George Pappas

Dr. George Pappas

Johannes Kepler University Linz
orcid

Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

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

Representative Publications

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18 June 2014 in Chemical Science
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AAAthina Anastasaki
Athina Anastasaki
VNVasiliki Nikolaou
Vasiliki Nikolaou
George PappasGeorge Pappas
George Pappas
QZQiang Zhang
Qiang Zhang
Chaoying WanChaoying Wan
Chaoying Wan
DHDavid M. Haddleton
David M. Haddleton
The ability to regulate the activation and deactivation steps via an external stimulus has always been a challenge in polymer chemistry. In an ideal photo-mediated system, whereby high monomer conversion and excellent end group fidelity can be maintained, precise control over the polymer composition and microstructure would be a significant breakthrough. Herein, we report, a versatile, simple and inexpensive method that allows for the synthesis of sequence-controlled multiblock copolymers in a one pot polymerization reaction at ambient temperature. In the absence of a conventional photoredox catalyst and dye-sensitisers, low concentrations of CuBr2 in synergy with Me6-Tren mediate acrylic block copolymerization under UV irradiation (λmax ≈ 360 nm). Four different acrylate monomers were alternated in various combinations within the polymer composition illustrating the potential of the technique. Narrow disperse undecablock copolymers were obtained (Đ < 1.2) with quantitative conversion achieved between the iterative monomer additions. The effect of the chain length was investigated allowing for higher molecular weight multiblock copolymers to be obtained. This approach offers a versatile and inexpensive platform for the preparation of high-order multiblock functional materials with additional applications arising from the precise spatiotemporal “on/off” control and resolution when desired.

1 April 2012 in Corrosion Science
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Ioannis A. KartsonakisIoannis A. Kartsonakis
Ioannis A. Kartsonakis
Elias KoumoulosElias Koumoulos
Elias Koumoulos
ABA.C. Balaskas
A.C. Balaskas
George PappasGeorge Pappas
George Pappas
Costas CharitidisCostas Charitidis
Costas Charitidis
GKG.C. Kordas
G.C. Kordas

27 July 2015 in Macromolecules
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Journal Article
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AAAthina Anastasaki
Athina Anastasaki
VNVasiliki Nikolaou
Vasiliki Nikolaou
GNGabit Nurumbetov
Gabit Nurumbetov
Nghia Truong PhuocNghia Truong Phuoc
Nghia Truong Phuoc
George PappasGeorge Pappas
George Pappas
DHDavid M. Haddleton
David M. Haddleton

1 January 2008 in Journal of Non-Crystalline Solids
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George PappasGeorge Pappas
George Pappas
PLP. Liatsi
P. Liatsi
Ioannis A. KartsonakisIoannis A. Kartsonakis
Ioannis A. Kartsonakis
IDI. Danilidis
I. Danilidis
GKG. Kordas
G. Kordas

1 September 2010 in Journal of Nanoscience and Nanotechnology
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Ioannis A. KartsonakisIoannis A. Kartsonakis
Ioannis A. Kartsonakis
IDIoannis L. Danilidis
Ioannis L. Danilidis
George PappasGeorge Pappas
George Pappas
GKGeorge C. Kordas
George C. Kordas
Titania nanocontainers were synthesized through a two-step process and then loaded with 8-hydroxyquinoline (8-HQ) and p-toluenesulfonic acid (p-TSA). The size of the containers was 242 ± 10 nm as determined by Scanning Electron Microscopy (SEM). X-Ray Diffraction Analysis (XRD) showed that the titania nanocontainers consist of anatase and rutile crystalline phases. The presence of 8-HQ and p-TSA in the nanocontainers was confirmed with Fourier Transform Infrared Spectroscopy (FT-IR). The loading of the inhibitors in the nanocontainers was estimated with Thermo Gravimetric Analysis (TGA). The loading amount of 8-HQ is 3.56% w/w and that of p-TSA is 6.13%. Based on the size of the nanocontainers and the assumption that they are not broken, the amount of approximately with 2.83 · 106 molecules of 8-HQ and 3.86 · 106 molecules of p-TSA per nanocontainer was estimated. Furthermore, release studies of 8-HQ and p-TSA in a corrosive environment were studied by potentiodynamic measurements showing that the inhibitors are released from the nanocontainers, suppressing the corrosion activities. SEM and Dynamic Light Scattering (DLS) measurements confirmed that the nanocontainers are not agglomerated and keep their shape after suspension in 0.5 M NaCl solution for more than 72 hours.

23 July 2010 in Journal of Nanoparticle Research
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EMEvaggelos D. Mekeridis
Evaggelos D. Mekeridis
Ioannis A. KartsonakisIoannis A. Kartsonakis
Ioannis A. Kartsonakis
George PappasGeorge Pappas
George Pappas
George KordasGeorge Kordas
George Kordas