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001-es BibID:	BIBFORM043092
Első szerző:	Keczánné Üveges Andrea (vegyész)
Cím:	Synthesis of Polymeric Nanoparticles by Cross-Linking Copolymerization / Üveges Andrea, Szalóki Melinda, Hartmann John F., Hegedűs Csaba, Borbély János
Dátum:	2008
ISSN:	0024-9297 1520-5835
Megjegyzések:	Soluble cross-linked nanoparticles were prepared by free radical copolymerization of styrene (ST, M1) and ethylene glycol dimethacrylate (EGDM, M2) monomers in homogeneous solution. Spherical nanoparticles were obtained in the early stage of polymerization, and no gelation occurred up to 66% of yield. The isolated particles are decorated with pendant vinyl groups that are target for further polymerization. The molar feed ratio was ST/EGDM = 5/5, the monomer concentration 0.556 mol/dm3 and the initiator concentration 5 mol %. It was found that as the conversion increased, the ratio of pendant vinyl groups reached a maximum value; however, the size of nanoparticles continued to increase with the reaction time. The molecular weight distributions were monomodal at short reaction times (30 and 60 min), however, at longer reaction times (90, 120, and 180 min) these became multimodal. This was caused by intraparticle reactions (branching and cross-linking) and possibly also by interparticle reactions (coupling). The reactive vinyl groups were detected by nuclear magnetic resonance spectroscopy (NMR). The size of nanoparticles in swollen state was determined by dynamic laser light scattering (DLS) method and in dried form by scanning electron microscopy (SEM). Molecular weight and distributions were measured by gel permeation chromatography (GPC).
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban egyetemen (Magyarországon) készült közlemény
Megjelenés:	Macromolecules. - 41 : 4 (2008), p. 1223-1228. -
További szerzők:	Szalóki Melinda (1981-) (vegyész) Hartmann, John F. Hegedűs Csaba (1953-) (fogszakorvos) Borbély János (1950-) (vegyész)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM043728
Első szerző:	Szalóki Melinda (vegyész)
Cím:	Preparation of reactive polymeric nanoparticles / Melinda Szaloki, Robert Scribanek, John F. Hartmann, Csaba Hegedus, Janos Borbely
Dátum:	2006
Megjegyzések:	Polyreactions of multivinyl monomers in emulsion droplets lead to formation of crosslinked macromolecules. In the emulsion polymerization the surfactant-mediated nanoparticles involves the monomers serving as nanoreactors. It prevents gelation while allowing the growth of particles the defined volume. In this study we describe the formation of reactive polymeric nanoparticles (RPNPs) for potential use as dental materials or as a component of industrial powder coatings. As dental filling materials, since the predominant portion of polymerization is performed in advance, limited volumetric shrinking is expected to be observed during the final in situ photopolymerization step. On the other hand no necessary or limited use of toxic monomers is required. The correlation of monomer feed, crosslinking density, particle size, reactivity and swelling behavior of RPNPs is described.
Tárgyszavak:	Természettudományok Kémiai tudományok konferenciacikk Polymeric nanoparticles
Megjelenés:	Polymeric Materials : Science & Engineering. - 94 : 1 (2006), p. 783-784. -
További szerzők:	Skribanek Róbert Hartmann, John F. Hegedűs Csaba (1953-) (fogszakorvos) Borbély János (1950-) (vegyész)
Internet cím:	Szerző által megadott URL Intézményi repozitóriumban (DEA) tárolt változat Szerző által megadott URL
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001-es BibID:	BIBFORM043841
Első szerző:	Szalóki Melinda (vegyész)
Cím:	Preparation of Reactive Polymeric Nanoparticles (RPNPs) / Szaloki M., Daroczi L., Hartmann J. F., Hegedus C., Borbely J.
Dátum:	2007
Megjegyzések:	Synthesis of polymeric nanoparticles attracts a great effort to obtain particles with desired size, surface and functionalities. Crosslinking polymerization methods have received considerable interest relation to the development of preparation of microgels, crosslinked nanoparticles, their composites and to study the gelation reactions. Many application fields have related to bulk crosslinked systems, e.g., in restorative dentistry, paint and powder coatings. Crosslinked nanoparticles can be formed in homogeneous solutions or under heterogeneous medium in micellar or emulsion conditions. Formation of polymers in emulsion also has an environmental aspect to reduce the volatile organic compounds (VOC). Reactive polymeric nanoparticles (PRNPs) were synthesized in heterogeneous medium by free radical non-linear copolymerization of mono (M1) and trivinyl acrylic (M2) monomers.
Tárgyszavak:	Természettudományok Kémiai tudományok előadáskivonat RPNPs
Megjelenés:	NSTI Nanotechnology Conference : technical proceedings, 2007 (4) / ed. Nano Science and Technology Institute. - 309-312. -
További szerzők:	Daróczi Lajos (1965-) (fizikus) Hartmann, John F. Hegedűs Csaba (1953-) (fogszakorvos) Borbély János (1950-) (vegyész)
Internet cím:	Szerző által megadott URL Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM006969
Első szerző:	Szalóki Melinda (vegyész)
Cím:	Preparation of reactive polymeric nanoparticles (RPNPs) / Melinda Szaloki, Robert Skribanek, Zsolt Dudas, John F. Hartmann, Csaba Hegedűs, Janos Borbely
Dátum:	2008
Megjegyzések:	A series of reactive polymeric nanoparticles (RPNPs) was prepared by free radical nonlinear copolymerization of mono (M 1) and trivinyl acrylic (M 2) monomers in miniemulsion. The crosslinking density was determined by the mole ratio of the trivinyl component. It was found that the unswelled latex nanoparticles showed a narrower dispersity than in the organic solution of macromolecules. In latex, the size increased with the ratio of M 2 monomer due to its higher polarity in the aqueous medium. However, the swollen nanoparticles, dissolved or dispersed in organic solvent, showed a higher dispersity as a function of composition and the crosslinking density. The residual vinyl groups adjacent to the nanoparticles were subjected to further crosslinking reactions. The reactive vinyl groups were detected by nuclear magnetic resonance spectroscopy (NMR). The size of particles in swollen state was determined by dynamic laser light scattering (DLS) method and the dried form by scanning electron microscopy (SEM). It was found that size of RPNPs is in the range of 50 to 500 nm. These particles possess properties that may allow their application in areas as disparate as dental filling material and as a component in industrial powder-based coatings.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Free radical nonlinear polymerization Reactive Polymeric Nanoparticles (RPNPs) Miniemulsion Number average vinyl functionality (NAVF) Crosslinking polymerization
Megjelenés:	Colloid and Polymer Science. - 286 : 4 (2008), p. 435-444. -
További szerzők:	Skribanek Róbert Dudás Zsolt Hartmann, John F. Hegedűs Csaba (1953-) (fogszakorvos) Borbély János (1950-) (vegyész)
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