scholarly journals CaO&CaSO4 and CaO&Al2(SO4)3 as Pectin Precipitants–Model of Overlapping Diffuse Layers

2018 ◽  
Vol 63 (1) ◽  
pp. 239-245
Author(s):  
Tatjana A. Kuljanin ◽  
Vladimir S. Filipović ◽  
Milica R. Nićetin ◽  
Biljana Lj. Lončar ◽  
Bojana V. Filipčev ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Sugar Beet ◽  
Surface Charge ◽  
Binary Mixtures ◽  
Theoretical Basis ◽  
Binary Systems ◽  
Purification Method ◽  
Absolute Value ◽  
Model Solutions ◽  
Diffuse Layers

This work is concerned with the theoretical basis of novel sugar beet juice purification method using binary systems CaO&CaSO4 and CaO&Al2(SO4)3. The Gouy–Chapman–Stern (GCS) model of overlapping of diffuse layers of EDLs on pectin surface and that on Ca2+ and Al3+ ions, theoretically explains this method. The change of the zeta potential was used to quantitatively indicate overlapping of diffuse layers. For the experiment two model solutions of pectin (0.1 % w/w) were prepared, while the concentrations of CaO&CaSO4 and CaO&Al2(SO4)3 in the range of 50–500 g dm-3 were used. The greater decrease in the absolute value of zeta potential indicated greater overlapping of diffuse layers between pectin particles and Ca2+ and Al3+ ions and faster coagulation of pectin. The overlapping degree increased with increased concentration of these binary systems. Pectin with a greater surface charge and multivalent Al3+ from CaO&Al2(SO4), exerted a greater impact on the zeta potential. Optimal quantities of the applied binary mixtures were as follows: 256–640 mg g-1 pectin. This is much lower than CaO commonly used in the conventional process of sugar beet juice purification (about 9 g g-1 pectin).

scholarly journals Comparison of methods of zeta potential and residual turbidity of pectin solutions using calcium sulphate/aluminium sulphate as a precipitant

2017 ◽  
pp. 177-185
Author(s):  
Tatjana Kuljanin ◽  
Vladimir Filipovic ◽  
Biljana Loncar ◽  
Milica Nicetin ◽  
Violeta Knezevic
Keyword(s):  
Zeta Potential ◽  
Sugar Beet ◽  
Binary Solution ◽  
Calcium Sulphate ◽  
Point Of View ◽  
Ion Binding ◽  
Purification Method ◽  
Electrophoretic Method ◽  
Common Process ◽  
Minimum Solution

The affinity of calcium ion binding from CaO used in the most common process of purification of sugar beet juice is relatively low. Therefore, large amounts of this compound are required. This paper presents the theoretical basis of a novel sugar beet juice purification method based on the application of the binary system CaSO4/Al2(SO4) . In order to monitor the process of coagulation and precipitation of pectin in the presence of CaSO4/Al2(SO4)3, two methods were compared: measurement of the zeta potential and of residual solution turbidity. The zeta potential of pectin solution was determined by electrophoretic method, while the residual turbidity was determined by spectrophotometry. Two model solutions of pectin (0.1 % w/w) were investigated. Studies were performed with 10 different concentrations of the binary solution CaSO4/Al2(SO4)3 (50 - 500 g dm-3). The amount of the precipitant CaSO4/Al2(SO4)3 (1:1 w/w) needed to achieve the minimum solution turbidity and charge neutralization of pectin particles (zero zeta potential) were measured and compared. Colloidal destabilization occurred before a complete neutralization of the surface charge of pectin particles (zeta potential ~ 0 mV). Optimal quantities (490 - 705 mg g-1 pectin) of the applied binary mixture, were obtained using both methods. This is much lower than the amount of CaO that is commonly used in the conventional process of sugar beet juice purification (about 9 g? g-1 pectin). The use of these precipitants could be important from both economic and environmental point of view.

scholarly journals Aluminium and calcium ions binding to pectin in sugar beet juice: Model of electrical double layer

2014 ◽  
Vol 68 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Tatjana Kuljanin ◽  
Lidija Jevric ◽  
Biljana Curcic ◽  
Milica Nicetin ◽  
Vladimir Filipovic ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Sugar Beet ◽  
Double Layer ◽  
Calcium Ions ◽  
Electrical Double Layer ◽  
Theoretical Basis ◽  
Sugar Industry ◽  
Double Electric Layer ◽  
Average Amount ◽  
Binding Properties

In sugar industry, there is a problem of the presence of undesirable macromolecules such as pectins in sugar beet juice. Separation of these compounds is done mostly by CaO. Calcium may cause undesirable process of alkalization of soil in the near environment of the sugar factory. The theoretical basis of new juice purificatin method based on the application of Al2(SO4)3, CaSO4 and their mixtures are presented. Two model solutions of pectin (0.1 % w/w) are investigated using a method of measuring zeta potential. Pure salts Al2(SO4)3 and CaSO4, showed better binding properties with the pectin than mixtures. Amount of all studied pure salts and mixtures of Al3+ and Ca2+ ions were significantly less (142 - 710 mg/gpectin) than the average amount of CaO used in classical process (about 9 g/gpectin). Mechanism of discharge of pectin macromolecules in the presence of mixtures of these ions using a model of double electric layer are suggested.

scholarly journals Dispersive evaluation and surface chemistry of advanced, multifunctional silica/lignin hybrid biomaterials

2013 ◽  
Vol 11 (11) ◽  
pp. 1860-1873 ◽  
Author(s):  
Magdalena Nowacka ◽  
Łukasz Klapiszewski ◽  
Małgorzata Norman ◽  
Teofil Jesionowski
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Electrochemical Sensors ◽  
Relevant Information ◽  
Structural Features ◽  
Kraft Lignin ◽  
Morphological Properties ◽  
Wide Range ◽  
Hybrid Biomaterials

AbstractAdvanced silica/lignin hybrid biomaterials were obtained using hydrated or fumed silicas (Aerosil®200) and Kraft lignin as precursors, which is a cheap and biodegradable natural polymer. To extend the possible range of applications, the silicas were first modified with N-2-(aminoethyl)-3-aminopropyltrimethoxsysilane, and then with Kraft lignin, which had been oxidized with sodium periodate. The SiO2/lignin hybrids and precursors were characterised by means of determination of their physicochemical and dispersive-morphological properties. The effectiveness of silica binding to lignin was verified by FT-IR spectroscopy. The zeta potential value provides relevant information regarding interactions between colloid particles. Measurement of the zeta potential values enabled an indirect assessment of stability for the studied hybrid systems. Determination of zeta potential and density of surface charge also permitted the quantitative analysis of changes in surface charge, and indirectly confirmed the effectiveness of the proposed method for synthesis of SiO2/lignin hybrid materials. A particularly attractive feature for practical use is their stability, especially electrokinetic stability. It is expected that silica/lignin hybrids will find a wide range of applications (polymer fillers, biosorbents, electrochemical sensors), as they combine the unique properties of silica with the specific structural features of lignin. This makes these hybrids biomaterials advanced and multifunctional.

CHARACTERIZATION OF A SURFACE-CHARGE MODULATION ELECTROFLUIDIC TRANSISTOR BY HYDRODYNAMIC MEASUREMENTS

2012 ◽  
Vol 11 (04) ◽  
pp. 1240021
Author(s):  
GUILLAUME LAFFITE ◽  
XU ZHENG ◽  
LOUIS RENAUD ◽  
FRANÇOIS BESSUEILLE ◽  
ELISABETH CHARLAIX ◽  
...  
Keyword(s):  
Experimental Study ◽  
Zeta Potential ◽  
Surface Charge ◽  
Gate Voltage ◽  
Silica Surface ◽  
Insulating Layer ◽  
Charge Regulation ◽  
Charge Modulation ◽  
Gating Effect

We present an experimental study on the electrofluidic transistor in this paper. A novel and easy way to integrate the transistor into a microchannel is developed. The performances of the insulating layer, especially the leakage current under gate voltage, are carefully characterized. The change of surface charge on silica surface by gate polarization is measured, however, by measuring the streaming current, the gating effect on zeta potential has not been observed. This result should imply new assumption in the understanding of the charge regulation in the electrical double layer under gate polarization.

scholarly journals Synthesis, and Characterization, and Evaluation of Cellular Effects of the FOL-PEG-g-PEI-GAL Nanoparticles as a Potential Non-Viral Vector for Gene Delivery

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
S. Ghiamkazemi ◽  
A. Amanzadeh ◽  
R. Dinarvand ◽  
M. Rafiee-Tehrani ◽  
M. Amini
Keyword(s):  
Gene Delivery ◽  
Zeta Potential ◽  
Surface Charge ◽  
Cell Line ◽  
Graft Copolymer ◽  
Viral Vector ◽  
Transfection Efficiency ◽  
High Surface ◽  
Liver Cells ◽  
Dna Complexes

In this manuscript, we synthesized the potential non viral vector for gene delivery with proper transfection efficiency and low cytotoxicity. Polyethylenimine (PEI) is a well-known cationic polymer which has high positive surface charge for condensing plasmid DNA. However; it is highly cytotoxic in many cell lines because of the high surface charge, non-biodegradability and non-biocompatibility. To enhance PEI biodegradability, the graft copolymer “PEG-g-PEI” was synthesized. To target cancer liver cells, two targeting ligands folic acid and galactose (lactobionic acid) which are over expressed on human hepatocyte carcinoma were attached to graft copolymer and “FOL-PEG-g-PEI-GAL” copolymer was synthesized. Composition of this grafted copolymer was characterized using1H-NMR and FTIR spectra. The molecular weight and zeta potential of this copolymer was compared to PEI. The particle size and zeta potential of FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratio were measured using dynamic light scattering (DLS). Cytotoxicity of the copolymer was also studied in cultured HepG2 human hepatoblastoma cell line. The FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratios exhibited no cytotoxicity in HepG2 cell line compared to PEI 25K as a control. The novel copolymer showed enhanced biodegradability in physiological conditions in compared with PEI and targeted cultured HepG2 cells. More importantly, significant transfection efficiency was exhibited in cancer liver cells. Together, our results showed that “FOL-PEG-g-PEI-GAL” nanoparticals could be considered as a useful non-viral vector for targeted gene delivery.

Effect of arsenate on adsorption of Zn(II) by three variable charge soils

Soil Research ◽  
2007 ◽  
Vol 45 (6) ◽  
pp. 465 ◽  
Author(s):  
Jing Liang ◽  
Ren-kou Xu ◽  
Diwakar Tiwari ◽  
An-zhen Zhao
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Iron Oxides ◽  
Initial Concentration ◽  
Variable Charge ◽  
Study Results ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Enhanced Adsorption ◽  
Variable Charge Soils

The effect of arsenate on adsorption of Zn(II) in 3 variable charge soils (Hyper-Rhodic Ferralsol, Rhodic Ferralsol, and Haplic Acrisol) and the desorption of pre-adsorbed Zn(II) in the presence of arsenate were investigated in this study. Results showed that the presence of arsenate led to an increase in both the adsorption and desorption of Zn(II) in these variable charge soils. It was also suggested that the enhanced Zn(II) adsorption by arsenate was mainly due to the increase in negative surface charge of the soils induced by the specific adsorption of arsenate, and the increase in electrostatically adsorbed Zn(II) was responsible for the increase in the desorption of Zn(II). The effect of arsenate on Zn(II) adsorption primarily depends on the initial concentration of arsenate and Zn(II), the system pH, and the nature of soils. The enhanced adsorption of Zn(II) increased with the increase in the initial concentration of arsenate and the amount of arsenate adsorbed by the soils. The presence of arsenate decreased the zeta potential of soil suspensions and soil IEP and thus shifted the adsorption edge of Zn(II) to a lower pH region. The effect of arsenate on Zn(II) adsorption in these 3 soils followed the order Hyper-Rhodic Ferralsol > Rhodic Ferralsol > Haplic Acrisol, which was consistent to the contents of iron oxides in these soils and the amount of arsenate adsorbed by the soils.

scholarly journals Studies of Some Properties and the Structure of Polyethylene Glycol (PEG) Macromolecules Adsorbed on a TiO2 Surface

2001 ◽  
Vol 19 (5) ◽  
pp. 397-407 ◽  
Author(s):  
S. Chibowski ◽  
M. Paszkiewicz
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Zeta Potential ◽  
Surface Charge ◽  
Adsorption Layer ◽  
Bulk Solution ◽  
Ionic Structure ◽  
Solution Interface ◽  
Main Factors ◽  
Presence And Absence

In the studies presented, the influence of the molecular weight of polyethylene glycol (PEG) on the adsorption and electrical properties at the metal oxide/polymer solution interface has been determined. The main factors responsible for the observed changes in the zeta potential and surface charge of titania were determined on the basis of the data obtained. It was demonstrated that changes in the ionic structure of the Stern layer depend on the molecular weight of PEG and its conformation. A possible mechanism for the changes in zeta potential both with pH and molecular weight was proposed on the basis of values of the surface charge difference (Δσ0) and the diffuse layer charge difference (Δσd) as determined in the presence and absence of the polymer. The thickness of the adsorption layer (δ) on the surface of titania was calculated from the zeta potential changes, both in the presence and absence of the polymer. A distinct influence of the PEG molecular weight was noted on the values of the adsorption layer thickness (δ) determined. The structures of the macromolecules in solution and at the solid/solution interface were compared and from the dependencies obtained some changes in the shape and dimensions of the polymer coils on passing from the bulk solution to the interface were proposed.

scholarly journals Tuning cell surface charge in E. coli with conjugated oligoelectrolytes

2016 ◽  
Vol 7 (3) ◽  
pp. 2023-2029 ◽  
Author(s):  
Chelsea Catania ◽  
Alexander W. Thomas ◽  
Guillermo C. Bazan
Keyword(s):  
Zeta Potential ◽  
Cell Surface ◽  
Surface Charge ◽  
E Coli ◽  
Cell Surface Charge

Conjugated oligoelectrolytes intercalate into and associate with membranes, thereby changing the surface charge of microbes, as determined by zeta potential measurements.

Salmonella Sofia Differs from Other Poultry-Associated Salmonella Serovars with Respect to Cell Surface Hydrophobicity

2008 ◽  
Vol 71 (12) ◽  
pp. 2421-2428 ◽  
Author(s):  
T. W. R. CHIA ◽  
N. FEGAN ◽  
T. A. McMEEKIN ◽  
G. A. DYKES
Keyword(s):  
Zeta Potential ◽  
Cell Surface ◽  
Physicochemical Properties ◽  
Surface Charge ◽  
Hydrophobic Interaction ◽  
Salmonella Enterica ◽  
Food System ◽  
Cell Surface Hydrophobicity ◽  
Bacterial Attachment ◽  
Salmonella Serovars

Salmonella enterica is one of the most important foodborne pathogens. Salmonella enterica subsp. II 4,12:b:– (Salmonella Sofia) is commonly found in Australian poultry. It has been suggested that physicochemical properties such as surface charge and hydrophobicity may affect bacterial attachment to surfaces and their ability to persist in food systems. A possible link between hydrophobicity cell surface charge and persistence of Salmonella from the poultry system was examined. Hydrophobicity of Salmonella Sofia (n = 14), Salmonella Typhimurium (n = 6), Salmonella Infantis (n = 3), and Salmonella Virchow (n = 2) was assayed using hydrophobic interaction chromatography, bacterial adherence to hydrocarbons (BATH), using xylene or hexadecane, and the contact angle method (CAM). Cellular surface charge (CSC) of the isolates was determined using zeta potential measurements. The majority (12 of 14) of Salmonella Sofia isolates were found to be hydrophobic when assayed using BATH with xylene, except isolates S1635 and S1636, and the other serovars were found to be hydrophilic. Salmonella Sofia isolates were not significantly different (P > 0.05) from isolates of other serovars as measured by hydrophobic interaction, BATH with hexadecane, or the CAM. No significant differences (P > 0.05) in zeta potential measurements were observed between isolates. Principal component analysis using results from all four measures of hydrophobicity allowed clear differentiation between isolates of the serovar Salmonella Sofia (except S1635 and S1636) and those of other Salmonella serovars. Differences in physicochemical properties may be a contributing factor to the Salmonella Sofia serovar's ability to attach to surfaces and persist in a food system.

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