precursor material
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2021 ◽  
Vol 155 ◽  
pp. 106279
Author(s):  
Johanna A. Serna-Jiménez ◽  
Fernando Luna-Lama ◽  
Álvaro Caballero ◽  
María de los Ángeles Martín ◽  
Arturo F. Chica ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4143
Author(s):  
Mubarak Usman Kankia ◽  
Lavania Baloo ◽  
Nasiru Danlami ◽  
Bashar S. Mohammed ◽  
Sani Haruna ◽  
...  

Petroleum sludge is a waste product resulting from petroleum industries and it is a major source of environmental pollution. Therefore, developing strategies aimed at reducing its environmental impact and enhance cleaner production are crucial for environmental mortar. Response surface methodology (RSM) was used in designing the experimental work. The variables considered were the amount of petroleum sludge ash (PSA) in weight percent and the ratio of sodium silicate to sodium hydroxide, while the concentration of sodium hydroxide was kept constant in the production of geopolymer mortar cured at a temperature of 60 °C for 20 h. The effects of PSA on density, compressive strength, flexural strength, water absorption, drying shrinkage, morphology, and pore size distribution were investigated. The addition of PSA in the mortar enhanced the mechanical properties significantly at an early age and 28 days of curing. Thus, PSA could be used as a precursor material in the production of geopolymer mortar for green construction sustainability. This study aimed to investigate the influence of PSA in geopolymer mortar.


2021 ◽  
Vol 21 (10) ◽  
pp. 5181-5187
Author(s):  
E. H. Coldebella ◽  
E. F. Chagas ◽  
A. P. Albuquerque ◽  
R. J. Prado ◽  
M. Alzamora ◽  
...  

We report an experimental study of the bimagnetic nanocomposites CoFe2/CoFe2O4. The precursor material, CoFe2O4 was prepared using the conventional stoichiometric combustion method. The nano-structured material CoFe2/CoFe2O4 was obtained by total oxygen reduction of CoFe2O4 using a thermal treatment at 350 °C in H2 atmospheres following the partial oxidation in O2 atmospheres at 380 °C during 120; 30; 15, 10, and 5 min. The X-ray diffraction, Mössbauer spectroscopy and transmission electronic microscopy images confirmed the formation of the material CoFe2/CoFe2O4. The magnetic hysteresis for the nanocomposite with different saturation magnetization (from 87 to 108 emu/g) also confirms the formation of the CoFe2/CoFe2O4 with different content of CoFe2O4. Furthermore, the magnetic hysteresis curves for all samples presented a single magnetic behavior, suggesting the magnetic coupling between the phases of the nanocomposite. The effects of high energy milling on the magnetic properties of the precursor material and nanocomposites samples were evaluated.


2021 ◽  
Vol 58 (5) ◽  
pp. 353-359
Author(s):  
Omid Shojaei

Abstract Bleach activators decrease the energy consumption and fabrics damage in the process of laundry and industrial cotton bleaching. Herein, we demonstrate a low-cost, two-step method for the synthesis of sodium nonanoyloxybenzene sulfonate and sodium lauroyloxybenzene sulfonate from phenol as a simple precursor material for efficient bleach activators. Initially, phenol was sulfonated to sodium p-phenolsulfonate. In the second step, it was acylated with nonanoyl chloride and dodecanoyl chloride to synthesize sodium nonanoyloxybenzene sulfonate and sodium lauroyloxybenzene sulfonate, respectively. Sodium p-phenolsulfonate and the obtained bleach activators were characterized by thermogravimetric analysis, IR-, and 1H NMR spectroscopy. The investigation of their detergency efficiency on different stains and substrates revealed that the as-synthesized bleach activators outperform the commercial tetraacetylethylenediamine (TAED) at room temperature (25°C). The detergency efficiency of sodium lauroyloxybenzene sulfonate for hydrophobic stains at a rather low temperature of 40°C remarkably rises to about 90%.


Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1382
Author(s):  
Florian Patrick Schäfke ◽  
Susanne Elisabeth Thürer ◽  
Hans Jürgen Maier ◽  
Christian Klose

Metal foams are attractive for lightweight construction in the automotive sector since they provide high-energy absorption and good damping properties, which is crucial, e.g., for crash structures. Currently, however, foams are produced separately and then pasted into the components. Consequently, the overall mechanical properties depend significantly on the quality of the adhesive bond between the foam and the structural component. A new process route for the manufacture of hybrid foamed hollow aluminum profiles is proposed. In this approach, a foamable precursor material is directly integrated into the extrusion process of the hollow structural profile. To this end, special low-melting alloys were developed in this study to enable foaming inside the aluminum profile. The melting intervals of these alloys were examined using differential scanning calorimetry. One of the promising AlZnSi alloys was atomized, mixed with a foaming agent and then compacted into semi-finished products for subsequent co-extrusion. The foaming behavior, which was investigated by means of X-ray microscopy, is shown to depend primarily on the mass fraction of the foaming agent as well as the heat treatment parameters. The results demonstrate that both the melting interval and the foaming behavior of AlZn22Si6 make this particular alloy a suitable candidate for the desired process chain.


2021 ◽  
Vol 36 (16) ◽  
pp. 3248-3257
Author(s):  
Fabian Friess ◽  
Andreas Lendlein ◽  
Christian Wischke

AbstractShape-memory polymer micronetworks (MN) are micrometer-sized objects that can switch their outer shape upon external command. This study aims to scale MN sizes to the low micrometer range at very narrow size distributions. In a two-step microfluidic strategy, the specific design of coaxial class capillary devices allowed stabilizing the thread of the dispersed phase to efficiently produce precursor particles in the tip-streaming regime at rates up to ~ 170 kHz and final sizes down to 4 µm. In a subsequent melt-based microfluidic photocrosslinking of the methacrylate-functionalized oligo(ɛ-caprolactone) precursor material, MN could be produced without particle aggregation. A comprehensive analysis of MN properties illustrated successful crosslinking, semi-crystalline morphology, and a shape-switching functionality for all investigated MN sizes (4, 6, 9, 12, 22 µm). Such functional micronetworks tailored to and below the dimension of cells can enable future applications in technology and medicine like controlling cell interaction. Graphic abstract


2021 ◽  
Vol 03 (02) ◽  
pp. 69-75
Author(s):  
Thikra K. AL-KAFIJI

To produce a polymeric material for use in electronic applications, traditional ‘wet’ methods of synthesis include chemical and electrochemical polymerization.. In addition, organic precursors that are unable to polymerize using conventional techniques have been found to undergo polymerization using this technique. Interest in the use of plasma polymerization originated due to its advantages, which include the ability to produce films that are of uniform thickness, pinhole-free, chemically inert and thermally stable The low cost of this fabrication technique is attributed to the associated low consumption of precursor material and the absence of any need for other chemicals and/or solvents, therefore making it ecologically friendly. The purpose of this work was to report the capability of converting Olive oil to a solid state thin film and study its optical properties. The FTIR spectrum indicated the presence of hydroxyl groups ,methylene (ــــCH2) group , C ـــO ester group,and so on for the rest of the chemical groups, the entire range of spectra looks very similar for the Olive oil.Major optical properties are determined from analysis of absorption and emission spectra to both of pure Olive oil and prepared doped Ag sample.Absorption spectrum showed of pure olive oil has a strong two peak around wavelength at 411 nm and 690 nm, with three other weak peaks appears at wavelength around 463 nm.All these peaks are disappearing and heavily overlap one another. from absorption spectrum of doped Ag, in which it could see only wide absorption peak at 358nm.


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