Zakład Fizyki Makromolekularnej
Strona główna
Zespół
Badania
Aparatura
Seminaria
Publikacje
Nasze
konferencje
Aktywność
konferencyjna
Projekty
Programy
Najbliższe
wydarzenia
Linki
Kontakt

wizyta

od 2020-09-20

Dr Aleksandra Wypych  | 2005-10 <> 2008-09

Stażysta podoktorski

  0000-0002-2281-6233     8549657500  

Zainteresowania naukowe:
Dynamika molekularna materiałów polimerowych badana z użyciem spektroskopii dielektrycznej.

Publikacje      Projekty      Doktorzy      Magistrowie           Seminaria


8.

Krysiak E., Wypych-Puszkarz A., Krysiak K., Nowaczyk G., Makrocka-Rydzyk M., Jurga S., Ulański J.

Core-shell system based on titanium dioxide with elevated value of dielectric permittivity: Synthesis and characterization In this work we report a reproducible and efficient method of surface modification of titania nanoparticles (rutile) via reversible-deactivation radical polymerization. Herein, we graft poly(di (ethylene glycol) methyl ether methacrylate) from the surface of TiO2in an amount of 21 wt% within the reaction time of 3 h 15 min. The amount of grafted polymer was assessed by Thermogravimetric Analysis and it is one of the highest reported till now for this ceramic nanoparticles by atom transfer radical polymerization. The properties of inorganic-organic, i.e. core-shell material, as well as of pristine TiO2 and neat polymer were examined by Infrared and Dielectric Spectroscopies. The shape of the nanoparticles and the thickness of the polymer coating shell were investigated by means of High Resolution Transmission Electron Microscopy. The obtained nanocomposite exhibits dielectric permittivity e0= 18 and loss tangent around 1 102 at 20C. The described method allows controlling a length and chemical structure of the grafted polymer from ceramic core, thus to tailor a physical properties of nanoparticles and of nanocomposites.
(C) 2015 Elsevier B.V. All rights reserved.

Synthetic Metals, 209(3), 150-157 (2015)

DOI: 10.1016/j.synthmet.2015.06.028


7.

Jenczyk J., Dobies M., Makrocka-Rydzyk M., Wypych A., Jurga S.

The segmental and global dynamics in lamellar microphase-separated poly(styrene-b-isoprene) diblock copolymer studied by 1H NMR and dielectric spectroscopy The nuclear magnetic resonance (NMR) and dielectric spectroscopy (DS) methods were used to investigate the segmental and global dynamics in lamellar microphase separated poly(styrene-b-isoprene) (SI) diblock copolymer. For the first time, the susceptibility representation of the NMR relaxation data is applied to the analysis of the molecular dynamics in complex polymer systems like the diblock copolymer. This approach in combination with the frequency-temperature superposition (FTS) allows one to compare directly the NMR and DS data in an extended frequency range providing a unique comprehensive picture of various relaxation processes present in the system studied. The findings of these investigations include structural relaxations of the polyisoprene (PI) and the polystyrene (PS) blocks, a normal mode relaxation of the PI block, and an extra low frequency interfacial relaxation. Special attention has been devoted to influence of the copolymer morphology on the segmental and global dynamics in PI.
(C) 2013 Published by Elsevier Ltd.

European Polymer Journal, 49(12), 3986-3997 (2013)

DOI: 10.1016/j.eurpolymj.2013.09.003   (Pobrane:  2020-10-23)


6.

Wypych A., Szpotkowski K., Jurga S., Domka L., Kozak M.

Interactions of a cationic surfactant - (benzyloxymethyl) dodecyldimethylammonium chloride with model biomembrane systems Phospholipids are the main components of biological membranes. The aim of the present study was to determine the influence of a cationic surfactant on phospholipid structure and dynamics. Fourier transform infrared (FTIR) and dielectric relaxation (DRS) spectroscopies as well as small-angle Xray scattering (SAXS) with synchrotron radiation have been used to analyse the structure of fully hydrated 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) in the presence of a quaternary ammonium surfactant: (benzyloxymethyl) dodecyldimethylammoniumchloride (BzMDDAC). The presence of the surfactant caused changes in the temperature of the DMPC phase transition, as revealed using FTIR and DRS measurements. This change results from the disappearance of the multilamellar phase of DMPC and the formation of the unilamellar (most likely bicellar) phase, as indicated by the SAXS results.
(C) 2013 Elsevier B.V. All rights reserved.

Colloids and Surfaces B: Biointerfaces, 108, 212-218 (2013)

DOI: 10.1016/j.colsurfb.2013.03.010   (Pobrane:  2021-01-20)


5.

Makrocka-Rydzyk M., Wypych A., Dobies M., Jancelewicz M., Jurga S., Cho HY., Gao HF., Matyjaszewski K.

Molecular dynamics in PBA/PEO miktoarm star copolymers Molecular dynamics of miktoarm star copolymers consisting of poly(n-butyl acrylate) PBA and polyethylene oxide (PEO) arms was studied by means of Broadband Dielectric Spectroscopy (BDS) and Nuclear Magnetic Resonance (NMR) methods. The spectroscopic studies were performed for three types of copolymers differing in the composition, namely materials containing 76%, 46% and 16% molar fraction of PBA arms. The local processes, described by the Arrhenius law (e.g. the anisotropic rotation of methyl groups and the anisotropic local motions in the PEO chain), were observed for the studied systems below the glass transition temperature. It was found that the investigated PBA/PEO miktoarm star copolymers are characterized by single glass transition, which may result from similar values of glass transition temperatures of the PBA and PEO polymers. The segmental dynamics in the studied systems was quantitatively described by using the Vogel-Fulcher-Tammann (VFT) relation applied to combined NMR and BDS data. Moreover, above the glass transition temperature the interfacial polarization and conductivity phenomena were detected with the BDS method for all systems under study.
(C) 2013 Elsevier Ltd. All rights reserved.

Polymer, 54(13), 3341-3349 (2013)

DOI: 10.1016/j.polymer.2013.04.004


4.

Makrocka-Rydzyk M., Wypych A., Szpotkowski K., Kozak M., Jurga S., Gao H.F., Cho H.Y., Matyjaszewski K.

Structural studies of poly(butyl acrylate) - poly(ethylene oxide) miktoarm star polymers Structural behavior of miktoarm star polymers comprising poly(butyl acrylate) (PBA) and poly(ethylene oxide) (PEO) arms was studied by means of Differential Scanning Calorimetry (DSC), Wide Angle X-Ray Scattering (WAXS), Polarized Optical Microscopy (POM) and Fourier Transform Infrared Spectroscopy (FTIR) methods. The aim of this study was to correlate changes in the composition of the arms of the PBA/PEO miktoarm star polymers with their structures. As a consequence of increasing PBA content, the decrease in crystallinity of the studied PBA/PEO heteroarm star copolymers was observed. Regardless of the copolymer composition, fraction of oxyethylene units in the crystalline PEO phase was similar in all investigated systems. The POM images showed spherulitic morphology of the materials having low PBA content, while an increase in PBA arms fraction leads to the formation of less ordered structures. The analysis of FTIR vibrational spectrum indicates helical conformation of PEO chains in the crystalline phase. Isothermal crystallization studies carried out using the FTIR technique suggest the existence of isolated domains in the nanoscopic scale of investigated materials.

Polymer, 52(24), 5513-5520 (2011)

DOI: 10.1016/j.polymer.2011.09.020   (Pobrane:  2020-10-23)


3.

Jenczyk J., Makrocka-Rydzyk M., Wypych A., Głowinkowski S., Jurga S., Radosz M.

The phase structure and molecular dynamics in poly(styrene-b-isoprene) diblock copolymer Molecular dynamics of polyisoprene, polystyrene and poly(styrene-b-isoprene) diblock copolymer has been studied by means of broadband dielectric and magnetic resonance spectroscopies. The measurements of dielectric permittivity as well as NMR second moment, spin-lattice relaxation times T(1) and T(1ρ), in wide range of temperature were performed. It was found that the copolymer exhibits all motions observed in the neat components i.e., three motions connected with polyisoprene blocks (segmental, normal-mode and methyl group rotation) and one (segmental) related to polystyrene blocks. The mutual interaction between polystyrene and polyisoprene chains leads to stiffening of polyisoprene blocks and loosening of polystyrene structure. The polyisoprene segmental and normal-mode motions were analyzed in terms of the Havriliak-Negami model and Vogel-Fulcher-Tamman (VFT) relation. Based on NMR spin-diffusion experiment the size of polystyrene domains in copolymer was evaluated and accounts to 9 nm.
(C) 2010 Elsevier B.V. All rights reserved.

Journal od Non-Crystalline Solids, 356(11-17), 582-588 (2010)

DOI: 10.1016/j.jnoncrysol.2009.06.046   (Pobrane:  2020-10-23)


2.

Jancelewicz M., Nowaczyk G., Makrocka-Rydzyk M., Wypych A., Fojud Z., Jurga S., Maciejewski H.

Molecular dynamics in grafted polydimethylsiloxanes Rheological and dielectric behavior of linear PDMS and alkyl-modified PDMS melts has been studied. Molecular dynamics of linear PDMS, being a model of grafted polydimethylsiloxanes studied, has been examined carefully with particular attention paid to its ability to form the semicrystalline phase. Random incorporation of alkyl groups into PDMS chain has been shown to prevent the polymer crystallization. The glass transition temperature of the grafted PDMS changes proportionally to the modifier content. Both techniques allow characterization of the main alpha-relaxation, which is related to the glass transition and exhibits similar behavior in all systems. This relaxation is discussed in terms of the Vogel-Fulcher-Tammann-Hesse (VFTH) approach. The fragility of grafted PDMS materials was found to be higher as compared to the linear polymer. The analysis of the rheological data shows the existence of additional slow relaxation, which has been interpreted as the polymer chain motion.
(C) 2010 Elsevier B.V. All rights reserved.

Journal of Non-Crystalline Solids, 356(11-17), 669-675 (2010)

DOI: 10.1016/j.jnoncrysol.2009.07.036   (Pobrane:  2020-10-21)


1.

Kozak M., Wypych A., Szpotkowski K., Jurga S., Skrzypczak A.

Structural and spectroscopic studies of DMPC/cationic surfactant system Aqueous suspension of a mixture of 1,2-dimyrilstoyl-sn-glycero-3-phosphocholine (DMPC) and (dodecyloxymethyl)dodecydimethylammonium (DDMDDAC) has been investigated by Fourier transform infrared spectroscopy (FTIR), small angle scattering of synchrotron radiation (SAXS) and dielectric spectroscopy (DS). The introduction of surfactant to DMPC water solution probably induces formation of discoidal (bicellar) phase, as revealed by SAXS studies. The presence of the surfactant has been found to decrease the main phase transition temperature, i.e., from rippled gel to liquid crystalline phase, as indicated by the DS and FTIR results. The small steps in the real part of dielectric permittivity plot vs. temperature can be related to the: planar gel to rippled gel (L(beta') -> P(beta')) and rippled gel-liquid crystal (P(beta') -> L(alpha)) phase transitions, which is supported by the temperature dependencies of the symmetric and anti-symmetric CH(2) band frequencies from FTIR measurements.
(C) 2010 Elsevier B.V. All rights reserved.

Journal of Non-Crystalline Solids, 356(11-17), 747-753 (2010)

DOI: 10.1016/j.jnoncrysol.2009.07.043


 © Opisy i zdjęcia: Zakład Fizyki Makromolekularnej  | Ta stona używa ciasteczek
     Zaktualizowano: podstrony  2021-06-21  / bazę danych:   2021-08-30  by Webmaster: Zbigniew Fojud