Microemulsion Synthesis of Nd0.5Ca0.5MnO3 and Nd0.5Sr0.5MnO3 Nanoparticles

2006 ◽  
Vol 962 ◽  
Author(s):  
Z. Q. Wang ◽  
K. B. Yin ◽  
F. Gao ◽  
K. F. Wang ◽  
Z. F. Ren ◽  
...  
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Charge Order ◽  
Freezing Behavior ◽  
Average Particle ◽  
High Quality ◽  
Spin Freezing ◽  
Microemulsion Synthesis ◽  
Order State

ABSTRACTNd0.5Ca0.5MnO3 (NCMO) and Nd0.5Sr0.5MnO3 (NSMO) nanoparticles have been synthesized using microemulsion synthesis method, with hexamethylene alkyl, a mixture of OP and 1-hexanol, NaOH as oil phase, surfactant, and precipitating agent, respectively. The phase formation of NCMO and NSMO nanoparticles was examined. The final NCMO and NSMO nanoparticles have average particle size of 24 and 50 nm, respectively, and present high-quality crystallinity. Measurements of the magnetic properties suggest that the charge-order state favored for bulk NCMO phase collapses in NCMO nanoparticles. The spin freezing behavior for both NCMO and NSMO nanoparticles was identified.

Formation of metal-carbon nanocomposites based on Cu-Fe alloy nanoparticles and carbonized polyacrylonitrile

2021 ◽  
Vol 1 ◽  
pp. 58-66
Author(s):  
A.A. Vasilev ◽  
◽  
E.L. Dzidziguri ◽  
M.N. Efimov ◽  
D.G. Muratov ◽  
...  
Keyword(s):  
Particle Size ◽  
Carbon Nanostructures ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Carbon Matrix ◽  
Synthesis Temperature ◽  
Average Particle ◽  
Synthesis Of Nanoparticles ◽  
Fe Nanoparticles ◽  
Average Size

A method for the synthesis of nanoparticles of the Cu-Fe bimetallic system with limited mutual solubility of the components is proposed. The synthesis method consists of a one-stage process of IR pyrolysis of precursors in the form of films obtained from a joint solution of polyacrylonitrile and hydrates-nitrates of iron and copper. The effect of the synthesis temperature on the structure formation of the nanocomposites and the phase composition of bimetallic Cu-Fe nanoparticles dispersed in the carbon matrix was studied. The analysis showed a simultaneous presence of Fe and Cu phases in nanocomposites, presumably with a low solubility of the components. The average particle size is 14-17 nm and changes insignificantly with an increase in the synthesis temperature from 400 to 700°C. An increase in the synthesis temperature to 800°C led to a broadening of the particle size distribution and the increase in the average size. The formation of complex carbon nanostructures on Cu-Fe nanoparticles is found.

Microwave Synthesis of Nano-Titanium Carbide

2011 ◽  
Vol 399-401 ◽  
pp. 561-564 ◽  
Author(s):  
Ping An Liu ◽  
Qing Song Yang ◽  
An Ze Shui ◽  
Hui Wang ◽  
Xiao Su Cheng ◽  
...  
Keyword(s):  
Particle Size ◽  
Low Temperature ◽  
Carbon Black ◽  
Titanium Carbide ◽  
Microwave Synthesis ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Synthesis Temperature ◽  
Synthesis Rate ◽  
Average Particle

A new synthesis technology of titanium carbide with microwave is introduced in this article. Microwave synthesis technology is a fast and relatively low temperature of synthesis method. Nano-titanium carbide powders were synthesized by carbothermal reduction of titanium dioxide and carbon black with the microwave synthesis method at 1100°C-1400°C in argon gas atmosphere. Nano-TiO2powder and carbon black were used as raw materials. The TiC powders were characterized with the XRD and TEM. The experimental results show that the synthesis rate is quick, even at relatively low synthesis temperature. The average particle size of the TiC powders synthesized by the microwave synthesis technology under low temperature (<1300°C) is less than 50nm, and the average particle size augments with increasing the microwave synthesis temperature and time.

Synthesis and Characterization of Monodisperse Nanocrystalline HZSM-5 Zeolite

2013 ◽  
Vol 423-426 ◽  
pp. 135-138
Author(s):  
Jun Fang Wei ◽  
Fang Zhu ◽  
Xiao Yan Zhang
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Ammonium Hydroxide ◽  
Crystallization Time ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Influence Of Crystallization

A monodisperse nanocrystalline HZSM-5 zeolite was prepared by varying-temperature synthesis method with aluminum nitrate (Al (NO3)3), tetraethyl orthosilicate (TEOS), and tetrapropyl ammonium hydroxide (TPAOH) as raw materials. X-ray diffraction (XRD) characterization results showed that the crystallinity of HZSM-5 prepared by varying-temperature synthesis method was higher than constant-temperature synthesis . The influence of crystallization temperature and time on morphology and particle size of HZSM-5 is represented by scanning electronic microscopy (SEM) characterization: nanocrystalline HZSM-5 with more regular morphology and smaller particle size can be prepared by varying-temperature synthesis method. The minimum average particle size is 0.3μm. The particle size will grow up to 3.0μm with the crystallization time prolonged.

The Influence of Surfactants on Crystallization of Nanocrystalline HZSM-5 Zeolite

2013 ◽  
Vol 423-426 ◽  
pp. 117-120
Author(s):  
Jun Fang Wei ◽  
Fang Zhu ◽  
Xiao Yan Zhang
Keyword(s):  
Particle Size ◽  
Hydrothermal Synthesis ◽  
Anionic Surfactant ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray

With addition of surfactants, a nanocrystalline HZSM-5 zeolite was prepared by hydrothermal synthesis method. X-ray diffraction (XRD) characterization results showed that surfactants can constraint the crystallization of HZSM-5. Scanning electronic microscopy (SEM) characterization revealed that nanocrystalline HZSM-5 with more regular morphology and smaller particle size can be prepared with suitable surfactants as additives. The HZSM-5 particles were 200-800 nm in size and constructed by primary HZSM-5 nanocrystals of 3050 nm. The average particle size will grow up to 800 nm with a cationic surfactant, and decrease to 200 nm with a anionic surfactant.

scholarly journals Physical Characteristic and Antibacterial Activity of Silver Nanoparticles from Green Synthesis Using Ethanol Extracts of Phaleria macrocarpa (Scheff.) Boerl Leaves

2019 ◽  
Vol 24 (1) ◽  
pp. 22 ◽  
Author(s):  
Tri Puji Lestari ◽  
Fitia Abbas Tahlib ◽  
Johan Sukweenadhi ◽  
Kartini Kartini ◽  
Christina Avanti
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Silver Nanoparticle ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Antibacterial Properties ◽  
Ethanol Extract ◽  
Average Particle

The Green Synthesis method is widely developed due to its environmentally friendly, cost-effective, and easy application for nanoparticle-scale synthesis. Among all metal nanoparticles, silver nanoparticles are the most utilized products in the field of nanotechnology. Biomolecules contained in plant extracts can reduce the size of silver particles to nano size. This study aims to determine the antibacterial properties and activity of silver nanoparticles synthesized with the ethanol extract of mahkota dewa leaves. The formation of silver nanoparticles is monitored with UV-Vis absorption and its change in color. Parameters evaluated are shape, size, particle size distribution, composition, metal residue, and a functional group of nanoparticles, using Scanning Electron Microscopy (SEM), Particle Size Analyzer (PSA), X-Ray Diffraction (XRD), and Fourier Transform InfraRed (FTIR) instrument. The research on UV-Vis color and absorption show black silver color with the wavelength of 450-465nm. The characterization result shows spherical-shaped silver nanoparticle. Furthermore, PDI best value on concentration of 0.125% is 0,221±0,0482 with average particle size of 130,300±12,6858 nm. The diffraction pattern of silver nanoparticle with XRD test indicates that the nanoparticles contain the silver component. Antibacterial activity test shows that silver nanoparticles have a greater inhibition zone than AgNO3, and 0.125% ethanol extract of mahkota dewa leaves against Escherichia coli and Staphylococcus aureus. From the results of the study, it can be concluded that the ethanol extract from mahkota dewa leaves can be used as a bioreductor agent to produce silver nanoparticles which have greater antimicrobial activity compared to Ag and ethanol extract from mahkota dewa leaves.

scholarly journals BIOSYNTHESIS AND CHARACTERIZATION OF GOLD NANOPARTICLES AND THEIR INTERACTION STUDY WITH METFORMIN

2020 ◽  
Vol 21 (2) ◽  
pp. 56
Author(s):  
Dian Anggraini ◽  
Siti Suhartati ◽  
Iwan Syahjoko Saputra ◽  
Sudirman Sudirman
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Leaf Extract ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Spherical Shape ◽  
Imperata Cylindrica ◽  
Average Particle ◽  
Interaction Study

BIOSYNTHESIS AND CHARACTERIZATION OF GOLD NANOPARTICLES AND THEIR INTERACTION STUDY WITH METFORMIN. Synthesis of gold nanoparticles successfully carried using Imperata cylindrica L leaf extract. In this study, the approach used through green synthesis method is a reaction betwen of the HAuCl4 solution (concentration variation as 3; 5; 7 x 10-4 M) with Imperata cylindrica L leaf extract. Results of UV-Vis showed of gold nanoparticles has a maximum wavelength at 530 nm with absorbance value of 1.4. Results of FTIR shows a shift the absorption peak at wavenumber of 3392 cm-1 to 3404 cm-1. PSA and PZC showed the distribution of gold nanoparticles was 48.84 nm with a charge of 20.5 mV. Gold nanoparticles has a spherical shape and an average particle size of 20 nm which can be seen from the results of the characterization using TEM. XRD showed crystalize size average of gold nanoparticles as 20.47 nm. The interaction between of gold nanoparticles with metformin can be seen in the absorbance decrease of 0.38 at a wavelength of 531 nm and the results of PSA shows an average particle size of AuNPs@metformin is 122 nm. From the characterization data can be concluded the gold nanoparticles were successfully synthesized using natural bioreductors by utilizing secondary metabolites from Imperata cylindrica L leaf extract.

Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

Formulating SLN and NLC as Innovative Drug Delivery Systems for Non-Invasive Routes of Drug Administration

2020 ◽  
Vol 27 (22) ◽  
pp. 3623-3656 ◽  
Author(s):  
Bruno Fonseca-Santos ◽  
Patrícia Bento Silva ◽  
Roberta Balansin Rigon ◽  
Mariana Rillo Sato ◽  
Marlus Chorilli
Keyword(s):  
Drug Delivery ◽  
Particle Size ◽  
Drug Release ◽  
Drug Loading ◽  
Average Particle Size ◽  
Delivery Systems ◽  
Average Particle ◽  
Minor Importance ◽  
Routes Of Administration ◽  
Non Invasive

Colloidal carriers diverge depending on their composition, ability to incorporate drugs and applicability, but the common feature is the small average particle size. Among the carriers with the potential nanostructured drug delivery application there are SLN and NLC. These nanostructured systems consist of complex lipids and highly purified mixtures of glycerides having varying particle size. Also, these systems have shown physical stability, protection capacity of unstable drugs, release control ability, excellent tolerability, possibility of vectorization, and no reported production problems related to large-scale. Several production procedures can be applied to achieve high association efficiency between the bioactive and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes Lipid-based nanocarriers (LNCs) versatile delivery system for various routes of administration. The route of administration has a significant impact on the therapeutic outcome of a drug. Thus, the non-invasive routes, which were of minor importance as parts of drug delivery in the past, have assumed added importance drugs, proteins, peptides and biopharmaceuticals drug delivery and these include nasal, buccal, vaginal and transdermal routes. The objective of this paper is to present the state of the art concerning the application of the lipid nanocarriers designated for non-invasive routes of administration. In this manner, this review presents an innovative technological platform to develop nanostructured delivery systems with great versatility of application in non-invasive routes of administration and targeting drug release.

Azithromycin nanosuspension preparation using evaporative precipitation into aqueous solution (EPAS) method and its comparative dissolution study

2020 ◽  
Vol 17 ◽  
Author(s):  
Mohammad Hossain Shariare ◽  
Tonmoy Kumar Mondal ◽  
Hani Alothaid ◽  
Md. Didaruzzaman Sohel ◽  
MD Wadud ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Dissolution Rate ◽  
Average Particle Size ◽  
Scale Up ◽  
Average Particle ◽  
Total Drug ◽  
Residual Solvent ◽  
Dissolution Study ◽  
Drug Content

Aim: EPAS (evaporative precipitation into aqueous solution) was used in the current studies to prepare azithromycin nanosuspensions and investigate the physicochemical characteristics for the nanosuspension batches with the aim of enhancing the dissolution rate of the nanopreparation to improve bioavailability. Methods: EPAS method used in this study for preparing azithromycin nanosuspension was achieved through developing an in-house instrumentation method. Particle size distribution was measured using Zetasizer Nano S without sample dilution. Dissolved azithromycin nanosuspensions were also compared with raw azithromycin powder and commercially available products. Total drug content of nanosuspension batches were measured using an Ultra-Performance Liquid Chromatography (UPLC) system with Photodiode Array (PDA) detector while residual solvent was measured using gas chromatography (GC). Results: The average particle size of azithromycin nanosuspension was 447.2 nm and total drug content was measured to be 97.81% upon recovery. Dissolution study data showed significant increase in dissolution rate for nanosuspension batch when compared to raw azithromycin and commercial version (microsuspension). The residual solvent found for azithromycin nanosuspension is 0.000098023 mg/ mL or 98.023 ppb. Conclusion: EPAS was successfully used to prepare azithromycin nanoparticles that exhibited significantly enhanced dissolution rate. Further studies are required to scale up the process and determine long term stability of the nanoparticles.

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