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1

Impact of carbon nanoforms on hiPSC-derived cardiomyocytes

Benko A., Andrysiak K., Fraczek-Szczypta A., Stepniewski J., Dulak J.

Engineering of Biomaterials

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2018

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Vol. 21, no. 148

109

2

Efficiency testing of artificial neural networks in predicting the properties of carbon nanomaterials as potential systems for nervous tissue stimulation and regeneration

Sasiada M., Fraczek-Szczypta A., Tadeusiewicz R.

Bio-Algorithms and Med-Systems

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2017

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Vol. 13, no. 1

25--35

EN

A new method of predicting the properties of carbon nanomaterials from carbon nanotubes and graphene oxide, using electrophoretic deposition (EPD) on a metal surface, was investigated. The main goal is to obtain the basis for nervous tissue stimulation and regeneration. Because of the many variations of the EPD method, costly and time-consuming experiments are necessary for optimization of the produced systems. To limit such costs and workload, we propose a neural network-based model that can predict the properties of selected carbon nanomaterial systems before they are produced. The choice of neural networks as predictive learning models is based on many studies in the literature that report neural models as good interpretations of real-life processes. The use of a neural network model can reduce experimentation with unpromising methods of systems processing and preparation. Instead, it allows a focus on experiments with these systems, which are promising according to the prediction given by the neural model. The performed tests showed that the proposed method of predictive learning of carbon nanomaterial properties is easy and effective. The experiments showed that the prediction results were consistent with those obtained in the real system.

3

Haemocompatibility and cytotoxic studies of non-metallic composite materials modified with magnetic nano and microparticles

Szymonowicz M., Rybak Z., Fraczek-Szczypta A., Paluch D., Rusak A., Nowicka K., Blazewicz M.

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 3

49--58

EN

Purpose: Preventing the formation of blood clots on the surface of biomaterials and investigation of the reasons of their formation are the leading topics of the research and development of biomaterials for implants placed into the bloodstream. Biocompatibility and stability of a material in body fluids and direct effect on blood cell counts components are related both to the structure and physico-chemical state of an implant surface. The aim of this study was to determine haemocompatibility and cytotoxicity of polysulfone-based samples containing nano and micro particles of magnetite (Fe3O4). Methods: The polysulfone-based samples modified with nanometric and micrometric magnetite particles were examined. Physicochemical properties of the composites were determined by testing their wettability and surface roughness. The action of haemolytic, activation of coagulation system and cytotoxicity of composites was evaluated. Results: Wettability and roughness of materials were correlated with nanoparticles and microparticles content. In the tests of plasma coagulation system shortening of activated partial thromboplastin time for polysulfone with nano magnetite and with micro magnetite particles was observed in comparison with pure polysulfone. Prothrombine time and thrombine time values as well as fibrinogen concentration were unchanged. Haemolysis values were normal. Morphology and viability of cells were normal. Conclusions: Composites made from polysulfone modified with nanoparticles and microparticles of magnetite cause neither haemolytic nor cytotoxic reaction. These composites evoke plasma endogenous system activation.

4

PAN Precursor Fibres Containing Multi-Walled Carbon Nanotubes

Szparaga G., Mikołajczyk T., Fraczek-Szczypta A.

Fibres & Textiles in Eastern Europe

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2013

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Vol. 21, no. 6 (102)

33--38

EN

The spinning conditions of wet spun polyacrylonitrile (PAN) fibres containing multi-walled carbon nanotubes (MWCNTs) were investigated. On the basis of images from a transmission electron microscope, it was shown that the MWCNTs are well dispersed in the fibre matrix as well as straightened and oriented in the direction of the fibre axis. The presence of MWCNTs in the fibre matter caused an increase in the crystallinity of the precursor fibres and a decrease in their porosity. The tenacity of the composite fibres was lower than that of pure PAN fibres, which was caused by the fact that carbon nanotubes hindered deformation in the drawing stages, resulting in a lower draw ratio possible to be obtained of composite fibres compared to standard fibres. For the PAN precursor fibres obtained a two stage carbonisation process was conducted: The first stage was conducted in an oxidative atmosphere (at 140 °C for 5 hours and then at 200 °C for 6 hours in air). The second stage was conducted in an inert atmosphere (at 1000 °C for 5 minutes in argon atmosphere). The strength of carbon fibres containing MWCNTs obtained shows, in the majority, no significant differences in comparision to reference fibres without MWCNTs. However, the tensile strength was lower.

PL

Zbadano wpływ warunków formowania włókien poliakrylonitrylowych (PAN) zawierających wielościenne nanorurki węglowe (MWCNT) otrzymywanych metodą z roztworu na mokro. Na podstawie obrazów uzyskanych z mikroskopu transmisyjnego stwierdzono, iż nanorurki węglowe są dobrze rozproszone w tworzywie włókien i zorientowane w kierunku osi włókna. Obecność nanorurek węglowych w tworzywie włókien skutkowała wzrostem stopnia krystaliczności włókien oraz obniżeniem ich porowatości. Wytrzymałość właściwa włókien kompozytowych była niższa w porównaniu do wytrzymałości włókien niezawierających nanorurek węglowych. Było to spowodowane faktem, iż nanorurki węglowe utrudniały procesy deformacyjne podczas rozciągu, co skutkowało niższą wartością rozciągu całkowitego uzyskiwanego dla włókien kompozytowych w porównaniu do włókien bez nanorurek węglowych. Dla uzyskanych włókien węglowych przeprowadzono dwuetapowy proces karbonizacji: pierwszy etap w atmosferze utleniającej (w temp. 140 °C w czasie 5 godzin, a następnie w 200 °C w czasie 6 godzin, w atmosferze powietrza), drugi etap w atmosferze argonu (w temp. 1000 °C w czasie 5 minut). Dzięki zastosowaniu nanorurek węglowych niestety nie uzyskano spodziewanego istotnego polepszenia wytrzymałości włókien węglowych.

5

Strength Properties of Polyacrylonitrile (PAN) Fibres Modified with Carbon Nanotubes with Respect to their Porous and Supramolecular Structure

Mikołajczyk T., Rabiej S., Szparaga G., Boguń M., Fraczek-Szczypta A., Błażewicz S.

Fibres & Textiles in Eastern Europe

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2009

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Vol. 17, no. 6 (77)

13--21

EN

This work was dedicated to the investigation of the influence of the effect of carbon nanotubes on the porous and supramolecular structure of precursor polyacrylonitrile (PAN) fibres. A relationship was found between the structure of the fibers produced in a two-stage and three-stage drawing process and the strength properties of those fibres. The structural parameters and properties of PAN fibres modified with carbon nanotubes were compared with corresponding values for the fibres without nanoadditives. It was found that the introduction of carbon nanotubes into the material of PAN fibres increases their deformability at successive stages of drawing to a degree depending on the type of nanotube. This was the main reason for their higher strength properties in comparison with the fibres without a nanoadditive.

PL

W pracy zbadano wpływ rodzaju nanorurek węglowych na strukturę porowatą i nadmolekularną prekursorowych włókien poliakrylonitrylowych. Ustalono związek pomiędzy strukturą wytworzoną po dwu i trójetapowym procesie rozciągania, a właściwościami wytrzymałościowymi tych włókien. Parametry strukturalne i właściwości włókien PAN modyfikowanych nanorurkami węglowymi porównano z odpowiednimi wskaźnikami dla włókien niezawierających nanododatku. Stwierdzono, iż z wprowadzeniem do tworzywa włókien PAN nanorurek węglowych związane jest zwiększenie podatności na deformację w kolejnych etapach rozciągu w stopniu uzależnionym od rodzaju nanorurek. Stanowi to główną przyczynę ich wyższych właściwości wytrzymałościowych w porównaniu do włókien bez nanododatku.