Raffaele Longo

Dr. Raffaele Longo

University of Salerno, Department of Industrial Engineering
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 February 2022 in Journal of Thermal Analysis and Calorimetry
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Raffaele LongoRaffaele Longo
Raffaele Longo
MCMichelina Catauro
Michelina Catauro
Andrea SorrentinoAndrea Sorrentino
Andrea Sorrentino
Liberata GuadagnoLiberata Guadagno
Liberata Guadagno
Nowadays, continuous development of soft-electronics and wearable devices opens to the development needs of stretchable and flexible materials able to interface with the human body. In this scenario, biopolymers are particularly intriguing materials given their biocompatibility and biodegradability. For the application in this specific field the material requires several properties such as biological and mechanical performance and thermal stability. In this study, membranes able to fulfill some of these requirements are described. The electrospun membranes, composed of a blend of polycaprolactone (PCL) and gelatin (GN), have been produced in various configurations. The results show how blend or coaxial systems have different effects on both the interactions between the polymers and their thermal and mechanical properties. An important result of the chosen experimental conditions is the narrow dimensional distribution of the nanofiber diameters constituting the electrospun membranes. Thermal and mechanical tests evidenced that, by properly choosing the material composition and the method of the electrospinning process, membranes capable of withstanding high strain values before the failure can be obtained. In particular, optimizing the electrospinning process and using a blend PCL/GN with a mass ratio of 80/20, it is possible to increase the thermal stability up to 310 °C and confer to the sample the ability to reach a percentage of strain up to 350%.

26 March 2021 in Nanomaterials
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Raffaele LongoRaffaele Longo
Raffaele Longo
Giuliana GorrasiGiuliana Gorrasi
Giuliana Gorrasi
Liberata GuadagnoLiberata Guadagno
Liberata Guadagno
Nanoparticles (NPs) in the biomedical field are known for many decades as carriers for drugs that are used to overcome biological barriers and reduce drug doses to be administrated. Some types of NPs can interact with external stimuli, such as electromagnetic radiations, promoting interesting effects (e.g., hyperthermia) or even modifying the interactions between electromagnetic field and the biological system (e.g., electroporation). For these reasons, at present these nanomaterial applications are intensively studied, especially for drugs that manifest relevant side effects, for which it is necessary to find alternatives in order to reduce the effective dose. In this review, the main electromagnetic-induced effects are deeply analyzed, with a particular focus on the activation of hyperthermia and electroporation phenomena, showing the enhanced biological performance resulting from an engineered/tailored design of the nanoparticle characteristics. Moreover, the possibility of integrating these nanofillers in polymeric matrices (e.g., electrospun membranes) is described and discussed in light of promising applications resulting from new transdermal drug delivery systems with controllable morphology and release kinetics controlled by a suitable stimulation of the interacting systems (nanofiller and interacting cells).

14 December 2022 in Materials & Design
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Liberata GuadagnoLiberata Guadagno
Liberata Guadagno
FAFrancesca Aliberti
Francesca Aliberti
Raffaele LongoRaffaele Longo
Raffaele Longo
MRMarialuigia Raimondo
Marialuigia Raimondo
RPRoberto Pantani
Roberto Pantani
LVLuigi Vertuccio
Luigi Vertuccio

26 January 2023 in Nanomaterials
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Liberata GuadagnoLiberata Guadagno
Liberata Guadagno
Raffaele LongoRaffaele Longo
Raffaele Longo
FAFrancesca Aliberti
Francesca Aliberti
Patrizia LambertiPatrizia Lamberti
Patrizia Lamberti
Vincenzo TucciVincenzo Tucci
Vincenzo Tucci
LVLuigi Vertuccio
Luigi Vertuccio
This work proposes nanocomposites with carbon nanotubes characterized by self-sensing and self-heating properties. Recently, a growing interest in these two properties has been found in many industrial sectors, especially in the aerospace and automotive fields. While the self-sensing function allows diagnosing the presence of micro-damage in the material thanks to the detection of residual resistance, the self-heating function is exploited to properly tune the heating performance in terms of the heating rate and final temperature values. An electrical percolation value of around 0.5% by weight of carbon nanotubes was found by electrical characterization. The AC conductivity of the nanocomposites, in the range of 100 Hz to 1 MHz, evidences that beyond a CNTs amount of 0.5% wt/wt, they are characterized by a purely resistive behavior. The self-sensing analysis displayed a gauge factor value of 4.1. The solid thermal stability up to 300 °C makes the material suitable as a heating element at high temperatures. SEM investigations and temperature maps evidence a good dispersion of the conductive filler in the epoxy matrix and, consequently, good isotropy in heat distribution. As regards the trend of electrical resistance by varying the temperature, the electro-thermal investigation has shown the presence of both Positive Temperature Coefficient (PTC) and Negative Temperature Coefficient (NTC) behaviors with a predominance of NTC as soon as the temperature becomes closer to the glass transition temperature of the epoxy resin.

28 September 2020 in Polymers
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Giuliana GorrasiGiuliana Gorrasi
Giuliana Gorrasi
Raffaele LongoRaffaele Longo
Raffaele Longo
GIANLUCA VISCUSIGIANLUCA VISCUSI
GIANLUCA VISCUSI
Membranes based on poly(ε-caprolactone)/poly(3-hydroxybutyrate) blends (PCL/PHB at 50 wt%) were obtained by electrospinning and curcumin encapsulated at 1 wt% as active agent, as drug delivery systems for biomedical applications. PCL and PHB were also separately electrospinned and loaded with 1 wt% of curcumin. The processing parameters of PHB were drastically different from PCL and the blend PCL/PHB; in fact, the temperature used was 40 °C, and the distance injector–collector was 28 cm. Different conditions were used for PCL: lower temperature (i.e., 25 °C) and shorter distance injector–collector (i.e., 18 cm). The blend was processed in the same conditions of PCL. The fibers obtained with PHB showed diameters in the order of magnitude of micron (i.e., ≈ 3.45 µm), while the PCL mats is composed of fiber of nanometric dimensions (i.e., ≈ 340 nm). PCL/PHB blend allowed to obtain nanometric fibers (i.e., ≈520 nm). Same trend of results was obtained for the fibers’ porosity. The morphology, thermal, mechanical and barrier properties (sorption and diffusion) through water vapor were evaluated on all the electrospun fibers, as well as the release behavior of curcumin, and correlated to the processing parameter and the fibers’ morphologies.

13 May 2023 in Polymers
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Liberata GuadagnoLiberata Guadagno
Liberata Guadagno
Andrea SorrentinoAndrea Sorrentino
Andrea Sorrentino
Raffaele LongoRaffaele Longo
Raffaele Longo
Marialuigia RaimondoMarialuigia Raimondo
Marialuigia Raimondo
In this study, a tetrafunctional epoxy resin was loaded with 5 wt% of three different types of polyhedral oligomeric silsesquioxane (POSS) compounds, namely, DodecaPhenyl POSS (DPHPOSS), Epoxycyclohexyl POSS (ECPOSS), Glycidyl POSS (GPOSS), and 0.5 wt% of multi-walled carbon nanotubes (CNTs) in order to formulate multifunctional structural nanocomposites tailored for aeronautic and aerospace applications. This work aims to demonstrate how the skillful combination of desired properties, such as good electrical, flame-retardant, mechanical, and thermal properties, is obtainable thanks to the advantages connected with nanoscale incorporations of nanosized CNTs with POSS. The special hydrogen bonding-based intermolecular interactions between the nanofillers have proved to be strategic in imparting multifunctionality to the nanohybrids. All multifunctional formulations are characterized by a Tg centered at values close to 260 °C, fully satisfying structural requirements. Infrared spectroscopy and thermal analysis confirm the presence of a cross-linked structure characterized by a high curing degree of up to 94% and high thermal stability. Tunneling atomic force microscopy (TUNA) allows to detect the map of the electrical pathways at the nanoscale of the multifunctional samples, highlighting a good dispersion of the carbon nanotubes within the epoxy resin. The combined action of POSS with CNTs has allowed to obtain the highest values of self-healing efficiency if compared to those measured for samples containing only POSS in the absence of CNTs.