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1

Activated biocarbons obtained from post-fermentation residue as potential adsorbents of organic pollutants from the liquid chase

Nowicki Piotr, Gruszczyńska Karolina, Urban Teresa, Wiśniewska Małgorzata

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 2

art. no. 146357

EN

A series of new synthetic carbonaceous adsorbents has been prepared via physical and chemical activation of residue of alcoholic fermentation of corn starch. Two different variants of thermal treatment procedure - microwave and conventional heating have been applied for preparing of the activated biocarbons. All the samples under investigation were characterised by elementary analysis, surface area measurements as well as determination of the number of surface functional groups. The electrokinetic properties of examined materials were studied using potentiometric titration and electrophoresis methods, which enabled determination of the surface charge density and zeta potential of activated biocarbon particles. Moreover, sorption properties of the carbonaceous materials towards two organic dyes - methylene blue and malachite green were tested. The final products were activated biocarbons of medium developed surface area ranging from 21 to 879 m2/g, showing acidic character of the surface and various content of surface functional groups. More favourable textural parameters as well as sorption properties toward both organic dyes were revealed by chemically activated samples. The obtained results indicated also considerable effect of adsorbed dye molecules on the structure of electrical double layer formed at the solid/liquid interface.

2

Badania fazy ciekłej dwufazowych modelowych iłów na granicy plastyczności

Olchawa A., Gorączko A., Ziółkowska D.

Przegląd Geologiczny

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2014

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Vol. 62, nr 10/2

654--56

EN

The paper presents investigations into the relationship between specific surface area of two monomineralic clays and their plastic limits. Two clays – sodium montmorillonite and calcium kaolinite were used to study. For montmorillonite, the quantity of interlayer water at plastic limit is approximately 30% of water content. The number of the layers of water molecules on the external surface area ne = 13÷14. For kaolinite (i.e. non- -swelling clay minerals which only contain water on external surface area), the number of layers of water molecules on the external surface area ne = 63.

3

The changing shape of a liquid drop in an electric field

Jayalal A. A. S. N., Wijewardena Gamalath K. A. I. L.

International Letters of Chemistry, Physics and Astronomy

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2012

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Vol. 3

24-40

EN

An approximate extension of the slender body theory was used to determine the static shape of a conically ended dielectric fluid drop in an electric field. Using induced surface charge density, hydrostatic pressure and the surface tension of the liquid with interfacial tension stresses and Maxwell electric stresses, a governing equation was obtained for Spender geometries for the equilibrium configuration and numerically solved for 3D. For an applied electric field, the electric energy on a spherical drop can be maximized in a weak dielectric by increasing the applied electric field. The minimum dielectric constant ratio needed to produce a conical end is 14.5 corresponding to a cone angle 31.25° .There is a sharp increment of the aspect ratio after reaching the threshold value of the applied field strength and the deformation of the fluid drop increases with the increase in dielectric constant of the fluid drop. For a particular dielectric constant ratio, the threshold electric field producing conical interface increases with the increased surface tension of the liquid. The threshold electric field for a water drop is 1.0854×104 units and the corresponding aspect ratio is 15. For the minimum dielectric ratio the cone angle of the drop decreases with applied field making the drop more stable at higher fields.

4

Adsorption of Ca(II) and Fe(III) ions at the SnO2/electrolyte solution interface

Janusz W., Skwarek E.

Physicochemical Problems of Mineral Processing

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2011

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Vol. 46

72-82

EN

Adsorption of Ca(II) and Fe(III) ions at the SnO2/NaCl solution interface as well as the effect of adsorption on the structure of electrical double layer were presented in this paper. The influence of ionic strength, pH and presence of ions on adsorption of Ca(II) and Fe(III) at the SnO2/NaCl solution interface were also investigated. Adsorption was investigated in the pH range of 2 to 10. The zeta potential, surface charge density, adsorption density, pH50% and ΔpH10-90% parameters for different concentrations of carrying electrolyte were presented. The adsorption reaction constants involving the surface hydroxyl groups were determined using the numerical optimization method.

PL

Cyna i jej związki mają szereg praktycznych i istotnych zastosowań od wielu lat. Obecnie zasoby naturalne cyny są nieduże. Szacuje się, że wystarczą na około 40 lat. Dlatego należy podjąć próbę odzysku cyny z materiałów zawierających ten pierwiastek. Przeprowadzono pomiary adsorpcji jonów wapnia i żelaza, dla jego różnych stężeń początkowych, w funkcji pH dla układu SnO2/roztwór NaCl. Kształt krzywej adsorpcji w funkcji pH ma postać krawędzi adsorpcji. Wzrost stężenia początkowego jonów Ca(II) i Fe(III) powoduje przesunięcie krawędzi w kierunku zasadowym w skali pH. Wyznaczono charakterystyczne parametry krawędzi adsorpcji tj. pH50% i ΔpH10-90%. W oparciu o zależność adsorpcji od pH obliczono również stałe adsorpcji jonów Ca(II) i Fe(III). Zależność gęstości ładunku powierzchniowego od pH w obecności jonów Ca(II) i Fe(III) jest w dobrej korelacji z zależnością adsorpcji jonów Ca(II) i Fe(III) od pH. Adsorpcja jonów Ca(II) i Fe(III) na powierzchni SnO2 prowadzi do wzrostu stężenia grup ujemnie naładowanych

5

The Electrical Double Layer at the Hydroxyapatite/NaClO4 Solution Interface

Janusz W., Skwarek E., Złotucha A., Reszka M.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 1-2

57-67

EN

Physicochemical properties of hydroxyapatite [Ca10(OH)2(PO4)6] samples surface were studied and physicochemical quantities characterizing the electrical double layer of the hydroxyapatite/NaClO4 solution interface were determined. The investigated samples were synthesized by two methods. Hydroxyapatite (HAP) was investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), adsorption-desorption of nitrogen (ASAP), photon correlation spectroscopy (PCS), infrared spectroscopy (IR), and AFM microscope. The surface area, the average volume of pores and the size of particles of hydroxyapatite of the samples were determined. The surface charge density and the potential were studied as a function of pH and the point of zero charge and the isoelectirc point of samples were determined. On the basis of potentiometric titrations the values of surface ionization and complexation constants were calculated.

6

A biochemical model for characterising the surface-active phospolipid bilayer of articular cartilage relative to acid-base equilibrium

Pawlak Z., Kotynska J., Figaszewski Z., Gadomski A., Gudaniec A., Oloyede A.

Archives of Materials Science and Engineering

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2008

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Vol. 29, nr 1

24-29

EN

Purpose: This paper, addresses the question of how changes in acid - base equilibrium influence change in the charge density of the phospholipid bilayer on articular cartilage surfaces during lubrication. Design/methodology/approach: Liposomes have been used to mimic biological phospholipid membranes on articular cartilage surface where proteins are bounded, ions are transported, energy is transducted, and cellular processes take place. The charge density of the membrane was determined as a function of pH and electrolyte concentration from the microelectrophoretic method. Liposome membrane was prepared as an aqueous solution of NaCl under various pH conditions. Microelectrophoresis was used to examine the local acid-base equilibrium of the electrolytes with the membrane surface, which can be considered to model the phospholipids interface in articular cartilage. Findings: The adsorbed ions (H+, OH-, Na+, Cl-) which are present in the electrically charged solutions of liposome membrane comprising phosphatidycholine (PC), were found to exhibit pH-responsive quasi-periodic behavior. Research limitations/implications: We have established that the acid-base dissociation behavior in phospholipid bilayers of articular cartilage is a key to understanding biolubrication processes. For example,previous investigators found that the formation of the multilayer of polyisopeptide/hyaluronic acid depends on surface properties such as film thickness, surface friction, surface wetability; wetness and swelling behavior. Future work should consider the adsorption of polyelectrolyte ions, e.g., the glycoprotein lubricin and hyaluronan, on the liposome membrane surface in the presence of H+ and OH- ions. Originality/value: A novel model of the joints’ phospholipid bilayers has been created using liposome membrane This model can be applied in the investigation of polyelectrolyte ions such as lubricin, in articular cartilage. We have demonstrated that the acid-base processes on charged surfaces is a key mechanism in facilitating lubrication in human joints.

7

Changes in electrical charge of phosphatidylcholine and phosphatidylserine liposomal membranes caused by adsorption of monovalent ions

Dobrzyńska I., Kotyńska J., Figaszewski Z.

Chemia Analityczna

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2007

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Vol. 52, No. 6

931-944

EN

The effect of adsorption of ions (H+, Na+. OH-, Cl-) on the electric charge of the iiposome membrane formed from phosphatidylcholine (PC), phosphatidylserine (PS) and their mixtures in different molar ratios was studied. Surface charge density of the membrane was determined from electrophoretic mobility measurements at various pH of the solution. A four-equilibria model describing adsorption of ions on the PC membrane and a six-equilibria model describing the adsorption of ions on the PS membrane was presented The correctness of the models was confirmed by mathematical calculations. The association constants for PC and PS Iiposome membrane surfaces with the adsorbed ions were determined. The correctness of the proposed models was proven by comparing the theoretical charge variation curves for PC and PS membranes with the experimental data.

PL

Zbadano wpływ adsorpcji jonów H+, Na+. OH-, Cl- na ładunek elektryczny membran liposomalnych utworzonych z fosfalydylocholiny (PC), fostatydyloscryny (PS) i ich mieszanin o różnym składzie molowym. Gęstość ładunku powierzchniowego wyznaczono na podstawie pomiarów ruchliwości elektro foretyc/jicj liposomów przy równych pH. Przedstawiono modele opisujące adsorpcję jonów z roztworu. Adsorpcję na membranach Ibsfaty-d\ locholinowych opisano na pomocą modelu zawierającego cztery równania równowagi, a na membranach fosfatydyloloserynowych wykorzystując sześć równań równowagi. Słuszność proponowanych modeli potwierdzono przez porównanie obliczonych teoretycznie zmian gęstości ładunku na powierzchni liposomów z wynikami doświadczalnymi. Wyznaczono stale asocjacji powierzchni membran liposomów z jonami obecnymi w roztworze.

8

Partial discharges behaviour in a rod-plane arrangement with an insulating barrier

Mouhoubi S., Boubakeur A.

Archives of Electrical Engineering

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2007

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Vol. 56, nr 3-4

187-196

EN

Apparent charge and surface charge density have been measured under AC voltage in a rod-plane arrangement with a dielectric barrier. It is shown from our study that apparent charge characteristics depend on the position of the barrier in the rod-plane air gap and that partial discharges (PD) activity is minimum when the barrier touches the rod electrode. The influence of the barrier width and its thickness was also investigated. The measurement of the surface charge density in the vicinity of the plane electrode was achieved by means of a capacitive probe, with different positions of the barrier in the rod-plane air gap.

PL

W artykule opisano wyniki pomiarów ładunku pozornego oraz gęstości ładunku powierzchniowego występujących przy napięciu przemiennym w układzie elektrod pręt-płyta z przegrodą izolacyjną. Z badań wynika, że charakterystyki ładunku pozornego zależą od miejsca umieszczenia przegrody w odstępie między elektrodami w powietrzu i że poziom wyładowań niezupełnych (PD) jest najmniejszy gdy przegroda dotyka elektrody prętowej. Badano także wpływ szerokości i grubości przegrody. Pomiary gęstości ładunku powierzchniowego w pobliżu elektrody płaskiej wykonywano przy użyciu sondy pojemnościowej, dla różnych pozycji przegrody w odstępie powietrznym pręt-płyta.

9

Adsorption of Ni(II) ions at the Fe2Tio5/electrolyte solution interface - the electrical double layer structure

Skwarek E., Janusz Wł.

Physicochemical Problems of Mineral Processing

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2006

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Vol. 40

149-159

EN

Physicochemical properties of Fe2TiO5 (pseudobrookite structure) surface was studied and basic properties of electrical double layer of the Fe2TiO5/NaCl+Ni2+ solution system were described. The adsorption of Ni (II) at the pseudobrookite/aqueous solutions interface was studied over the pH range of 3 to 11. The influence of ionic strength, pH, and presence of ions was researched. ć potential, surface charge density, adsorption density, pH50% and ΔpH10-90% parameters for different concentrations of background electrolyte were presented. The adsorption constants of surface hydroxyl groups’ reactions were determined using numerical optimization.

PL

Związki tytanu występujące w postaci dyspersji są stosowane w wielu gałęziach przemysłu. Wśród nich właściwości powierzchniowe zostały dobrze opisane dla ditlenku tytanu, natomiast niektórych związków tytanu są nieznane, należy do nich Fe2TiO5 występujący w przyrodzie jako pseudobrukit. Przeprowadzono pomiary adsorpcji jonów niklu, dla jego różnych stężeń początkowych, w funkcji pH dla układu Fe2TiO5/roztwór NaCl. Kształt krzywej adsorpcji w funkcji pH ma postać krawędzi adsorpcji. Wzrost stężenia początkowego jonów Ni(II), powoduje przesunięcie krawędzi w kierunku zasadowym skali pH. Wyznaczono charakterystyczne parametry krawędzi adsorpcji tj. pH50% i ΔpH10-90%. W oparciu o zależność adsorpcji od pH stosując model TLM, obliczono również stałe reakcji adsorpcji jonów Ni (II) metodą optymalizacji numerycznej. Zależność gęstości ładunku powierzchniowego od pH w obecności jonów Ni (II), jest w dobrej korelacji z zależnością adsorpcji jonów Ni (II) od pH. Adsorpcja jonów niklu na powierzchni Fe2TiO5 prowadzi do wzrostu stężenia grup ujemnie naładowanych.

10

Nanosilica Partially Modifiedby Hexamethyldisilazane in Air

Gun'ko V., Voronina O., Voronin E., Zarko V., Pakhlov E., Leboda, Skubiszewska-Zięba J., Janusz W., Chibowski S.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 11

1787-1804

EN

Unmodified and modified nanosilicas containing different content of trimethylsilyl (TMS) groups grafted by interaction with various amounts of hexamethyldisilazane (HMDS) in a reactor contacting with air were studied using infrared spectroscopy, adsorption and potentiometric titration methods. Contribution of narrow gaps between spherical primary silica particles forming aggre gates decreases with in creasing TMS loading (tetaTMS), because of blocking of these gaps by grafted functionalities. Contribution of broader gaps corresponding to mesopores de ends slightly on tetaTMS, and changes in contribution of macropores are rather random. IR spectra of modified samples depict changes in bands of the O-H stretch ingvibrations at 3750 and 3300 cm-1 (reduced with qTMS) and 3680 and 3500 cm-1 (changed nonlinearly with qTMS), since HMDS can interact with silanols and ad sorbed water and af fect the ad sorbed amounts of water. Enhance ment of the hydrophobic properties of the surface reduces the amounts of adsorbed water, and the IR band in tensity at 3300 cm-1 di minishes. The adsorption of poly(vinyl pyrrolidone) on silicas decreases with tetaTMS in consequence of changes in the surface structure and the reduction of adsorption potential. The silylation diminishes the su face charge density and the electrostatic surface poten tial, and the point of zero charge shifts to ward larger pH values with in creasing tetaTMS value.