Modulations in Self-Organization Properties of Surfactant in Aqueous Ionic Liquid Media

2020 ◽  
Vol 234 (10) ◽  
pp. 1603-1621
Author(s):  
Harsh Kumar ◽  
Arjuna Katal ◽  
Naval Kishor Rawat
Keyword(s):  
Electrostatic Interactions ◽  
Structural Changes ◽  
Anionic Surfactants ◽  
Sodium Dodecyl ◽  
Aggregation Behavior ◽  
Liquid Media ◽  
Fluorescence Studies ◽  
Thermodynamical Parameters ◽  
Different Temperatures ◽  
Ft Ir

AbstractIonic liquids (ILs) give a wide scope of favorable applications due to their much-upgraded properties. The strong electrostatic interactions between the cationic moiety of IL and the anionic surfactant play a very important role in the assembly of the large aggregates. We have investigated the aggregation behavior of anionic surfactants and IL in aqueous solution. Different temperatures and concentrations of IL have been taken to study the effect on critical micelles concentrations of surfactant. The critical micelle concentration values obtained by conductivity measurements are further confirmed by the fluorescence studies. The method is based on the fit of the experimental obtained raw data of fluorescence spectroscopy to a simple nonlinear category of a Boltzmann type sigmoidal function. Thermodynamical parameters of micellization $\Delta H_{m}^{0}$, $\Delta G_{m}^{0}$ and $\Delta S_{m}^{0}$ have been considered to study the effect of aqueous IL 1-butyl-3-methylimidazolium bromide concentration and temperature on aggregation behavior of surfactant sodium dodecyl sulfate. FT-IR spectra have been studies to verify the structural changes arise in the aqueous IL and surfactant system.

scholarly journals Removal of anionic surfactants from wastewater by magnetic mineral sorbents

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Oksana Vladimirovna Makarchuk ◽  
Tetiana Anatolievna Dontsova
Keyword(s):  
Magnetic Separation ◽  
Anionic Surfactants ◽  
Sodium Dodecyl ◽  
Lauryl Sulfate ◽  
Magnetic Sorbents ◽  
Low Concentrations ◽  
Sodium Dodecyl Benzenesulfonate ◽  
Different Temperatures ◽  
Natural Clays ◽  
The Creation

The simplest and most effective method of removing low concentrations of anionic surfactants such as sodium dodecyl benzenesulfonate (SDBS) and sodium lauryl sulfate (SLS) is adsorption. Among adsorbents the natural clays are cheap and promising for these purposes. However, there are significant difficulties in removal of spent sorbent after the adsorption process. So, the creation of magnetic sorbents that can be effectively removed from water after sorption by magnetic separation will be a successful decision. The aim of this investigation is the creation of cheap and efficient magnetic sorbents based on natural clays and magnetite for anionic surfactant removal from wastewater. We have synthe-sized a series of magnetic sorbents from different natural clays with a content of magnetite from 2 to 10 wt%. The ability of magnetic sorbents to remove SDBS and SLS from aqueous solutions has been studied for different adsorbate concen-trations by varying the amount of adsorbent, temperature and shaking time. Thermodynamic parameters were calculated from the slope and intercept of the linear plots of ln K against 1/T. Analysis of adsorption results obtained at different temperatures showed that the adsorption pattern on magnetic sorbents correspond to the Langmuir isotherm. It is shown that with increasing the content of magnetite in the magnetic sorbents improves not only their separation from water by magnetic separation, but adsorption capacity to SDBS and SLS. Thus, we obtained of cheap magnetic sorbents based on natural clays and magnetite by the easy way, which not only quickly separated from the solution by magnetic separation, but effectively remove anionic surfactants.

Surfactants-Controlled Morphosynthesis of Strontium Carbonate

2011 ◽  
Vol 194-196 ◽  
pp. 683-688
Author(s):  
Chao You ◽  
Qiang Zhang ◽  
Yun Zhao ◽  
Qing Ze Jiao
Keyword(s):  
Fourier Transform ◽  
Anionic Surfactants ◽  
Sodium Dodecyl ◽  
Strontium Carbonate ◽  
Controlled Synthesis ◽  
Sorbitan Monolaurate ◽  
X Ray ◽  
Ft Ir ◽  
Complex Micelles ◽  
Scanning Electron

The controlled synthesis of SrCO3microstructures with different morphologies, such as flower-like, cauliflower-like and finger-like, were successfully achieved in the presence of mixed nonionic/anionic surfactants polyoxyethylene (20) sorbitan monolaurate (Tween20) and sodium dodecyl sulfate (SDS). Results indicated that SDS/Tween20 complex micelles played important roles in the morphological control of SrCO3microstructures. Also, the influence of CO32-concentration on the morphology of SrCO3crystals was investigated and discussed. X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and field-emission scanning electron microscope (FE-SEM) were used to characterize the as-synthesized crystals.

Heat Treatment Influence on the Corrosion Resistance of a Cu-Al-Fe-Mn Bronze

2018 ◽  
Vol 69 (5) ◽  
pp. 1055-1059 ◽  
Author(s):  
Mariana Ciurdas ◽  
Ioana Arina Gherghescu ◽  
Sorin Ciuca ◽  
Alina Daniela Necsulescu ◽  
Cosmin Cotrut ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Structural Changes ◽  
Heating Temperature ◽  
Galvanic Corrosion ◽  
Cooling Water ◽  
Open Circuit ◽  
Water Quenching ◽  
Heat Treated ◽  
Different Temperatures

Aluminium bronzes are exhibiting good corrosion resistance in saline environments combined with high mechanical properties. Their corrosion resistance is obviously confered by the alloy chemical composition, but it can also be improved by heat treatment structural changes. In the present paper, five Cu-Al-Fe-Mn bronze samples were subjected to annealing heat treatments with furnace cooling, water quenching and water quenching followed by tempering at three different temperatures: 200, 400 and 550�C. The heating temperature on annealing and quenching was 900�C. The structure of the heat treated samples was studied by optical and scanning electron microscopy. Subsequently, the five samples were submitted to corrosion tests. The best resistance to galvanic corrosion was showed by the quenched sample, but it can be said that all samples are characterized by close values of open-circuit potentials and corrosion potentials. Concerning the susceptibility to other types of corrosion (selective leaching, pitting, crevice corrosion), the best corrosion resistant structure consists of a solid solution, g2 and k compounds, corresponding to the quenched and 550�C tempered sample.

scholarly journals Effects on Lignin Redistribution in Eucalyptus globulus Fibres Pre-Treated by Steam Explosion: A Microscale Study to Cellulose Accessibility

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 507
Author(s):  
Eduardo Troncoso-Ortega ◽  
Rosario del P. Castillo ◽  
Pablo Reyes-Contreras ◽  
Patricia Castaño-Rivera ◽  
Regis Teixeira Mendonça ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Eucalyptus Globulus ◽  
Steam Explosion ◽  
Laser Scanning ◽  
Structural Changes ◽  
Micro Particles ◽  
Cellulose Accessibility ◽  
Ft Ir ◽  
Enzymatic Accessibility ◽  
Physical And Chemical

The objective of this study was to investigate structural changes and lignin redistribution in Eucalyptus globulus pre-treated by steam explosion under different degrees of severity (S0), in order to evaluate their effect on cellulose accessibility by enzymatic hydrolysis. Approximately 87.7% to 98.5% of original glucans were retained in the pre-treated material. Glucose yields after the enzymatic hydrolysis of pre-treated material improved from 19.4% to 85.1% when S0 was increased from 8.53 to 10.42. One of the main reasons for the increase in glucose yield was the redistribution of lignin as micro-particles were deposited on the surface and interior of the fibre cell wall. This information was confirmed by laser scanning confocal fluorescence and FT-IR imaging; these microscopic techniques show changes in the physical and chemical characteristics of pre-treated fibres. In addition, the results allowed the construction of an explanatory model for microscale understanding of the enzymatic accessibility mechanism in the pre-treated lignocellulose.

Effects of in-Office and at-Home Bleaching on Human Enamel and Dentin: An in vitro Application of Fourier Transform Infrared Study

2008 ◽  
Vol 62 (11) ◽  
pp. 1274-1279 ◽  
Author(s):  
Feride Severcan ◽  
Kurtulus Gokduman ◽  
Ayca Dogan ◽  
Sukran Bolay ◽  
Saadet Gokalp
Keyword(s):  
Fourier Transform ◽  
Structural Changes ◽  
Protein Denaturation ◽  
Random Coil ◽  
Protein Ratio ◽  
Band Frequency ◽  
Human Enamel ◽  
Ft Ir ◽  
At Home

In-office and at-home bleaching techniques are widely used methods for the whitening of teeth. However, the safety of these techniques has not been clarified yet. The aim of the current study is to investigate the in-office- and at-home-bleaching-induced structural and quantitative changes in human enamel and dentin at the molecular level, under in vitro conditions. The Fourier transform mid-infrared (mid-FT-IR) spectroscopic technique was used to monitor bleaching-induced structural changes. Band frequency and intensity values of major absorptions such as amide A, amide I, phosphate (PO4), and carbonate (CO3−2) bands, for treatment groups and control, were measured and compared. The results revealed that both procedures have negligible effects on dentin constituents. In office-bleached enamel, in addition to demineralization, a decrease in protein and polysaccharide concentrations, mineral-to-protein ratio, and the strength of hydrogen bonds around NH groups, as well as a change in protein secondary structure were observed. The protein structure changed from β-sheet to random coil, which is an indication of protein denaturation. However, no significant variations were observed for at-home bleached enamel. The control, at-home, and in-office bleached enamel samples were differentiated with a high accuracy using cluster analysis based on FT-IR data. This study revealed that office bleaching caused deleterious alterations in the composition and structure of enamel that significantly affected the crystallinity and mineralization of the tissue. Therefore, at-home bleaching seems to be much safer than in-office bleaching in terms of molecular variations.

The Impact of Heat Treatment on Pyrophyllite Structure and Acid-Soluble Properties

2011 ◽  
Vol 366 ◽  
pp. 326-329 ◽  
Author(s):  
Jun Jun Wu ◽  
Hai Feng Chen ◽  
Shi Jiang Zhao ◽  
Bin Li
Keyword(s):  
Heat Treatment ◽  
Thermal Activation ◽  
Acid Leaching ◽  
Basic Structure ◽  
Hydrochloric Acid Concentration ◽  
Activation Temperature ◽  
Different Temperatures ◽  
Ft Ir ◽  
Heat Activation ◽  
The Impact

This paper studied the influence of heat treatment on the pyrophyllite structure and acid-soluble properties of alumina. Qualitative tests had been performed in studying pyrophyllite crystal at different temperatures by XRD, TG-DTA, FT-IR and quantitative analysis of Al2O3. The quantitative titration method studied the dissolve characteristics of the different heat treatment samples in different acid conditions, and then a numerical simulation was done. The results showed that at temperatures below 480 °C, the pyrophyllite did not change the basic structure. 480~700 °C dehydroxylation reaction occurred, and the structure water of pyrophyllite is removed, and then turned into partial pyrophyllite. Dissolution experiments showed that after thermal activation the behavior of alumina in acid the dissolution was different, which was affected by hydrochloric acid concentration, heat activation temperature and acid leaching time. When the calcinations temperature was 700 °C, the dissolution amount of alumina was largest. These works could provide some theoretical basis for further application of pyrophyllite research.

scholarly journals Aggregation behavior of self-assembled nanoparticles made from carboxymethyl-hexanoyl chitosan and sodium dodecyl sulphate surfactant in water

2019 ◽  
Vol 278 ◽  
pp. 253-261 ◽  
Author(s):  
Andrés F.C. Rengifo ◽  
Sandra C. Santos ◽  
Vania R. de Lima ◽  
Alvaro J.P. Agudelo ◽  
Luis H.M. da Silva ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Aggregation Behavior ◽  
Hexanoyl Chitosan ◽  
Self Assembled

scholarly journals Removal of anionic surfactants by sorption onto Aminated Mesoporous Carbon

2013 ◽  
Vol 19 (3) ◽  
pp. 347-357 ◽  
Author(s):  
S.E. Moradi ◽  
J. Khodaveisy ◽  
R. Dashti
Keyword(s):  
Contact Time ◽  
Mesoporous Carbon ◽  
Anionic Surfactants ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Langmuir Model ◽  
Carbon Adsorbents ◽  
Solution Ph ◽  
Batch Mode ◽  
Ft Ir

Direct and indirect releases of large quantities of surfactants to the environment may result in serious health and environmental problems. Therefore, surfactants should be removed from water before release to the environment or delivery for public use. In the present work, the removal of anionic surfactants, benzene sulfonate (BS), p-toluene sulfonate (TS) and 4-octylbenzene sulfonate (OBS) from water by adsorption onto Amino modified mesoporous carbon (AMC) were studied. The AMC surface chemistry and textural properties was characterized by nitrogen adsorption, XRD and FT-IR analyses. Experiments were conducted in batch mode with the variables such as amount of contact time, solution pH, dose of adsorbent and temperature. Finally, the adsorption isotherms of anionic surfactants on mesoporous carbon adsorbents were in agreement with a Langmuir model. AMC has shown higher anionic surfactants adsorption capacity than the untreated mesoporous carbon, which can explain by strong interaction between anionic surfactant and cationic surface of adsorbent.

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