Nickel (Ni)-iron (Fe) alloy in the form of Ni81Fe19 (permalloy) is a widely used material in technological soft magnetic applications. Understanding the magnetization behavior in detail in such materials is substantial from both a scientific point of view and industrial demands. Therefore, the main purpose of the present article is to discuss the angular dependence of magnetization in Ni81Fe19 nanowires by micromagnetic simulation using the object-oriented micromagnetic framework (OOMMF) platform. These investigations have been implemented on different widths/thicknesses (T) up to 150 nm with an identical stretch of 1 µm. There was a reduction in the remanent magnetization by increasing the wire angle with respect to the magnetic field applied, which displayed excellent agreement with calculations performed theoretically. This was designated for the effect of shape anisotropy on behavior. The angular dependence of the switching behavior was analyzed and compared theoretically with the classical domain wall reversal models. The magnetic reversal for wires ≤30 nm was well defined by the uniform rotation of the Stoner–Wohlfarth model, whereas for nanostructures ≥50 nm was analyzed by the nonuniform rotation of the curling model. The critical thickness for the transition between these models was theoretically calculated and found to be around 30 ± 5 nm, which is in good agreement with the other findings presented in the literature using other materials of ferromagnetic wires. The micromagnetic spin structure was obtained instantaneously before and after switching events for relatively thick (150 nm) nanostructures at different angles, suggesting that the reversal is not as simple as predicted by the domain wall reversal of nonuniform rotation of the curling model.
{"title":"Angular Dependence of Magnetization Behavior in Ni81Fe19 Nanowires by Micromagnetic Simulations","authors":"Musaab Salman Sultan","doi":"10.1155/2023/3152014","DOIUrl":"https://doi.org/10.1155/2023/3152014","url":null,"abstract":"Nickel (Ni)-iron (Fe) alloy in the form of Ni81Fe19 (permalloy) is a widely used material in technological soft magnetic applications. Understanding the magnetization behavior in detail in such materials is substantial from both a scientific point of view and industrial demands. Therefore, the main purpose of the present article is to discuss the angular dependence of magnetization in Ni81Fe19 nanowires by micromagnetic simulation using the object-oriented micromagnetic framework (OOMMF) platform. These investigations have been implemented on different widths/thicknesses (T) up to 150 nm with an identical stretch of 1 µm. There was a reduction in the remanent magnetization by increasing the wire angle with respect to the magnetic field applied, which displayed excellent agreement with calculations performed theoretically. This was designated for the effect of shape anisotropy on behavior. The angular dependence of the switching behavior was analyzed and compared theoretically with the classical domain wall reversal models. The magnetic reversal for wires ≤30 nm was well defined by the uniform rotation of the Stoner–Wohlfarth model, whereas for nanostructures ≥50 nm was analyzed by the nonuniform rotation of the curling model. The critical thickness for the transition between these models was theoretically calculated and found to be around 30 ± 5 nm, which is in good agreement with the other findings presented in the literature using other materials of ferromagnetic wires. The micromagnetic spin structure was obtained instantaneously before and after switching events for relatively thick (150 nm) nanostructures at different angles, suggesting that the reversal is not as simple as predicted by the domain wall reversal of nonuniform rotation of the curling model.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136079561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iman N. Jasem, Hiba H. Abdullah, Mohammed Jalal Abdulrazzaq
This study experimentally demonstrates the operation of a dual-wavelength passively Q-switched erbium-doped fiber laser that incorporates CaCO3 nanoparticles as a saturable absorber (SA). The SA was prepared by using the drop-casting method, wherein CaCO3 nanoparticles were embedded in a polyvinyl alcohol (PVA) polymer to form a CaCO3/PVA film SA. The film was integrated into a ring laser cavity with a 976 nm pump to generate Q-switched pulses. The properties of the SA were examined experimentally, and its modulation depth is approximately 47%. As the pump power increased from 180 mW to 270 mW and the pulse repetition rate increased from 12.67 kHz to 21.3 kHz, the corresponding pulse width decreased from 35.27 μs to 18.74 μs. The signal-to-noise ratio was approximately 25 dB, highlighting the laser’s stability. The results indicate that the proposed CaCO3/PVA SA is suitable for realizing portable Q-switched lasers.
{"title":"Dual-Wavelength Passively Q-Switched Erbium-Doped Fiber Laser Incorporating Calcium Carbonate Nanoparticles as Saturable Absorber","authors":"Iman N. Jasem, Hiba H. Abdullah, Mohammed Jalal Abdulrazzaq","doi":"10.1155/2023/8858582","DOIUrl":"https://doi.org/10.1155/2023/8858582","url":null,"abstract":"This study experimentally demonstrates the operation of a dual-wavelength passively Q-switched erbium-doped fiber laser that incorporates CaCO3 nanoparticles as a saturable absorber (SA). The SA was prepared by using the drop-casting method, wherein CaCO3 nanoparticles were embedded in a polyvinyl alcohol (PVA) polymer to form a CaCO3/PVA film SA. The film was integrated into a ring laser cavity with a 976 nm pump to generate Q-switched pulses. The properties of the SA were examined experimentally, and its modulation depth is approximately 47%. As the pump power increased from 180 mW to 270 mW and the pulse repetition rate increased from 12.67 kHz to 21.3 kHz, the corresponding pulse width decreased from 35.27 μs to 18.74 μs. The signal-to-noise ratio was approximately 25 dB, highlighting the laser’s stability. The results indicate that the proposed CaCO3/PVA SA is suitable for realizing portable Q-switched lasers.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135385824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nguyen Duc Vu Quyen, Tran Ngoc Tuyen, Dinh Quang Khieu, Ho Van Minh Hai, Dang Xuan Tin, Bui Thi Hoang Diem, Le Van Thanh Son, Nguyen Thi Kieu Diem, Le Thi Nguyet, Bui Thi Thuy, Ho Thi Thuy Dung
Agricultural wastes including bagasse and rice husk ashes are employed for synthesizing spherical nanosilica materials via the ultrasonic-assisted precipitation process in the present study. The comparison between them and nanosilica prepared from pure sodium silicate is also carried out. The role of the NH4OH : ethanol volume ratio is demonstrated. The obtained nanosilica is characterized by modern methods including X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), infrared spectroscopy (IR), scanning electron microscopy (SEM), and nitrogen adsorption/desorption isotherms (BET). The nanosilica material is employed as an effective adsorbent for the removal of methylene blue (MB) from an aqueous solution. The suitable pH and adsorbent dosage are determined at 8 and 0.375 g·L−1. The adsorption isotherm study is surveyed based on Langmuir and Freundlich isotherm models. Pseudo-second-order kinetic model and Weber–Morris intraparticle diffusion model well describe the chemical nature of the adsorption. The thermodynamic parameters of the reaction are determined based on the Van’t Hoff equation.
{"title":"Separation of Spherical Nanosilica from Agricultural Wastes in Vietnam via Ultrasonic-Assisted Precipitation and Application for Effective Removal of Methylene Blue from Aqueous Solution","authors":"Nguyen Duc Vu Quyen, Tran Ngoc Tuyen, Dinh Quang Khieu, Ho Van Minh Hai, Dang Xuan Tin, Bui Thi Hoang Diem, Le Van Thanh Son, Nguyen Thi Kieu Diem, Le Thi Nguyet, Bui Thi Thuy, Ho Thi Thuy Dung","doi":"10.1155/2023/8884113","DOIUrl":"https://doi.org/10.1155/2023/8884113","url":null,"abstract":"Agricultural wastes including bagasse and rice husk ashes are employed for synthesizing spherical nanosilica materials via the ultrasonic-assisted precipitation process in the present study. The comparison between them and nanosilica prepared from pure sodium silicate is also carried out. The role of the NH4OH : ethanol volume ratio is demonstrated. The obtained nanosilica is characterized by modern methods including X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), infrared spectroscopy (IR), scanning electron microscopy (SEM), and nitrogen adsorption/desorption isotherms (BET). The nanosilica material is employed as an effective adsorbent for the removal of methylene blue (MB) from an aqueous solution. The suitable pH and adsorbent dosage are determined at 8 and 0.375 g·L−1. The adsorption isotherm study is surveyed based on Langmuir and Freundlich isotherm models. Pseudo-second-order kinetic model and Weber–Morris intraparticle diffusion model well describe the chemical nature of the adsorption. The thermodynamic parameters of the reaction are determined based on the Van’t Hoff equation.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134886439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jeaneth M. Medina-Pérez, Melanie A. Zegarra-Zegarra, J. Villanueva-Salas, B. M. Salazar-Pinto, S. S. Flores-Calla, Angel G. Ramírez-Valverde, Hugo G. Jiménez-Pacheco, E. G. Gonzales-Condori
Lactobionic acid (LBA) is a polyhydroxy acid with attractive properties in the pharmaceutical, cosmetic, food, medical, and chemical industries, making it a versatile product with multiple applications, which supports the various studies aimed at its production by increasingly more simple, efficient, and environmentally friendly processes. For this reason, the purpose of this research was to synthesize gold nanoparticles (AuNPs) by a synthesis process using Myrciaria dubia (Camu camu) fruit extract. Subsequently, AuNPs were used to produce LBA from lactose. The results demonstrate that the Myrciaria dubia extract manages to synthesize AuNPs that were characterized by UV/vis spectrophotometry, energy-dispersive X-ray spectroscopy (EDX), and Zetasizer. LBA was quantified by FTIR-ATR spectroscopy and ion chromatography. The results showed that AuNPs succeeded in producing LBA from lactose showing the highest LBA production efficiency at a dose of 0.5 g/L and a temperature of 60°C. It has been shown that the AuNPs obtained by synthesis using the Myrciaria dubia extract efficiently catalyze the production of LBA from lactose, with a yield of 45.24%, which can be used to produce LBA for industrial or research purposes.
{"title":"Production of Lactobionic Acid Using Gold Nanoparticles Synthesized with Fruit Myrciaria dubia Extract","authors":"Jeaneth M. Medina-Pérez, Melanie A. Zegarra-Zegarra, J. Villanueva-Salas, B. M. Salazar-Pinto, S. S. Flores-Calla, Angel G. Ramírez-Valverde, Hugo G. Jiménez-Pacheco, E. G. Gonzales-Condori","doi":"10.1155/2023/5654802","DOIUrl":"https://doi.org/10.1155/2023/5654802","url":null,"abstract":"Lactobionic acid (LBA) is a polyhydroxy acid with attractive properties in the pharmaceutical, cosmetic, food, medical, and chemical industries, making it a versatile product with multiple applications, which supports the various studies aimed at its production by increasingly more simple, efficient, and environmentally friendly processes. For this reason, the purpose of this research was to synthesize gold nanoparticles (AuNPs) by a synthesis process using Myrciaria dubia (Camu camu) fruit extract. Subsequently, AuNPs were used to produce LBA from lactose. The results demonstrate that the Myrciaria dubia extract manages to synthesize AuNPs that were characterized by UV/vis spectrophotometry, energy-dispersive X-ray spectroscopy (EDX), and Zetasizer. LBA was quantified by FTIR-ATR spectroscopy and ion chromatography. The results showed that AuNPs succeeded in producing LBA from lactose showing the highest LBA production efficiency at a dose of 0.5 g/L and a temperature of 60°C. It has been shown that the AuNPs obtained by synthesis using the Myrciaria dubia extract efficiently catalyze the production of LBA from lactose, with a yield of 45.24%, which can be used to produce LBA for industrial or research purposes.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82742962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. J. Beden, Hassan A. Dumboos, M. K. Ismael, Mohanad Kadhim Mejbel
Bismuth oxide (Bi2O3) has attracted considerable research interest in test thin films made utilizing the reactive plasma sputtering (RPS) technology-assisted annealing treatment, allowing the development of diverse BixOx thin films. SEM, phase X-ray diffraction patterns, UV-Vis spectrometers, and D.C. two-probes are used to identify the crystallographic structure and assess the films’ optical-electrical properties. The XRD examination showed that forming Bi2O3 films with an amorphous to multiphase crystalline structure for sputtering time of 40 min was due to soda glass substrate temperature at a range of 30–35°C. Thin films of Bi2O3 crystal structures improved with annealing heat treatment at 200, 300, 400, and 500°C. Yet the formation of crystalline phase (β-Bi2O3 with δ-Bi2O3) Bi2O3 nanostructures occurred at higher temperatures. SEM images showed transparent particles highly affected by annealing temperatures. The nanostructures were about 102–510 nm long, and the diameter was 50–100 nm. The Bi2O3 film optical band gaps and nanostructures ranged from 2.75 to 3.05 eV. The annealing temperature differences affected the crystallite sizes, optical band gaps, and surface roughness. The findings showed that these differences caused the phase transition in Bi2O3 structures. The electrical calculation revealed that the electrical conductivity improved with annealing temperatures of 150–250°C while declining with temperature (300–500)°C with typical semiconductor films.
{"title":"The Role of Annealing Treatment on Crystallographic, Optical, and Electrical Features of Bi2O3 Thin Films Prepared Using Reactive Plasma Sputtering Technology","authors":"S. J. Beden, Hassan A. Dumboos, M. K. Ismael, Mohanad Kadhim Mejbel","doi":"10.1155/2023/8638512","DOIUrl":"https://doi.org/10.1155/2023/8638512","url":null,"abstract":"Bismuth oxide (Bi2O3) has attracted considerable research interest in test thin films made utilizing the reactive plasma sputtering (RPS) technology-assisted annealing treatment, allowing the development of diverse BixOx thin films. SEM, phase X-ray diffraction patterns, UV-Vis spectrometers, and D.C. two-probes are used to identify the crystallographic structure and assess the films’ optical-electrical properties. The XRD examination showed that forming Bi2O3 films with an amorphous to multiphase crystalline structure for sputtering time of 40 min was due to soda glass substrate temperature at a range of 30–35°C. Thin films of Bi2O3 crystal structures improved with annealing heat treatment at 200, 300, 400, and 500°C. Yet the formation of crystalline phase (β-Bi2O3 with δ-Bi2O3) Bi2O3 nanostructures occurred at higher temperatures. SEM images showed transparent particles highly affected by annealing temperatures. The nanostructures were about 102–510 nm long, and the diameter was 50–100 nm. The Bi2O3 film optical band gaps and nanostructures ranged from 2.75 to 3.05 eV. The annealing temperature differences affected the crystallite sizes, optical band gaps, and surface roughness. The findings showed that these differences caused the phase transition in Bi2O3 structures. The electrical calculation revealed that the electrical conductivity improved with annealing temperatures of 150–250°C while declining with temperature (300–500)°C with typical semiconductor films.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78330003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Synthesis of cerium oxide (CeO2) nanoparticles (NPs) via biological approach has received a lot of interest to reduce the harmful effects of chemical synthesis. In the present study, Colocasia esculenta leaf extract facilitated the preparation of CeO2-NPs by using the sol-gel technique. The crystal structural of CeO2-NPs was proven by X-ray powder diffraction (XRD) investigation to be cubic with size of 2.94 nm according to Debye–Scherrer equation. As demonstrated in the transmission electron microscopy (TEM) image, CeO2-NPs have a spherical form with an average size of 2.04 nm which is almost consistent with a finding from XRD analysis. Energy dispersive X-ray (EDX) measurements exhibited high-intensity peaks attributed to Ce and oxygen and further proved the creation of CeO2-NPs. The Fourier transform infrared spectroscopy (FTIR) analysis revealed the presence of Ce-O stretching, indicating the formation of CeO2-NPs. Functional groups of O-H, C-O, and C=O peaks were found in a spectrum due to the phytochemical components that were responsible for reducing and stabilizing during the synthesis process of CeO2-NPs. The examined UV-visible spectra exhibited the absorbance peak at 213 nm. The synthesized NPs produced in this study were further investigated for mung bean seed germination, whereby the influence of grain germination and growth rate demonstrated the significant finding.
{"title":"Synthesis of Green Cerium Oxide Nanoparticles Using Plant Waste from Colocasia esculenta for Seed Germination of Mung Bean (Vigna radiata)","authors":"Nor Monica Ahmad, Nor’ Aishah Hasan","doi":"10.1155/2023/9572025","DOIUrl":"https://doi.org/10.1155/2023/9572025","url":null,"abstract":"Synthesis of cerium oxide (CeO2) nanoparticles (NPs) via biological approach has received a lot of interest to reduce the harmful effects of chemical synthesis. In the present study, Colocasia esculenta leaf extract facilitated the preparation of CeO2-NPs by using the sol-gel technique. The crystal structural of CeO2-NPs was proven by X-ray powder diffraction (XRD) investigation to be cubic with size of 2.94 nm according to Debye–Scherrer equation. As demonstrated in the transmission electron microscopy (TEM) image, CeO2-NPs have a spherical form with an average size of 2.04 nm which is almost consistent with a finding from XRD analysis. Energy dispersive X-ray (EDX) measurements exhibited high-intensity peaks attributed to Ce and oxygen and further proved the creation of CeO2-NPs. The Fourier transform infrared spectroscopy (FTIR) analysis revealed the presence of Ce-O stretching, indicating the formation of CeO2-NPs. Functional groups of O-H, C-O, and C=O peaks were found in a spectrum due to the phytochemical components that were responsible for reducing and stabilizing during the synthesis process of CeO2-NPs. The examined UV-visible spectra exhibited the absorbance peak at 213 nm. The synthesized NPs produced in this study were further investigated for mung bean seed germination, whereby the influence of grain germination and growth rate demonstrated the significant finding.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78977187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. A. Hussain, Haider Abdulelah, A. H. Amteghy, Raed A. Dheyab, Ban Hamdan AlMulla
Due to relatively low price and nontoxicity of photovoltaic (PV) systems, dye-sensitized solar cells (DSSCs) recently gained a lot of attention in terms of improving their performance and longevity. Because most of the major elements are impacted by their separate production and layering procedures, the substances in DSSCs are critical to achieving these goals. Methylene blue dye sensitizer-based solar cells were effectively constructed in this work, and DSSC performance was assessed. The morphologies of nanocrystalline CdS thin films were investigated by the FE-SEM machine, and then XRD patterns of 1 layer, 2 layers, and 3 layers of nanocrystalline CdS thin films were analyzed. The thicknesses of the prepared samples were about 391 nm, 457 nm, and 912 nm for 1, 2, and 3 layers of nanocrystalline CdS thin film, respectively. J-V characteristics of the multilayer CdS thin films have been studied under a 100 mW/cm2 sunlight source. The experimental results revealed that the highest power conversion efficiency of a 3 layer porous-nanowall CdS/MB device was about 0.47%.
{"title":"Effect of Multilayers CdS Nanocrystalline Thin Films on the Performance of Dye-Sensitized Solar Cells","authors":"A. A. Hussain, Haider Abdulelah, A. H. Amteghy, Raed A. Dheyab, Ban Hamdan AlMulla","doi":"10.1155/2023/7998917","DOIUrl":"https://doi.org/10.1155/2023/7998917","url":null,"abstract":"Due to relatively low price and nontoxicity of photovoltaic (PV) systems, dye-sensitized solar cells (DSSCs) recently gained a lot of attention in terms of improving their performance and longevity. Because most of the major elements are impacted by their separate production and layering procedures, the substances in DSSCs are critical to achieving these goals. Methylene blue dye sensitizer-based solar cells were effectively constructed in this work, and DSSC performance was assessed. The morphologies of nanocrystalline CdS thin films were investigated by the FE-SEM machine, and then XRD patterns of 1 layer, 2 layers, and 3 layers of nanocrystalline CdS thin films were analyzed. The thicknesses of the prepared samples were about 391 nm, 457 nm, and 912 nm for 1, 2, and 3 layers of nanocrystalline CdS thin film, respectively. J-V characteristics of the multilayer CdS thin films have been studied under a 100 mW/cm2 sunlight source. The experimental results revealed that the highest power conversion efficiency of a 3 layer porous-nanowall CdS/MB device was about 0.47%.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78833992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Valeriy A. Nebol’sin, E. Levchenko, V. Yuryev, N. Swaikat
In this paper, we focus on the thermodynamics of redox reactions occurring during the vapor-liquid-solid (VLS) growth of silicon nanowires (NWs) with the participation of liquid solutions of metal catalysts. The growth of NWs is difficult with the participation of Ti, Al, and Mg particles; this is because in this case, the drops of the metal catalyst are strongly oxidized and crystals either do not form at all or are characterized by instability in the direction of growth. However, the particles of Cu, Ni, and Fe give a much more stable growth of NWs. We have also established that if the oxide film of catalytic particles is formed by the basic metal oxides, then the silicon-NWs' growth slows down. In this work, we have concluded that only metals with a lower chemical affinity for O2 than Si are applicable as catalysts for the NWs' growth.
{"title":"Thermodynamics of Silicon Nanowire Growth under Unintended Oxidation of Catalytic Particles","authors":"Valeriy A. Nebol’sin, E. Levchenko, V. Yuryev, N. Swaikat","doi":"10.1155/2023/3485793","DOIUrl":"https://doi.org/10.1155/2023/3485793","url":null,"abstract":"In this paper, we focus on the thermodynamics of redox reactions occurring during the vapor-liquid-solid (VLS) growth of silicon nanowires (NWs) with the participation of liquid solutions of metal catalysts. The growth of NWs is difficult with the participation of Ti, Al, and Mg particles; this is because in this case, the drops of the metal catalyst are strongly oxidized and crystals either do not form at all or are characterized by instability in the direction of growth. However, the particles of Cu, Ni, and Fe give a much more stable growth of NWs. We have also established that if the oxide film of catalytic particles is formed by the basic metal oxides, then the silicon-NWs' growth slows down. In this work, we have concluded that only metals with a lower chemical affinity for O2 than Si are applicable as catalysts for the NWs' growth.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88582538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Kantaria, Tengiz Kantaria, P. Heiduschka, N. Eter, D. Tugushi, R. Katsarava
Ophthalmic drug delivery for treating various eye diseases still remains a challenge in ophthalmology. One perspective way of overcoming this problem is to use nanoscale biodegradable drug carriers that are able to safely deliver pharmaceuticals directly to the locus of disease and maintain a therapeutic concentration of drug for a long time. The goal of the present study was the preparation of drug- (dexamethasone-, DEX-) loaded pseudo-protein nanoparticles (NPs) and investigation of drug encapsulation efficiency and drug release kinetics. DEX-loaded pseudo-protein NPs (DEX-NPs) were successfully prepared by the nanoprecipitation method. DEX-NPs were characterized by size (average diameter, AD), size distribution (polydispersity index, PDI), and surface charge (zeta-potential, ZP) using the dynamic light scattering technique. DEX encapsulation characteristics were determined using the UV-spectrophotometric method, and kinetics of DEX release from DEX-NPs was studied according to the dialysis method in PBS at 37°C. The obtained results showed that size of DEX-NPs varies within 143.6–164.1 nm depending on DEX content during the preparation. DEX incorporation characteristics were determined—encapsulation efficiency (EE) and actual drug loading (DL) were high enough and reached 55.1 and 10.2%, respectively. The kinetics of DEX release from DEX-NPs showed a typical biphasic release pattern—an initial rapid (burst) release and further much more continuous slow release. Based on the obtained data, we can conclude that the elaborated DEX-NPs have potential for the application in ophthalmology as ocular drug delivery nanocarriers.
{"title":"Dexamethasone-Loaded Pseudo-Protein Nanoparticles for Ocular Drug Delivery: Evaluation of Drug Encapsulation Efficiency and Drug Release","authors":"T. Kantaria, Tengiz Kantaria, P. Heiduschka, N. Eter, D. Tugushi, R. Katsarava","doi":"10.1155/2023/8827248","DOIUrl":"https://doi.org/10.1155/2023/8827248","url":null,"abstract":"Ophthalmic drug delivery for treating various eye diseases still remains a challenge in ophthalmology. One perspective way of overcoming this problem is to use nanoscale biodegradable drug carriers that are able to safely deliver pharmaceuticals directly to the locus of disease and maintain a therapeutic concentration of drug for a long time. The goal of the present study was the preparation of drug- (dexamethasone-, DEX-) loaded pseudo-protein nanoparticles (NPs) and investigation of drug encapsulation efficiency and drug release kinetics. DEX-loaded pseudo-protein NPs (DEX-NPs) were successfully prepared by the nanoprecipitation method. DEX-NPs were characterized by size (average diameter, AD), size distribution (polydispersity index, PDI), and surface charge (zeta-potential, ZP) using the dynamic light scattering technique. DEX encapsulation characteristics were determined using the UV-spectrophotometric method, and kinetics of DEX release from DEX-NPs was studied according to the dialysis method in PBS at 37°C. The obtained results showed that size of DEX-NPs varies within 143.6–164.1 nm depending on DEX content during the preparation. DEX incorporation characteristics were determined—encapsulation efficiency (EE) and actual drug loading (DL) were high enough and reached 55.1 and 10.2%, respectively. The kinetics of DEX release from DEX-NPs showed a typical biphasic release pattern—an initial rapid (burst) release and further much more continuous slow release. Based on the obtained data, we can conclude that the elaborated DEX-NPs have potential for the application in ophthalmology as ocular drug delivery nanocarriers.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89728091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Superhydrophobic cotton fabric with photoinduced reversibly switchable wettability was prepared by a coating of the hydrophobic copolymer and α-Fe2O3 nanoparticles. The surface morphology of the fabric was observed by scanning electron microscope (SEM). The wettability of the surface was tested under UV illumination and after storage in the dark. The chemical composition of the cotton fabric surfaces before and after UV illumination was analyzed using an X-ray photoelectron spectroscope (XPS) and FTIR. The experimental results showed that the prepared cotton fabric exhibited the excellent superhydrophobic property with a contact angle (CA) of 157.3 ± 2.9°, and became superhydrophilic after UV illumination for 64 h. The surface wettability reverted back to its initial superhydrophobic state after being stored in the dark for 30 d. Based on the XPS and FTIR analyses, the possible mechanism was discussed, and the switchable wettability was caused by the content change of the hydroxyl groups on the α-Fe2O3 surface. Moreover, the superhydrophobic cotton fabric also became superhydrophilic after sunlight illumination for 120 h.
{"title":"Study on the Cotton Fabrics with Photoinduced Reversibly Switchable Wettability","authors":"Caining Zhang, Xuman Wang","doi":"10.1155/2023/8422293","DOIUrl":"https://doi.org/10.1155/2023/8422293","url":null,"abstract":"Superhydrophobic cotton fabric with photoinduced reversibly switchable wettability was prepared by a coating of the hydrophobic copolymer and α-Fe2O3 nanoparticles. The surface morphology of the fabric was observed by scanning electron microscope (SEM). The wettability of the surface was tested under UV illumination and after storage in the dark. The chemical composition of the cotton fabric surfaces before and after UV illumination was analyzed using an X-ray photoelectron spectroscope (XPS) and FTIR. The experimental results showed that the prepared cotton fabric exhibited the excellent superhydrophobic property with a contact angle (CA) of 157.3 ± 2.9°, and became superhydrophilic after UV illumination for 64 h. The surface wettability reverted back to its initial superhydrophobic state after being stored in the dark for 30 d. Based on the XPS and FTIR analyses, the possible mechanism was discussed, and the switchable wettability was caused by the content change of the hydroxyl groups on the α-Fe2O3 surface. Moreover, the superhydrophobic cotton fabric also became superhydrophilic after sunlight illumination for 120 h.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87827656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：