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1
Content available Flocculation efficiency of hybrid polymers with trivalent metal cations
Schmidt B.
Polish Journal of Chemical Technology
|
2018
|
Vol. 20, nr 4
96--101
EN
Acrylamide/acrylic acid copolymers (AAm/AA) have been synthesized by microemulsion polymerization in absence and presence of trivalent cations Al+3  and Fe+3 . Starch materials were obtained by introducing cations Al+3  and Fe+3 , in the form of aqueous solutions of sulphates(VI) (modif. starch/Me+3 ), into the oxidized starch (modif. starch). The flocculation performance of obtained polyacrylamide copolymers and the one based on the natural polymer was compared with the performance of the commercial AAm/AA flocculant (CF). All materials were characterized by capillary viscometry, FTIR and DSC methods. An aqueous suspension of talc was used for the flocculation studies. The flocculation effectiveness was evaluated on the basis of reduction of suspension extinction and the sludge volume. It was found that synthesized AAm/AA/Me+3  copolymers and modif. starch/Me+3  materials exhibit better flocculation properties for a model talc suspension than a commercially available floculant.
2
Content available Wpływ rodzaju środka sieciującego na szczepione kopolimery akryloamidowe skrobi ziemniaczanej i ich właściwości sorpcyjne względem wody oraz kationów Fe3+ i Cu2+
Schmidt B.
Polimery
|
2018
|
T. 63, nr 5
347--352
PL
Otrzymano akryloamidowe kopolimery szczepione skrobi ziemniaczanej o stosunku masowym akryloamidu do kwasu akrylowego równym 2 : 1, sieciowane trzema akrylowymi związkami stosowanymi w różnym stężeniu. Jako inicjator reakcji wykorzystano dichlorowodorek 2,2’-­azobis(2-me­tylo­propionamidyny). Kopolimery skrobi scharakteryzowano za pomocą spektroskopii w podczerwieni, różnicowej kalorymetrii skaningowej oraz reowiskozymetrycznie. Właściwości sorpcyjne w stosunku do kationów Fe3+ i Cu2+ analizowano metodą spektrofotometryczną, a w wypadku wody określano w testach wodochłonności i pęcznienia.
EN
Potato starch grafted acrylamide copolymers with weight ratio of acrylamide (AAm) to acrylic acid (AA) of 2 : 1, crosslinked with three acrylic compounds at various concentrations, were prepared. 2,2’-azobis(2-methylpropionamidine) dihydrochloride was used as a radical initiator. Starch copolymers were characterized by infrared spectroscopy, differential scanning calorimetry and rheoviscometry. The Fe3+and Cu2+ cations sorption properties were analyzed using spectrophotometric method. Also, water absorption and swelling tests were performed.
3
Content available Kopolimery akrylowe skrobi otrzymywane metodą reaktywnego wytłaczania
Schmidt B.
Przetwórstwo Tworzyw
|
2017
|
T. 23, Nr 1 (175)
46--52
PL
W pracy opisano otrzymanie kopolimerów skrobia-g-poli(akryloamid-co-kwas akrylowy) metodą reaktywnego wytłaczania przy stałej prędkości obrotowej ślimaków - 90 obr./min. Jako inicjator reakcji zastosowano AAPH [dichlorowodorek 2,2’-azodi(2-amidyniopropanu] oraz trzy środki sieciujące: N,N’-metylenobisakryloamid (MBA), mieszaninę tri- i tetraakrylanu pentaerytrytu (PETIA ) oraz akrylowy związek wielofunkcyjny o nazwie handlowej EBECRYL 40. Przedstawiono parametry pracy wytłaczarki oraz wpływ użytych środków sieciujących na wodochłonność wytłoczy i ich wygląd. Charakterystykę fizykochemiczną otrzymanych kopolimerów szczepionych skrobi przeprowadzono metodą spektroskopii w podczerwieni i skaningowej kalorymetrii różnicowej. Otrzymane kopolimery szczepione skrobi posiadają zdolność absorbowania wody; zdolne są do 10-krotnego powiększenia swojej masy w porównaniu do masy wyjściowej absorbenta. Najlepszym środkiem sieciującym dla testowanych akrylowych kopolimerów skrobi okazała się PETIA.
EN
The work describes starch-g-poly(acrylamide-co-acrylic acid) copolymers obtained during the reactive extrusion processes with constant extrusion screw speed rotation - 90 rpm. 2.2’-azobis(2-methylpropionamidine) dihydrochloride (AAPH) was used as a reaction initiator and three crosslinking agents were applied: N’N-methylenebisacrylamide (MBA), mixture of pentaerythritol tetracrylate and pentaerythritol triacrylate (PETIA ) and acrylic multifunctional compound trade name EBECRYL 40. The parameters of the extruder during reaction and the impact of used crosslinking agents for water absorption of starch copolymers and their appearance have been shown. Physicochemical characteristics of the starch graft copolymer have been done by infrared spectroscopy and differential scanning calorimetry. The starch grafted copolymers have the ability to absorb water; they are capable of a 10-fold increase their weight compared to the initial absorbent mass. The best crosslinking agent for the tested starch graft acrylate copolymers has been proved PETIA.
4
Content available PANI/NaTaO3 composite photocatalyst for enhanced hydrogen generation under UV light irradiation
Zielińska B., Schmidt B., Mijowska E., Kaleńczuk R.
Polish Journal of Chemical Technology
|
2017
|
Vol. 19, nr 3
115--119
EN
A PANI/NaTaO3  composite was successfully synthesized by an oxidative polymerization of aniline monomer in hydrochloric acid solution containing sodium tantalate. NaTaO3  at a monoclinic structure was produced via hydrothermal method. The photocatalytic activities of the unmodified NaTaO3  and PANI/NaTaO3  were evaluated for hydrogen generation from an aqueous HCOOH solution and under UV light irradiation. The results showed that the evolution rate of H2  increased significantly when NaTaO3  was modified with PANI. The enhancement of the photocatalytic activity of PANI/NaTaO3  composite was ascribed to the effective charge transfer and separation between NaTaO3  and PANI, which reduced their recombination. This indicates that PANI modification of tantalate photocatalysts may open up a new way to prepare highly efficient catalytic materials for H2  generation.
5
Content available remote Acoustical estimation of fish distribution and abundance in two Spitsbergen fjords
Szczucka J., Hoppe Ł., Schmidt B., Fey D. P.
Oceanologia
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2017
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No. 59 (4)
585--591
EN
Over recent decades, the Arctic region has been subjected to rapid climate change stemming from global warming. The advance of Atlantic waters to high latitudes is notable. The increased abundance of fish, such as cod (Gadus morhua) and haddock (Melanogrammus aeglefinus), has been reported near the western coast of Spitsbergen and entering fjords together with Atlantic waters. This study used multifrequency acoustics to measure fish distribution and abundance in 2013–2014 in two Arctic fjords, the colder Hornsund, which is typically of Arctic character, and the warmer Kongsfjorden, which is more of Atlantic character. The study revealed a bimodal fish size distribution with larger fish in the deep parts of fjords, and smaller fish distributed in more shallow waters. An evident increase in the abundance of large fish, most probably Atlantic cod, was observed in Hornsund and especially in Kongsfjorden in 2014 in comparison to 2013. The intense inflow of Atlantic water on the shelf in 2014 is suggested as the explanation for this phenomenon.
6
Content available remote Właściwości mieszanin poli(terenalanu trimetylenu) i polietylenu o niskiej gęstości
Janik J, Pilawka R, Gorący K, Wilpiszewska K, Schmidt B
Przemysł Chemiczny
|
2013
|
T. 92, nr 11
1984-1986
PL
Przedmiotem badań były mieszaniny polimerowe oparte na poli(tereftalanie trimetylenu) (PTT) i polietylenie niskiej gęstości (PE-LD), wytworzone pod kątem możliwości otrzymania nowych materiałów polimerowych o zmodyfikowanych właściwościach. Celem pracy było zbadanie właściwości mieszanin PTT/PE-LD o zawartości 5% mas. PTT, wytworzonych w procesie wytłaczania. Badania obejmowały układy PTT/PE-LD bez, jak i z udziałem kompatybilizatora w postaci wosku polietylenowego (w ilości 1, 3 i 5% mas.). Określono ich właściwości mechaniczne, termiczno-reologiczne (DSC, MFR), morfologię (SEM) i spektrofoto metrię (FTIR). Dodatek 5% mas. PTT do PE-LD w sposób widoczny wpływa na zmianę właściwości mechanicznych, termicznych i reologicznych w porównaniu z PE-LD. Analiza wyników dla mieszanin bez i z udziałem wosku polietylenowego wykazała, że domieszka 1% i 3% mas. wosku nie wpływa znacząco na zmianę tych właściwości w porównaniu z niekompatybilizowaną mieszaniną, natomiast przy zawartości 5% mas. w układzie PTT/PE-LD widoczny jest wpływ na zmianę badanych właściwości, świadczący o kompatybilizującym działaniu tej ilości wosku na mieszalność PTT i PE-LD, co potwierdza struktura SEM.
EN
Poly(trimethylene terephthalate)/polyethylene (9:95) blends (PTT/PE-LD) were prepd. by extrusion optionally in presence of polyethylene wax (1–5% by mass) and studied for mech., thermal and rheolog. properties. The addn. of PTT to PE-LD resulted in improving its properties. The addn. of polyethylene wax (5% by mass) to the PTT/PE-LD blends resulted in homogenization of their macrostructure and improving their mech. properties.
7
Content available remote Carboxymethyl starch with high degree of substitution: synthesis, properties and application
Spychaj T., Zdanowicz M., Kujawa J., Schmidt B.
Polimery
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2013
|
T. 58, nr 7-8
503--511
PL
Przedstawiono wyniki badań nad otrzymywaniem karboksymetyloskrobi (CMS) o wysokim stopniu podstawienia DS = 0,9, ze skrobi ziemniaczanej w zawiesinie izopropanol/woda. Dokonano oceny wpływu zmiennych parametrów reakcji eteryfikacji skrobi na wartości DS, efektywność reakcji (RE), liczbowo średnią masę molową (Mn) oraz lepkość 2-proc. roztworu wodnego. Pomiary metodami laserowej mikroskopii skaningowej (LSM), dyfrakcji rentgenowskiej (XRD) oraz spektroskopii w podczerwieni (FT-IR) pozwoliły na ocenę zmian struktury morfologicznej ziarna CMS oraz absorbancji widma skrobi natywnej po modyfikacji. Przeprowadzono również badania nad możliwością wykorzystania CMS (o wysokim stopniu podstawienia DS = 0,94, jak również w celach porównawczych o średnim stopniu podstawienia DS = 0,39) do flokulacji, ewentualnie dyspergowania, wybranych zawiesin wodnych: siarczanu żelaza(II), tlenku żelaza(III), laurynianu żelaza(III) oraz glinokrzemianów: kaolinu i montmorylonitu wapniowego. Stwierdzono, że CMS, zwłaszcza o wysokim DS, wykazuje cechy flokulanta względem siarczanu żelaza(II) oraz tlenku żelaza(III); natomiast jest dobrym środkiem dyspergującym w stosunku do zawiesin minerałów glinokrzemianowych.
EN
Highly substituted (degree of substitution, DS about 0.9) carboxymethyl starch (CMS) was prepared in isopropanol/water suspension. The influence of etherification reaction parameters on DS, reaction efficiency, number average molar mass as well as the viscosity of 2 wt. % aqueous solution was determined. Using laser scanning microscopy, X-ray diffraction and infrared spectroscopy techniques allowed to evaluate the morphological changes of modified starch granules when compared to native starch ones. An attempt to apply CMS (of high and medium DS: 0.94 and 0.39, respectively) for flocculation or dispergation tests of selected aqueous suspensions [iron(II) sulphate, iron(III) oxide, iron(III) laurate and aluminosilicates: kaolinite and calcium montmorillonite] has been performed. In case of iron(II) sulphate and iron(III) oxide high substituted CMS exhibited effective flocculating properties. Moreover, it worked as a good dispersing agent for mineral aluminosilicate suspensions.
8
Content available remote Badanie procesu sieciowania mieszanin żywica epoksydowa/żywica winyloestrowa
Pilawka R., Gorący K., Schmidt B., Janik J., Wilpiszewska K.
Przemysł Chemiczny
|
2012
|
T. 91, nr 6
1251-1254
PL
Przedstawiono wyniki badań procesu sieciowania kompozycji epoksydowo-winyloestrowych z różnymi układami środków sieciujących. Proces sieciowania badano metodą mikrokalorymetrii skaningowej oraz reometrii przy użyciu reometru naprężeniowego typu ARES. Określenie zależności lepkości od temperatury w czasie sieciowania mieszanin z żywic reaktywnych pozwoliło wyjaśnić zjawiska zachodzące podczas tego procesu, wpływ lepkości na możliwość dosieciowywania materiałów epoksydowo-winyloestrowych w czasie ogrzewania powyżej temperatury zeszklenia oraz temperaturę zeszklenia.
EN
A blend of epoxy and vinylester resins was crosslinked by using: 2-ethyl-imidazole with (PhCO)₂O₂ or triethylene-tetraamine with AcEt hydroperoxide in Me₂ phthalate as mixed initiators at 120°C for 2 h to study the curing course by differential scanning calorimetry and viscosity changes. Two sepd. exothermic effects were obsd.
9
Content available remote Starch-grafted-N-vinylformamide copolymers manufactured by reactive extrusion: synthesis and characterization
Spychaj T., Schmidt B., Ulfig K., Markowska-Szczupak A.
Polimery
|
2012
|
T. 57, nr 2
95-100
EN
Potato starch grafted with N-vinylformamide (NVF) copolymers have been manufactured by reactive extrusion in presence of radical initiators: 2,2'-azobis(2-methylpropionamidine) dihydrogen chloride or 2,2'-azobis(isobutyronitrile). During extrusion the following parameters have been changed: screw speed, temperature profile and initiator type whereas constant weight ratio of the reaction components NVF/starch/water 40:100:34 was kept. Raw copolymerization products have been evaluated by solubility tests in alkali aqueous solution at pH 9.0. Contents of graft copolymer in raw copolymerization products have been determined on a basis of extraction with water/ethanol mixture in the ratio of 70:30. FT-IR spectra of starch-g-NVF copolymers have been recorded and polysaccharide chains were subjected to enzymatic degradation using a- and b-amylases. Residual poly(N-vinylformamide) (PNVF) chains were characterized via gel permeation chromatography. Molecular weights of grafted PNVF were compared with literature data of polyacrylamide chains grafted on potato starches.
PL
W obecności inicjatorów rodnikowych: dichlorowodorku 2,2'-azobis(2-metylopropionamidyniowego) (AAPH) lub 2,2'-azobis(izobutyronitrylu) (AIBN) otrzymywano kopolimery szczepione N-winyloformamidu (NVF) na skrobi ziemniaczanej. W toku reaktywnego wytłaczania zmieniano szybkość obrotową ślimaków, profil temperaturowy (rys. 1) oraz rodzaj inicjatora, stały natomiast był stosunek masowy NVF/skrobia/woda 40:100:34. Badano rozpuszczalność w lekko alkalicznym roztworze wodnym (pH 9,0) surowych produktów kopolimeryzacji. Zawartość kopolimeru szczepionego w surowych kopolimerach określano na podstawie ekstrakcji mieszaniną woda/etanol (70:30) (tabela 1). Rejestrowano też widma FT-IR kopolimerów skrobia-g-NVF (rys. 2), a część polisacharydową kopolimerów poddano degradacji enzymatycznej za pomocą a- i b-amylaz. Pozostałe po degradacji enzymatycznej łańcuchy poli(N-winyloformamidowe) (PNVF) charakteryzowano metodą chromatografii żelowej (GPC) (rys. 3). Oznaczone wartości liczbowo średnich mas molowych naszczepionego PNVF porównywano z literaturowymi danymi dotyczącymi łańcuchów poliakryloamidu szczepionego na skrobi ziemniaczanej (tabela 2).
10
Content available remote Sorpcja Cu2+ i Fe3+ na szczepionych kopolimerach skrobi z reaktywnego wytłaczania
Schmidt B., Spychaj T.
Przemysł Chemiczny
|
2010
|
T. 89, nr 12
1628-1630
11
Content available Starch graft copolymers as superabsorbents obtained via reactive extrusion processing
Zdanowicz M., Schmidt B., Spychaj T.
Polish Journal of Chemical Technology
|
2010
|
Vol. 12, nr 2
14-17
EN
Starch graft copolymers have been obtained via grafting of acrylic monomers i.e. acrylamide (AAm) and acrylic acid (AA) during the reactive extrusion processes. 2,2'-azobis (2-methylpropionamidine) dihydrochloride (AAPH) was used as a radical initiator and N'N-methylenebisacrylamide (MBA), mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (trade name PETIA) and alkoxylated pentaerithritol acrylate (trade name Ebecryl 40) were applied as acrylic crosslinkers. The obtained materials were characterized by FTIR and their water sorption properties investigated using swelling (vol. %) and sorption (wt. %) tests. Sorption of water into these graft copolymer samples reached values of ca. 6 – 13 g of water per g of dry materials. It was also found that water sorption values were dependent on ratio of AAm and AA as well as on a type of the applied crosslinking agent.
12
Content available Diel Vertical Migration observed by acoustic doppler current profiler
Schmidt B., Szczucka J.
Hydroacoustics
|
2010
|
Vol. 13
235-242
EN
This paper presents the results of continual 17-week ADCP measurements applied to investigate the migratory behaviour of the Baltic animals. The velocities of vertical migration are determined in different ways and the results are compared. Strict correlation of the moments when downward or upward migration starts with sunrise and sunset times, is confirmed. Additionally, vertical and horizontal movements of water content are examined. Even though quite slow in comparison with horizontal flow, vertical migration exists independently of other factors.
13
Content available Pomiar mocy mechanicznej maszyn elektrycznych poprzez pomiar kąta skręcenia wału
Barszcz T., Urbanek J, Schmidt B.
Maszyny Elektryczne : zeszyty problemowe
|
2009
|
Nr 82
233-237
EN
Mechanical power carries important information about the technical state of rotating machinery. Dynamic measurement of the mechanical power is especially important for electrical machines. The paper presents the idea of mechanical power measurement by measurement of the angular twist of the shaft. The measurement is based on analysis of pulses from two disks, installed at two ends of the machine. It gives accurate information about changes of the rotational speed as well as the twist angle of the shaft. Next, the paper presents developed data processing algorithms. It is impossible in practice to machine ideal impulse disks and thus it is necessary to apply the compensation of results based on measured innacuracies. The proposed method is discussed and shown applicable for measurement of the angular twist of the power generation turboset. The method was validated on a test rig. The design of the rig and test measurements are presented. Measured mechanical power was compared with the electric power measured by traditional methods. High correlation of these values was achieved.
14
Content available remote Nanocluster memories by ion beam synthesis of Si in SiO2
Schmidt B., Heinig K. H., Röntzsch L., Stegemann K. H.
Materials Science Poland
|
2007
|
Vol. 25, No. 4
1213--1222
EN
Ion implantation and ion irradiation induced interface mixing were used to synthesise silicon nanoclusters in the gate oxide of metal-oxide-semiconductor (MOS) structures aiming at electronic memory applications. In the present study silicon nanocrystals for multi-dot floating-gate memories produced by ion irradiation through SiO2/Si nterfaces have been investigated to demonstrate possible advantages of this approach compared to conventional application of ion beam synthesis to the fabrication of silicon nanocrystal memories. The memory properties of the fabricated structures as a function of Si+-irradiation dose and post-irradiation annealing temperature and time have been examined through electrical measurements on n-channel MOS field-effect transistors. Low-voltage operating devices that can endure more than 106 programming/erasing cycles have been successfully achieved. More research is still required to improve charge retention and ensure the standard 10-year retention time needed for true non-volatile memory applications.
15
Content available Echosounder and ADCP investigation of Baltic fauna
Schmidt B., Szczucka J.
Hydroacoustics
|
2007
|
Vol. 10
175-182
EN
The Baltic fauna is rather meagre, what is connected with their miserable habitat. The area of our investigation is a specific basin because of its land-locked location, brackish water and small depth. It is characterised by enormous diversity of time-variable hydrological conditions. All species of fauna are subjected to the continuous stress of having to adapt to rapid changes in the temperature and salinity of the surrounding water and are exposed to highly variable environment during their every-day vertical migration between the food-rich sea surface and safer deep. The purpose of this paper is to present the results of acoustic investigations of the live interior of the Baltic Sea by means of various acoustic instruments (echosounders and acoustic Doppler current meters). The interpretation of our acoustic images helps to understand the nature and behaviour of the sound scatterers.
16
Content available Influence of the ADCP geometry on the results of measurement
Szczucka J., Schmidt B.
Hydroacoustics
|
2005
|
Vol. 8
227-232
EN
The problem of verification of the fundamental rule of operation of Acoustic Doppler Current Profiler assuming the uniform current field within the four acoustic beams is studied. Analysis of scattering differences observed in four beams allows us to conclude about the homogeneity or inhomogeneity of the flow field. Geometry of the measurement performed by the ADCP is presented. The distance between beams, sampling volume and vertical resolution are studied in connection with the system parameters and depth of beam penetration. The so called anomaly index is invented in order to find the areas of the strongest variability. Examples of the inhomogeneity of the acoustic field within the measuring setup are presented and analysed. Differences observed in the strength of echosignal obtained by ADCP (150 kHz) and ELAC echosounder (30 kHz) are also analysed. Some reasonable explanations are examined, like the resonance of gas bubbles included inside the bodies and directional response of animals.
17
Content available Bioacoustic measurements by use of acoustic doppler current profiler
Szczucka J., Schmidt B.
Hydroacoustics
|
2004
|
Vol. 7
209-216
EN
Nowadays, each oceanographic vessel is equipped with an Acoustic Doppler Current Profiler. Its task is to determine the value and direction of the vector of water current. It measures the Doppler shift in the frequency of the acoustic wave backscattered by neutrally floating particles suspended in the sea water. A by-product of such measurement is proportional to backscattering strength SV. Starting with the pilot work by Flagg and Smith [3], an ADCP becomes a useful tool for the investigations of the distribution and migration of zooplankton. It enables current and zooplankton abundance to be obtained simultaneously. The presented paper is an attempt to exploit the data collected in a routine way by the ADCP mounted on r/v ‘Oceania’ to characterise the biological aggregations, and especially to estimate the distribution of zooplankton and to observe their diel vertical migration.
18
Content available remote Dependence of electrical conductance of a-Si:H films on Na concentration in glass substrate
Pantchev B., Danesh P., Kreissig U., Schmidt B.
Opto-Electronics Review
|
2001
|
Vol. 9, No. 4
431-434
EN
The electrical conductance of a-Si:H is studied in films deposited on ion-exchanged optical wavequides in glass substrates. The effect of chemical composition of the near-surface region of the wavequide is considered from the viewpoint of the electrical instability of a-Si:H related with the penetration of Na ions from the substrate into the film. The optical wavequides have been prepared by Ag+ - Na+ or K+ - Na+ thermal or field-assisted ion exchange in soda-lime glass (SLG). The Na concentration in the near-surface region of the glass substrate has been estabilished by means of elastic recoil detection analysis (ERDA). The obtained results demonstrate the possibility of reduction of electrical instability of a-Si:H films deposited on optical wavequides in glass. It is shown that in some cases an additional Na depletion of the near-surface region is necessary to avoid Na contamination of the a-Si:H films.
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