistry of two new ruthenium catalysts evidences the crucial role of the spatial orientation of phenyl groups in the N-heterocyclic carbene ligands in determining the temperature range within the curing cycles is feasible without deactivating the self-healing mechanisms (ring-opening metathesis polymerization reactions) inside the thermosetting resin. The exceptional activity and thermal stability of the HG2MesPhSyncatalyst, with the syn orientation of phenyl groups, highlight the relevant potentiality and the future perspectives of this complex for the activation of the self-healing function in aeronautical resins.FindingsThe HG2MesPhSyncomplex, with the syn orientation of the phenyl groups, is able to activate metathesis reactions within t...
La pregunta que titula este trabajo procura leer en la obra de Jorge Luis Borges algunas de las c... more La pregunta que titula este trabajo procura leer en la obra de Jorge Luis Borges algunas de las características que lo sitúan como uno de los más importantes escritores no solamente en su país, sino para la moderna literatura de la cultura occidental. Con este propósito, este ensayo explora los principales procedimientos de algunos de sus textos –en especial los que pertenecen a la tradición literaria argentina- que pueden mostrar esta cuestión. Asimismo, este trabajo lee el pensamiento político del escritor, pese a sus bien conocidas opiniones acerca de la autonomía del arte
La Aurora Y El Poniente Borges 2000 Pags 127 142, 2000
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Papers by elisa calabrese