Prospects for surfactant peat derivatives

2021 ◽  
Author(s):  
Valerya Tatarintseva ◽  
Marina Trufanova ◽  
Svetlana Selyanina ◽  
Olga Yarygina ◽  
Ivan Zubov
Keyword(s):  
Surface Tension ◽  
Surface Layer ◽  
Chemical Composition ◽  
Humic Substances ◽  
Surface Activity ◽  
High Surface ◽  
Scattering Method ◽  
Water Interface ◽  
High Biological Activity ◽  
Group Chemical

<p>Peat is a caustobiolith traditionally used as a renewable source of organic substances, in particular humic substances (HS). They are considered to have high biological activity and therefore are widely used in industry and agriculture.</p><p>Geoclimatic conditions have a significant impact on the peat accumulation process. Accordingly, peat from various regions differs in composition and physicochemical characteristics of the main components. This affects the properties of peat-based products.</p><p>The study of the group chemical composition of high-moor peat from different climatic regions (Western Siberia and the Belomor-Kuloy plateau) was performed according to the certified author’s method. The study revealed that there are both similarities and a number of differences in peat group chemical composition. All samples showed the low ash-content (up to 3.5%) and the content of easily-hydrolyzable components is inversely proportional to the degree of peat decomposition. This is due to their greater bioavailability compared to other organic matter components. Despite the similar values of the bitumen content in the peat samples (3.5-4.2%), the composition and content of HS differ significantly: 26% and 13-15% for the peat samples from the Siberian region and the Belomor-Kuloy plateau respectively. The ratio of humic and fulvic acids in the peat samples are 3.8 and 1.8 that is consistent with differences in the degree of decomposition.</p><p>Humic substances macromolecules are diphilic, so they can show surface activity in solutions. By the Wilhelmy method it was found that for the adsorption of humic substances into the surface layer to an equilibrium state is required 16-20 hours. While the greatest changes (by 65-85%) occur during the first 30-60 minutes. The maximum depression of surface tension was 31.5-35.8 mN/m. This is characteristic of compounds with high molecular weight. The presence of bitumen components, which also have surface activity, in the HS solution, accelerates the achievement of adsorption equilibrium at the air–water interface.</p><p>Based on the measuring of the surface tension the surface activity was determined. The surface activity characterizes the process of the surface layer formation of a surfactant solution at the air–water interface with an infinite dilution. This parameter was calculated depending on HS solution concentration. The surface activity value of HS solutions extracted from Siberian peat is 2 2.1 N/ m*g that is 2 times higher than the HS solutions from the Belomor-Kuloy plateau. Removal of bitumens from the peat leads to an increase of the surface activity of HS solution from Siberian peat at twice it was before, but for Belomor-Kuloy plateau peat it decreases by 10%. The observed differences can be associated with the peculiarities of the composition of the bitumen. This trend has been confirmed by calculation of the critical micelle concentration and the measurement of the hydrodynamic sizes of particles in solutions using the dynamic light-scattering method.</p><p>It was revealed high surface activity of HS solution. So the range of their possible use could be extended (synthetic detergents, emulsifiers, etc.).</p><p>The reported study was funded by RFBR according to the research projects № 20-35-90037, 18-05-60151, and 18-05-70087.</p>

scholarly journals Surface activity of salt-tolerant Serratia spp. and crude oil biodegradation in saline soil

2012 ◽  
Vol 58 (No. 9) ◽  
pp. 412-416 ◽  
Author(s):  
T. Wu ◽  
W.J. Xie ◽  
Y.L. Yi ◽  
X.B. Li ◽  
H.J. Yang ◽  
...  
Keyword(s):  
Surface Tension ◽  
Salt Tolerance ◽  
Crude Oil ◽  
Surface Activity ◽  
High Surface ◽  
Saline Soils ◽  
Surface Tension Reduction ◽  
Oil Biodegradation ◽  
Soil Solutions ◽  
Nacl Concentration

An ideal strain for crude oil degradation in saline soils would be one with high salt-tolerance. A novel bacterial strain, Serratia sp. BF40, was isolated from crude oil contaminated saline soils. Its salt-tolerance, surface activity and ability to degrade crude oil in saline soils were evaluated. It can grow in liquid culture with NaCl concentration less than 6.0%. Its surface activity characterized as an efficient surface tension reduction, was significantly affected by salinity above 2.0%. BF40 inoculation could decrease surface tension of soil solutions and facilitate crude oil removal in soils with 0.22–1.20% salinity, but the efficiency was both significantly lower than its biosurfactant addition. The BF40 strain has a high potential for biodegradation of crude oil contaminated saline soils in view of its high surface activity and salt-tolerance, which is the first report of biosurfactant producing by the genus Serratia for petroleum degrading. We suggest that biosurfactant addition is an efficient strategy. Simultaneously, the growing status of the strain and how to boost its surface activity in saline soils should deserve further studies in order to achieve a continuous biosurfactant supply.

The Role of Surface Phenomena in Modified Cement Dispersions at Studying Poly-Functional Modifiers' Mechanism of Action

2020 ◽  
Vol 299 ◽  
pp. 1038-1043
Author(s):  
Mikhail M. Kosukhin ◽  
Andrei M. Kosukhin
Keyword(s):  
Solid Solution ◽  
Surface Tension ◽  
Chemical Composition ◽  
Phase Boundary ◽  
Disperse Phase ◽  
Surface Activity ◽  
Mechanism Of Action ◽  
Organic Substances ◽  
Molecular Weights

The research findings of colloid and chemical properties of poly-functional modifiers (PFM) with various chemical compositions and qualitative and quantitative proportions of polar organic substances with various molecular weights have been presented. The possibility of regulating the properties of PFM and concrete mixes, modified by them by means of not only changing the chemical composition of modifiers, but combining the types and quantity of active admixtures of polar organic substances with various molecular weights has been shown. It has been demonstrated that the modifiers under study possess the surface activity at solid-solution phase boundary, reducing the surface tension σsolid-liquid (σs-l) At the same time the surface tension at the solution-air phase boundary can remain the same or reduce to a certain extent depending on the modifier’s chemical composition. PFM and superplasticizer (SP) SB-3, which have, unlike SP S-3, the certain surface activity at solid-solution boundary, increase the air entrainment into concrete mix by 0.5÷1.5%, additionally increasing the freeze-thaw resistance of concretes of both fluid and equal-workable compositions without affecting their strength. The adsorption of modifiers on the disperse phase of suspension is conditioned by dispersion forces and, independently of its kind, is of monomolecular nature. For the localization of PFM molecules on the surface of a particle, its molecule should have a system of bonded aromatic rings or conjugated double bonds. The adsorbed modifier’s molecules should make the disperse phase surface hydrophilic and for this purpose they should contain hydrophilic groups along the full length. All this predetermines the role of adsorption-solvation factor in modifiers’ mechanism of action.

scholarly journals NEW DIALCYDTHIOPHOPHATE COLLECTOR FOR FLOTATION OF SILVER-CONTAINING ORES

2018 ◽  
pp. 45-53 ◽  
Author(s):  
V. I. Ryaboy ◽  
S. E. Levkovets ◽  
G. A. Efremova ◽  
O. E. Koval
Keyword(s):  
Surface Tension ◽  
Surface Activity ◽  
High Surface ◽  
Cost Ratio ◽  
Silver Recovery ◽  
Optimal Cost ◽  
Surface Active Properties ◽  
Surface Active

In order to create a more effective dialkyldithiophosphate collector used in combination with potassium butylxanthate in flotation of silver ores (m. Dukat), the effect of a number of dialkyldithiophosphate collectors was studied depending on their surface-active properties and hydrophobic ability. It is shown that their collective strength, with close hydrophobic ability, increases as their surfaceactive properties increase and reaches a maximum at a surface tension of 42-45.3 mN/m, and then begins to decrease. The reduction of the hydrophobic ability, even with their high surface-active properties, for example, for hydrolyzed samples, significantly reduces the recovery of silver. Taking into account the studied influence of surface activity and the hydrophobic ability of the reagents, a more efficient dialkyldithiophosphate collector has been developed, increasing silver recovery compared with the standard reagent by 1.8-3.4 %, depending on the ore enrichment. Improving the extraction of silver without reducing the selectivity of the process also contributes to the optimal cost ratio of the proposed dialkyldithiophosphate collector and xanthate.

From Surface Tension to Molecular Distribution: Modeling Surfactant Adsorption at the Air–Water Interface

Langmuir ◽  
2021 ◽  
Vol 37 (7) ◽  
pp. 2237-2255 ◽  
Author(s):  
Mengsu Peng ◽  
Timothy T. Duignan ◽  
Cuong V. Nguyen ◽  
Anh V. Nguyen
Keyword(s):  
Surface Tension ◽  
Surfactant Adsorption ◽  
Water Interface ◽  
Molecular Distribution ◽  
Distribution Modeling ◽  
Air Water Interface

scholarly journals Surface Activity of Humic Acid and Its Sub-Fractions from Forest Soil

2021 ◽  
Vol 13 (15) ◽  
pp. 8122
Author(s):  
Shijie Tian ◽  
Weiqiang Tan ◽  
Xinyuan Wang ◽  
Tingting Li ◽  
Fanhao Song ◽  
...  
Keyword(s):  
Surface Tension ◽  
Particle Size ◽  
Humic Acid ◽  
Forest Soil ◽  
Surface Activity ◽  
Self Assembly ◽  
Average Particle Size ◽  
Gaussian Model ◽  
Exponential Model ◽  
Average Particle

Surface activity of humic acid (HA) and its six sub-fractions isolated from forest soil were characterized by surface tension measurements, dynamic light scattering, and laser doppler electrophoresis. The surface tension of HA and its sub-fractions reduced from 72.4 mN·m−1 to 36.8 mN·m−1 in exponential model with the increasing concentration from 0 to 2000 mg·L−1. The critical micelle concentration (CMC) and Z-average particle size ranged from 216–1024 mg·L−1 and 108.2–186.9 nm for HA and its sub-fractions, respectively. The CMC have related with alkyl C, O-alkyl C, aromatic C, and carbonyl C (p < 0.05), respectively, and could be predicted with the multiple linear regression equation of CMC, CMC = 18896 − 6.9 × C-296 × alkyl C-331 × aromatic C-17019 × H/C + 4054 × HB/HI (p < 0.05). The maximum particle size was 5000 nm after filtered by a membrane with pore size of 450 nm, indicating HA and its sub-fractions could progressed self-assembly at pH 6.86. The aggregate sizes of number-base particle size distributions were mainly in six clusters including 2 ± 1 nm, 5 ± 2 nm, 10 ± 3 nm, 21 ± 8 nm, 40 ± 10 nm, and >50 nm analyzed by Gaussian model that maybe due to the inconsistency of the components and structures of the HA sub-fractions, requiring further study. It is significance to explore the surface activity of HA and its sub-fractions, which is helpful to clarify the environmental behavior of HA.

Metastability in Monolayer Films Transferred onto Solid Substrates by the Langmuir-Blodgett Method: IR Evidence for Transfer-Induced Phase Transitions

1994 ◽  
Vol 48 (10) ◽  
pp. 1196-1203 ◽  
Author(s):  
Fazale R. Rana ◽  
Suci Widayati ◽  
Brian W. Gregory ◽  
Richard A. Dluhy
Keyword(s):  
Fatty Acid ◽  
Conformational Changes ◽  
Structural Changes ◽  
High Surface ◽  
Solid Substrate ◽  
Water Interface ◽  
Monolayer Films ◽  
Langmuir Blodgett ◽  
Monomolecular Film ◽  
Air Water Interface

The rate at which a monomolecular film is deposited onto a solid substrate in the Langmuir-Blodgett process of preparing supported monolayer films influences the final structure of the transferred film. Attenuated total reflectance infrared spectroscopic studies of monolayers transferred to germanium substrates show that the speed at which the substrate is drawn through the air/water interface influences the final conformation in the hydrocarbon chains of amphiphilic film molecules. This transfer-induced effect is especially evident when the monolayer is transferred from the expanded region of surface-pressure-molecular-area isotherms at low surface pressures; the effect is minimized when the film molecules are transferred from condensed phases at high surface pressures. This phenomenon has been observed for both a fatty acid and a phospholipid, which suggests that these conformational changes may occur in a variety of hydrocarbon amphiphiles transferred from the air/water interface. This conformational ordering may be due to a kinetically limited phase transition taking place in the meniscus formed between the solid substrate and aqueous subphase. In addition, the results obtained for both the phospholipid and fatty acid suggest that the structure of the amphiphile may help determine the extent and nature of the transfer-speed-induced structural changes taking place in the monomolecular film.

Tracing surfactant transformation from cellular release to insertion into an air-liquid interface

2004 ◽  
Vol 286 (5) ◽  
pp. L1009-L1015 ◽  
Author(s):  
T. Haller ◽  
P. Dietl ◽  
H. Stockner ◽  
M. Frick ◽  
N. Mair ◽  
...  
Keyword(s):  
Surface Tension ◽  
Cultured Cells ◽  
High Surface ◽  
Lamellar Body ◽  
Liquid Interface ◽  
Alveolar Type ◽  
Tensile Forces ◽  
Modify Surface ◽  
Fluorescence Imaging Microscopy ◽  
Air Liquid Interface

Pulmonary surfactant is secreted by alveolar type II cells as lipid-rich, densely packed lamellar body-like particles (LBPs). The particulate nature of released LBPs might be the result of structural and/or thermodynamic forces. Thus mechanisms must exist that promote their transformation into functional units. To further define these mechanisms, we developed methods to follow LBPs from their release by cultured cells to insertion in an air-liquid interface. When released, LBPs underwent structural transformation, but did not disperse, and typically preserved a spherical appearance for days. Nevertheless, they were able to modify surface tension and exhibited high surface activity when measured with a capillary surfactometer. When LBPs inserted in an air-liquid interface were analyzed by fluorescence imaging microscopy, they showed remarkable structural transformations. These events were instantaneous but came to a halt when the interface was already occupied by previously transformed material or when surface tension was already low. These results suggest that the driving force for LBP transformation is determined by cohesive and tensile forces acting on these particles. They further suggest that transformation of LBPs is a self-regulated interfacial process that most likely does not require structural intermediates or enzymatic activation.

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