rus
Issue #7-8/2023
A.V.Blinov, I.M.Shevchenko, A.A.Gvozdenko, Z.A.Rekhman, A.B.Golik, A.A.Blinova, M.V.Vakulenko
STUDY OF THE INFLUENCE OF PRECURSOR TYPE ON THE DISPERSION CHARACTERISTICS OF SELENIUM NANOPARTICLES
STUDY OF THE INFLUENCE OF PRECURSOR TYPE ON THE DISPERSION CHARACTERISTICS OF SELENIUM NANOPARTICLES
DOI: https://doi.org/10.22184/1993-8578.2023.16.7-8.426.433
In the framework of this work, the influence of the type of precursor and stabilizer on the dispersion characteristics of selenium nanoparticles, in particular, the average hydrodynamic radius and ζ potential of the particles, was studied. Nanoparticles were obtained by chemical reduction in an aqueous medium. Lithium, sodium, and potassium selenites were used as a precursor, and ascorbic acid was used as a reducing agent, and 4 surfactants were used as a stabilizer: anionic – sodium laureth sulfate, cationic – CTAC, nonionic – Tween-80, amphoteric – cocamidopropyl betaine. For samples stabilized with sodium laureth sulfate, a negative value of this indicator is observed, while using other stabilizers, a positive value of the ζ-potential is observed. The optimal surfactant is cocamidopropyl betaine, which is due to the fact that when changing the concentrations of substances, it showed the smallest changes in the average hydrodynamic radius and ζ-potential of selenium nanoparticles. It is shown that the type and concentration of the precursor have little effect on the average hydrodynamic radius of selenium nanoparticles. It has been established that an increase in the concentration of the precursor leads to a decrease in modulus ζ-potential of particles. It is important to note that the type of precursor does not significantly affect the ζ potential of selenium nanoparticles.
In the framework of this work, the influence of the type of precursor and stabilizer on the dispersion characteristics of selenium nanoparticles, in particular, the average hydrodynamic radius and ζ potential of the particles, was studied. Nanoparticles were obtained by chemical reduction in an aqueous medium. Lithium, sodium, and potassium selenites were used as a precursor, and ascorbic acid was used as a reducing agent, and 4 surfactants were used as a stabilizer: anionic – sodium laureth sulfate, cationic – CTAC, nonionic – Tween-80, amphoteric – cocamidopropyl betaine. For samples stabilized with sodium laureth sulfate, a negative value of this indicator is observed, while using other stabilizers, a positive value of the ζ-potential is observed. The optimal surfactant is cocamidopropyl betaine, which is due to the fact that when changing the concentrations of substances, it showed the smallest changes in the average hydrodynamic radius and ζ-potential of selenium nanoparticles. It is shown that the type and concentration of the precursor have little effect on the average hydrodynamic radius of selenium nanoparticles. It has been established that an increase in the concentration of the precursor leads to a decrease in modulus ζ-potential of particles. It is important to note that the type of precursor does not significantly affect the ζ potential of selenium nanoparticles.
Теги: dispersion characteristics particle potential precursor selenium дисперсные характеристики nanoparticles наночастицы потенциал частиц прекурсор селен
INTRODUCTION
Every year interest in selenium nanoparticles only increases. It plays an important role in antioxidant defense of the body, has antitumor and immunomodulatory activity, and is part of enzymes that rid the body of free radicals and excess peroxides [1–7]. Particular attention is attracted by the unique properties of the obtained particles: photovoltaic, catalytic, biological, semiconductor [8]. The attention of scientists is especially attracted by the low toxicity of selenium nanoparticles compared to its organic and inorganic forms [9, 10]. There are several methods of nanoparticle synthesis, which include physical (pulsed laser ablation, vapor deposition, hydrothermal method [11–13]), biological (reduction of selenium nanoparticles with biological agents [14, 15]), and chemical methods of production. The most widely used chemical synthesis methods are based on reduction of oxidized forms of inorganic selenium, especially selenites and selenates with reducing agents such as proteins, phenols, alcohols, and amines [16–20]. Methods for preparing selenium nanoparticles from organoselenium compounds using biotechnological methods are also known. [21]. Various stabilizers are used to control the size of selenium nanoparticles: polymers, biologically active substances, surfactants [22–26].
The aim of this work is to study the effect of the type of alkali metal selenite-based precursor on the dispersion characteristics of selenium nanoparticles stabilized by different classes of surfactants.
RESEARCH METHODS
Selenium nanoparticles stabilized by various surfactants were obtained by chemical reduction in aqueous medium. Lithium, sodium, potassium selenites ("LenReactiv", Russia) were used as selenium-containing precursor, ascorbic acid ("LenReactiv", Russia) was used as reducing agent, and four surfactants were chosen as stabilizers: anionactive – sodium laureth sulfate, cationactive – CTAH, non-ionogenic – Tween-80, amphoteric – cocamidopropyl betaine (GC ETS, Russia). The synthesis was carried out under constant stirring, temperature and atmospheric pressure.
Initially, selenium-containing precursor and stabilizer were dissolved in distilled water. The second step was to prepare a solution of ascorbic acid in distilled water. Lastly, the reducing agent solution was poured into precursor and stabilizer solution. The resulting sol was stirred for 15 minutes. The concentrations of substances are presented in Table 1.
The average hydrodynamic radius of the obtained samples of selenium nanoparticles was determined by photon correlation spectroscopy on the Photocor-Complex unit (Antec-97 LLC, Russia). The ζ-potential of the obtained samples was determined by acoustic and electroacoustic spectroscopy on the DT-1202 unit manufactured by Dispersion Technology Inc., USA.
RESULTS
At the first stage, influence of precursor type on the size and ζ-potential of selenium nanoparticles was studied. The average hydrodynamic radius and electrokinetic potential of the obtained samples were measured immediately after synthesis. The results are presented in Fig.1 and Tables 2 and 3.
DISCUSSION
The analysis of Table 2 and Fig.1 showed that the type and concentration of precursor as well as the type of surfactant have a negligible effect on the average hydrodynamic radius of selenium nanoparticles. The highest value of the mean hydrodynamic radius of selenium nanoparticles is observed in the sample stabilized with sodium laureth sulfate and obtained from lithium selenite (R = 26 ± 4 nm), the lowest value of the mean hydrodynamic radius is observed in the sample stabilized with cocamidopropyl betaine and obtained from selenic acid (R = 13 ± 2 nm).
The analysis of Table 3 showed that the type of surfactant significantly affects the value of ζ-potential of selenium nanoparticles: the samples stabilized with sodium laureth sulfate have a negative value of this index, while the other stabilizers have a positive value of ζ-potential (Fig.2). The highest value of ζ-potential of selenium nanoparticles is observed in the sample stabilized with cetyltrimethylammonium chloride and obtained from selenic acid (ζ-potential = + 14.69 mV), the lowest value concerned to the sample stabilized with sodium laureth sulfate and obtained from lithium selenite (ζ-potential = -30.46 mV). It was found that increasing the precursor concentration leads to a modulo decrease in the ζ-potential of the particles. At precursor concentration of 0.015 mol/L ζ-potential of selenium nanoparticles obtained from lithium selenate and stabilized with sodium laureth sulfate is – 30.46 mV, at precursor concentration of 0.075 mol/L ζ-potential decreases modulo – 7.09 mV. It is important to note that in addition to nanoparticles, both positively charged ions (alkali metal ions) and negatively charged ions (oxalic acid ions) are present in the solution, which influence the ζ-potential value of selenium nanoparticles and their stability according to the Schulze-Gardi rule. The type of precursor was found to have no significant effect on the ζ-potential of selenium nanoparticles. Thus, the ζ-potential of selenium nanoparticles stabilized by cetyltrimethylammonium chloride at a precursor concentration of 0.015 mol/L is: 14.69 mV using selenic acid; 15.65 mV using lithium selenate; 5.42 mV using sodium selenate; 15.71 mV using potassium selenate.
CONCLUSIONS
In this work, influence of precursor and stabilizer type on dispersion characteristics of selenium nanoparticles, in particular, the average hydrodynamic radius and ζ-potential of the particles was studied. The type of surfactant was found to have a significant effect on the ζ-potential value of selenium nanoparticles and an insignificant effect on the mean hydrodynamic radius of the particles. The samples stabilized with sodium laureth sulfate have a negative value of this index, while the other stabilizers have a positive value of ζ-potential. The optimal surfactant is cocamidopropyl betaine, which is due to the fact that it showed the smallest changes in the average hydrodynamic radius and ζ-potential of selenium nanoparticles when changing the concentrations of substances.
It is shown that precursor type and concentration have an insignificant effect on the average hydrodynamic radius of selenium nanoparticles. It is established that the increase in the precursor concentration leads to a modulus decrease in the ζ-potential of the particles. At a precursor concentration of 0.015 mol/L, the ζ-potential of selenium nanoparticles derived from lithium selenate and stabilized with sodium laureth sulfate is – 30.46 mV, while at a precursor concentration of 0.075 mol/L, the ζ-potential decreases modulo – 7.09 mV. It is important to note that precursor type has no significant effect on the ζ-potential of selenium nanoparticles.
ACKNOWLEDGMENTS
The study was carried out with financial support from the Russian Science Foundation of the Russian Federation (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.
Every year interest in selenium nanoparticles only increases. It plays an important role in antioxidant defense of the body, has antitumor and immunomodulatory activity, and is part of enzymes that rid the body of free radicals and excess peroxides [1–7]. Particular attention is attracted by the unique properties of the obtained particles: photovoltaic, catalytic, biological, semiconductor [8]. The attention of scientists is especially attracted by the low toxicity of selenium nanoparticles compared to its organic and inorganic forms [9, 10]. There are several methods of nanoparticle synthesis, which include physical (pulsed laser ablation, vapor deposition, hydrothermal method [11–13]), biological (reduction of selenium nanoparticles with biological agents [14, 15]), and chemical methods of production. The most widely used chemical synthesis methods are based on reduction of oxidized forms of inorganic selenium, especially selenites and selenates with reducing agents such as proteins, phenols, alcohols, and amines [16–20]. Methods for preparing selenium nanoparticles from organoselenium compounds using biotechnological methods are also known. [21]. Various stabilizers are used to control the size of selenium nanoparticles: polymers, biologically active substances, surfactants [22–26].
The aim of this work is to study the effect of the type of alkali metal selenite-based precursor on the dispersion characteristics of selenium nanoparticles stabilized by different classes of surfactants.
RESEARCH METHODS
Selenium nanoparticles stabilized by various surfactants were obtained by chemical reduction in aqueous medium. Lithium, sodium, potassium selenites ("LenReactiv", Russia) were used as selenium-containing precursor, ascorbic acid ("LenReactiv", Russia) was used as reducing agent, and four surfactants were chosen as stabilizers: anionactive – sodium laureth sulfate, cationactive – CTAH, non-ionogenic – Tween-80, amphoteric – cocamidopropyl betaine (GC ETS, Russia). The synthesis was carried out under constant stirring, temperature and atmospheric pressure.
Initially, selenium-containing precursor and stabilizer were dissolved in distilled water. The second step was to prepare a solution of ascorbic acid in distilled water. Lastly, the reducing agent solution was poured into precursor and stabilizer solution. The resulting sol was stirred for 15 minutes. The concentrations of substances are presented in Table 1.
The average hydrodynamic radius of the obtained samples of selenium nanoparticles was determined by photon correlation spectroscopy on the Photocor-Complex unit (Antec-97 LLC, Russia). The ζ-potential of the obtained samples was determined by acoustic and electroacoustic spectroscopy on the DT-1202 unit manufactured by Dispersion Technology Inc., USA.
RESULTS
At the first stage, influence of precursor type on the size and ζ-potential of selenium nanoparticles was studied. The average hydrodynamic radius and electrokinetic potential of the obtained samples were measured immediately after synthesis. The results are presented in Fig.1 and Tables 2 and 3.
DISCUSSION
The analysis of Table 2 and Fig.1 showed that the type and concentration of precursor as well as the type of surfactant have a negligible effect on the average hydrodynamic radius of selenium nanoparticles. The highest value of the mean hydrodynamic radius of selenium nanoparticles is observed in the sample stabilized with sodium laureth sulfate and obtained from lithium selenite (R = 26 ± 4 nm), the lowest value of the mean hydrodynamic radius is observed in the sample stabilized with cocamidopropyl betaine and obtained from selenic acid (R = 13 ± 2 nm).
The analysis of Table 3 showed that the type of surfactant significantly affects the value of ζ-potential of selenium nanoparticles: the samples stabilized with sodium laureth sulfate have a negative value of this index, while the other stabilizers have a positive value of ζ-potential (Fig.2). The highest value of ζ-potential of selenium nanoparticles is observed in the sample stabilized with cetyltrimethylammonium chloride and obtained from selenic acid (ζ-potential = + 14.69 mV), the lowest value concerned to the sample stabilized with sodium laureth sulfate and obtained from lithium selenite (ζ-potential = -30.46 mV). It was found that increasing the precursor concentration leads to a modulo decrease in the ζ-potential of the particles. At precursor concentration of 0.015 mol/L ζ-potential of selenium nanoparticles obtained from lithium selenate and stabilized with sodium laureth sulfate is – 30.46 mV, at precursor concentration of 0.075 mol/L ζ-potential decreases modulo – 7.09 mV. It is important to note that in addition to nanoparticles, both positively charged ions (alkali metal ions) and negatively charged ions (oxalic acid ions) are present in the solution, which influence the ζ-potential value of selenium nanoparticles and their stability according to the Schulze-Gardi rule. The type of precursor was found to have no significant effect on the ζ-potential of selenium nanoparticles. Thus, the ζ-potential of selenium nanoparticles stabilized by cetyltrimethylammonium chloride at a precursor concentration of 0.015 mol/L is: 14.69 mV using selenic acid; 15.65 mV using lithium selenate; 5.42 mV using sodium selenate; 15.71 mV using potassium selenate.
CONCLUSIONS
In this work, influence of precursor and stabilizer type on dispersion characteristics of selenium nanoparticles, in particular, the average hydrodynamic radius and ζ-potential of the particles was studied. The type of surfactant was found to have a significant effect on the ζ-potential value of selenium nanoparticles and an insignificant effect on the mean hydrodynamic radius of the particles. The samples stabilized with sodium laureth sulfate have a negative value of this index, while the other stabilizers have a positive value of ζ-potential. The optimal surfactant is cocamidopropyl betaine, which is due to the fact that it showed the smallest changes in the average hydrodynamic radius and ζ-potential of selenium nanoparticles when changing the concentrations of substances.
It is shown that precursor type and concentration have an insignificant effect on the average hydrodynamic radius of selenium nanoparticles. It is established that the increase in the precursor concentration leads to a modulus decrease in the ζ-potential of the particles. At a precursor concentration of 0.015 mol/L, the ζ-potential of selenium nanoparticles derived from lithium selenate and stabilized with sodium laureth sulfate is – 30.46 mV, while at a precursor concentration of 0.075 mol/L, the ζ-potential decreases modulo – 7.09 mV. It is important to note that precursor type has no significant effect on the ζ-potential of selenium nanoparticles.
ACKNOWLEDGMENTS
The study was carried out with financial support from the Russian Science Foundation of the Russian Federation (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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