Ewa Piorkowska

Prof. Ewa Piorkowska

Centre of Molecular & Macromolecular Studies, Polish Academy of Sciences, 90001 Lodz, Poland

Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

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

Representative Publications

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5 December 2011 in Journal of Applied Polymer Science
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Journal Article
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MKMarcin Kowalczyk
Marcin Kowalczyk
EPEwa Piorkowska
Ewa Piorkowska

29 February 2012 in Journal of Applied Polymer Science
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Journal Article
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MKMarcin Kowalczyk
Marcin Kowalczyk
MPMiroslaw Pluta
Miroslaw Pluta
EPEwa Piorkowska
Ewa Piorkowska
NKNelli Krasnikova
Nelli Krasnikova

10 September 2014 in Colloid and Polymer Science
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AZAnna Zubrowska
Anna Zubrowska
EPEwa Piorkowska
Ewa Piorkowska
AKAnna Kowalewska
Anna Kowalewska
MCMichal Cichorek
Michal Cichorek
Polylactide (PLA), a main biodegradable and biobased candidate for the replacement of petrochemical polymers, is stiff and brittle at room conditions. It is therefore of high interest to formulate new PLA-based materials suitable for applications demanding flexibility and toughness. In this work, novel blends of PLA with polyhedral oligomeric silsesquioxanes (POSS) grafted with longer (P1) and shorter (P2) arms of ethylene glycol derivatives were prepared and studied. It was hypothesized that, owing to their architecture with the central POSS cage grafted with arms, miscibility and stability of the blends could be improved. Indeed, PLA/P1 blends were homogeneous despite P1 relatively high M w of 9,500 g mol−1. The blend with 20 wt% of P1, having T g at 16 °C, was transparent and flexible, elastomer-like material with excellent drawability. The blend remained homogeneous and retained its good drawability as well as flexibility during 6 months of aging at room temperature: a 2 % secant modulus of elasticity well below 100 MPa, a low yield stress below 2 MPa, and and a large strain at break of 8 (800 %). Contary to that, PLA/P2 blends were only partially miscible. Nevertheless, owing to the liquid state of the dispersed phase, the blend with 15 wt% of P2 was transparent and ductile, with T g at 49 °C, a relatively high yield strength of 29 MPa, and a large strain at break of 2.3 (230 %). The toughening mechanism involved the initiation of crazes and facilitation of their propagation by the liquid inclusions via the local plasticization effect.

1 May 2019 in Journal of Alloys and Compounds
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DKDorota Kowalczyk
Dorota Kowalczyk
SBStefan Brzezinski
Stefan Brzezinski
IKIrena Kaminska
Irena Kaminska
SWStanislawa Wrobel
Stanislawa Wrobel
UMUrszula Mizerska
Urszula Mizerska
TMTomasz Makowski
Tomasz Makowski

29 January 2022 in Materials
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TMTomasz Makowski
Tomasz Makowski
MSMariia Svyntkivska
Mariia Svyntkivska
EPEwa Piorkowska
Ewa Piorkowska
UMUrszula Mizerska
Urszula Mizerska
WFWitold Fortuniak
Witold Fortuniak
Dorota KregielDorota Kregiel
Dorota Kregiel
Graphene oxide (GO) was deposited on a cotton fabric and then thermally reduced to reduced graphene oxide (rGO) with the assistance of L-ascorbic acid. The GO reduction imparted electrical conductivity to the fabric and allowed for electrochemical deposition of Ag° particles using cyclic voltammetry. Only the Ag°/rGO composite coating imparted antibacterial properties to the fabric against Escherichia coli and Staphylococcus aureus. Ag°/rGO-modified fibers were free of bacterial film, and bacterial growth inhibition zones around the material specimens were found. Moreover, Ag°/rGO-modified fabric became superhydrophobic with WCA of 161°.

13 November 2014 in Colloid and Polymer Science
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Journal Article
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Przemyslaw SowinskiPrzemyslaw Sowinski
Przemyslaw Sowinski
EPEwa Piorkowska
Ewa Piorkowska
SBSeverine A. E. Boyer
Severine A. E. Boyer
Jean-Marc HAUDINJean-Marc HAUDIN
Jean-Marc HAUDIN
KZKinga Zapala
Kinga Zapala
Nucleation of the γ-form in isotactic polypropylene (PP) under high pressure was investigated. Three nucleating agents were used to nucleate crystallization of PP under atmospheric pressure: commercial Hyperform HPN-20E from Milliken Chemical, poly(tetrafluoroethylene) particles nucleating the α-form, and calcium pimelate nucleating the β-form. Crystallization of neat PP and PP with addition of 0.2 wt% of the nucleating agents was studied. Specimens were either kept at 200 °C under pressure of 200 MPa for time ranging from 2 min to 4 h or for 15 min under pressure ranging from 1.3 to 300 MPa. After cooling to ambient temperature and releasing the pressure, the specimens were analyzed by DSC, WAXD, and PLM to have an insight into the structure and to determine a crystallinity level and contents of crystallographic forms. Both α-nucleating agents strongly nucleated crystallization of PP under high pressure in the γ-form, whereas the β-nucleating agent had only a slight effect. The results show the possibility to use nucleating agents to nucleate the γ-form of PP under high pressure.