rus
Issue #3-4/2024
A.A.Nagdalian, A.V.Blinov, A.A.Kravtsov, R.Sh.Zakaeva, P.S.Leontev, M.A.Taravanov, A.O.Senkova
STUDY OF THE FORMATION PROCESS OF MANGANESE DIOXIDE NANOPARTICLES STABILIZED BY ALKYLDIMETHYLBENZYLAMMONIUM CHLORIDE
STUDY OF THE FORMATION PROCESS OF MANGANESE DIOXIDE NANOPARTICLES STABILIZED BY ALKYLDIMETHYLBENZYLAMMONIUM CHLORIDE
DOI: https://doi.org/10.22184/1993-8578.2024.17.3-4.230.239
Samples of nanosized manganese dioxide stabilized with alkyldimethylbenzylammonium chloride were obtained by chemical deposition. During optimization, it was revealed that for the synthesis of manganese dioxide nanoparticles with an average hydrodynamic radius of less than 1200 nm, the optimal synthesis parameters are: temperature from 20 to 35 °C, KMnO4 mass from 4 to 5 g and stabilizer concentration from 4 to 5%. Study of the samples using scanning electron microscopy showed that a sample of nano-sized manganese dioxide stabilized with alkyldimethylbenzylammonium chloride is formed by irregularly shaped aggregates ranging in size from 1 to 75 μm, which consist of nanoparticles with a diameter from 50 to 250 nm. The structure was studied using X-ray diffractometry and it was found that the resulting sample has a tetragonal crystal lattice with space group I4/m; presence of this phase is indicated by presence of low-intensity broadened peaks. As a result of analyzing the data obtained by modeling the interaction of the alkyldimethylbenzylammonium chloride molecule and manganese oxide through the nitrogen, it was established that the presented compounds are energetically favorable (∆E = 1299.571 kcal/mol), and interaction occurs through nitrogen. This compound has a chemical hardness value η ≥ 0.030 eV, which indicates its stability. As a result of the analysis of the IR-spectra of alkyldimethylbenzylammonium chloride and nano-sized manganese dioxide stabilized by alkyldimethylbenzylammonium chloride, it can be concluded that interaction between alkyldimethylbenzylammonium chloride and manganese dioxide occurs through nitrogen.
Samples of nanosized manganese dioxide stabilized with alkyldimethylbenzylammonium chloride were obtained by chemical deposition. During optimization, it was revealed that for the synthesis of manganese dioxide nanoparticles with an average hydrodynamic radius of less than 1200 nm, the optimal synthesis parameters are: temperature from 20 to 35 °C, KMnO4 mass from 4 to 5 g and stabilizer concentration from 4 to 5%. Study of the samples using scanning electron microscopy showed that a sample of nano-sized manganese dioxide stabilized with alkyldimethylbenzylammonium chloride is formed by irregularly shaped aggregates ranging in size from 1 to 75 μm, which consist of nanoparticles with a diameter from 50 to 250 nm. The structure was studied using X-ray diffractometry and it was found that the resulting sample has a tetragonal crystal lattice with space group I4/m; presence of this phase is indicated by presence of low-intensity broadened peaks. As a result of analyzing the data obtained by modeling the interaction of the alkyldimethylbenzylammonium chloride molecule and manganese oxide through the nitrogen, it was established that the presented compounds are energetically favorable (∆E = 1299.571 kcal/mol), and interaction occurs through nitrogen. This compound has a chemical hardness value η ≥ 0.030 eV, which indicates its stability. As a result of the analysis of the IR-spectra of alkyldimethylbenzylammonium chloride and nano-sized manganese dioxide stabilized by alkyldimethylbenzylammonium chloride, it can be concluded that interaction between alkyldimethylbenzylammonium chloride and manganese dioxide occurs through nitrogen.
INTRODUCTION
Manganese is a hard but at the same time brittle transition metal of silvery-white colour. Manganese is one of the essential trace elements for normal physiological development of plants and animals [1, 2]. This element is found in many tissues and organs of various organisms [3–5]. According to the data given in [1] such metals as Cu, Fe, Mn and Zn are associated with key metabolic processes of the cell, such as respiration, photosynthesis, fixation and assimilation of basic nutrients. In addition, manganese activates enzymes and is a member of metalloenzyme systems involved in electron transfer [6]. Manganese is included in the process of plant defence against various diseases, also an important function of manganese is participation of this metal in nitrogen metabolism of plants [7, 8].
The paper [10] presents materials that speak about the positive effect of manganese in the oxide form (MnO2) on plants. It is noted that the use of manganese fertilisers helps to increase crop yields, and also the use of manganese fertilisers has a beneficial effect on the agricultural products quality. Manganese fertilisation increases content of protein, sugars, crude protein, fats, gluten and vitamins in plants [11]. Manganese application has a positive effect on the fruit condition and development and berry plants [12]. Yield and sugar content of berries increase, vitamin C content increases.
However, the use of microcrystalline manganese oxide has low efficiency, because it requires high costs for obtaining mineral fertilisers [14]. A more effective and modern method of increasing manganese content in plants is the use of nanosized forms of MnO2 [15, 16]. In [16], data on the use of nanosized manganese (IV) oxides in the cultivation of mache bean (Vigna radiata) were presented. It was found that at higher doses nanoparticles of manganese (IV) oxide are not toxic to plants, unlike manganese salts such as MnSO4, often used as fertilisers. Using biochemical and biophysical methods, it was found that chloroplasts treated with Mn nanoparticles showed greater photophosphorylation and oxygen release compared to control and MnSO4-treated chloroplasts [17]. Water splitting by the oxygen-evolving complex was enhanced by MnO2 nanoparticles in the isolated chloroplast, as confirmed by polarographic and spectroscopic techniques [18]. Thus, we can conclude about the effectiveness of MnO2 nanoparticles as a fertiliser for plants.
One of the effective ways to obtain MnO2 nanoparticles is the addition of various stabilisers during the synthesis process [19]. The use of stabilisers makes it possible to obtain nanoparticles with the required sizes in the nanometre range and shapes [20, 21]. Thus, the aim of this work is to determine the optimal stabilisers and their ratios to form the of MnO2 nanoparticles molecular system with cationic surfactants.
RESEARCH METHODS
The samples of MnO2 nanoparticles were prepared by sol-gel method. Alkyldimethylbenzylammonium chloride (Catamine AB) was used as a stabiliser.
The synthesis was carried out by chemical precipitation of manganese dioxide by interaction of aqueous solution of methionine, in which alkyldimethylbenzylammonium chloride and aqueous solution of KMnO4 were also dissolved. The molar ratio of methionine and KMnO4 is 1:1. The resulting gel was centrifuged to remove the reaction products.
To study structure and phase composition of the obtained samples were studied by scanning electron microscopy on MIRA-LMH of Tescan company and X-ray phase analysis on X-ray diffractometer "PANalytical Empyrean".
Quantum chemical modelling of the manganese dioxide interaction was carried out in QChem software using the molecular editor – IQmol [21], using the following build parameters: calculation – Energy, method – HF, basis: 6-31G, convergence – 5, force field – Ghemical.
The samples were also investigated by IR spectroscopy on a Fourier 1201 IR spectrometer.
The obtained samples of nanosized copper dioxide were studied by the method of dynamic light scattering on the Photocor-Complex unit. Statistica 10.0 software was used to process the experimental data and to automate calculations in order to identify gross errors, estimate dispersions, determine the adequacy of coefficients and derived equations.
At the next stage of the study, the methodology for the synthesis of nanosized manganese dioxide was optimised. Preliminary experiments allowed us to identify factors that have a significant influence on the process of synthesis of nanosized manganese dioxide:
mass concentration of alkyldimethylbenzylammonium chloride relative to the mass of obtained oxide, %;
mass of KMnO4, g;
temperature, T.
The response function (output parameter) is: R – hydrodynamic radius of nanoparticles, nm.
An orthogonal plan of 9 experiments in triplicate was used to study the three factors when they were varied at three levels. The levels of variation of the main parameters are presented in Table 1.
Based on the levels of variation of the variables, an experiment planning matrix was prepared as shown in Table 2.
RESULTS
The influence of varying factors on the process of formation of nanosized manganese oxide was studied by graph-analytical method by constructing ternary graphs. Fig.1 shows the ternary surface of dependence of the average hydrodynamic radius of manganese dioxide nanoparticles on the variable parameters.
In the first stage of the study, the manganese dioxide samples were examined by scanning electron microscopy and the results are shown in Fig.2.
The obtained samples of manganese dioxide nanoparticles were also studied by XRD analysis and the results of this study are shown in Fig.3.
Quantum chemical modelling of the interaction of MnO2 with alkyldimethylbenzylammonium chloride was also carried out, and the results are presented in Table 3 and Fig.4.
In the next step, the obtained sample was investigated by IR spectroscopy and the results are shown in Fig.5.
DISCUSSION
Analysis of the obtained SEM micrographs revealed that the sample of manganese dioxide stabilised with alkyldimethylbenzylammonium chloride is composed of irregularly shaped aggregates ranging in size from 1 to 75 μm, which in turn are composed of nanoparticles with diameters ranging from 50 to 250 nm.
As a result of X-ray phase analysis we can conclude about the presence of amorphous phase of manganese dioxide with hexagonal crystal lattice having space group I4/m, presence of this phase is indicated by presence of weakly intense broadened peaks.
When analysing the data obtained by modelling interaction of alkyldimethylbenzylammonium chloride molecule and manganese oxide through nitrogen, it was found that the presented compound is energetically favourable (∆E = 1299.571 kcal/mol). This compound possesses the value of chemical rigidity η ≥ 0.030 eV, which indicates its stability.
Analysis of the IR spectrum of manganese oxide nanoparticles stabilised with alkyldimethylbenzylammonium chloride showed presence of bands of bond deformation vibrations: at 667 cm–1 – O–H bond, at 751 cm–1 – CH2 bond, at 816 and 952 cm–1, and at 1125, 1180 and 1204 cm–1 – CH3 bond, at 1547 cm–1 – N-H bond. The region from 1356 to 1414 is characteristic of the strain vibrations of the O-H bond. Presence of vibrational bands at 1047 cm–1 corresponds to the valence vibrations of the C–Cl bond, and at 1639 cm-1 to the valence vibrations of C=C. In addition, bands characteristic of the C–H bond are present at 2861, 2922 and 2969 cm–1.
Analysis of the IR spectrum of alkyldimethylbenzylammonium chloride showed presence of vibrational bands at 670 cm–1 characteristic of valence vibrations of CH. The region from 740 to 760 cm–1 corresponds to the strain vibrations of CH2. In the region 1590 to 1610 cm–1, valence vibrations of the ring are observed, and in the region 1500 to 1650 cm–1, strain vibrations of N–H are observed. The presence of vibrational bands at 1125 cm–1 is asymmetric vibrations of the ring. The region from 1375 to 1380 cm–1 corresponds to strain vibrations of CH3. Thus, it can be concluded that interaction between alkyldimethylbenzylammonium chloride and manganese dioxide occurs via nitrogen.
The ternary surface analysis showed that the synthesis temperature and concentration of alkyldimethylbenzylammonium chloride and KMnO4 mass have a significant effect on the average hydrodynamic radius of manganese dioxide nanoparticles. Thus, analysing the ternary surface, it can be concluded that for the synthesis of manganese dioxide nanoparticles with an average hydrodynamic radius of less than 1200 nm, the optimum synthesis parameters are temperature from 20 to 35 °C, KMnO4 mass from 4 to 5 g and stabiliser concentration from 4 to 5%.
CONCLUSIONS
The study of the obtained nanoscale manganese dioxide stabilised with alkyldimethylbenzylammonium chloride revealed that the sample is a variety of irregularly shaped aggregates ranging in size from 1 to 75 μm, which consist of nanoparticles with diameters ranging from 50 to 250 nm. According to the results of X-ray phase analysis, we can conclude about presence of amorphous phase of manganese dioxide with hexagonal crystal lattice having space group I4/m, presence of this phase is indicated by presence of weakly intense broadened peaks. Analysis of the data obtained by modelling the interaction of alkyldimethylbenzylammonium chloride molecule and manganese oxide through nitrogen shows that the presented compound is energetically favourable (∆E = 1299.571 kcal/mol). Interaction occurs via nitrogen. This compound has a chemical rigidity η ≥ 0.030 eV, indicating its stability. From the analysis of IR spectra of alkyldimethylbenzylammonium chloride and nanoscale manganese dioxide stabilised by alkyldimethylbenzylammonium chloride, it can be concluded that interaction between alkyldimethylbenzylammonium chloride and manganese dioxide occurs via nitrogen. Optimisation revealed that for manganese dioxide nanoparticles synthesis with an average hydrodynamic radius of less than 1200 nm, the optimum synthesis parameters are temperature from 20 to 35 °C, KMnO4 mass from 4 to 5 g and stabiliser concentration from 4 to 5%.
ACKNOWLEDGMENTS
This work was supported by the grant of the Russian Science Foundation No. 23-76-10046, https://rscf.ru/en/project/23-76-10046
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.
Manganese is a hard but at the same time brittle transition metal of silvery-white colour. Manganese is one of the essential trace elements for normal physiological development of plants and animals [1, 2]. This element is found in many tissues and organs of various organisms [3–5]. According to the data given in [1] such metals as Cu, Fe, Mn and Zn are associated with key metabolic processes of the cell, such as respiration, photosynthesis, fixation and assimilation of basic nutrients. In addition, manganese activates enzymes and is a member of metalloenzyme systems involved in electron transfer [6]. Manganese is included in the process of plant defence against various diseases, also an important function of manganese is participation of this metal in nitrogen metabolism of plants [7, 8].
The paper [10] presents materials that speak about the positive effect of manganese in the oxide form (MnO2) on plants. It is noted that the use of manganese fertilisers helps to increase crop yields, and also the use of manganese fertilisers has a beneficial effect on the agricultural products quality. Manganese fertilisation increases content of protein, sugars, crude protein, fats, gluten and vitamins in plants [11]. Manganese application has a positive effect on the fruit condition and development and berry plants [12]. Yield and sugar content of berries increase, vitamin C content increases.
However, the use of microcrystalline manganese oxide has low efficiency, because it requires high costs for obtaining mineral fertilisers [14]. A more effective and modern method of increasing manganese content in plants is the use of nanosized forms of MnO2 [15, 16]. In [16], data on the use of nanosized manganese (IV) oxides in the cultivation of mache bean (Vigna radiata) were presented. It was found that at higher doses nanoparticles of manganese (IV) oxide are not toxic to plants, unlike manganese salts such as MnSO4, often used as fertilisers. Using biochemical and biophysical methods, it was found that chloroplasts treated with Mn nanoparticles showed greater photophosphorylation and oxygen release compared to control and MnSO4-treated chloroplasts [17]. Water splitting by the oxygen-evolving complex was enhanced by MnO2 nanoparticles in the isolated chloroplast, as confirmed by polarographic and spectroscopic techniques [18]. Thus, we can conclude about the effectiveness of MnO2 nanoparticles as a fertiliser for plants.
One of the effective ways to obtain MnO2 nanoparticles is the addition of various stabilisers during the synthesis process [19]. The use of stabilisers makes it possible to obtain nanoparticles with the required sizes in the nanometre range and shapes [20, 21]. Thus, the aim of this work is to determine the optimal stabilisers and their ratios to form the of MnO2 nanoparticles molecular system with cationic surfactants.
RESEARCH METHODS
The samples of MnO2 nanoparticles were prepared by sol-gel method. Alkyldimethylbenzylammonium chloride (Catamine AB) was used as a stabiliser.
The synthesis was carried out by chemical precipitation of manganese dioxide by interaction of aqueous solution of methionine, in which alkyldimethylbenzylammonium chloride and aqueous solution of KMnO4 were also dissolved. The molar ratio of methionine and KMnO4 is 1:1. The resulting gel was centrifuged to remove the reaction products.
To study structure and phase composition of the obtained samples were studied by scanning electron microscopy on MIRA-LMH of Tescan company and X-ray phase analysis on X-ray diffractometer "PANalytical Empyrean".
Quantum chemical modelling of the manganese dioxide interaction was carried out in QChem software using the molecular editor – IQmol [21], using the following build parameters: calculation – Energy, method – HF, basis: 6-31G, convergence – 5, force field – Ghemical.
The samples were also investigated by IR spectroscopy on a Fourier 1201 IR spectrometer.
The obtained samples of nanosized copper dioxide were studied by the method of dynamic light scattering on the Photocor-Complex unit. Statistica 10.0 software was used to process the experimental data and to automate calculations in order to identify gross errors, estimate dispersions, determine the adequacy of coefficients and derived equations.
At the next stage of the study, the methodology for the synthesis of nanosized manganese dioxide was optimised. Preliminary experiments allowed us to identify factors that have a significant influence on the process of synthesis of nanosized manganese dioxide:
mass concentration of alkyldimethylbenzylammonium chloride relative to the mass of obtained oxide, %;
mass of KMnO4, g;
temperature, T.
The response function (output parameter) is: R – hydrodynamic radius of nanoparticles, nm.
An orthogonal plan of 9 experiments in triplicate was used to study the three factors when they were varied at three levels. The levels of variation of the main parameters are presented in Table 1.
Based on the levels of variation of the variables, an experiment planning matrix was prepared as shown in Table 2.
RESULTS
The influence of varying factors on the process of formation of nanosized manganese oxide was studied by graph-analytical method by constructing ternary graphs. Fig.1 shows the ternary surface of dependence of the average hydrodynamic radius of manganese dioxide nanoparticles on the variable parameters.
In the first stage of the study, the manganese dioxide samples were examined by scanning electron microscopy and the results are shown in Fig.2.
The obtained samples of manganese dioxide nanoparticles were also studied by XRD analysis and the results of this study are shown in Fig.3.
Quantum chemical modelling of the interaction of MnO2 with alkyldimethylbenzylammonium chloride was also carried out, and the results are presented in Table 3 and Fig.4.
In the next step, the obtained sample was investigated by IR spectroscopy and the results are shown in Fig.5.
DISCUSSION
Analysis of the obtained SEM micrographs revealed that the sample of manganese dioxide stabilised with alkyldimethylbenzylammonium chloride is composed of irregularly shaped aggregates ranging in size from 1 to 75 μm, which in turn are composed of nanoparticles with diameters ranging from 50 to 250 nm.
As a result of X-ray phase analysis we can conclude about the presence of amorphous phase of manganese dioxide with hexagonal crystal lattice having space group I4/m, presence of this phase is indicated by presence of weakly intense broadened peaks.
When analysing the data obtained by modelling interaction of alkyldimethylbenzylammonium chloride molecule and manganese oxide through nitrogen, it was found that the presented compound is energetically favourable (∆E = 1299.571 kcal/mol). This compound possesses the value of chemical rigidity η ≥ 0.030 eV, which indicates its stability.
Analysis of the IR spectrum of manganese oxide nanoparticles stabilised with alkyldimethylbenzylammonium chloride showed presence of bands of bond deformation vibrations: at 667 cm–1 – O–H bond, at 751 cm–1 – CH2 bond, at 816 and 952 cm–1, and at 1125, 1180 and 1204 cm–1 – CH3 bond, at 1547 cm–1 – N-H bond. The region from 1356 to 1414 is characteristic of the strain vibrations of the O-H bond. Presence of vibrational bands at 1047 cm–1 corresponds to the valence vibrations of the C–Cl bond, and at 1639 cm-1 to the valence vibrations of C=C. In addition, bands characteristic of the C–H bond are present at 2861, 2922 and 2969 cm–1.
Analysis of the IR spectrum of alkyldimethylbenzylammonium chloride showed presence of vibrational bands at 670 cm–1 characteristic of valence vibrations of CH. The region from 740 to 760 cm–1 corresponds to the strain vibrations of CH2. In the region 1590 to 1610 cm–1, valence vibrations of the ring are observed, and in the region 1500 to 1650 cm–1, strain vibrations of N–H are observed. The presence of vibrational bands at 1125 cm–1 is asymmetric vibrations of the ring. The region from 1375 to 1380 cm–1 corresponds to strain vibrations of CH3. Thus, it can be concluded that interaction between alkyldimethylbenzylammonium chloride and manganese dioxide occurs via nitrogen.
The ternary surface analysis showed that the synthesis temperature and concentration of alkyldimethylbenzylammonium chloride and KMnO4 mass have a significant effect on the average hydrodynamic radius of manganese dioxide nanoparticles. Thus, analysing the ternary surface, it can be concluded that for the synthesis of manganese dioxide nanoparticles with an average hydrodynamic radius of less than 1200 nm, the optimum synthesis parameters are temperature from 20 to 35 °C, KMnO4 mass from 4 to 5 g and stabiliser concentration from 4 to 5%.
CONCLUSIONS
The study of the obtained nanoscale manganese dioxide stabilised with alkyldimethylbenzylammonium chloride revealed that the sample is a variety of irregularly shaped aggregates ranging in size from 1 to 75 μm, which consist of nanoparticles with diameters ranging from 50 to 250 nm. According to the results of X-ray phase analysis, we can conclude about presence of amorphous phase of manganese dioxide with hexagonal crystal lattice having space group I4/m, presence of this phase is indicated by presence of weakly intense broadened peaks. Analysis of the data obtained by modelling the interaction of alkyldimethylbenzylammonium chloride molecule and manganese oxide through nitrogen shows that the presented compound is energetically favourable (∆E = 1299.571 kcal/mol). Interaction occurs via nitrogen. This compound has a chemical rigidity η ≥ 0.030 eV, indicating its stability. From the analysis of IR spectra of alkyldimethylbenzylammonium chloride and nanoscale manganese dioxide stabilised by alkyldimethylbenzylammonium chloride, it can be concluded that interaction between alkyldimethylbenzylammonium chloride and manganese dioxide occurs via nitrogen. Optimisation revealed that for manganese dioxide nanoparticles synthesis with an average hydrodynamic radius of less than 1200 nm, the optimum synthesis parameters are temperature from 20 to 35 °C, KMnO4 mass from 4 to 5 g and stabiliser concentration from 4 to 5%.
ACKNOWLEDGMENTS
This work was supported by the grant of the Russian Science Foundation No. 23-76-10046, https://rscf.ru/en/project/23-76-10046
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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