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Conductive polymer based nanocomposite membranes for biomedical applications

Stodolak-Zych E., Chmielewska M., Jeleń P.

Engineering of Biomaterials

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2017

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Vol. 20, no. 139

2--7

EN

The aim of this work was to examine composite membranes obtained by means of phase inversion from a synthetic stable polymer – polyvinylidene difluoride (PVDF). The piezoelectric polymer was modified with 0.5-1wt% addition of commercial carbon fillers: graphite oxide (GO, 1wt%), multiwalled carbon nanotubes (CNT, 1wt%) and functionalized nanotubes (CNT-COOH, 0.5wt%). The membranes were obtained by solidification of nanocomposite solutions in coagulation bath (CH3OH). The obtained series of materials differed in surface porosity (P), electric conductivity (σ) and surface free energy (SFE). It was proved that presence of carbon nanoadditive influenced microstructure of the membranes: the mean size of pores in the membrane rose in the following order: GO→CNT→CNT-COOH. The very same system depicted the influence of the filler on the membrane structure: the increase in membrane crystallinity (λ) and the β phase share (FT Raman). From all the examined nanocomposite systems, the PVDF modified with 0.5wt% CNT-COOH displayed the most advantageous electric properties. These nanocomposite membrane (PVDF/CNT-COOH) could be used as a low-voltage electrodes in biomedical application. Yet, taking into account the other physicochemical, mechanical and structural properties, the membranes modified with 1wt% CNT and 1wt% GO were also interesting.

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Chitosan-based nanocomposites as potential materials for nerve regeneration

Turek A., Dudziński K., Stodolak-Zych E.

Engineering of Biomaterials

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2014

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Vol. 17, no. 128-129

86--87

EN

The nanocomposite material based on chitosan was obtained and characterized. Commercially produced biopolymer at 85% deacetylization degree was used. The biopolymer matrix was modified with carbon nanofillers such as graphite oxide (GO), carbon nanotubes (CNTs) and nanontubes with the surface affected by carboxyl groups (CNT-COOH). The obtained nanocomposites were formed by means of two methods: casting (to manufacture nanocomposite foils) and liofilization (to manufacture porous nanocomposite materials). Their electrical properties and microstructure were examined. The tests proved that adding the carbon nano-filler results in high resistivity (graphite foils, carbon nanotubes) and also the average size of pores in liofilized materials. Additionally, the electric potential of the materials may be improved by surface processing (EPD- electrophoretic deposition). The described materials are an alternative to polymer nerve implants e.g. tubes or hydrogels which are already present on the market and applied to regenerate nerves.

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Wybrane właściwości kompozytów polipropylenu z szungitem

Żenkiewicz M., Richert J., Rytlewski P., Moraczewski K., Stepczyńska M.

Polimery

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2010

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T. 55, nr 2

119-126

PL

Przedstawiono wyniki badań dotyczących wpływu zawartości szungitu (0-50% mas.) w kompozytach z osnową polipropylenową, na wybrane właściwości użytkowe i przetwórcze. Ocenie poddano m.in. wytrzymałość mechaniczną, udarność, wskaźnik szybkości płynięcia. Metodą różnicowej kalorymetrii skaningowej (DSC) oraz termograwimetrii sporządzono charakterystykę termiczną kompozytów a właściwości termomechaniczne określono za pomocą dynamicznej analizy mechanicznej (DMA). Zbadano również rezystywność skrośną i powierzchniową a także wyznaczono zwilżalność, na podstawie której obliczono wartość swobodnej energii powierzchniowej metodą Owensa-Wendta. Stwierdzono, że kompozyty polipropylenowe napełniane szungitem są materiałami hydrofobowymi, wykazują mniejszą niż polipropylen podatność na odkształcenia wzdłużne pod wpływem rozciągania i mniejszą udarność a także lepsze właściwości antyelektrostatyczne oraz gorsze elektroizolacyjne.

EN

The results of investigations of the influence of shungite content (up to 50 weight %) in polypropylene matrix on the selected functional and processing properties of the composites are presented. Among others, mechanical strength (Fig. 2-5), impact strength (Fig. 6), and melt flow rate (Fig. 7) were evaluated. Thermal characteristics of the composites prepared was studied by differential scanning calorimetry (DSC, Fig. 8, 9) and thermogravimetry (Fig. 10, 11). Thermo-mechanical properties were determined by dynamic mechanical analysis (DMA, Fig. 12). Surface and volume resistivity has been studied as well (Fig. 14). Wettability was also determined (Fig. 13) and on this basis the values of surface free energy were calculated according to Owens-Wendt method. It was found that shungite filled polypropylene composites were hydrophobic materials less susceptible to longitudinal strain at tension, showing lower impact strength, better anti-electrostatic properties and worse electro-insulating ones.