Particle Size Analysis of Fe3O4 Nanoparticles Coated by Polyethyleneglycol

2015 ◽  
Vol 820 ◽  
pp. 373-377 ◽  
Author(s):  
Fernanda A. Sampaio da Silva ◽  
Edwin E.G. Rojas ◽  
Marcos Flávio de Campos

Nanotechnology has been shown as an important tool for developing intelligent devices. In particular, magnetic nanoparticles have been studied due their applications in cancer treatments. However, nanoparticles need to be tightly controlled in relation to size, shape and coating. It makes particles suitable for in vivo applications. In this work, magnetite nanoparticles were used for particle size characterization. Fe3O4 crystals were coated by polyethyleneglycol (PEG 4000). Three different techniques were performed to obtain the nanoparticles average diameter: Rietveld Analysis, Scherrer Equation and Nanosight®. Results indicate good properties.

2014 ◽  
Vol 92 ◽  
pp. 215-220
Author(s):  
Carolina del Roveri ◽  
Letícia H. Godoy ◽  
Antenor Zanardo ◽  
Luciano L. Silva ◽  
Maria Margarita T. Moreno ◽  
...  

Lavrinhas, a city located 234 km northeast of São Paulo, Brazil, presents syenitic rocks with high content of nepheline, whose preliminary field assessment indicated its potential to be used in the production of ceramic products. The paper aimed to study this raw material with fluxing properties and to determine the best processing methods based on mineralogy and texture, in order to achieve better removal efficiency of the nepheline. Petrographic characterization was carried out in two rock samples, as well as the particle size characterization of the untreated material, the split into fractions for magnetic separation tests and optical microscope observation of the products. In addition, chemical and particle size analysis and melting tests were performed. The latter concerned the material melting color evaluation before and after the magnetic separation, as well as its potential use in glazes and engobes, compared to a standard sample of Nepheline, and inferences for the use in porcelain masses. Preliminary tests showed that after the removal of residual iron oxide, the nepheline raw material bearer has potential to be used in the formulation of porcelain masses, replacing other fluxing materials with higher benefit.


2017 ◽  
Vol 28 (4) ◽  
pp. 462-476 ◽  
Author(s):  
Felippe Fernandes ◽  
Cristiano Poleto

Purpose The purpose of this paper is to analyse the results of particle size profiles carried out in the dam Mãe d’água, located in the metropolitan region of Porto Alegre, Rio Grande do Sul, becoming a tool of support for geochemistry evaluation works of sediments in this basin. Design/methodology/approach The methodology comprised the particle size analysis of eight cores sampled using the extraction profile technique “Sampling Cores.” A total of 56 sub-samples were obtained at different depths, varying between 0 and 52 cm. The particle size analysis of the sub-samples was carried out with the protocol relating to Brazilian analysis standards NBR 7,181; for determination of the particle size distribution of thick sediments, the sieve method was used, and for fine sediments, the pipette method was used. Findings The results show that for the different depths, the sediment profiles show similarity in their sedimentary deposition layers. Cores T1, T6, T7 and T8 showed a classification with predominance of mud. Cores T2 and T5 showed variations throughout their sedimentary profile, varying of mud predominance to sand with gravel, and on cores T3 and T4, the predominant characteristic is sand with mud and sand with gravel, respectively. Originality/value It can be seen in this paper that energy of sedimentological flow reaches it in a different way, creating these three sectors (first, sand with gravel; second, sand with mud and third, mud) with different characteristics – morphodynamic and sedimentological. These characteristics are important for the study of the heavy metals on the soil and therefore for reducing the risk of contamination of water courses.


2020 ◽  
Vol 17 (3) ◽  
pp. 257-268
Author(s):  
Parth Patel ◽  
Tejas Barot ◽  
Pratik Kulkarni

Background: Nanocarriers improve the efficacy of drugs by facilitating their specific delivery and protecting them from external environment resulting in a better performance against diseases. Objective: In this study, it was aimed to improve the efficacy of capecitabine against colorectal cancer by its entrapment in niosomes. Ether injection method was used to prepare niosomes composed of span 20 and cholesterol. Methods: Niosomes were evaluated by evaluating the entrapment efficiency, in-vitro drug release and cytotoxicity of capecitabine loaded niosomes. Niosomes were characterized by particle size analysis, transmission electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry for surface morphology and drug excipient interactions. Results: High encapsulation efficiency (90.55%) was observed, which is anticipated to resolve the multi-drug resistance problem. Reported particle size was 180.9 + 5 nm with a negative zeta potential - 21 + 0.5 mV and the kinetic study showed a concentration-dependent release of the drug from the niosome. DSC study proved entrapment of the entire drug and its non-covalent bonding with the excipients. Cytotoxicity study of niosomes on CaCO2 cell line showed an improved IC>50 value as compared to the free drug. Conclusion: Enhanced cytotoxicity observed in the results further supports the suitability of niosome as a nanocarrier for pharmaceutical drug delivery.


Author(s):  
EL- Assal I. A. ◽  
Retnowati .

Objective of the present investigation was enthused by the possibility to develop solid lipid nanoparticles (SLNs) of hydrophilic drug acyclovir. Also study vitro and vivo drug delivery. Methods: Drug loaded SLNs (ACV-SLNs) were prepared by high pressure homogenization of aqueous surfactant solutions containing the drug-loaded lipids in the melted or in the solid state with formula optimization study (Different lipid concentration, drug loaded, homogenization / stirring speed and compritol 888ATO: drug ratio). ACV - SLN incorporated in cream base. The pH was evaluated and rheological study. Drug release was evaluated and compared with simple cream- drug, ACV – SLN with compritol 888ATO and marketed cream. The potential of SLN as the carrier for dermal delivery was studied. Results: Particle size analysis of SLNs prove small, smooth, spherical shape particle ranged from 150 to 200 nm for unloaded and from 330 to 444 nm for ACV loaded particles. The EE% for optimal formula is 72% with suitable pH for skin application. Rheological behavior is shear thinning and thixotropic. Release study proved controlled drug release for SLNs especially in formula containing compritol88 ATO. Stability study emphasized an insignificant change in SLNs properties over 6 month. In-vivo study showed significantly higher accumulation of ACV in stratum corneum, dermal layer, and receptor compartment compared with blank skin. Conclusion: AVC-loaded SLNs might be beneficial in controlling drug release, stable and improving dermal delivery of antiviral agent(s).


Circular ◽  
1985 ◽  
Author(s):  
Lawrence J. Poppe ◽  
A.H. Eliason ◽  
J.J. Fredericks

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