Nevena Manolova - Academia.edu (original) (raw)
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European Polymer Journal, 2008
European Polymer Journal, 2012
European Polymer Journal, 2006
Cited By (since 1996):1, Export Date: 18 October 2014
Materials Science and Engineering: C, 2014
Journal of Sol-Gel Science and Technology, 2011
Journal of Bioactive and Compatible Polymers, 2010
Nanofibrous polyacrylonitrile membranes (PANNFM) were obtained by electrospinning and then prepar... more Nanofibrous polyacrylonitrile membranes (PANNFM) were obtained by electrospinning and then prepared for immobilizing acetylcholinesterase (AChE). Initially, the chemical modification of PANNFM with ethylenediamine produced reactive groups to overcome their inertness and hydrophobicity. The natural polymer, chitosan, was then tethered on the nanofibrous membranes to improve their biocompatibility. Scanning electron microscopy (SEM) and cross-section SEM were used to determine morphological and
Journal of Sol-Gel Science and Technology, 2009
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013
Materials Science and Engineering: C, 2016
Materials Science and Engineering: C, 2016
New self-cleaning materials of polymer fibers decorated with a hybrid between nanosized zinc oxid... more New self-cleaning materials of polymer fibers decorated with a hybrid between nanosized zinc oxide and expanded graphite (EG) or fullerene (C60) were obtained. The new materials were prepared by applying electrospinning in conjunction with electrospraying. Poly(l-lactide) (PLA) was selected as a biocompatible and (bio)degradable polymer carrier. PLA solution was electrospun in combination with electrospraying of a suspension that contained the ZnO/EG or ZnO/C60 hybrid. Mats with different content of EG or C60 were obtained. The new materials were characterized by scanning and transmission electron microscopy (SEM and TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction analysis (XRD). The photocatalytic activity of the materials was evaluated by using model dyes. The formation of a hybrid between ZnO and EG led to enhancement of the photocatalytic activity of the mats at ZnO/EG weight ratios of 90/10 and 85/15. Increase in the photocatalytic activity of the ZnO-containing mats was also achieved by the formation of a hybrid between ZnO and C60 at a fullerene content of 0.5 and 1.0wt.% in respect to ZnO weight. The new materials exhibited antibacterial activity as evidenced by the performed studies against Staphylococcus aureus.
European Polymer Journal
ABSTRACT
Applied Surface Science, 2014
ABSTRACT New hybrid fibrous materials from the biocompatible and biodegradable aliphatic polyeste... more ABSTRACT New hybrid fibrous materials from the biocompatible and biodegradable aliphatic polyester poly(L- lactide) (PLA) and pristine or surface-functionalized nanosized zinc oxide were prepared. The application of the techniques: (i) electrospinning of a suspension of ZnO in PLA solution, or (ii) simultaneous electrospinning of PLA solution and electrospraying of a ZnO suspension in PLA solution (at low PLA concentration) enabled the fabrication of hybrid materials of diverse design: non-woven textile consisting of fibers in which ZnO was deposited on the fibers' surface (designated as type "on") or was mainly in the fibers' bulk (designated as type "in"). The photocatalytic activity of the new fibrous materials was estimated in respect to Methylene Blue (MB) and Reactive Red (RR) dyes. Type "on" hybrid materials had higher photocatalytic activity as compared to type "in" materials. It was shown that type "on" materials preserved their photocatalytic activity in respect to MB even after three repeated uses, while for the RR dye the same held true for ZnO-on-PLA mats only. The type "on" materials exhibited antimicrobial activity against the pathogenic microorganism Staphylococcus aureus as evidenced by the performed microbiological tests.
Journal of Polymer Science: Polymer Chemistry Edition, 1983
ABSTRACT The initiation reaction of the polymerization of α-methylstyrene by trityl tetrachlorofe... more ABSTRACT The initiation reaction of the polymerization of α-methylstyrene by trityl tetrachloroferate and tritylhexachloroantimonate in 1,2-dichloroethane at 20°C was studied. The rate constants were 14 × 10−3 and 27 × 10−3 L mol−1s−1, respectively. The dissociation constants of tritylterachloroferate (Kd = 0.88 × 10−4M−1) and tritylhexachloroantimonate (Kd = 2.64 × 10−4M−1) was determined. The effect of electron acceptors and donors on the dissociation equilibrium and initiation rate was investigated. It was shown that in strongly dissociated ion pairs such as stable carbenium salts the electron donors and acceptors have no appreciable effect on the magnitude of the dissociation. The temperature dependence of the rate constants in the −20–+20°C range yielded the following thermodynamic parameters for trityltetrachloroferate: Ei = 8.54 kcal/mol; A = 3.2 × 104 mol−1s−1; ΔH* = 8 kcal/mol; and S* = −39.8 eu.
European Polymer Journal, 2008
European Polymer Journal, 2012
European Polymer Journal, 2006
Cited By (since 1996):1, Export Date: 18 October 2014
Materials Science and Engineering: C, 2014
Journal of Sol-Gel Science and Technology, 2011
Journal of Bioactive and Compatible Polymers, 2010
Nanofibrous polyacrylonitrile membranes (PANNFM) were obtained by electrospinning and then prepar... more Nanofibrous polyacrylonitrile membranes (PANNFM) were obtained by electrospinning and then prepared for immobilizing acetylcholinesterase (AChE). Initially, the chemical modification of PANNFM with ethylenediamine produced reactive groups to overcome their inertness and hydrophobicity. The natural polymer, chitosan, was then tethered on the nanofibrous membranes to improve their biocompatibility. Scanning electron microscopy (SEM) and cross-section SEM were used to determine morphological and
Journal of Sol-Gel Science and Technology, 2009
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013
Materials Science and Engineering: C, 2016
Materials Science and Engineering: C, 2016
New self-cleaning materials of polymer fibers decorated with a hybrid between nanosized zinc oxid... more New self-cleaning materials of polymer fibers decorated with a hybrid between nanosized zinc oxide and expanded graphite (EG) or fullerene (C60) were obtained. The new materials were prepared by applying electrospinning in conjunction with electrospraying. Poly(l-lactide) (PLA) was selected as a biocompatible and (bio)degradable polymer carrier. PLA solution was electrospun in combination with electrospraying of a suspension that contained the ZnO/EG or ZnO/C60 hybrid. Mats with different content of EG or C60 were obtained. The new materials were characterized by scanning and transmission electron microscopy (SEM and TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction analysis (XRD). The photocatalytic activity of the materials was evaluated by using model dyes. The formation of a hybrid between ZnO and EG led to enhancement of the photocatalytic activity of the mats at ZnO/EG weight ratios of 90/10 and 85/15. Increase in the photocatalytic activity of the ZnO-containing mats was also achieved by the formation of a hybrid between ZnO and C60 at a fullerene content of 0.5 and 1.0wt.% in respect to ZnO weight. The new materials exhibited antibacterial activity as evidenced by the performed studies against Staphylococcus aureus.
European Polymer Journal
ABSTRACT
Applied Surface Science, 2014
ABSTRACT New hybrid fibrous materials from the biocompatible and biodegradable aliphatic polyeste... more ABSTRACT New hybrid fibrous materials from the biocompatible and biodegradable aliphatic polyester poly(L- lactide) (PLA) and pristine or surface-functionalized nanosized zinc oxide were prepared. The application of the techniques: (i) electrospinning of a suspension of ZnO in PLA solution, or (ii) simultaneous electrospinning of PLA solution and electrospraying of a ZnO suspension in PLA solution (at low PLA concentration) enabled the fabrication of hybrid materials of diverse design: non-woven textile consisting of fibers in which ZnO was deposited on the fibers' surface (designated as type "on") or was mainly in the fibers' bulk (designated as type "in"). The photocatalytic activity of the new fibrous materials was estimated in respect to Methylene Blue (MB) and Reactive Red (RR) dyes. Type "on" hybrid materials had higher photocatalytic activity as compared to type "in" materials. It was shown that type "on" materials preserved their photocatalytic activity in respect to MB even after three repeated uses, while for the RR dye the same held true for ZnO-on-PLA mats only. The type "on" materials exhibited antimicrobial activity against the pathogenic microorganism Staphylococcus aureus as evidenced by the performed microbiological tests.
Journal of Polymer Science: Polymer Chemistry Edition, 1983
ABSTRACT The initiation reaction of the polymerization of α-methylstyrene by trityl tetrachlorofe... more ABSTRACT The initiation reaction of the polymerization of α-methylstyrene by trityl tetrachloroferate and tritylhexachloroantimonate in 1,2-dichloroethane at 20°C was studied. The rate constants were 14 × 10−3 and 27 × 10−3 L mol−1s−1, respectively. The dissociation constants of tritylterachloroferate (Kd = 0.88 × 10−4M−1) and tritylhexachloroantimonate (Kd = 2.64 × 10−4M−1) was determined. The effect of electron acceptors and donors on the dissociation equilibrium and initiation rate was investigated. It was shown that in strongly dissociated ion pairs such as stable carbenium salts the electron donors and acceptors have no appreciable effect on the magnitude of the dissociation. The temperature dependence of the rate constants in the −20–+20°C range yielded the following thermodynamic parameters for trityltetrachloroferate: Ei = 8.54 kcal/mol; A = 3.2 × 104 mol−1s−1; ΔH* = 8 kcal/mol; and S* = −39.8 eu.