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1

Treatment of dairy waste by anaerobic co-digestion with sewage sludge

Pilarska A. A., Pilarski K., Witaszek K., Waliszewska H., Zborowska M., Waliszewska B., Kolasiński M., Szwarc-Rzepka K.

Ecological Chemistry and Engineering. S

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2016

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Vol. 23, nr 1

99--115

EN

The results of anaerobic digestion (AD) of buttermilk (BM) and cheese whey (CW) with a digested sewage sludge as inoculum is described. The substrate/inoculum mixtures were prepared using 10% buttermilk and 15% cheese whey. The essential parameters of the materials were described, including: total solids (TS), volatile solids (VS), pH, conductivity, C/N ratio (the quantitative ratio of organic carbon (C) to nitrogen (N)), alkalinity, chemical oxygen demand (COD). The potential directions of biodegradation of the organic waste types, as used in this study, are also presented. Appropriate chemical reactions illustrate the substrates and products in each phase of anaerobic decomposition of the compounds that are present in buttermilk and cheese whey: lactic acid, lactose, fat, and casein. Moreover, the biogas and biomethane production rates are compared for the substrates used in the experiment. The results have shown that buttermilk in AD generates more biogas (743 m3/Mg VS), including methane (527 m3/Mg VS), when compared with cheese whey (600 m3/Mg VS, 338 m3/Mg VS for biogas and methane, respectively).

2

Synthesis and characterization of hydroxyapatite/chitosan composites

Szatkowski T., Kołodziejczak-Radzimska A., Zdarta J., Szwarc-Rzepka K., Paukszta D., Wysokowski M., Ehrlich H., Jesionowski T.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 2

575--585

EN

Hydroxyapatite (HAp)/chitosan (CS) composites were synthesized via a one-step co-precipitation method from aqueous solution, with the use of calcium chloride (CaCl2) and disodium hydrogen phosphate (Na2HPO4). CS was obtained via partial deacetylation of chitin with the use of strong sodium hydroxide solution. Composites were prepared with various HAp/CS ratios (30/70, 50/50, 70/30, 85/15) for comprehensive comparison of their properties. Fourier Transform Infrared Spectroscopy (FT-IR) analysis showed that hydrogen bonds were formed between the organic matrix and the mineral compound, confirming a successful phase interconnection. X-ray diffraction patterns were obtained, enabling examination of the crystalline properties of the composites, including HAp identification. The porous structure parameters of the composites were investigated, and morphological analysis (SEM) was performed. Differential Thermal Gravimetry (DTG) analysis of the composites indicated that the material is thermally stable up to 200 oC. Additionally, Energy Dispersive Spectroscopy (EDS) analysis of the mineral was carried out to check the Ca/P ratio, and confirmed its similarity to pure HAp.

3

Hybrid composites with epoxy resin matrix manufactured with vacuum casting technology

Oleksy M., Heneczkowski M., Oliwa R., Budzik G., Dziubek T., Markowska O., Szwarc-Rzepka K., Jesionowski T.

Polimery

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2014

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T. 59, nr 9

677—681

EN

The paper presents the methodology of the process of manufacturing of technical profile models on the example gear wheels made of epoxy composites cast in silicone molds using vacuum casting technology. Research on preparation of epoxy resin composites filled with hybrid modifiers has been carried out. Mechanical and processing properties of composites have been evaluated, particularly in terms of application in rapid prototyping of gear wheels. Considerable improvement of tensile strength (up to 44 %) and unnotched impact strength (up to 93 %) has been observed. Geometric accuracy of gear wheels prepared by casting of the analyzed hybrid composites has been determined using a coordinate measuring machine. Morphology of the brittle fracture of studied composites has been observed on brittle fractures using a scanning electron microscope (SEM).

PL

W artykule przedstawiono metodykę procesu wytwarzania modeli profili technicznych na przykładzie kół zębatych wykonanych z kompozytów epoksydowych metodą odlewania próżniowego w formach silikonowych. Otrzymano kompozyty na osnowie żywicy epoksydowej napełnione modyfikatorami hybrydowymi. Oceniono właściwości użytkowe i przetwórcze kompozytów, zwłaszcza pod względem możliwości ich zastosowania w metodach szybkiego prototypowania do otrzymywania kół zębatych. Stwierdzono wyraźną poprawę wytrzymałości na rozciąganie (do 44 %) oraz udarności bez karbu (do 93 %). Na stanowisku współrzędnościowym określono także dokładność geometryczną odlanych modeli kół zębatych, a za pomocą skaningowego mikroskopu elektronowego (SEM) zbadano ich morfologię, obserwowaną na kruchych przełomach.

4

Synthesis and physicochemical characterization of silicafillers modified with octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane

Szwarc-Rzepka K., Gogola N., Siwińska-Stefańska K., Marciniec B., Jesionowski T.

Polish Journal of Chemical Technology

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2013

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Vol. 15, nr 4

15-23

EN

Hybrid nanofillers of silica grafted with octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane were obtained by the method based on solvent evaporation with the use of both hydrated or emulsion spherical silica. Octakis({3-methacryloxypropyl}dimethylsiloxy) octasilsesquioxane was applied as a modifying agent and it was synthesized by employing the hydrosilylation reaction. The effectiveness of modification of the hybrid nanofillers obtained was verified using Fourier transform infrared spectroscopy and nuclear magnetic resonance (29Si and 13C CP MAS NMR). The products obtained were characterized by determination of their physicochemical properties and porous structure, including specific surface area, pore diameter and pore volume. Dispersion degree and particle size of the nanofillers was characterized by NIBS (Non-Invasive Back-scatter) method and laser diffraction technique, while their morphology by transmission electron microscopy.

5

Otrzymywanie i zastosowanie funkcjonalizowanych napełniaczy hybrydowych SiO2/F-SF POSS w żelowych elektrolitach polimerowych

Szwarc-Rzepka K., Walkowiak M., Osińska-Broniarz M., Dutkiewicz M., Maciejewski H., Jesionowski T.

Polimery

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2013

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T. 58, nr 10

748--758

PL

Metodą odparowania rozpuszczalnika wytwarzano układy hybrydowe SiO2/POSS. Do modyfikacji powierzchni krzemionki uwodnionej lub otrzymanej techniką emulsyjną zastosowano oktakis(dimetylosiloksy-1,1',2,2',3,3',4,4'-oktafluoropentyloksypropylo) oktasilseskwioksan (F-SF POSS). Efektywność modyfikacji napełniaczy potwierdzano przy użyciu spektroskopii w podczerwieni (FT-IR) oraz jądrowego rezonansu magnetycznego (29Si oraz 13C CP MAS NMR). Określano parametry struktury porowatej wytworzonych napełniaczy hybrydowych, takie jak: powierzchnia właściwa BET, średnica oraz objętość porów. Układy hybrydowe poddano ponadto analizie dyspersyjnej (metodą nieinwazyjnego wstecznego rozproszenia światła — NIBS) oraz morfologicznej (za pomocą transmisyjnej mikroskopii elektronowej TEM). Otrzymane modyfikowane napełniacze zastosowano jako dodatek do żelowych elektrolitów polimerowych. Elektrolity żelowe uzyskano na drodze aktywacji suchych membran kompozytowych w ciekłym roztworze soli litu. Badania elektrochemiczne obejmowały pomiary przewodnictwa właściwego techniką spektroskopii impedancyjnej w szerokim zakresie temperatury oraz wyznaczenie okien potencjałowych techniką liniowej woltametrii cyklicznej. Dodatek kompozytów POSS wpływa korzystnie na transport kationów litu, zwiększając przewodnictwo żeli na bazie PVdF/HFP w temperaturze pokojowej o ponad jeden rząd wielkości. Obserwowany wzrost przewodnictwa jest słabo skorelowany z ich zdolnością do absorpcji fazy ciekłej. Stabilność anodowa żeli rośnie nieznacznie w wyniku dodania napełniaczy POSS do membran PVdF/HFP. Badane napełniacze wykazują obiecujące właściwości w kontekście przyszłych prac badawczo-rozwojowych nad nowatorskimi elektrolitami stałymi do akumulatorów litowych o zwiększonym poziomie bezpieczeństwa.

EN

Hybrid SiO2/POSS fillers were obtained using the method based on solvent evaporation. Octakis({1,1,2,2,3,3,4,4-octafluoropentyloxypropyl}dimethylsiloxy) octasilsesquioxane (F-SF POSS) was used to modify the surface of silica, hydrated or prepared via emulsion method. The effectiveness of modification was evaluated by FT-IR spectroscopy and nuclear magnetic resonance (29Si and 13C CP MAS NMR). The parameters of porous structure of the prepared hybrid fillers, such as surface area BET, mean pore diameter and pore volume were determined. The hybrid products were subjected to dispersive analysis (non-invasive backscattering method, NIBS) and morphological characterization (using transmission electron microscopy — TEM). The obtained hybrid systems were used as additives in gel polymer electrolytes, prepared by activation of dry composite membranes in a liquid solution of lithium salt. The electrolytes were subjected to electrochemical studies, including the measurements of specific conductivity by impedance spectroscopy in a wide range of temperatures and the determination of potential windows by the linear cyclic voltammetry. The addition of POSS composites had a beneficial effect on the transport of lithium cations and the room temperature conductivity of gel electrolytes based on PVdF/HFP membranes was enhanced by an order of magnitude. The observed increase in gel conductivity was poorly correlated with the ability of liquid phase absorption. The anodic stability of gels only slightly increased upon the addition of POSS to PVdF/HFP membranes. The fillers studied show promising properties in the context of future research and development studies on new solid electrolytes for lithium cells with increased safety.

6

Preparation and characterization of SiO2/silane/POSS functional hybrids

Szwarc-Rzepka K., Szatkowski T., Ciesielczyk F., Jesionowski T.

Physicochemical Problems of Mineral Processing

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2013

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Vol. 49, iss. 2

673--687

EN

Novel SiO2/silane/POSS functional hybrids have been synthesized via an immobilization method. Hybrid materials were obtained through a connection of emulsion silica with defined dispersive and morphological properties with (3-isocyanatepropyl)triethoxysilane and selected mono- or octasubstituted POSS compounds in organic solvent. Modification effectiveness of the obtained SiO2/silane/POSS hybrid systems was confirmed with the use of the Fourier transform infrared spectroscopy (FTIR). In order to determine the influence of bifunctionalization on coverage degree of the selected POSS compounds, elemental analysis (C, H, N contents) was performed. Moreover, parameters of porous structure of the obtained products were determined: BET surface area, total volume and mean size of pores. During analysis the thermal stability of silsesquioxanes cage, unmodified silica support, and hybrid systems have been investigated. For this purpose dispersive and morphological characterization (particle size distribution and TEM images) was performed.

7

Advanced biocomposites based on silica and lignin precursors

Klapiszewski Ł., Nowacka M., Szwarc-Rzepka K., Jesionowski T.

Physicochemical Problems of Mineral Processing

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2013

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Vol. 49, iss. 2

497--509

EN

A new method is proposed for obtaining biocomposites based on a combination of silica and lignin precursors. Amorphous silica was produced by two methods: one based on hydrolysis and condensation of tetraethoxysilane (sol–gel method) and the other involving precipitation in a polar medium. Additionally, the commercial silica known under the name of Syloid®244 was used. The silica surface was modified to ensure better affinity of the support to activated lignin. The biocomposites obtained were carefully characterised by determination of their physicochemical and dispersive–morphological properties. Electrokinetic stability of the biocomposites was evaluated on the basis of zeta potential dependence on pH. Thermal stability of the biocomposites and their porous structure parameters (surface area, pore diameter and pore volume) were established. The results indicate that silica/lignin biocomposites are much promising for application in many areas of science and industry.

8

Synthesis of hepta(isobuthyl)ethyltriethoxysilyl- octasilsesquioxane and its application as a modifier of both hydrated and emulsion silicas

Szwarc-Rzepka K., Ciesielczyk F., Zawisza M., Kaczmarek M., Dutkiewicz M., Marciniec B., Maciejewski H., Jesionowski T.

Physicochemical Problems of Mineral Processing

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2012

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Vol. 48, iss. 2

619-630

EN

Hepta(isobuthyl)ethyltriethoxysilyloctasilsesquioxane was synthesized by hydro-silylation of hepta(isobuthyl)vinyloctasilsesquioxane with triethoxysilane, over Karstedt catalyst and tetrahydrofuran. Hybrid systems of silica and monofunctional silsesquioxane (SiO2/POSS) were obtained by solvent evaporation, using emulsion silica (ES) and hydrated silica (HS), obtained by precipitation in emulsion or water media. For their surface modification hepta(isobuthyl)ethyltriethoxysilyloctasilsesquioxane was used. The hybrids were characterized by dispersion analysis (NIBS method and laser diffraction technique) and morphological analysis (transmission electron microscopy) as well as wettability profiles in an aqueous system. The adsorptive properties of the hybrids were evaluated on the basis of surface area BET, pore volume and size. The effectiveness of modification of the hybrid fillers was tested by FTIR and 29Si CP MAS NMR.