Publikācijas (ERAF1.1.1.2/VIAA/1/16/066) / Publications

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Browsing Publikācijas (ERAF1.1.1.2/VIAA/1/16/066) / Publications by Author "Zotti, Aldobenedetto"

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    Environmental effects on mechanical, thermophysical and electrical properties of epoxy resin filled with carbon nanofillers
    (AIP Publishing, 2019-12-12) Glaskova-Kuzmina, Tatjana; Aniskevich, Andrey; Sevcenko, Jevgenijs; Zotti, Aldobenedetto; Borriello, Anna; Zarrelli, Mauro
    The aim of this work was to establish the effect of environmental factors (moisture and temperature) on some mechanical, electrical and thermal properties of epoxy-based composites filled with carbon nanofillers: nanotubes (CNT), nanofibers (CNF) and hybrid nanofiller (nanotubes/nanofibers in the ratio 1:1) and to reveal the most environmentally stable NC. First, the nanocomposites (NC) containing different nanofiller contents were prepared to evaluate electrical percolation threshold and to choose NC at certain electrical conductivity for further characterization of the physical properties in initial state and during/after environmental ageing. The environmental ageing consisted of water absorption at 70 °C until equilibrium moisture content reached all samples in 4 weeks and 2) heating at 70 °C for the same time, and 3) freezing at -20 °C for 8 weeks. Two concurrent factors, temperature and moisture, led to post-curing of all materials studied without significant plastization. Some positive nanofiller effects were found for sorption, mechanical and thermophysical characteristics of RTM6 epoxy resin. Based on experimental results, the most environmentally stable NC was epoxy filled with 0.1 wt. % of CNT/CNF hybrid, which had the lowest effect of temperature and moisture on thermal and electrical conductivities, along with the lowest equilibrium water content and diffusivity.
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    Hydrothermal Aging of an Epoxy Resin Filled with Carbon Nanofillers
    (MDPI, 2020-05-18) Glaskova-Kuzmina, Tatjana; Aniskevich, Andrey; Papanicolaou, George; Portan, Diana; Zotti, Aldobenedetto; Borriello, Anna; Zarrelli, Mauro
    The effects of temperature and moisture on flexural and thermomechanical properties of neat and filled epoxy with both multiwall carbon nanotubes (CNT), carbon nanofibers (CNF), and their hybrid components were investigated. Two regimes of environmental aging were applied: Water absorption at 70 °C until equilibrium moisture content and thermal heating at 70 °C for the same time period. Three-point bending and dynamic mechanical tests were carried out for all samples before and after conditioning. The property prediction model (PPM) was successfully applied for the prediction of the modulus of elasticity in bending of manufactured specimens subjected to both water absorption and thermal aging. It was experimentally confirmed that, due to addition of carbon nanofillers to the epoxy resin, the sorption, flexural, and thermomechanical characteristics were slightly improved compared to the neat system. Considering experimental and theoretical results, most of the epoxy composites filled with hybrid carbon nanofiller revealed the lowest effect of temperature and moisture on material properties, along with the lowest sorption characteristics.