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17Т 66 (3)
ИЗВЕСТИЯ ВЫСШИХ УЧЕБНЫХ ЗАВЕДЕНИИ. Серия «ХИМИЯ И ХИМИЧЕСКАЯ ТЕХНОЛОГИЯ»
2023
V 66 (3)
ChemChemTech
2023
DOI: 10.6060/ivkkt.20236603.6722
ПОЛУЧЕНИЕ НОВЫХ МАТЕРИАЛОВ НА ОСНОВЕ КОМБИНАЦИИ СИНТЕТИЧЕСКИХ ЦЕОЛИТОВ И НАНОЧАСТИЦ СЕРЕБРА
Суан Минь Ву, Тхи Лан Фам, Тхи Ми Хань Ле, Тхи Тху Хоай Фам, Чи Май Нгуен, Дай Лам Чан
Суан Минь Ву (ORCID 0000-0002-7739-0946)*, Тхи Лан Фам (ORCID 0000-0002-8317-0763)*, Тхи Ми Хань Ле (ORCID 0000-0002-1350-4131), Чи Май Нгуен (ORCID 0000-0003-1769-5518), Дай Лам Чан (ORCID 0000-0003-1364-8001)
Институт тропических технологий, Вьетнамская Академия наук и технологий (ВАНТ), ул. Хоанг Куог Вьет, 18, Ханой, Социалистическая Республика Вьетнам, 100000
E-mail: [email protected] *, [email protected] *, [email protected], [email protected], [email protected]
Тхи Тху Хоай Фам (ORCID 0000-0003-2435-0921)
Университет экономики и технологий для промышленности, ул. Минь Хай, 454, Ханой, Социалистическая Республика Вьетнам, 100000 E-mail: [email protected]
Наносеребро давно известно как высокоэффективное дезинфицирующее средство, способное ограничивать рост и уничтожение многих видов плесени и бактерий. Наносеребро можно синтезировать разными способами, в зависимости от цели и требований использования. Наносеребро можно диспергировать в растворах или наносить на носители для различных применений. Однако в растворе наночастицы серебра часто агрегируют, снижая при этом свою антибактериальную активность. Чтобы повысить антибактериальную активность наносеребра и обеспечить возможность многократного восстановления и повторного использования, а также возможность хорошо диспергироваться в различных материалах, наносеребро часто наносят на носители. В этом исследовании было синтезировано наносеребро на поверхности цеолита с помощью таких методов, как химическое восстановление с помощью NaBH4, N2H4 или термическое восстановление при 350 °C. Ионы Ag+ адсорбируются на цеолите 4А по механизму ионного обмена, а затем восстанавливаются различными методами. Результаты показали, что при восстановлении Ag+ до Ag0 химическими реагентами наночастицы серебра распределяются на поверхности цеолита более равномерно, чем при термическом восстановлении. Содержание серебра на поверхности цеолита при восстановлении гидразином примерно в 3 раза выше, чем при восстановлении боргидридом натрия. Цеолит, содержащий наносеребро, обладает способностью обеззараживать кишечную палочку с концентрацией > 5 мг/мл. Образец Ag02/Z, в котором Ag+ до Ag0 восстановлен гидразином, обладает наилучшей антибактериальной активностью против E.coli по сравнению с остальными образцами. Диаметр стерильного кольца при концентрации 20 мг/мл составляет 9 мм.
Ключевые слова: цеолит, наносеребро, антибактериальный материал Для цитирования:
Суан Минь Ву, Тхи Лан Фам, Тхи Ми Хань Ле, Тхи Тху Хоай Фам, Чи Май Нгуен, Дай Лам Чан Получение новых материалов на основе комбинации синтетических цеолитов и наночастиц серебра. Изв. вузов. Химия и хим. технология. 2023. Т. 66. Вып. 3. С. 59-65. DOI: 10.6060/ivkkt.20236603.6722.
For citation:
Xuan Minh Vu, Thi Lan Pham, Thi My Hanh Le, Thi Thu Hoai Pham, Chi Mai Nguyen, Dai Lam Tran Obtaining new
materials based on a combination of synthetic zeolites and silver nanoparticles. ChemChemTech [Izv. Vyssh. Uchebn.
Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 3. P. 59-65. DOI: 10.6060/ivkkt.20236603.6722.
OBTAINING NEW MATERIALS BASED ON A COMBINATION OF SYNTHETIC ZEOLITES
AND SILVER NANOPARTICLES
Xuan Minh Vu, Thi Lan Pham, Thi My Hanh Le, Thi Thu Hoai Pham, Chi Mai Nguyen, Dai Lam Tran
Xuan Minh Vu *, Thi Lan Pham *, Thi My Hanh Le, Chi Mai Nguyen, Dai Lam Tran
Institute for Tropical Technology, Vietnam Academy of Science and Technology (VAST), Hoang Quoc Viet st.,
18, Hanoi, 100000, Vietnam
E-mail: [email protected] *, [email protected] *, [email protected], [email protected], tran-
Thi Thu Hoai Pham
University of Economics and Technology for Industries (UNETI), Minh Khai st., 454, Hanoi, 100000, Vietnam
E-mail: [email protected]
Nano silver has long been known as a highly effective disinfectant, capable of limiting the growth and eliminating many types of mold and bacteria. Nano silver can be synthesized by many different methods, depending on the purpose and requirements of use. Nano silver can be dispersed in solution or carried onto carriers for different applications. However, in solution, silver nanoparticles often tend to bind together, reducing antibacterial activity. In order to promote the antibacterial ability of nano silver and be able to recover and reuse many times, as well as to be able to disperse well into different materials, nano silver is often put on the carriers. In this study, nanosil-ver was synthesized on the surface of a zeolite by simple methods such as chemical reduction with NaBH4, N2H4 or thermal reduction at 350 °C Ag+ ions are adsorbed onto 4A zeolite by ion exchange mechanism, then reduced by different methods. The materials were morphologically analyzed by XRD, SEM, EDX methods. Results showed that the method of reducing Ag+ to Ag0 on zeolite surface by chemical agent produce more evenly distributed silver nano-sizedparticles than the thermal reduction method. The silver content on the zeolite surface of the hydrazine reduction method is about 3 times higher than that of the sodium borohydride reduction method. The highest content of silver nanocarrying to zeolite. Zeolite bearing nano silver has the ability to disinfect against E.Coli with a concentration of > 5 mg/ml. The Ag02/Z sample reducing Ag+ to Ag0 by Hy-drazin has the best antibacterial ability against E.coli compared with the remaining samples when the diameter of the sterile ring at the concentration of 20 mg/ml is 9 mm.
Key words: zeolite, nano silver, antibacterial material
INTRODUCTION
Nano silver has long been known as a highly effective disinfectant, capable of limiting the growth and eliminating many types of mold and bacteria. Nano silver can be synthesized by many different methods, depending on the purpose and requirements of use. Synthesis methods of nanosilver can be divided into two main groups, chemical and physical methods. Chemical methods are often used such as chemical reduction [1-5], substitution reaction [6], electrochemistry [7], etc. Physical methods are commonly used such as physical evaporation [8], thermal decomposition [9, 10], electromagnetic microwave radiation [11], and so on.
Among the above methods, chemical reduction and thermal decomposition are the methods with the simplest manufacturing process.
Nano silver can be dispersed in solution or carried onto carriers for different applications. However, in solution, silver nanoparticles often tend to bind together due to Van der Waals forces, reducing antibacterial activity. In order to promote the antibacterial ability of nano silver and be able to recover and reuse many times, as well as to be able to disperse well into different materials, nano silver is often put on the carriers. One of the commonly used carriers is zeolite, which is a medium capillary material with a uniform
capillary system and many other outstanding properties [12-15]. Silver nano-bearing zeolite is mainly made by impregnation, ion exchange between cations in the structural framework of zeolite and Ag+ ions in solution [16-20].
In this study, zeolite bearing nano-silver was fabricated by impregnation, then using different reduction methods to convert silver ions to silver nanoparti-cles, such as chemical reduction with NaBH4, N2H4 and physical reduction (decomposition by heat). The material was then subjected to structural analysis to evaluate the ability to form silver nanoparticles on zeolite and evaluate its antibacterial activity.
MATERIALS AND METHODS
Material
AgNO3, Zeolite 4A, NaBH4, made in China, are used directly in the experiments without further purification.
Fabrication of nanosilver- bearing zeolite Nanosilver-bearing zeolite is produced by different methods with and without chemical reductants. Before reducing Ag+ to nanosilver Ag0, zeolite must adsorb Ag+ on its surface, through direct ion exchanging or indirect through NH4+ ions. The synthesis of na-nosilver-bearing zeolite is carried out specifically as follows:
• Reduction by sodium borohydride: Neutralize 1kg Zeolite (pH~ 10.6) to pH = 6 in 1.3 L of distilled water using 2M nitric acid HNO3 solution. Add 17.5 g silver nitrate AgNO3 and stir at 60 °C in 2 h, leave to settle overnight, filter through blue-band filter paper to collect Ag+/Z deposit. Then, Ag+/Z was washed three times with distilled water and dried in an oven at 100 °C to completely dry, finally obtaining Ag+/Z powder.
Reduce Ag+ to Ag0 by sodium borohydride with the reaction below:
2Ag+ +2NaBH4 ^ 2Ag0 + H2 + B2H6 + 2Na+ (1) Ag+/Z powder was added to 0.1M NaBH4 solution, gently stirred for 30 min, then settled, filtered with blue-band filter paper and washed three times with distilled water. The product is then completely dried at 100 °C, denoted Ag01/Z.
• Reduction by hydrazin The synthesis of Ag+/Z is similar to the above, just replacing sodium borohydride with hydrazine. The reaction goes as follows:
4Ag+ + N2H4 + 4OH- ^ 4Ag0 + N2 + 4H2O (2) Ag+/Z powder was added to 50 ml of 25% hy-drazine solution, stirred for 4 h at 70 °C, then let stand overnight for the powder to settle at room temperature. The product was filtered with blue-band filter paper,
washed 3 times with distilled water and dried at 100 °C until constant weight. The sample is denoted as Ag02/Z. • Thermal decomposition: The method is based on the same principle as above but differs in the process of exchanging Ag+ ions on the zeolite surface and the reduction process does not use chemicals but uses heat. The principle behind the process is as follows:
Adsorption of NH4+ ions on zeolite surface:
NaZ + NH4NO3 ^ NH4Z + NaNO3 (3) Exchange Ag+ ions with NH4+ ions on zeolite
surface:
Ag+ + NH4Z ^ AgZ + NH4+ (4) Then calcined at high temperature so that Ag+ changes back to Ag0.
The specific manufacturing process is as follows: The zeolite powder is added to NH4NO3 solution with a solid-liquid mass ratio of 1:20, then magnetically stirred and heated at 80 °C for 4 h. Then, the mixture was filtered through blue-band filter paper and dried at 80 °C for 12 h. Repeat the above steps three times to obtain NH4+ adsorbed zeolite, denoted as NH4Z. To adsorb Ag+ ions onto zeolite, we continue to add NH4Z to 0.1 M AgNO3 solution, gently shake at 100 v/p for 2 h, then filter it through blue-band filter paper and wash it 3 times with distilled water, then dry at 100 °C. Repeat the above steps 3 times to obtain Ag+/Z. Heating Ag+/Z at 350 °C for 4 h, obtaining the material denoted Ag03/Z.
Structural analysis
The zeolite powder and zeolite bearing na-nosilver were morphologically analyzed and structurally characterized by modern physicochemical methods. Fe-SEM field emission scanning electron microscopy and energy dispersive X-ray spectroscopy were performed on the Hitachi S4800 instrument (Japan).
Test for antibacterial activity by agar perforation method
Prepare bacterial culture medium (MHA). Then, the MHA medium was autoclaved and poured into petri dishes with a volume of about 15 ml to create agar surfaces.
Preparation of test strains: Inoculate the test strains of bacteria into sterilized bacterial growth medium (TSB). Incubate at 37 °C for 6-8 h for bacterial strains to activate and proliferate. Determine the bacterial cell density by optical densitometry at 625 nm, the bacterial density must reach ~ 106 CFU/ml. This bacterial density will be fixed to proceed to use for the antibacterial activity test of the test sample.
Preparation of test substances: Using a pi-petteman, accurately aspirate 100 ^l of the prepared bacterial solution into a petri dish containing MHA
medium, spread the bacteria evenly over the agar surface of MHA medium with a glass spreader.
Wait for the agar surface to be relatively dry, proceed to punch holes of 6mm agar. Use a pipetteman to accurately aspirate 50 ^l of the test substances into the agar holes. Operations must be carried out under sterile conditions.
Incubate these petri dishes for 24 h at 37 °C, observe the results based on the size of the antibacterial ring. If the sample has an antibacterial ring, it indicates that the test substance is resistant to the test strain of bacteria.
RESULTS AND DISCUSSION
Character of nanosilver-bearing zeolite
The elemental composition on the surface of zeolite and zeolite bearing nanosilver was analyzed by X-ray energy dispersive spectroscopy. EDX spectra of zeolite (Z0) and zeolite bearing nanosilver were synthesized by different methods: reduction with NaBH4 (Ag01/Z), reduced by N2H4 (Ag02/Z), reduced by heat (Ag03/Z) are shown in Fig. 3.1.
The results of Fig. 1 show that the composition of zeolite consists of 4 main elements: oxygen, sodium, aluminum, and silicon, peaks appear with relatively strong intensity at energy levels of 0.525keV (O), 1.041, respectively. keV (Na), 1.5 keV (Al) and 1.739 keV (Si) and absolutely no trace of the element silver. Meanwhile, the EDX spectrum of Ag/Z has a peak at position 2.98 keV, indicating the presence of silver in the composition of Ag/Z. The peak at the 3 keV position of the Ag03/Z sample is higher than that of Ag02/Z and Ag01/Z, thereby predicting that the Ag content on the surface of the heat-reduced sample is higher than that of the chemical reduction. Mass and atomic percentages are also determined and presented in Table 1 below.
The results are shown in Table 1 shows that the mass % of silver atoms on samples Ag01/Z, Ag02/Z
and Ag03/Z are 1.6 %, 4.44% and 7.7%, respectively. Thereby, we can see that the Ag03/Z heat reduction sample has the highest Ag content, but this method will consume more energy than other methods. Of the two chemical reduction methods, the reduction with hydra-zine is more efficient than the reduction with NaBH4 with ~3 times higher silver content. To evaluate in more detail, we analyze other methods such as SEM, XRD and investigate the antibacterial activity of the material.
>
w CP
о
0
1
3
4
2 keV
Fig. 1. Energy-dispersive X-ray spectroscopies of Z0, Ag01/Z,
Ag02/Z, Ag03/Z samples Рис. 1. Энергодисперсионная рентгеновская спектроскопии образцов Z0, Ag01/Z, Ag02/Z, Ag03/Z
To better observe the surface structure and size of silver particles formed on the zeolite surface, field emission scanning electron microscopy can be used. Figure 2 shows the surface morphology of zeolite and zeolite bearing nanosilver at 30,000x magnification.
Observing the surface of zeolite in Fig. 2, we can see that silver nanoparticles have formed on the surface of zeolite in all samples Ag01/Z, Ag02/Z, Ag03/Z. In which, the method of reducing Ag+ to Ag0 by chemicals such as NaBH (Ag01/Z) and N2H4 (Ag02/Z)
Elemental composition on zeolite surface
Table 1
Element Z0 Ag01/Z Ag02/Z Ag03/Z
% mass % number of atoms % mass % number of atoms % mass % number of atoms % mass % number of atoms
O 55.53 66.76 52.1 63.07 49 60.9 57.17 70.6
Al 14.09 10.04 15.2 10.90 15.41 11.35 15.78 11.56
Si 14.56 9.96 15.3 10.55 15.14 10.72 15.26 10.73
Na 15.83 13.24 12.3 10.36 11.76 10.17 0.13 0.11
N 0 0 3.5 4.84 4.25 6.04 3.96 5.59
Ag 0 0 1.6 0.29 4.44 0.82 7.7 1.41
Total 100 100 100 100 100 100 100 100
о
gives silver particles with nano size < 100 nm. Silver na-noparticles on the surface of the Ag02/Z sample have a thicker density and are distributed quite evenly, which is also consistent with the results of elemental composition analysis by X-ray energy dispersive spec-troscopy. Ag03 does not use chemicals, but uses heat at 350 °C to create silver nanoparticles appearing in clusters from 0.2-1 ^m, not evenly distributed on the surface, but mainly forming between the slits of the boundary of the zeolite particles. This result shows that, reducing Ag+ to Ag0 on zeolite by chemical agent gives silver nanoparticle size smaller and more evenly distributed than thermal reduction method. Therefore, chemically reduced samples were selected to analyze the crystalline phase composition by X-ray diffraction spectroscopy.
The crystalline phase composition of zeolite bearing nanosilver was analyzed by X-ray diffraction and compared with the crystalline phase of the original zeolite. X-ray diffraction patterns of Z0, Ag01/Z, Ag02/Z are shown in Fig. 3.
Fig. 2. SEM images of Z0, Ag01/Z, Ag02/Z, Ag03/Z Рис. 2. СЭМ изображения обарзцов Z0, Ag01/Z, Ag02/Z, Ag03/Z
Through Fig. 3 we see that Z0 zeolite appears characteristic peaks at diffraction angles 29: 10,2°; 12.5°; 16.2°; 24.1°; 27.2°; 30° and 34°. With samples Ag01/Z, Ag02/Z, in addition to typical peaks of zeolite, there are also characteristic peaks of silver crystals at diffraction angles of 38°, 44°, and 64.4°, proving that in the composition of Ag01/ Z, Ag02/Z appeared silver crystals. From the size of the semi-spectral width of the silver peak at the 38° diffraction angle, we can calculate the silver crystal grain size based on the Scherrer formula. The results after calculating we calculate that the Ag crystal size of the Ag01/Z sample is 22.4 nm, and that of the Ag02/Z sample is 21.7 nm. Thus, the size of silver particles reduced by chemical method on the nanoscale zeolite surface is in the range of 22 nm.
Fig. 3. X-ray diffraction pattern of Z0, Ag01/Z, Ag02/Z Рис. 3. Рентгенограмма обарзцов Z0, Ag01/Z, Ag02/Z
Table 2
Sterile ring size for E. coli Таблица 2. Размер стерильного кольца для E. coli
No. Sample name Test concentration (mg/ml) Diameter of sterile ring (mm) of Gram (-) Escherichia coli
20.0 0
1 Z0 5.0 0
1.25 0
20.0 7
2 Ag01/Z 5.0 0
1.25 0
20.0 9
3 Ag02/Z 5.0 7
1.25 0
20.0 7
4 Ag03/Z 5.0 0
1.25 0
Thus, from the analysis results of X-ray energy scattering, scanning electron microscopy and X-ray diffraction, we can identify the method of reducing Ag+ to Ag0 on zeolite surface by chemical agent produce more evenly distributed silver nano-sized particles than the thermal reduction method. The silver content on the zeolite surface of the hydrazine reduction method is ~3 times higher than that of the sodium bo-rohydride reduction method. To evaluate the bactericidal effect of the material, samples of Ag01/Z, Ag02/Z and Ag03/Z were tested with E. coli and compared with the original zeolite.
Antibacterial activity test results The antibacterial ability against E.coli bacteria of the material was investigated by the agar perforation method. Samples were tested with concentrations 1.25 mg/mL, 5 mg/mL and 20 mg/mL.
The results in Table 2 show that the antibacterial ring has not appeared in all the samples, showing that at the concentration of 1.25 mg/ml zeolite carrying
nanosilver has not shown the antibacterial effect. The sterile ring has begun to appear for samples Ag02/Z, and samples Z0, Ag01/Z and Ag03/Z do not appear antibacterial rings. Thus, at a concentration of 5 mg/ml, the sample Ag02/Z has promoted its bactericidal ability, but the sterility ring width is still small, and the samples Z0, Ag01/Z and Ag03/X have not been able to kill bacteria at high concentrations.
Continuing to increase the concentration of substances to 4 times, equivalent to 20 mg/ml, we obtain the sterile ring image shown in Fig. 4.
Fig. 4. Test image for E.coli sterility determination of samples
Z0(a); Ag01/Z (b); Ag02/Z (c); Ag03/Z (d) at a concentration of 20 mg/ml
Рис. 4. Тестовое изображение стерильности образцов Z0(a);
Ag01/Z (b); Ag02/Z (c); Ag03/Z (d) в концентрации 20 мг/мл для E.coli
The image of the agar plate in Fig. 4 shows that the antibacterial ring was present on all the zeolite samples bearing silver, and the normal zeolite sample did not appear one. This proves that at the concentration of 20 mg/ml, all zeolite samples carrying silver nanopar-ticles reduced by chemical methods and heat treatment have antibacterial ability. However, the diameter of the sterile ring of sample Ag02/Z is larger than that of the other two samples.
Thus, zeolite itself does not have antibacterial ability when at all concentrations it does not show antibacterial ring. All zeolite samples carrying na-nosilver showed antibacterial activity at the concentration of 20 mg/mL. Sample Ag02/Z has the best antibacterial activity against E.coli compared with the other samples when the diameter of the sterile ring at
the concentration of 20 mg/ml is 9 mm, the samples Ag01/Z and Ag03/Z have the highest concentration of 9 mm. The sterile ring is less than 7 mm. At a lower concentration of 5 mg/ml, only the Ag02/Z sample was antibacterial with an antibacterial ring diameter of 7 mm, while the remaining samples did not have a sterile ring.
This result is also consistent with the conclusions drawn from the results of structural analysis of the material. The Ag02/Z material with silver nanopar-ticles reduced by N2H4 has a rather small Ag particle size, uniform distribution on the zeolite surface and a rather large content, which has the best antibacterial ability. Meanwhile, sample Ag03/Z has more silver concentration but uneven distribution, silver particles cluster together with large size, so the bactericidal effect is not high.
CONCLUSION
The zeolite bearing nano silver was synthesized by adsorbing Ag+ ions on the surface, then reducing Ag+ to Ag0 by different methods using chemical reducing agents and thermal decomposition. The results of the structural morphology analysis show that the chemical reduction method for silver particles has nano-size and is more evenly distributed than the thermal reduction method. The content of nanosilver on the zeolite surface of the hydazine reduction method is ~3 times higher than that of the sodium borohydride reduction method.
The zeolite samples bearing nanosilver were tested for resistance against E.coli strains by agar perforation method and compared with the original zeolite. The concentrations examined were 1.25 mg/mL, 5 mg/mL and 20 mg/mL. The results show that zeolite has no antibacterial ability; All zeolite samples carrying nano silver showed antibacterial activity at the concentration of 20 mg/ml. The Ag02/Z sample reducing Ag+ to Ag0 by Hydrazin has the best antibacterial ability against E.coli compared with the remaining samples when the diameter of the sterile ring at the concentration of 20 mg/ml is 9 mm, the largest is 9 mm, and the Ag01/Z samples. The sodium borohydride-reduced Z and the heat-reduced Ag03/Z have a sterile ring of less than 7 mm. At a lower concentration of 5 mg/ml, only the Ag02/Z sample was antibacterial with an antibacterial ring diameter of 7 mm, while the remaining samples did not have a sterile ring.
ACKNOWLEDGEMENTS
This work was supported by The Vietnam Academy of Science and Technology (VAST) under the grant number TDVLTT.01/21-23.
The authors declare the absence a conflict of interest warranting disclosure in this article.
Эта работа была поддержана Вьетнамской академией наук и технологий (VAST) под номером гранта TDVLTT.01/21-23.
Авторы заявляют об отсутствии конфликта интересов, требующего раскрытия в данной статье.
REFERENCES ЛИТЕРАТУРА
1. Jiraroj D., Tungasmita S., Tungasmita D.N. Silverions and silver nanoparticles in zeolite A composites for antibacterial activity. Powder Technol. 2014. V. 264. P. 418-422. DOI: 10.1016/j.powtec.2014.05.049.
2. Shameli K., Ahmad M.B., Zargar M., Yunus W.M.Z.W, Ibrahim N.A. Fabrication of silver nanoparticles doped in the zeolite framework and antibacterial activity. Inter. J. Nano-med. 2011. V. 6. P. 331-341. DOI: 10.2147/IJN.S16964.
3. Nagy A., Harrison A., Sabbani S., Munson Jr R.S., Dutta P.K, Waldman W.J. Silver nanoparticles embedded in zeolite membranes: release of silver ions and mechanism of antibacterial action. Inter. J. Nanomed. 2011. V. 6. P. 1833-1852. DOI: 10.2147/IJN.S24019.
4. Богачева Н.В., Тарбеева К.А., Огородова Н.Ю. Разработка пошаговой методики получения наночастиц серебра цитрат-ным методом. Изв. вузов. Химия и хим. технология. 2020. Т. 63. Вып. 5. С.65-69. DOI: 10.6060/ivkkt.20206305.6171. Bogacheva N.V., Tarbeeva K.A., Ogorodova N.Yu. Development of step-by-step method for producing silver na-noparti-cles by citrate method. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2020. V. 63. N 5. P. 65-69. DOI: 10.6060/ivkkt.20206305.6171.
5. Беспалов А.В., Иванова Я.О. Получение и устойчивость наноразмерных частиц серебра и палладия в среде ^№ди-метилформамида, стабилизированных простым полиэфиром Лапрол 5003. Изв. вузов. Химия и хим. технология. 2019. Т. 62. Вып. 5. С. 50-55. DOI:10.6060/ivkkt.20196205.5683.
Bespalov A.V., Ivanova Ya.O. Preparation and stability of silver and palladium nanoparticles stabilizedby poly-ether Laprol 5003 in N,N-dimethylformamide media. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2019. V. 62. N 5. P. 50-55. DOI: 10.6060/ivkkt.20196205.5683.
6. Khanna B.K., Gokhale R., Subbarao V.S. Poly (vinyl pyr-rolidone) coated silver nano powder via displacement reaction. J. Mater. Sci. 2004. V. 39. P. 3773-3776. DOI: 10.1023/B:JMSC.0000030735.08903.a9.
7. Yin B. Electrochemical synthesis of silver nanoparticles under protection of poly (N-vinylpyrrolidone). J. Phys. Chem. B. 2003. V. 107. P. 8898-8904. DOI: 10.1021/jp0349031.
8. Taneja B., Ayyub B., Chandra R. Size dependence of the optical spectrum in nanocrystalline silver. Phys. Rev. B. 2002. V. 65. P. 1-6. DOI: 10.1103/PhysRevB.65.245412.
9. Lee D.K., Kang Y.S. Synthesis of silver nanocrystallites by a new thermal decomposition method and their characterization. ETRI J. 2004. V. 26 (3). P. 252-256. DOI: 10.4218/etrij.04.0103.0061.
10. Li S., Wang Q., Yu H. Preparation of effective Ag-loaded zeolite antibacterial materials by solid phase ionic exchange method. J. Porous Mater. 2018. V. 25. P. 1797-1804. DOI: 10.1007/s10934-018-0593-4.
11. Jiang H. Variable frequency microwave synthesis of silver nanoparticles. J. Nanopart. Res. 2006. V. 8. P. 117-124. DOI: 10.1007/s11051-005-7522-6.
12. Гордина Н.Е., Борисова Т.Н., Клягина К.С., Румянцев Р.Н., Прозоров Д.А. Сравнительный анализ свойств цеолита типа LTA в зависимости от метода получения: гидротермальный и ультразвуковой. Изв. вузов. Химия и хим. технология. 2022. Т. 65. Вып. 9. С. 90-96. DOI: 10.6060/ivkkt.20226509.6633.
Gordina N.E., Borisova T.N., Klyagina K.S., Rumyantsev R.N., Prozorov D.A. Comparative analysis of the properties of LTA type zeolite depending on the production method: hydrothermal and ultrasonic. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2022. V. 65. N 9. P. 90-96. DOI: 10.6060/ivkkt.20226509.6633.
13. Wang Y., Wang C., Wang L., Wang L., Xiao F.S. Zeolite Fixed Metal Nanoparticles: New Perspective in Catalysis. Acc. Chem. Res. 2021. V. 54. P. 2579-2590. DOI: 10.1021 /acs.accounts.1 c00074.
14. Sandomierski M., Zielihska M., Voelkel A. Calcium zeolites as intelligent carriers in controlled release of bisphosphonates. Int. J. Pharm. 2020. V. 578. P. 119117. DOI: 10.1016/j.ijpharm.2020.119117.
15. Gennaro B., Catalanotti L., Cappelletti P. Surface modified natural zeolite as a carrier for sustained diclofenac release: A preliminary feasibility study. Colloid. Surf. B: Biointerfac. 2015. V. 130. P. 101-109. DOI: 10.1016/j.colsurfb.2015.03.052.
16. Zhou Y., Deng Y., He P. Antibacterial zeolite with a high silver-loading content and excellent antibacterial performance. RSC Adv. 2014. V. 4. P. 5283-5288. DOI: 10.1039/c3ra44750b.
17. Singh S., Park I.S., Shin Y., Lee Y.S. Comparative study on antimicrobial efficiency of AgSiO2, ZnAg, and Ag- Zeolite for the application of fishery plastic container. J. Mater. Sci. Eng. 2015. V. 4. P. 2169-0022. DOI: 10.4172/2169-0022.1000180.
18. Koc S.O., Koseoglu K., Galioglu S., Akata B., Salamov B.G. Effects of pressure and electric field on the charge transport mechanisms in the silver-modified porous microstructure. Mi-croporous Mesoporous Mater. 2016. V. 223. P. 18-26. DOI: 10.1016/j.micromeso.2015.10.024.
19. Alaya-Ibrahim S., Kovo A.S., Abdulkareem A.S., Ad-eniyi O.D., Yahya M.D. Development of nano-silver doped zeolite A synthesized from Nigerian Ahoko kaolin for treatment of wastewater of a typical textile company. Chem. Eng. Commun. 2020. V. 207. P. 1114-1137. DOI: 10.1080/00986445.2019.1641490.
20. Budtri N., Khongman S., Aekram S., Klinsuk J., Som-phong C., Lertsiriyothin W. Characterization and Morphology of Nanosilver Coating on Zeolite of ZSM-5, Mordenite, and Y Type. Key Eng. Mater. 2019. V. 801. P. 172-178. DOI: 10.4028/www. scientific.net/KEM. 801. 172.
Поступила в редакцию (Received) 12.09.2022 Принята к опубликованию (Accepted) 18.11.2022
