Facskó Ferenc (szerk.) (2012): Kutatások a Nyugat-magyarországi

A regionális fejlődés műszaki innovációs hátterének fejlesztése
L. CSOKA – T. R. APPEL – A. EITNER – G. JIRIKOWSKI – J. MAKOVITZKY (2012): Polarization
optical-histochemical characterization and supramolecular structure of carbohydrate
fi brils. ACTA HISTOCHEM -: (-)doi10.1016/j.acthis
Abstract – Topo-optical staining reactions were used to investigate the structures of bacterial
cellulose, insect chitosan and alginic acid from brown algae. Polysaccharide complexes,
glycosaminoglycans and sulfate groups were presented and demonstrated selectively. Chitosan
and alginic acid are structurally similar to glycosaminoglycans (GAGs), which are
constituents of human amyloid fi brils. The staining sequences shown can be used as reliable
methods for histochemistry with light and polarization microscopy. They will help to
clarify the complex protein–polysaccharide structure of amyloid fi brils.
CSOKA L. – HOEGER I. – ROJAS O.J. – PESZLEN I. – PAWLAK J. J. – PERALTA P. N. (2012): Piezoelectric
Eff ect of Cellulose Nanocrystals Thin Films. ACS MACRO LETTERS 1: pp.
867-870.
Abstract – Ultrathin fi lms of aligned cellulose nanocrystals (CNCs) were assembled on
mica supports by using electric fi eld-assisted shear. The relationship between polarization
gradients and strain mechanics of the obtained fi lms was examined by monitoring their
defl ection with an atomic force microscope operated in contact mode. The piezoelectric
response of the fi lms was ascribed to the collective contribution of the asymmetric crystalline
structure of the cellulose crystals. The magnitude of the eff ective shear piezoelectric
constant (d25) of highly ordered CNC fi lms was determined to be 2.1 Å/V, which is comparable
to that of a reference fi lm of a piezoelectric metal oxide.
L. CSOKA – D. K. BOZANIC – V. NAGY – S. DIMITRIJEVIC-BRANKOVIC – A. S. LUYT – G. GROZDITS –
V. DJOKOVIC (2012): Viscoelastic properties and antimicrobial activity of cellulose fi ber
sheets impregnated with Ag nanoparticles. CARBOHYDRATE POLYMERS 90:(2) pp.
1139-1146.
Abstract – A silver nanoparticle colloid was prepared by a modifi ed Tollens method using dglucose
as the reduction agent. The obtained nanoparticles were used for the modifi cation
of pine, linter and recycled cellulose fi bers. Although the silver contents were relatively low
(0.05–0.13 wt.%), the cellulose-sheets prepared from the modifi ed fi bers show improved
mechanical and viscoelastic properties. The tensile index (strength) increased with up to
30% in comparison to the index of the sheets obtained from the untreated fi bers. The infl uence
of the nanoparticles on the viscoelastic properties of the cellulose sheets was investigated
by dynamic mechanical analysis (DMA) in the temperature range from -120 to 20 °C
and with a force frequency of 100 Hz. A broad relaxation transition positioned at -80 °C was
observed in the loss modulus spectrum of all the cellulose sheets, while the Ag-modifi ed
sheets exhibited higher storage moduli values in the whole temperature range. The antimicrobial
activity tests show that the pine, silver and recycled cellulose fi ber sheets with silver
nanoparticles can be successfully employed to prevent the viability and growth of the common
pathogens Staphylococcus aureus, Escherichia coli and Candida albicans.
A projekt során létrejött eredmények mind alapkutatási szinten, mind pedig alkalmazott
anyagtudomány szinten jelentősek és előre mutatóak, a kapcsolódó iparág fejlesztési
irányainak alapjait tartalmazhatják. Célunk, hogy az eredményeket ipari szinten, termékek
formájában mielőbb alkalmazhassuk. A további kutatásokat pályázati forrásokból, az
iparági szereplőkkel közösen, a fejlesztési érdekeiknek megfelelően szeretnénk folytatni.
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