Włókna PAN zawierające wielościenne nanorurki węglowe formowane metodą z roztworu na mokro

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.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

Composites for Bone Surgery Based on Micro- and Nanocarbons

In this work capabilities of polymer composites modified with carbon materials for application in the bone surgery were compared. The composite materials were produced from synthetic polymer PTFE-PVDF-PP modified with a carbon phase such as: short carbon fibres, carbon nanotubes and carbon fabrics. Determination of mechanical properties of the composite materials indicated that the carbon phase improves strength and Young's modulus of the composite. Moreover, the mechanical parameters can be controlled by the form and amount of the carbon phase introduced into the polymer matrix. Both the fibres and the carbon nanotubes influenced wettability and surface energy of the composites. Also topography of the materials surface was altered, and its roughness was optimal for bone cells (profilometry). Osteoblasts contacted with the polymer-carbon composites showed increased viability comparing with the ones contacting with the pure polymer foil (viability, and cells proliferation: MTT method, concentration of bone protein: viniculine and β-actine). Results of the investigations indicated that the composite materials containing carbon phases are potential materials for repairing of bone tissue damages

Composites for Bone Surgery Based on Micro- and Nanocarbons

In this work capabilities of polymer composites modified with carbon materials for application in the bone surgery were compared. The composite materials were produced from synthetic polymer PTFE-PVDF-PP modified with a carbon phase such as: short carbon fibres, carbon nanotubes and carbon fabrics. Determination of mechanical properties of the composite materials indicated that the carbon phase improves strength and Young's modulus of the composite. Moreover, the mechanical parameters can be controlled by the form and amount of the carbon phase introduced into the polymer matrix. Both the fibres and the carbon nanotubes influenced wettability and surface energy of the composites. Also topography of the materials surface was altered, and its roughness was optimal for bone cells (profilometry). Osteoblasts contacted with the polymer-carbon composites showed increased viability comparing with the ones contacting with the pure polymer foil (viability, and cells proliferation: MTT method, concentration of bone protein: viniculine and β-actine). Results of the investigations indicated that the composite materials containing carbon phases are potential materials for repairing of bone tissue damages

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

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