Synthesis of Fe3O4 Magnetic Nanoparticles in a Helical Microreactor

2020 ◽  
Vol 842 ◽  
pp. 174-181
Author(s):  
Dan Wang ◽  
Mudassir Iqbal ◽  
Ming Qiao Zhu

Fe3O4 nanoparticles (NPs) have previously been employed in various fields owing to their unique physical and chemical properties. In this paper, Fe3O4 NPs are prepared by co-precipitation method in a helical microreactor under different reaction conditions which affect the size of Fe3O4 NPs. The product is characterized by FT-IR and XPS. Also, VSM characterization shows that Fe3O4 exhibits typical superparamagnetic behavior and the saturation magnetization of NPs is 53 emu/g.

2015 ◽  
Vol 69 (4) ◽  
pp. 361-370 ◽  
Author(s):  
Snezana Ilic-Stojanovic ◽  
Vesna Nikolic ◽  
Ljubisa Nikolic ◽  
Aleksandar Zdravkovic ◽  
Agnes Kapor ◽  
...  

The aim of this work was the preparation of the inclusion complex of naproxen with 2-hydroxypropyl-?-cyclodextrin (HP-?-CD) in order to improve the physical and chemical properties of naproxen. The molecular inclusion complexes of naproxen with HP-?-CD were prepared by using the co-precipitation method in the solid state with the molar ratio of 1:1. The structure of the obtained complex was characterized by using FTIR, 1H NMR, UV-Vis and XRD methods. The testing of naproxen photostability by the UV-Vis method indicated the degradation to aromatic ketone, 2-acetyl-6-methoxynaphthalene. FTIR analysis showed that the degradation started 15 days after the exposure of naproxen to daylight while the inclusion complex of naproxen: 2-hydroxypropyl-?-cyclodextrin was photostable for a period of 30 days.


Author(s):  
Jiabei Guo ◽  
Hui Jiang ◽  
Yan Teng ◽  
Yue Xiong ◽  
Zhuhui Chen ◽  
...  

Magnetic carbon nanotubes (MCNTs), consisting of carbon nanotubes (CNTs) and magnetic nanoparticles (MNPs), have enormous exploration and application potentials due to their superior physical and chemical properties, such as unique...


2021 ◽  
Vol 872 ◽  
pp. 67-71
Author(s):  
Suharno Rusdi ◽  
Farida Imtiyaz ◽  
Nopia Denvil Wulandari ◽  
Achmad Chafidz

The objectives of this study are to obtain essential oil from Sedap Malam (Tuberose) flower via extraction method and to characterize the physical and chemical properties of the essential oil produced, such as density, rendement, and chemical composition. The extraction process was carried out by using methanol solvent. The ratio between Sedap Malam flower and the methanol solvent was 1:5. After the extraction process of the essential oil finished, the essential oil and the solvent were separated via a simple distillation process. The collected essential oil was then characterized using Gas Chromatography-Mass Spectrophotometry (GC-MS) apparatus and Fourier Transform Infra-Red (FT-IR) analysis to investigate the content of the essential oil extracted from Sedap Malam flower. The physical characterization results showed that the essential oil has average rendement value of 12.605 % and density value of 1.0905 g/mL. Additionally, organoleptic test was carried to test the response of respondents toward the color and odor/fragrance of the essential oil extracted from Sedap Malam flower. Most of the responses were included in categories of “Like” and “Really like”. Additionally, for the fragrance, most of response of the respondents for all the four samples of essential oil were in category of “Really like”.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 997
Author(s):  
Chiara Allegretti ◽  
Francesca Denuccio ◽  
Letizia Rossato ◽  
Paola D’Arrigo

This review describes the use of phospholipase D (PLD) to perform the transphosphatidylation of the most common natural phospholipid (PL), phosphatidylcholine (PC) to obtain polar head modified phospholipids with real targeted applications. The introduction of different polar heads with distinctive physical and chemical properties such as charge, polarity and dimensions allows the obtainment of very different PLs, which can be exploited in very diverse fields of application. Moreover, the inclusions of a bioactive moiety in the PL polar head constitutes a powerful tool for the stabilization and administration of active ingredients. The use of this biocatalytic approach allows the preparation of compounds which cannot be easily obtained by classical chemical methods, by using mild and green reaction conditions. PLD is a very versatile enzyme, able to catalyze both the hydrolysis of PC to choline and phosphatidic acid (PA), and the transphosphatidylation reaction in the presence of an appropriate alcohol. The yield of production of the desired product and the ratio with the collateral PA formation is highly dependent on parameters such as the nature and concentration of the alcohol and the enzymatic source. The application of PLD catalyzed transformations for the production of a great number of PLs with important uses in medical, nutraceutical and cosmetic sectors will be discussed in this work.


This series of papers concerns relations between the physical and chemical properties of catalysts used for the formation of toluene from heptane. These have been prepared by the co-precipitation of chromium and aluminium oxides in a wide range of proportions. After prolonged treatment with hydrogen at 500°C the surface area was determined by measure­ment of the adsorption of nitrogen at –195∙8°C. The adsorption of hydrogen, heptane and benzene was measured from 0 to 500°C. Surface areas increased as the alumina content was raised. Chemisorption of hydrogen reached a maximum at about 70% Cr 2 O 3 . Results with heptane were obscured by decomposition of the hydrocarbon at temperatures above 200°C.


Author(s):  
Jianan Liu ◽  
Yanan Wang ◽  
Shuwen Gong ◽  
Wenzeng Duan ◽  
Xianqiang Huang

A highly efficient and reusable catalyst QA-HPMV was successfully prepared by the reaction of quinoline-2-formic acid (QA) with molybdovanadophosphoric heteropolyacid (H4PMo11VO40, HPMV) for the nitration of benzene. The physical and chemical properties of the sample was characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis and thermogravimetric analysis (TG). The characterization results showed that the formed QA-HPMV retained the Keggin structure of HPMV. As a catalyst for benzene nitration, QA-HPMV showed good catalytic performance and the yield of nitrobenzene was 82.5% under the optimized reaction conditions. As a heterogeneous catalyst, QA-HPMV can be easily recycled from the reaction medium by filtering and remained highly catalytic performance even after five runs of recycling.


2014 ◽  
Vol 5 (1) ◽  
pp. 42-53
Author(s):  
Dr. Firyal M. Ali AL-Salami ◽  
Abbas N. M. AL-Sharify ◽  
Khudheyer Jawad Kadhem

Two new monomers of N-4-antipyrinyl methyl nadamic acid M1 and N-Procaienyl methyl nadamic acid M2 were synthesized from reaction of 4-Aminoantipyrine or procaine with methyl nadic anhydride at room temperature with dioxane as a solvent. The prepared monomers M1 and M2 were polymerized free radically with AIBN as initiator to corresponding polyamic acids P1 and P2, Which were converted to their sodium salt polymers P3 and P4 to enhanced their solubility's in water. The physical and chemical properties were studied for monomers and polymers, also FT-IR ,1H-NMR  and UV. Spectroscopy was characterized of M1or M2. The intrinsic viscosity was measured by  Ostwald viscometer at 30 0C  .The swelling %was measured and the controlled release rates of drug polymers were studied in different pH values at 37 0C.


Author(s):  
Marvy Girgis ◽  
Jérémie Barbier ◽  
Alain Quignard ◽  
Isabelle Merdrignac ◽  
João Marques

Studying bitumen has always posed a challenge to researchers owing to its extreme complexity and unique properties. To classify it commercially and to determine bitumen grade, two standard empirical tests have been adopted within the European standardized bitumen binders system [EN 12591:2009 (2009) Bitumen and bituminous binders – Specifications for paving grade bitumens]: Softening Point (SP) and Penetration (PEN). The relationship between these two tests and the physical or chemical properties of bitumen is not well understood. For the first time, this study represents an attempt to build more understanding of such a relationship through a comprehensive study of the correlation between the two standard tests and many physical and chemical properties of bitumen. A second goal is to propose some predictive models for these two tests and compare their predictive accuracy. Therefore, 13 Straight Run Vacuum Residues (SRVR) samples from different geographical origins were analyzed to measure the following parameters: Dynamic Viscosity (VisDy), Conradson Carbon Residue (CCR), C5 Asphaltenes Content (AspC5), C7 Asphaltenes Content (AspC7), Elemental Analysis (including C, H, O, N, S, Ni, and V content), Simulated Distillation (SD), Fourier-Transform Infrared Spectroscopy (FT-IR), and proton nuclear magnetic resonance spectroscopy (H-NMR). Results of studying correlations using correlation matrix and Principal Component Analysis (PCA) have emphasized the prominent effect of asphaltenes content on the other properties and the results of SP and PEN. It has also shown the potential importance of the aliphaticity/aromaticity of bitumen. Then, four models were proposed for the prediction of SP and PEN: viscosity, FT-IR, H-NMR, and multi-parameter models. Partial least squares (PLS) regression was used for building all models, except viscosity ones. All SP models, except H-NMR model, exhibited very good accuracy compared to the standard method. On the other hand, PEN was more difficult to predict than SP and only the multi-parameter model of PEN showed relatively good accuracy of prediction.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


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