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1
Content available Effects of hypochlorite treatment on transport-separation properties of polysulfone capillary membranes
Wojciechowski C., Chwojnowski A., Łukowska E.
Problemy Eksploatacji
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2013
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nr 3
17--26
EN
Different types of polysulfone capillary membranes supplemented with porophores were obtained. The membranes were treated with sodium hypochlorite using the flowing method. The membrane ultrafiltration and retention was evaluated for chosen markers before and after treatment. Ultrafiltration increase and retention decrease for polyethylene glycols were observed, and there was not a difference in bovine albumin retention for post-treatment membranes. Hypochlorites caused porophores removal from the membrane structure resulting in opening the pore passages and increasing permeability without increasing pore size.
PL
Obróbce poddano różne typy kapilarnych membran polisulfonowych zawierających porofory. Membrany traktowano podchlorynem sodu metodą przepływową. Filtrowalność oraz retencję membran ultrafiltracyjnych przed i po obróbce oceniano za pomocą wybranych markerów. Membrany poddane obróbce charakteryzowały się wyższą filtrowalnością i niższą retencją dla glikolu polietylenowego przy niezmienionej retencji albuminy bydlęcej. Obróbka podchlorynem sodu spowodowała zmniejszenie ogólnej porowatości membran ultrafiltracyjnych i jednocześnie zwiększenie udziału porów otwartych, dzięki czemu wzrosła przepuszczalność membrany bez wzrostu rozmiarów porów.
2
Content available remote Studies on the structure of semi-permeable membranes by means of SEM problems and potential sources of errors
Chwojnowski A., Wojciechowski C., Lewińska D., Łukowska E., Nowak J., Kupikowska-Stobba B., Grzeczkowicz M.
Biocybernetics and Biomedical Engineering
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2012
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Vol. 32, no. 1
51-64
EN
The effect of sputtering with a conductor of the semi-permeable membranes surface on SEM pictures obtained is presented. On the example of photomicrographs of several different types of semi-permeable membranes, changes in the appearance of various membrane surfaces, uncovered and sputtered with thicker and thicker layers of the conductor are presented. It has been shown, how essential differences in the appearance of the studied material can be caused by the deposited conductor. It has been shown what errors in the interpretation of SEM images can be caused by applying the sputtered conductor layer with a thickness insufficient to the structure and properties of the studied material. Necessity of minimizing the layer thickness of the sputtered conductor and experimental determination of the sputtered layer thickness was found. Appropriateness of taking the pictures in the mode without sputtering and necessity of comparing the pictures with and without sputtering have been suggested. The useful way of carrying out magnifications' of membranes made of polymers of low melting points has been also presented.
3
Content available remote Preparation of sulfonated polysulfone membrane for enzymes immobilisation
Łukowska E., Wojciechowski C., Chwojnowski A., Dudziński K., Sabalińska S., Ciechanowska A., Czapiewska G.
Biocybernetics and Biomedical Engineering
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2012
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Vol. 32, no. 2
77-86
EN
The paper presents a method for the preparation of sulfonated polysulfone in order to receive a matrix to immobilisation of biomolecules. Optimum conditions of the synthesis are described. The phase inversion method was used to prepare a sulfonated polysulfone membrane and then urease was immobilized on the surface of the prepared matrix. Comparison of activity of native urease and the immobilized urease is presented.
4
Content available remote Membranes' porosity evaluation by computer-aided analysis of SEM images – a preliminary study
Chwojnowski A., Przytulska M., Wierzbicka D., Kulikowski J., Wojciechowski C.
Biocybernetics and Biomedical Engineering
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2012
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Vol. 32, no. 4
65-75
EN
The problem of quality control of membranes destined for medical applications is presented. The shape of the membranes surface, its structure, porosity and coarseness are of importance in contact with live cells or simply with live tissue, and as such they should be controlled. For this purpose, scanning electron microscopy (SEM) in our work was used. Results of capillary polysulphone (PSF) 70000 m.m. and polyetherosulphone (PES) 42000 m.m. membranes examination are described. An attempt to apply the computer-aided SEM images processing methods to the membranes' porosity evaluation was made and is presented in the paper. In particular, an approach to segmentation of contours of micropores in the visualized membranes' sections and to evaluation of their morphological parameters is described. An attempt to an approximate statistical reconstruction of 3-dimensional structure of micropores on the basis of collections of 2-dimensional membranes' sections is also described.
5
Content available remote Three dimensional polyethersulphone scaffold for chondrocytes cultivation - the future supportive material for articular cartilage regeneration
Dudziński K., Chwojnowski A., Gutowska M., Płończak M., Czubak J., Łukowska E., Wojciechowski C.
Biocybernetics and Biomedical Engineering
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2010
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Vol. 30, no. 3
65-76
EN
The this paper method of obtaining broad-pore membranes for application as scaffolds for chondrocyte cultivation is described. These membranes were obtained from polyethersulfone. They are characterized by the presence of both macropores of relatively large diameter, as well as micropores. These membranes are intended first of all for use in cultivation of the cartilage cells (chondrocytes). The membranes are obtained by the phase inversion method followed by dissolving cellulose present in the membrane. Cellulose is a macropore precursor. Cellulose is dissolved by means of a copper hydroxide ammonia complex. The membranes obtained are not cyto-toxic. The culture of chondrocytes derived from White New Zeeland breed rabbits developed very well on these membranes. The cell cultures were studied by observation under an optical microscope and scanning electron microscope. The protein mass increase on the membrane was determined by flame analysis. The results of these experiments did not show any negative effects of the membranes on the cell culture. Just the opposite, the cartilage cells development on the membranes proceeded very well. The results obtained show that the membrane developed is a very good scaffold for cell cultivation.
6
Content available remote Polysulphone and polyethersulphone hollow fiber membranes with developed inner surface as material for bio-medical applications
Chwojnowski A., Wojciechowski C., Dudziński K., Łukowska E.
Biocybernetics and Biomedical Engineering
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2009
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Vol. 29, no. 3
47-59
EN
A method of obtaining hollow fibers with developed internal surface has been elaborated. As materials were selected synthetic polymers, namely polysulphone Udel P-1700 and polyethersulphone Ultrason E2020P. This method enables the obtaining of such membranes by means of a spinneret with smooth walls and the installation for spinning hollow fibers. A mechanism of the formation of corrugations on the membrane internal surface has been proposed. The effect of spinning parameters on membrane formation has been described. An explanation of the reasons of formation of defects on the external skin layer has been proposed.
7
Content available remote Influence of changes in composition of the membrane-forming solution on the structure of alginate-polyethersulfone microcapsules
Kupikowska B., Lewińska D., Dudziński K., Jankowska-Śliwińska J., Grzeczkowicz M., Wojciechowski C., Chwojnowski A.
Biocybernetics and Biomedical Engineering
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2009
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Vol. 29, no. 3
61-69
EN
The aim of this study was to evaluate the effects of changes in composition of the membrane-forming solution on the structure of alginate-polyethersulfone microcapsules as determined by optical microscopy and scanning electron microscopy. The microcapsules were produced from 4 solutions of different concentrations and molecular weights of synthetic polymer (polyethersulfone, PES) and porophore (polyvinylpyrrolidone, PVP). The composition of the membrane-forming solution strongly affected the structure of microcapsules. An increase in PES concentration caused a decrease in the membrane thickness. The inner and outer layers of the membrane became thinner and denser, while the pores of the middle finger-like zone turned into more regular, channel-like structures. The size of the pores was not directly affected by the molecular weight of porophore, however, an increase in its concentration resulted in formation of the larger inner surface pores, but the smaller outer surface pores.
8
Content available remote Evaluation of the new polyurethanes capillary membrane for cell immunoisolation. Results from in vitro studies
Resiak I., Wojciechowski C.
Biocybernetics and Biomedical Engineering
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2004
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Vol. 24, no. 2
69-79
EN
Highly biocompatible and mechanically resistant semipermeable membranes are required for macroencapsulation of cells or tissues. For this purpose two series of aromatic as well as aliphatic polyurethanes were elaborated for the production of hollow fibre membranes by the phase inversion method and the wet spinning technique. The influence of the polyurethane structure, i.e. type of the hard segments and content of the soft segments on the membrane morphology and its transport properties were investigated.
9
Content available remote Dokonania i perspektywy górnictwa węgla brunatnego w Polsce
Wojciechowski C., Kozłowski Z.
Przegląd Górniczy
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2003
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T. 59, nr 10
30-40
PL
W artykule przedstawiono historię eksploatacji węgla brunatnego na ziemiach polskich oraz obecny stan górnictwa węgla brunatnego w naszym kraju. Zwrócono uwagę na fakt, że energia elektryczna produkowana z węgla brunatnego jest energią najtańszą, co przy posiadanych znacznych zasobach węgla brunatnego w Polsce powinno stanowić podstawę utrzymania znaczącego wydobycia węgla brunatnego w przyszłości.
EN
History of brown coal mining on Polish land as well as the present state of brown coal mining in our country are presented. Attention is paid to the fact, that electric energy produced from brown coal is the cheapest one what in Poland having significant reserves of brown coal should be the basis for maintenance of considerable output of brown coal in the future.
10
Warunki utrzymania strategicznej roli węgla brunatnego w polskiej energetyce.
Wojciechowski C., Czapla Z., Włodarczyk B., Żuk S., Kozłowski Z.
Prace Naukowe Instytutu Górnictwa Politechniki Wrocławskiej. Konferencje
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2002
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Vol. 98, nr 34
5-25
PL
Aktualnie wydobywany w czterech polskich kopalniach węgiel brunatny odgrywa znaczną rolę gospodarczą stanowiąc surowiec dla produkcji 35-40 % energii elektrycznej w Polsce. Energia elektryczna produkowana z węgla brunatnego jest zdecydowanie tańsza niż z innych źródeł. Według prognoz gospodarczych w ciągu najbliższych 20 lat zapotrzebowanie na energie elektryczną w Polsce wzrośnie. Powoduje to konieczność zaplanowania sposobów pokrycia tych potrzeb. W tej sytuacji oczywistym jest konieczność maksymalnego wykorzystania zasobów czynnych kopalń węgla brunatnego. Ograniczane stopniowo wydobycie w czynnych rejonach musi być zastępowane sukcesywnie przez uruchamianie eksploatacji złóż perspektywicznych - olbrzymie złoża Legnica, gdzie można wybudować kopalnie o wydobyciu rzędu 60 mln Ng/rok. Dla utrzymania strategicznej roli węgla brunatnego e energetyce niezbędne jest uruchomienie w Polsce rzeczywistego rynku energii umożliwiającego efektywna działalność czynnych zagłębi dla maksymalnego wykorzystania zasobów oraz umożliwienie przygotowania zagospodarowanie złóż perspektywicznych.
EN
At present, lignite won in four Polish mines plays an important economic role as a raw material for generation of about 35-40% of electric energy in Poland. The lignite-generated electricity is also decidedly less cost expensive than that generated from other sources. As per the economic forecasts, the electricity requirements in Poland will increase, in the nearest 20 years. It results in a necessity to plan ways for meeting these requirements. In such circumstances, an obvious thing is necessity for maximum utilization of reserves from active lignite mines, which can satisfy all the requirements for next approx. 15 years and afterwards, during subsequent 30 years, the reserves in active regions will be fully exhausted. The gradually limited production in active regions should progressively be replaced by starting with exploitation of prospective depostis for which the tremendous reserves of Legnica deposit are most suitable, where it is possible to construct mines of production in the order of 60 milion Mg and replace decreasing production of active mines. However, for maintaining strategic role of lignite in power generation industry, it is necessary to provide in Poland a real energy market enabling an effective activity of active basins for maximum utilization of reserves and also, making it possible to prepare management of prospective deposits.
11
Content available remote Preliminary studies on polymer membrane structure by the DSC method
Rudnik E., Resiak I., Wojciechowski C., Winiarska A.
Polimery
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1999
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T. 44, nr 4
292-293
EN
Preliminary studies concerning characterization of the polymer membrane structure, using the differential scanning calorimetry (DSC) method, are reported. The procedure for the determination of membrane pore radii was checked and modified conditions were applied for commercial cellulosic membranes.
PL
Przedstawiono wyniki wstępnych badań struktury membran polimerowych metodą skaningowej kalorymetrii różnicowej (DSC). Badania te polegały na pomiarze średnicy porów i oszacowaniu rozkładu średnic porów celulozowych membran ultrafiltracyjnych w zakresie 2-50 nm. Zastosowano metodę Ishikiriyamy i in. (1995) polegającą na pomiarze przebiegu topnienia (lub krystalizacji) wody zawartej w porach membrany. W przypadku topnienia i przy założeniu, że pory są cylindryczne, a warstwa wody nie ulegającej krystalizacji ma grubość rzędu l nm, słuszna jest zależność R = (33,3/AT) + 0,68, w której R jest promieniem porów, a AT = T - T0, gdzie T - zmierzona temperatura topnienia, T0 - punkt potrójny wody. W przypadku badanej membrany Cuprophan F18/200 UF5.5 ("Akzo") obliczono z tej zależności średnice porów w zakresie od 5,5 do 8,8 nm. Na podstawie piku topnienia wody krystalizującej można ocenić rozkład średnic porów. Potwierdzono więc przydatność omawianej metody do oznaczania średnicy porów membran ultrafiltracyjnych i dobrano warunki pomiaru w przypadku handlowych membran celulozowych.
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