Robert Pietrzak

Robert Pietrzak
Adam Mickiewicz University | UAM · Laboratory of Applied Chemistry

Professor

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145
Publications
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Publications

Publications (145)
Article
Full-text available
Abstract Hesperidin and hesperetin are polyphenols that can be found predominantly in citrus fruits. They possess a variety of pharmacological properties such as neuroprotective and antidiabetic activity. However, the bioavailability of these compounds is limited due to low solubility and restricts their use as pro-healthy agents. This paper descri...
Article
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In the present work, we reported on the efficiency of the removal of organic dyes by adsorption on activated carbons prepared from the residue of supercritical extraction of marigold. The performance of adsorbents prepared was tested towards methyl red, methylene blue, malachite green, and crystal violet at room temperature. The effects of carboniz...
Article
Full-text available
This paper deals with the adsorption of heavy metal ions (Cu2+ and Zn2+) on the carbonaceous materials obtained by chemical activation and ammoxidation of Polish brown coal. The effects of phase contact time, initial metal ion concentration, solution pH, and temperature, as well as the presence of competitive ions in solution, on the adsorption cap...
Article
Microwave and conventional heating have been combined to obtain highly microporous nitrogen-doped activated biocarbons. In order to generate nitrogen groups bonded in different ways into the carbonaceous matrix, the modification with urea was performed at two different stages of processing, i.e., precursor or char. Additionally, the effects of chem...
Article
Full-text available
The waste materials left after supercritical extraction of hop cones and marigold flowers were tested as precursors of activated bio-carbons. Adsorbents were produced by means of the physical (also called thermal) activation method using CO2 as the gasifying agent. All the activated bio-carbons were tested for the removal of NO2 and H2S from the ga...
Article
Production of activated bio-carbons from the residue of supercritical extraction of hops has been described. The precursor was first subjected to pyrolysis at 500 and 700 °C in nitrogen atmosphere. The bio-chars were next subjected to physical activation at 700 and 800 °C in carbon dioxide atmosphere. The effects of pyrolysis and activation tempera...
Article
A series of new synthetic spherical carbonaceous sorbents has been prepared by carbonization and physical activation of strongly acidic ion exchange resin - Wofatit RH. The carbonaceous materials were prepared using two different variants of thermal treatment - microwave and conventional heating. The samples obtained were characterized using variou...
Article
Waste PET bottles have been processed towards carbonaceous material through pyrolysis at 500 °C in nitrogen atmosphere followed by chemical activation with K2CO3. The obtained carbon was found to feature hierarchical pore structure, as evidenced by nitrogen sorption isotherm analysis. Composite sulfur-carbon electrode has been prepared using this c...
Article
Activated bio-carbons were developed from residues of supercritical extraction of raw plans such as: raspberries, blackcurrant, nettle and green tea. The physicochemical properties of the activated bio-carbons were characterized by low-temperature nitrogen sorption and Boehm titration. All materials were used for the adsorption of methylene blue an...
Article
The main aim of the study was to compare the sorption capacity of hay-based activated biochars, obtained using conventional and microwave furnance, relative to copper(II) ions and ionic polyacrylamides (PAM). Surface properties of the solids were characterized by, inter alia, N2 adsorption/desorption isotherm method, whereas their tendency to aggre...
Article
This work concerns development of a hybrid sorbent material for removal of hydrogen sulphide from air. The material was based on activated carbon and iron compounds obtained from waste iron(II) sulphate(VI) heptahydrate. The iron salt was deposited on the carbonaceous support and subjected to oxidation (Fe2+ to Fe3+) using atmospheric oxygen, in al...
Article
Full-text available
Residues after supercritical extraction of hops were chosen as activated bio-carbons precursor. The actual adsorbent was prepared by physical activation of the starting material. Some amount of the activated bio-carbon was divided into two parts. One of them was washed with distilled water, while the other part of the activated bio-carbon was washe...
Article
Full-text available
A series of new nitrogen-doped activated carbons has been obtained via the reaction with urea and chemical activation of Polish brown coal. In order to obtain nitrogen groups bonded in different ways to the carbonaceous matrix, the modification with urea was performed at two different stages of processing, i.e. precursor or char. Additionally, the...
Article
The oxidized mesoporous carbons obtained by hard or soft-template methods have been used for removal of heavy metal ions – Ni²⁺and Co²⁺ from the liquid phase. The materials were functionalized with 0.5 and 5 M solutions of nitric(V) acid. The use of two different temperatures of oxidation 70 °C and 100 °C, permitted achieving functionalization in t...
Article
Full-text available
Preparation of polymeric membranes based on cellulose acetate and modified by adding different amounts of a pore generating agent, which was polyvinylpyrrolidone (PVP), is presented and potential application of the membranes obtained for the removal of iron and copper ions from liquid phase is examined. Addition of various amounts of PVP has an imp...
Article
Activated carbons were prepared by physical and direct activation of sawdust pellets coming from coniferous trees, with the use of microwave radiation. The activated carbons obtained were used as adsorbents for the removal of methylene blue (MB) from aqueous solutions. Liquid-phase adsorption experiments were conducted and the maximum adsorption ca...
Article
Full-text available
Ordered mesoporous carbon obtained by the soft template method was subjected to oxidation with the use of ammonium persulfate or nitric acid. The material was modified in different conditions in order to generate on its surface oxygen functional groups. Functionalization of carbon with nitric acid or ammonium persulfate at low temperatures caused a...
Article
Carbon xerogels studied were synthesized by two methods. The first was based on polycondensation of resorcinol and formaldehyde. The material obtained in this way was subjected to surface oxidation and modification with amine groups followed by impregnation with copper(II) chloride. In the second method copper(II) acetate was introduced at the stag...
Article
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The nanostructure of poly(acrylic acid) (PAA) adsorption layer on the surface of mesoporous-activated carbon HPA obtained by physical activation of residue after supercritical extraction of hops was characterized. This characterization has been done based on the analysis of determination of adsorbed polymer amount, surface charge density, and zeta...
Article
The phosphorus-containing activated carbons have been obtained by activation of the low quality hay and the chars obtained by its pyrolysis with 50% phosphoric acid at 600 °C in a stream of nitrogen. Furthermore, the study was performed on two series of carbonaceous materials prepared from hay using different heating methods – microwave and convent...
Article
Preparation of bio-activated carbons from hay by direct activation with the use of microwave radiation was studied. The influence of process variables such as the temperature and activation time on textural, chemical-surface properties and sorption properties of the products obtained was studied. The resulting bio-carbons were characterized by low-...
Article
Polymer nanocomposite was prepared by the conventional sol-gel method using formaldehyde and resorcinol. The surface of the nanocomposite was functionalized with methylamine. Some of the samples were additionally impregnated with copper(II) chloride. All the materials obtained were characterized by FT-IR spectroscopy, low-temperature nitrogen sorpt...
Article
The catalytic activity of Ce- and La-based catalysts supported on mesoporous carbons was studied in dry methane reforming reaction (DMR). Mesoporous carbons were prepared by hard template method using ordered silica (SBA-15 and KIT-6) as templates and sucrose as carbon precursor. After sucrose pyrolysis samples were washed with 5 wt% hydrofluoric a...
Article
Pistachio nutshells were chosen as activated carbons precursor because current method of their disposal - combustion - is not profitable due to the low calorific value. Carbonaceous adsorbents were prepared by means of chemical, physical and direct activation of starting material. The influence of different parameters of activation procedure on the...
Article
Obtaining useful sorbents from spent materials is of great importance. The paper presents the results of tests determining the kinetic and adsorption parameters on the removal of heavy metal Cu(II), Cd(II), Co(II) and Pb(II) ions on the carbonaceous adsorbents W1 KPS, W2 KPS, D1 CC3 and D2 CC3 obtained from spent ion exchangers. Among others the so...
Article
Carbonaceous materials were obtained from waste tyres and their potential application as hydrogen sulphide adsorbents was investigated. The adsorbents were obtained by pyrolysis of waste tyres and physical (CO2) or chemical (KOH) activation at 550 and 800ºC. The effect of modification conditions on the performance of waste tyres based materials as...
Article
High surface area, biomass-derived carbon has been prepared by means of chemical activation of waste fruit peels with potassium carbonate and investigated as novel sulfur cathode component for lithium-sulfur batteries As evidenced by scanning electron microscopy and nitrogen absorption isotherms, the synthesized material features hierarchical micro...
Article
The adsorption properties of microporous activated carbon (CSDA) obtained by direct activation of cherry stones in relation to low-molecular weight poly(acrylic acid) − PAA were examined. The solution pH influence and molecular weight of the polymer were examined. The PAA adsorbed amounts were correlated with the solid surface charge density and ze...
Article
Full-text available
Carbonaceous adsorbents were obtained from the residue after supercritical extraction of marigold subjected to physical activation and used as nitrogen dioxide and iodine adsorbents. The effect of carbonisation and activation temperature on the textural parameters, acid–base character of the surface and sorption properties of the activated carbons...
Article
Full-text available
A new technology of obtaining activated carbons by physical and direct activation of biomass with the use of microwave radiation is described. The effect of activation temperature (700 and 800 °C) and two periods of time (15 and 30 min) on the textural parameters, acid–base character of the surface and sorption properties of activated carbons was t...
Article
Full-text available
New carbonaceous adsorbents were prepared by means of direct, physical and chemical activation of corn cobs and cherry stones as well as coffee and tobacco industry waste materials. The effect of activation method on the textural parameters, acid-base character of the surface and sorption properties toward toxic gases of the materials obtained was...
Article
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A series of new functionalised carbonaceous materials were prepared by means of oxidation and ammoxidation of commercially available multi-walled carbon nanotubes. The effect of oxygen and nitrogen doping on the textural, surface as well as thermal properties of the prepared adsorbents was tested. The materials were characterized by elemental analy...
Article
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Mesoporous carbon of regular structure was subjected to oxidation by ammonium persulfate at 30, 60 or 100 °C. The mesostructure and pore evolution were characterised by XRD, TEM, and N2 sorption techniques. The functional groups present on the surface of the carbon materials were identified by FTIR and thermogravimetric studies. It was established...
Article
Full-text available
Activated carbons have been obtained by physical activation of residue left after supercritical extraction of hops. The effect of pyrolysis temperature on the physicochemical properties of the adsorbents prepared was tested. The carbonaceous materials were characterised by low-temperature nitrogen sorption, determination of pH and the number of sur...
Article
A technology for obtaining activated carbons by physical activation of hay with the use of microwave radiation is described. The effect of pyrolysis temperature on the textural parameters, acid-base character of the surface and sorption properties of activated carbons has been tested. The sorption properties of the activated carbons obtained were c...
Article
Full-text available
The polymer membranes containing 18 wt% of cellulose acetate and different amounts of polyvinylpyrrolidone (PVP) as a cross-linker agent were used in the process of iron and copper ions removal from liquid phase. Depending on the content of PVP (changed from 1 to 4 wt.%) the membrane surfaces were characterised by different hydrophilic character an...
Article
Full-text available
Two series of functionalised carbonaceous adsorbents were prepared by means of oxidation and nitrogenation of commercially available activated carbon and multi-walled carbon nanotubes. The effect of nitrogen and oxygen incorporation on the textural, surface, thermal and sorption properties of the adsorbents prepared was tested. The materials were c...
Article
The adsorption properties of two silica composite materials: MgxOy–SiO2 and ZnxOy–SiO2 in relation to poly(vinyl alcohol)—PVA were examined. For each mixed oxide three solids differing in the metal oxide (MgxOy or ZxOy) content were applied (0.2; 1 and 3 mmol/g SiO2), respectively. The polymeric sample was characterized with molecular weight 100 kD...
Article
A series of new carbonaceous adsorbents has been obtained by means of chemical activation of common tropical fruit peels with potassium carbonate. The influence of the precursor on the porous structure development, acidic and basic surface group generation, as well as the sorptive properties of the adsorbents prepared towards liquid pollutants, was...
Article
Following the preparation of an inclusion complex of β-cyclodextrin and meropenem, methods based on FT-IR, Raman and DSC were used for its characterization. An analysis of changes in the stability of meropenem after complexation showed that the complex may serve as a valuable delivery system significantly contributing to enhanced meropenem stabilit...
Article
Ordered mesoporous carbons modified with cerium were applied for removal of tartrazine and sunset yellow FCF from aqueous solutions. These novel materials were characterised by different techniques such as X-ray diffraction, low-temperature nitrogen sorption, scanning electron microscopy and laser diffraction. Unique physicochemical properties of t...
Article
Full-text available
A series of carbonaceous adsorbents was obtained by physical and chemical activation of pistachio nut shells. The effect of activation method on the textural, acid-base and adsorption properties of the materials obtained was tested. The materials prepared were characterized by iodine and methylene blue removal at room temperature. Depending on the...
Article
The ordered mesoporous silicas SBA-15 and KIT-6, modified with lanthanum, have been for the first time applied in investigation of ibuprofen adsorption and release. The materials of hexagonal and regular structure were obtained by the hydrothermal method using a triblock copolymer Pluronic P123 as a template. The mesoporous silicas were impregnated...
Article
Full-text available
A technology of obtaining nitrogen-enriched activated carbons from coniferous tree sawdust by direct activation of the precursor and physical activation with CO2 is described. The effect of activation time, pyrolysis temperature as well as modification with urea on the textural parameters, acid–base character of the surface and sorption properties...
Article
Activated carbons obtained from sawdust pellets from coniferous wood were used as adsorbents of nitrogen dioxide and hydrogen sulphide. The precursor was subjected to pyrolysis at 400 °C in nitrogen atmosphere and next to physical activation at 600 and 700 °C by CO2. Some part of the precursor was also subjected to direct activation at 600 °C by CO...
Article
The activated carbons were synthesized from hay with CO2 as an activating agent. Furthermore hay and the chars obtained by pyrolysis were treated with urea, in order to introduce nitrogen to their structure, and then subjected to physical activation. The porous structure of activated carbons before and after impregnation was characterised by nitrog...
Article
Full-text available
This study aimed to obtain and characterize an RU-β-CD complex in the context of investigating the possibility of changes in the solubility, stability, antioxidative and microbiological activity as well as permeability of complexated rutin as against its free form. The formation of the RU-β-CD complex via a co-grinding technique was confirmed by us...
Article
Cherry stones were used as a precursor for the preparation of activated carbons by physical and chemical activation with CO2 and KOH, respectively. The effect of pyrolysis temperature (500 and 800 °C) and activation method on the acid–base character of the surface, textural parameters as well as sorption properties of adsorbents prepared toward gas...
Article
Ordered mesoporous carbons of regular structure have been for the first time modified with lanthanum(III) chloride. The physicochemical properties of materials were characterised by X-ray diffraction, electron transmission microscopy and low-temperature nitrogen sorption. The results show that lanthanum(III) chloride strongly determine structural,...
Article
The sorption properties of chars and activated carbons obtained from coffee industry waste materials toward hydrogen sulphide are characterised. The effects of pyrolysis temperature and method of activation as well as porous structure, acid–base character of the surface and mineral matter content on the efficiency of H2S removal are checked. Moreov...
Article
A method for obtaining activated carbons from cherry stones by chemical activation with NaOH is described. Carbonaceous adsorbents were obtained by two methods of activation (physical mixing and impregnation) and two variants of thermal treatment (at a constant or increasing temperature). Cherry stones were proved to be effective cheap precursors o...
Article
Mesoporous carbons, CMK-3 and CMK-8 were synthesised by hard template method with the use of ordered silicas SBA-15, KIT-6 as solid state matrices and sucrose as carbon precursor. The physicochemical properties of materials obtained were characterised by X-ray diffraction, electron transmission microscopy and low-temperature nitrogen adsorption. Th...
Article
Preparation of polymeric membranes based on polyethersulfone (PES) modified by adding different amounts of a pore-forming agent (PVP) is presented, and potential application of the membranes obtained for removal of phenol from the liquid phase is examined. The addition of various amounts of PVP has been shown to bring about changes in the content o...
Article
Mesoporous silica materials, such as SBA-3, SBA-15, SBA-16 and KIT-6 were synthesized using tetraethyl orthosilicate as the silica source and different surfactants as templates. The products were characterised by a number of techniques, including low-temperature nitrogen sorption, X-ray diffraction and transmission electron microscopy. Results of t...
Article
A method for obtaining carbonaceous adsorbents from used corrugated cardboard by physical activation with CO2 is described. The effect of pyrolysis temperature (500–800 °C) and time (30 and 60 min) as well as activation on the adsorbents textural parameters, acid–base character of surface and sorption properties toward nitrogen dioxide have been te...
Article
Preparation of polymeric membranes based on polyethersulfone (PES) modified by adding different amounts of pore generating agent (PVP) is presented and potential application of the membranes obtained for removal of copper and iron ions from the liquid phase is examined. It has been shown that addition of various amounts of PVP affects the physical...
Article
Porous carbon material containing CaO and MgO, prepared by carbonization of poly(ethylene terephthalate) mixed with a natural dolomite, was examined as a sorbent material for simultaneous removal of CO2 and SO2 from air in dry conditions and in a presence of humidity, at temperatures ranging from 20 degrees C to 70 degrees C. Attained results clear...
Article
Porous carbons loaded with CaO and MgO were prepared through a one-step process from mixtures of poly(ethylene terephthalate) and dolomite mineral. Obtained hybrid materials were examined as sorbents for CO2 gas contained in air. The influence of pore structure, loadings of the oxides, moisture, and temperature on the efficiency of gas removal is p...
Article
A one-step process for the preparation of CaO-containing porous carbons is described. Mixtures of poly(ethylene terephthalate) with natural limestone were pyrolyzed and thus hybrid sorbents could be easily obtained. The polymeric material and the mineral served as a carbon precursor and CaO delivering agent, respectively. We discuss effects of the...
Article
N-containing carbon materials were obtained from waste plum stones submitted to pyrolysis under Ar flow at 700 °C or to activation under steam at 800 °C and enriched with nitrogen by heating in a NH3/air mixture at 270 °C or in NO at 300 °C. In situ mixtures of TiO2 and carbons were prepared by the slurry method and methylene blue photodegradation...
Article
Full-text available
A technology for obtaining carbonaceous adsorbents by physical and chemical activation of waste materials from coffee industry is described. The effect of pyrolysis temperature and type of activation procedure on the textural parameters, acid–base character of the surface and sorption properties of activated carbons has been tested. The resulting c...
Article
Full-text available
The adsorption of amino acids such as l-phenylalanine and l-histidine was carried out on a series of mesoporous carbons obtained with the use ordered silicas KIT-6, SBA-16, SBA-15 as templates and furfuryl alcohol as carbon precursor. Small angle XRD analysis confirmed the ordered mesoporous structures of all materials obtained. They were also char...
Article
The method of synthesis of polymeric membranes based on polyethersulfone (PES) and modified by addition of carbonaceous materials (char or activated carbon) is presented and their potential application for removal of copper ions from liquid phase are examined. The addition of carbon brings about changes in the content of the surface oxygen group bu...