rus
Issue #6/2023
A.V.Blinov, Z.A.Rekhman, A.A.Gvozdenko, A.B.Golik, A.A.Blinova, Ya.A.Oblogin
SYNTHESIS OF SELENIUM NANOPARTICLES STABILIZED WITH SODIUM ALPHA-OLEFIN SULFONATE
SYNTHESIS OF SELENIUM NANOPARTICLES STABILIZED WITH SODIUM ALPHA-OLEFIN SULFONATE
DOI: https://doi.org/10.22184/1993-8578.2023.16.6.346.353
In this study, we performed the synthesis and optimization of the procedure for obtaining selenium nanoparticles stabilized with sodium alpha-olefin sulfonate (AOS). Nanosized selenium was obtained by chemical reduction with ascorbic acid in an aqueous medium. Selenious acid acted as the selenium-containing precursor. As a result, the optimizing synthesis technique, it was found that sample No. 9 is optimal for studying the effect of active acidity medium and ionic strength on aggregative stability. As a result of a multifactorial experiment, the optimal parameters for the synthesis of selenium nanoparticles were established. Due to the computer quantum-chemical modeling, it was established that interaction process between a selenium molecule and sodium alpha-olefin sulfonate (AOS) is energetically favorable. It is shown that the sol of selenium nanoparticles is stable in a neutral medium, and also that aggregative stability is significantly affected by three-charged positive Fe3 + ions.
In this study, we performed the synthesis and optimization of the procedure for obtaining selenium nanoparticles stabilized with sodium alpha-olefin sulfonate (AOS). Nanosized selenium was obtained by chemical reduction with ascorbic acid in an aqueous medium. Selenious acid acted as the selenium-containing precursor. As a result, the optimizing synthesis technique, it was found that sample No. 9 is optimal for studying the effect of active acidity medium and ionic strength on aggregative stability. As a result of a multifactorial experiment, the optimal parameters for the synthesis of selenium nanoparticles were established. Due to the computer quantum-chemical modeling, it was established that interaction process between a selenium molecule and sodium alpha-olefin sulfonate (AOS) is energetically favorable. It is shown that the sol of selenium nanoparticles is stable in a neutral medium, and also that aggregative stability is significantly affected by three-charged positive Fe3 + ions.
Теги: alpha-olefin sulfonate quantum-chemical modeling reducing agent selenium nanoparticles sol альфа-олефин сульфонат восстановитель золь квантово-химическое моделирование наночастицы селена
Original paper
SYNTHESIS OF SELENIUM NANOPARTICLES STABILIZED WITH SODIUM ALPHA-OLEFIN SULFONATE
A.V.Blinov1, Cand. of Sci. (Tech), Associate Professor, ORCID: 0000-0002-4701-8633
Z.A.Rekhman1, Assistant, ORCID: 0000-0003-2809-4945 / zafrehman1027@gmail.com
A.A.Gvozdenko1, Assistant, ORCID: 0009-0005-9113-9335
A.B.Golik1, Assistant, ORCID: 0000-0003-2580-9474
A.A.Blinova1, Cand. of Sci. (Tech), Associate Professor, ORCID: 0000-0001-9321-550X
Ya.A.Oblogin1, Student, Laboratory Assistant, ORCID: 0009-0003-5180-9045
Abstract. In this study, we performed the synthesis and optimization of the procedure for obtaining selenium nanoparticles stabilized with sodium alpha-olefin sulfonate (AOS). Nanosized selenium was obtained by chemical reduction with ascorbic acid in an aqueous medium. Selenious acid acted as the selenium-containing precursor. As a result, the optimizing synthesis technique, it was found that sample No. 9 is optimal for studying the effect of active acidity medium and ionic strength on aggregative stability. As a result of a multifactorial experiment, the optimal parameters for the synthesis of selenium nanoparticles were established. Due to the computer quantum-chemical modeling, it was established that interaction process between a selenium molecule and sodium alpha-olefin sulfonate (AOS) is energetically favorable. It is shown that the sol of selenium nanoparticles is stable in a neutral medium, and also that aggregative stability is significantly affected by three-charged positive Fe3 + ions.
Keywords: selenium nanoparticles, alpha-olefin sulfonate, quantum-chemical modeling, sol, reducing agent
For citation: A.V. Blinov, Z.A. Rekhman, A.A. Gvozdenko, A.B. Golik, A.A. Blinova, Y.A. Oblogin. Synthesis of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate. NANOINDUSTRY. 2023. V. 16, no. 6. PP. 346–353. https://doi.org/10.22184/1993-8578.2023.16.6.346.353.
INTRODUCTION
Selenium is a trace element that plays an important role in the functioning of the immune system and the regulation of redox mechanisms [1]. However, the inorganic and organic forms of selenium have increased toxicity, and therefore, the nanoform of selenium, which has high biological activity, low toxicity, antioxidant, anti-inflammatory properties, is attracting more and more attention, and selenium nanoparticles are used as a carrier for targeted drug delivery [2–5].
The chemical method for the synthesis of selenium nanoparticles is the main and fairly simple method for obtaining colloidal systems [6]. Stabilization of selenium nanoparticles is also an important process, due to which it is possible to control the size and shape of the resulting nanoparticles [7]. Among the main stabilizers are biopolymers (chitosan, polyvinylpyrrolidone, methylcellulose, etc.) and surfactants (alkyldimethylbenzylammonium chloride, cocamidopropyl betaine, etc.) [8–11].
Anionic surfactants are responsible for the cleaning power of any soap, as well as most shampoos [12, 13]. In an aqueous solution, they decompose with the formation of negatively charged ions, the hydrophobic part of the anionic surfactant molecule binds dirt particles, and then, due to the hydrophilic part of the surfactant molecule, they are retained by water and washed out from the surface [14]. One of these surfactants is sodium alpha-olefin sulfonate (AOS), which is actively used to stabilize various nanosystems [15–17].
The purpose of this article is to study a method for the synthesis of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate.
RESEARCH METHODS
Selenium nanoparticles were synthesized by chemical reduction of a selenium-containing precursor in an aqueous medium in the presence of a stabilizer. Selenious acid (H2SeO3) acted as a precursor, ascorbic acid (C6H8O6) was used as a reducing agent, and an anionic surfactant, sodium alpha-olefin sulfonate (AOS), was used as a stabilizer.
The synthesis of selenium nanoparticles was carried out in several stages: at the beginning, a 0.036 M solution of selenious acid was prepared, in which weighed portions of AOS were dissolved, then a 0.088 M solution of ascorbic acid was prepared. Finally, the reducing agent solution was added dropwise to the selenious acid solution, and the sample was stirred for 5–10 minutes.
The average hydrodynamic radius of the obtained samples of selenium nanoparticles was determined by photon correlation spectroscopy using a Photocor-Complex setup (OOO Antek-97, Russia). The ζ potential of the obtained samples was determined by acoustic and electroacoustic spectroscopy using a DT-1202 setup manufactured by Dispersion Technology Inc., USA.
To optimize the experimental parameters, a multivariate experiment was performed with three input parameters and three levels of variation. The output parameters were the average hydrodynamic radius of particles (rav) and the electrokinetic potential.
Mathematical processing of the experimental results was carried out in the Neural Statistica Network application package, and a neural network was formed using the application programs.
Quantum-chemical modeling of the interaction process of selenium nanoparticles stabilized with sodium alpha olefin sulfonate was carried out in the QChem program using the IQmol molecular editor. The calculation was carried out on the equipment of the data processing center (Schneider Electric) of the North Caucasian Federal University. The calculation of the total energy and other characteristics was carried out with the following parameters: calculation: Energy, method: HF, basis: 3-21G, convergence – 5, force field – Ghemical.
To study the effect of the active acidity of the medium on the stability of selenium nanoparticles, solutions with different pH values were added to the samples in a ratio of 1:1.
To study the effect of the ionic strength of a solution on the stability of selenium nanoparticles, five series of solutions were prepared: solutions of sodium chloride (NaCl), iron chloride (FeCl3), barium chloride (BaCl2), sodium sulfate (Na2SO4), and potassium phosphate (K3PO4). The concentrations of the solutions were 0.1 M, 0.25 M, 0.5 M, 0.75 M, and 1 M. To assess the stability, 1 ml of selenium nanoparticle sol was added to 9 ml of the solution.
RESULTS
At the first stage, optimization of the procedure for the synthesis of selenium nanoparticles, the results of the study are presented in Table 1.
As a result of mathematical data processing, a three-dimensional ternary surface was obtained, describing the relationship with the average hydrodynamic radius and concentrations of the precursor, reducing agent, and stabilizer, which is shown in Fig.1.
Next, computer quantum-chemical modeling of selenium nanoparticles interaction stabilized with sodium alpha-olefin sulfonate (AOS) was carried out. The data obtained are presented in Fig.2, as well as in Table 2.
At the next stage, we studied the effect of the active acidity of the medium and ionic strength on the stability of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate (AOS). The data obtained are presented in Fig.3 and 4.
DISCUSSION
An analysis of the results of studying the sols of selenium nanoparticles by dynamic light scattering showed that a monomodal distribution is observed in all samples and it was found that samples No. 3, 7
and 8 have the largest radius (1312, 556 and 326 nm, respectively), samples No. 2, 4 and 9 have the smallest radius (15, 12 and 17 nm, respectively). However, as a result of the analysis of the study of samples by the method of acoustic and electroacoustic spectroscopy, it was found that sols No. 4 and No. 9 have the highest value of the electrokinetic potential (–38.29 mV and –49.89 mV, respectively). To study the effect of pH and ionic strength on the aggregative stability of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate, sample No. 9 was chosen.
An analysis of the three-dimensional ternary surface showed that the concentrations of selenious acid and ascorbic acid have a significant effect on the average hydrodynamic radius of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate. Thus, over the entire range of selenious acid concentrations and at concentrations of ascorbic acid from 0.6 to 1.6 mol/l, the average particle radius varies from 900 to 1180 nm. It should be noted that the optimal radius of about 20 nm has a sample that was obtained with the following parameters: C (H2SeO3) – 0.15 mol/l, C (C6H8O6) – 1.60 mol/l, C (AOS) – 0, 09 mol/l.
As a result of computer quantum-chemical modeling, it was found that the difference in the total energy of the sodium alpha-olefin sulfonate (AOS) molecule and the Se-sodium alpha-olefin sulfonate (AOS) molecular system is more than 2238 kcal/mol, which indicates an energetically favorable process of bond formation between selenium and sodium alpha-olefin sulfonate.
An analysis of the dependence of the radius on the active acidity of the medium showed that, at low pH, the sample has a radius of about 750 nm. This fact can be explained by the fact that a large number of hydrogen protons in an acidic medium determines the electrical neutrality of the potential-forming layer. In a neutral medium, the sol of selenium nanoparticles has a radius of about 80 nm, and upon transition to the alkaline region, the average particle radius increases to 450 nm at pH=12. This is due to desorption of sodium alpha-olefin sulfonate molecules from the surface of selenium particles, which results in polymerization with the formation of polyselenides [18].
The study of the effect of ionic strength on the stability of selenium nanoparticles showed that cations have a greater effect on the average radius and coagulation of particles than anions. It should be noted that with an increase in the charge of a positive ion, its effect on a negatively charged particle increases in connection with the Schulze-Hardy rule. Thus, when exposed to ferric iron salts, the radius increases up to 11 000 nm. However, when salts of phosphoric acid are added, the size also increases to 1700 nm. Presumably, the presence of 3 K+ cations in one molecule of potassium orthophosphate has this effect.
CONCLUSIONS
In this paper, the synthesis of selenium nanoparticles stabilized by sodium alpha-olefin sulfonate was carried out, as well as the optimization of the production method. As a result of a multifactorial experiment, it was found that sample No. 9, which was chosen for the study of aggregative stability, has the optimal radius (17 nm) and the largest ζ-potential (–49.89 mV). As a result of the analysis of the ternary surface, it was found that the optimal parameters for the synthesis of selenium nanoparticles stabilized by AOS are: C (H2SeO3) – 0.15 mol/l, C (C6H8O6) – 1.60 mol/l, C (AOS) – 0.09 mol/l. Computer quantum-chemical simulation of the interaction of a selenium molecule with sodium alpha-olefin sulfonate showed that the total interaction energy is more than 2238 kcal/mol, which indicates the energy benefit of this process. The study of the influence of the active acidity of the medium showed that the sample is stable in a neutral medium, and in an acidic and alkaline medium, the average radius increases to 750 and 450 nm, respectively. We also studied the effect of ionic strength on the stability of a sample of selenium nanoparticles: it was found that three-charged cations (Fe3+) have a significant effect on the aggregative stability, under the influence of which the radius increases to 11 000 nm.
ACKNOWLEDGMENTS
This study was supported by the Russian Science Foundation grant No. 23-16-00120, https://rscf.ru/project/23-16-00120
PEER REVIEW INFO
Editorial board thanks the anonymous reviewer(s) for their contribution to the peer review of this work. It is also grateful for their consent to publish papers on the journal’s website and SEL eLibrary eLIBRARY.RU.
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
SYNTHESIS OF SELENIUM NANOPARTICLES STABILIZED WITH SODIUM ALPHA-OLEFIN SULFONATE
A.V.Blinov1, Cand. of Sci. (Tech), Associate Professor, ORCID: 0000-0002-4701-8633
Z.A.Rekhman1, Assistant, ORCID: 0000-0003-2809-4945 / zafrehman1027@gmail.com
A.A.Gvozdenko1, Assistant, ORCID: 0009-0005-9113-9335
A.B.Golik1, Assistant, ORCID: 0000-0003-2580-9474
A.A.Blinova1, Cand. of Sci. (Tech), Associate Professor, ORCID: 0000-0001-9321-550X
Ya.A.Oblogin1, Student, Laboratory Assistant, ORCID: 0009-0003-5180-9045
Abstract. In this study, we performed the synthesis and optimization of the procedure for obtaining selenium nanoparticles stabilized with sodium alpha-olefin sulfonate (AOS). Nanosized selenium was obtained by chemical reduction with ascorbic acid in an aqueous medium. Selenious acid acted as the selenium-containing precursor. As a result, the optimizing synthesis technique, it was found that sample No. 9 is optimal for studying the effect of active acidity medium and ionic strength on aggregative stability. As a result of a multifactorial experiment, the optimal parameters for the synthesis of selenium nanoparticles were established. Due to the computer quantum-chemical modeling, it was established that interaction process between a selenium molecule and sodium alpha-olefin sulfonate (AOS) is energetically favorable. It is shown that the sol of selenium nanoparticles is stable in a neutral medium, and also that aggregative stability is significantly affected by three-charged positive Fe3 + ions.
Keywords: selenium nanoparticles, alpha-olefin sulfonate, quantum-chemical modeling, sol, reducing agent
For citation: A.V. Blinov, Z.A. Rekhman, A.A. Gvozdenko, A.B. Golik, A.A. Blinova, Y.A. Oblogin. Synthesis of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate. NANOINDUSTRY. 2023. V. 16, no. 6. PP. 346–353. https://doi.org/10.22184/1993-8578.2023.16.6.346.353.
INTRODUCTION
Selenium is a trace element that plays an important role in the functioning of the immune system and the regulation of redox mechanisms [1]. However, the inorganic and organic forms of selenium have increased toxicity, and therefore, the nanoform of selenium, which has high biological activity, low toxicity, antioxidant, anti-inflammatory properties, is attracting more and more attention, and selenium nanoparticles are used as a carrier for targeted drug delivery [2–5].
The chemical method for the synthesis of selenium nanoparticles is the main and fairly simple method for obtaining colloidal systems [6]. Stabilization of selenium nanoparticles is also an important process, due to which it is possible to control the size and shape of the resulting nanoparticles [7]. Among the main stabilizers are biopolymers (chitosan, polyvinylpyrrolidone, methylcellulose, etc.) and surfactants (alkyldimethylbenzylammonium chloride, cocamidopropyl betaine, etc.) [8–11].
Anionic surfactants are responsible for the cleaning power of any soap, as well as most shampoos [12, 13]. In an aqueous solution, they decompose with the formation of negatively charged ions, the hydrophobic part of the anionic surfactant molecule binds dirt particles, and then, due to the hydrophilic part of the surfactant molecule, they are retained by water and washed out from the surface [14]. One of these surfactants is sodium alpha-olefin sulfonate (AOS), which is actively used to stabilize various nanosystems [15–17].
The purpose of this article is to study a method for the synthesis of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate.
RESEARCH METHODS
Selenium nanoparticles were synthesized by chemical reduction of a selenium-containing precursor in an aqueous medium in the presence of a stabilizer. Selenious acid (H2SeO3) acted as a precursor, ascorbic acid (C6H8O6) was used as a reducing agent, and an anionic surfactant, sodium alpha-olefin sulfonate (AOS), was used as a stabilizer.
The synthesis of selenium nanoparticles was carried out in several stages: at the beginning, a 0.036 M solution of selenious acid was prepared, in which weighed portions of AOS were dissolved, then a 0.088 M solution of ascorbic acid was prepared. Finally, the reducing agent solution was added dropwise to the selenious acid solution, and the sample was stirred for 5–10 minutes.
The average hydrodynamic radius of the obtained samples of selenium nanoparticles was determined by photon correlation spectroscopy using a Photocor-Complex setup (OOO Antek-97, Russia). The ζ potential of the obtained samples was determined by acoustic and electroacoustic spectroscopy using a DT-1202 setup manufactured by Dispersion Technology Inc., USA.
To optimize the experimental parameters, a multivariate experiment was performed with three input parameters and three levels of variation. The output parameters were the average hydrodynamic radius of particles (rav) and the electrokinetic potential.
Mathematical processing of the experimental results was carried out in the Neural Statistica Network application package, and a neural network was formed using the application programs.
Quantum-chemical modeling of the interaction process of selenium nanoparticles stabilized with sodium alpha olefin sulfonate was carried out in the QChem program using the IQmol molecular editor. The calculation was carried out on the equipment of the data processing center (Schneider Electric) of the North Caucasian Federal University. The calculation of the total energy and other characteristics was carried out with the following parameters: calculation: Energy, method: HF, basis: 3-21G, convergence – 5, force field – Ghemical.
To study the effect of the active acidity of the medium on the stability of selenium nanoparticles, solutions with different pH values were added to the samples in a ratio of 1:1.
To study the effect of the ionic strength of a solution on the stability of selenium nanoparticles, five series of solutions were prepared: solutions of sodium chloride (NaCl), iron chloride (FeCl3), barium chloride (BaCl2), sodium sulfate (Na2SO4), and potassium phosphate (K3PO4). The concentrations of the solutions were 0.1 M, 0.25 M, 0.5 M, 0.75 M, and 1 M. To assess the stability, 1 ml of selenium nanoparticle sol was added to 9 ml of the solution.
RESULTS
At the first stage, optimization of the procedure for the synthesis of selenium nanoparticles, the results of the study are presented in Table 1.
As a result of mathematical data processing, a three-dimensional ternary surface was obtained, describing the relationship with the average hydrodynamic radius and concentrations of the precursor, reducing agent, and stabilizer, which is shown in Fig.1.
Next, computer quantum-chemical modeling of selenium nanoparticles interaction stabilized with sodium alpha-olefin sulfonate (AOS) was carried out. The data obtained are presented in Fig.2, as well as in Table 2.
At the next stage, we studied the effect of the active acidity of the medium and ionic strength on the stability of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate (AOS). The data obtained are presented in Fig.3 and 4.
DISCUSSION
An analysis of the results of studying the sols of selenium nanoparticles by dynamic light scattering showed that a monomodal distribution is observed in all samples and it was found that samples No. 3, 7
and 8 have the largest radius (1312, 556 and 326 nm, respectively), samples No. 2, 4 and 9 have the smallest radius (15, 12 and 17 nm, respectively). However, as a result of the analysis of the study of samples by the method of acoustic and electroacoustic spectroscopy, it was found that sols No. 4 and No. 9 have the highest value of the electrokinetic potential (–38.29 mV and –49.89 mV, respectively). To study the effect of pH and ionic strength on the aggregative stability of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate, sample No. 9 was chosen.
An analysis of the three-dimensional ternary surface showed that the concentrations of selenious acid and ascorbic acid have a significant effect on the average hydrodynamic radius of selenium nanoparticles stabilized with sodium alpha-olefin sulfonate. Thus, over the entire range of selenious acid concentrations and at concentrations of ascorbic acid from 0.6 to 1.6 mol/l, the average particle radius varies from 900 to 1180 nm. It should be noted that the optimal radius of about 20 nm has a sample that was obtained with the following parameters: C (H2SeO3) – 0.15 mol/l, C (C6H8O6) – 1.60 mol/l, C (AOS) – 0, 09 mol/l.
As a result of computer quantum-chemical modeling, it was found that the difference in the total energy of the sodium alpha-olefin sulfonate (AOS) molecule and the Se-sodium alpha-olefin sulfonate (AOS) molecular system is more than 2238 kcal/mol, which indicates an energetically favorable process of bond formation between selenium and sodium alpha-olefin sulfonate.
An analysis of the dependence of the radius on the active acidity of the medium showed that, at low pH, the sample has a radius of about 750 nm. This fact can be explained by the fact that a large number of hydrogen protons in an acidic medium determines the electrical neutrality of the potential-forming layer. In a neutral medium, the sol of selenium nanoparticles has a radius of about 80 nm, and upon transition to the alkaline region, the average particle radius increases to 450 nm at pH=12. This is due to desorption of sodium alpha-olefin sulfonate molecules from the surface of selenium particles, which results in polymerization with the formation of polyselenides [18].
The study of the effect of ionic strength on the stability of selenium nanoparticles showed that cations have a greater effect on the average radius and coagulation of particles than anions. It should be noted that with an increase in the charge of a positive ion, its effect on a negatively charged particle increases in connection with the Schulze-Hardy rule. Thus, when exposed to ferric iron salts, the radius increases up to 11 000 nm. However, when salts of phosphoric acid are added, the size also increases to 1700 nm. Presumably, the presence of 3 K+ cations in one molecule of potassium orthophosphate has this effect.
CONCLUSIONS
In this paper, the synthesis of selenium nanoparticles stabilized by sodium alpha-olefin sulfonate was carried out, as well as the optimization of the production method. As a result of a multifactorial experiment, it was found that sample No. 9, which was chosen for the study of aggregative stability, has the optimal radius (17 nm) and the largest ζ-potential (–49.89 mV). As a result of the analysis of the ternary surface, it was found that the optimal parameters for the synthesis of selenium nanoparticles stabilized by AOS are: C (H2SeO3) – 0.15 mol/l, C (C6H8O6) – 1.60 mol/l, C (AOS) – 0.09 mol/l. Computer quantum-chemical simulation of the interaction of a selenium molecule with sodium alpha-olefin sulfonate showed that the total interaction energy is more than 2238 kcal/mol, which indicates the energy benefit of this process. The study of the influence of the active acidity of the medium showed that the sample is stable in a neutral medium, and in an acidic and alkaline medium, the average radius increases to 750 and 450 nm, respectively. We also studied the effect of ionic strength on the stability of a sample of selenium nanoparticles: it was found that three-charged cations (Fe3+) have a significant effect on the aggregative stability, under the influence of which the radius increases to 11 000 nm.
ACKNOWLEDGMENTS
This study was supported by the Russian Science Foundation grant No. 23-16-00120, https://rscf.ru/project/23-16-00120
PEER REVIEW INFO
Editorial board thanks the anonymous reviewer(s) for their contribution to the peer review of this work. It is also grateful for their consent to publish papers on the journal’s website and SEL eLibrary eLIBRARY.RU.
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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