Lignin from Hydrolyzed Wood By-Product as an Eco-Friendly Emulsion Stabilizer

2017 ◽  
Author(s):  
Sandra Livcha ◽  
Galia Shulga ◽  
Elina Zhilinska ◽  
Brigita Neiberte ◽  
Anrijs Verovkins ◽  
...  
Keyword(s):  
Wood Residue ◽  
Lignin Concentration ◽  
Surface Active Properties ◽  
Surface Active ◽  
Decreasing Ph ◽  
Alkaline Delignification ◽  
Soda Lignin ◽  
Hydrolysis Of ◽  
Electrostatic Mechanism

Aspen sulfur-free soda lignin was obtained as a result of alkaline delignification of hydrolyzed sawdust, a by-product of wood mechanical processing. The pre-hydrolysis of aspen sawdust was performed for enhancing the yield of lignin from the wood residue as well as to decrease the energy consumption of its milling for obtaining a filler for composites. The obtained lignin was characterized by a chemical composition, particle sizes and zeta potential values as well as by the surface-active properties at the air-water and oil-water interfaces. The surface tension of the lignin solutions at the air-water interface decreases with dropping 34 values and increasing lignin concentration due to hydrophobization of the lignin macromolecules, which is strengthened in the presence of a low molecular salt. The study of the obtained lignin as an emulsion stabilizer has shown that the O/W emulsion stabilized with alkaline lignin solutions with a concentration less than 0.1% demonstrates the highest stability with the formed smallest emulsion particles, having the highest negative charge, but the stabilization proceeds via the electrostatic mechanism. With decreasing pH values and increasing lignin concentration in the emulsion, the stabilization mechanism is more complicated with a growing role of steric factors.

Characteristics and Properties of Soda Lignin Obtained from Aspen Wood By-Products

2012 ◽  
Vol 51 (4) ◽  
pp. 421-427 ◽  
Author(s):  
S. Livča ◽  
A. Verovkins ◽  
G. Shulga ◽  
B. Neiberte ◽  
S. Vitolina
Keyword(s):  
Aqueous Solutions ◽  
Surface Active Substance ◽  
Particle Sizes ◽  
Aspen Wood ◽  
Air Interface ◽  
Surface Active Properties ◽  
Surface Active ◽  
Alkaline Delignification ◽  
Soda Lignin ◽  
By Products

In the work, soda lignin was obtained under laboratory alkaline delignification conditions from aspen sawdust. The chemical composition and the surface-active properties of this lignin in aqueous solutions were studied. The high indices of Klason lignin and the content of methoxyl groups indicated the insignificant presence of non-lignin admixtures, including lignocarbohydrate complexes, in the purified lignin. It was shown that aspen lignin was a surface active substance, the surface activity of which at the water-air interface grew with falling the solution рН values. Simultaneously, with decreasing рН, the particle sizes of aspen lignin in the aqueous solutions increased, but zeta potential of the lignin particles had the tendency to decrease.

scholarly journals Metabolism and motility in prebiotic structures

2011 ◽  
Vol 366 (1580) ◽  
pp. 2885-2893 ◽  
Author(s):  
Martin M. Hanczyc
Keyword(s):  
Self Assembly ◽  
Oil Droplets ◽  
Chemical Systems ◽  
Chemical Structures ◽  
Chemical Agents ◽  
Surface Active Properties ◽  
Hydrophobic Substances ◽  
Simple Chemical ◽  
Surface Active ◽  
Hydrolysis Of

Easily accessible, primitive chemical structures produced by self-assembly of hydrophobic substances into oil droplets may result in self-moving agents able to sense their environment and move to avoid equilibrium. These structures would constitute very primitive examples of life on the Earth, even more primitive than simple bilayer vesicle structures. A few examples of simple chemical systems are presented that self-organize to produce oil droplets capable of movement, environment remodelling and primitive chemotaxis. These chemical agents are powered by an internal chemical reaction based on the hydrolysis of an oleic anhydride precursor or on the hydrolysis of hydrogen cyanide (HCN) polymer, a plausible prebiotic chemistry. Results are presented on both the behaviour of such droplets and the surface-active properties of HCN polymer products. Such motile agents would be capable of finding resources while escaping equilibrium and sustaining themselves through an internal metabolism, thus providing a working chemical model for a possible origin of life.

scholarly journals The Synergistic Effects of Rhamnolipids and Antibiotics Against Bacteria

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Ella Shusterman ◽  
Abigail Mottahedeh ◽  
Merideth McCarthy
Keyword(s):  
Burkholderia Pseudomallei ◽  
Bacterial Infections ◽  
Synergistic Effects ◽  
Genetically Modify ◽  
Cell Permeability ◽  
Slowing Down ◽  
Surface Active Properties ◽  
Zones Of Inhibition ◽  
Surface Active

Antibiotics are used to combat bacterial infections by slowing down and preventing the proliferation of bacteria. Antibiotic resistance is a threat to human health, attributed to its overuse and misuse. Altering the membrane permeability to induce antibiotic uptake may be an effective strategy used against both Gram-positive and Gram-negative infectious bacteria. Rhamnolipids (RLs) are biosurfactants produced by Pseudomonas aeruginosa. RLs surface-active properties operate by creating holes in bacterial cell membranes, increasing target cell permeability; allowing antibiotics to penetrate the cell.    Rhamnolipids enhance the effect of antibiotics by targeting the intracellular machinery of bacteria. This project tested the susceptibility of bacteria when exposed to antibiotics with and without the addition of RLs, to quantitatively determine if RLs increase antibiotic potency. By analyzing the zones of inhibition data, the results demonstrated that RLs potentiated the antibiotics. Notably, kanamycin coupled with RLs had the most effect inhibiting bacterial growth.  To further assess rhamnolipid biosynthesis, a BLAST search was performed exclusively on two genes, rhlA and rhlB. These genes code for the production of two proteins necessary for rhamnolipids. The search indicated a 48% correlation with putative proteins found in Burkholderia pseudomallei. Therefore, based on the experimental results and the BLAST analysis, further research should be conducted to explore the possible role of using rhamnolipids as antibiotic enhancers. Specifically, future experiments could focus on isolating the putative proteins of B.pseudomallei to genetically modify E.coli. Furthermore, isolated studies analyzing the genes of proteins to determine their role in the pathogenicity of Burkholderia species.

scholarly journals Properties of Isolated Lignin From Model Wastewater

2015 ◽  
Vol 1 ◽  
pp. 282
Author(s):  
Sanita Skudra ◽  
Galia Shulga ◽  
Vadims Shakels ◽  
Lubova Belkova ◽  
Skaidrite Reihmane
Keyword(s):  
Surface Activity ◽  
Emulsion Stability ◽  
Water Emulsion ◽  
Reduced Viscosity ◽  
Surface Active Properties ◽  
Oil In Water ◽  
Surface Active ◽  
Oil Water ◽  
Decreasing Ph ◽  
Oil In Water Emulsion

Model wastewater, imitating the hydrothermal treatment of birch wood in the basins of veneer production, was obtained under laboratory conditions. Birch lignin (BLIG) was isolated from the model wastewater by precipitation with concentarted sulphuric acid. The increase in reduced viscosity with decreasing concentration of BLIG in the water solutions indicated its polyelectrolyte behaviour. The presence of both ionized functional groups and hydrophobic aromatic fragments in the BLIG molecules favoured its surface active properties. With decreasing pH and increasing concentration, the surface activity of BLIG at the air-water and oil-water interfaces increased, indicating the enhanced hydrophobicity of lignin fragments due to the protonization of its acidic groups. The pronounced surface activity of BLIG was in accordance with the very low value of its critical micelle concentration. The dependence of the emulsion stability on the ionic strength may testify the predominant structural mechanical mechanism of the stabilization of the rapeseed oil-in-water emulsion, containing BLIG as a stabilizer. The revealed surface properties of the isolated lignin allow predicting its application for lowering surface tension in different disperse systems to prevent the coalescence and agglomeration phenomena.

Effect of grain size on the vapour phase hydration of monoclinic and triclinic modifications of tricalcium silicate; role of high temperature activation

1991 ◽  
Vol 56 (10) ◽  
pp. 1993-2008
Author(s):  
S. Hanafi ◽  
G. M. S. El-Shafei ◽  
B. Abd El-Hamid
Keyword(s):  
Particle Size ◽  
Vapour Phase ◽  
Tricalcium Silicate ◽  
Active Centers ◽  
Thermally Activated ◽  
Grain Sizes ◽  
Intermediate Size ◽  
Surface Active ◽  
Temperature Activation

The hydration of tricalcium silicate (C3S) with three grain sizes of monoclinic (M) and triclinic (T) modifications and on their thermally activated samples were investigated by exposure to water vapour at 80°C for 60 days. The products were investigated by XRD, TG and N2 adsorption. The smaller the particle size the greater was the hydration for both dried and activated samples from (M). In the activated samples a hydrate with 2θ values of 38.4°, 44.6° and 48.6° could be identified. Hydration increased with particle size for the unactivated (T) samples but after activation the intermediate size exhibited enhanced hydration. Thermal treatment at 950°C of (T) samples increased the surface active centers on the expense of those in the bulk. Changes produced in surface texture upon activation and/or hydration are discussed.

Role of the Structure and Electronic Properties of Fe2O3-MoO3 Catalyst on the Dehydration of Isopropyl Alcohol

1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said
Keyword(s):  
Active Sites ◽  
Isopropyl Alcohol ◽  
Oxide Catalyst ◽  
Flow System ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Composition ◽  
Surface Active

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.

scholarly journals Research of surface-active properties and sizes of pectin molecules after post-alcohol grain distillery dreg

2021 ◽  
Vol 640 (5) ◽  
pp. 052014
Author(s):  
A S Kaishev ◽  
N S Kaisheva ◽  
H N Gyulbyakova ◽  
E A Maslovskaya ◽  
V A Karpenko
Keyword(s):  
Surface Active Properties ◽  
Surface Active
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