scholarly journals Wet-chemical method for the metallization of a para-aramid filament yarn wound on a cylindrical dyeing package

2016 ◽  
Vol 87 (10) ◽  
pp. 1192-1202 ◽  
Author(s):  
Toty Onggar ◽  
Gosbert Amrhein ◽  
Anwar Abdkader ◽  
Rolf-Dieter Hund ◽  
Chokri Cherif

High-performance yarns such as aramid fibers are nowadays used to reinforce composite materials due to their advantageous physico-chemical properties and their low weight. They are also resistant to heat and fire. Para-aramid filament yarns (p-AFs) wound on a cylindrical dyeing package have been silvered successfully by means of a newly developed wet-chemical filament yarn metallization process on a laboratory scale. The surface morphology of untreated and silvered p-AF was determined by means of scanning electron microscopy. The chemical structure of the surfaces (contents of carbon, oxygen, nitrogen and silver) was determined by means of energy-dispersive X-ray spectroscopy (EDX). The eliminated and newly formed groups of p-AF before and after silvering were detected by infrared spectroscopy (Fourier transform—attenuated total reflectance). After metallization, the silver layer thickness, the mass-related silver content and washing and rubbing fastness were assessed. Furthermore, textile-physical examinations concerning Young's modulus, elongation at break and electrical conductivity were performed. Subsequently, the electrically conductive p-AFs were integrated in thermoset composite materials reinforced by glass fibers and para-aramid.

2014 ◽  
Vol 70 (2) ◽  
Author(s):  
Mohamad Azuwa Mohamed ◽  
Wan Norharyati Wan Salleh ◽  
Juhana Jaafar ◽  
Norhaniza Yusof

The evolution of desirable physico-chemical properties in high performance photocatalyst materials involves steps that must be carefully designed, controlled, and optimized. This study investigated the role of key parameter in the preparation and photocatalytic activity analysis of the mixed phase of anatase/rutile TiO2 nanoparticles, prepared via sol-gel method containing titanium-n-butoxide Ti(OBu)4 as a precursor material, nitric acid as catalyst, and isopropanol as solvent. The prepared TiO2 nanoparticles were characterized by means of XRD, SEM, and BET analyses, and UV-Vis-NIR spectroscopy. The results indicated that the calcination temperature play an important role in the physico-chemical properties and photocatalytic activity of the resulting TiO2 nanoparticles. Different calcination temperatures would result in different composition of anatase and rutile. The photocatalytic activity of the prepared mixed phase of anatase/rutile TiO2 nanoparticles was measured by photodegradation of 50 ppm phenol in an aqueous solution. The commercial anatase from Sigma-Aldrich and Degussa P25 were used for comparison purpose. The mixed phase of anatase/rutile TiO2 nanoparticles (consists of 38.3% anatase and 61.7% rutile) that was prepared at 400°C exhibited the highest photocatalytic activity of 84.88% degradation of phenol. The result was comparable with photocatalytic activity demonstrated by Degussa P25 by 1.54% difference in phenol degradation. The results also suggested that the mixed phase of anatase/rutile TiO2 nanoparticles is a promising candidate for the phenol degradation process. The high performance of photocatalyst materials may be obtained by adopting a judicious combination of anatase/rutile and optimized calcination conditions.


2014 ◽  
Vol 983 ◽  
pp. 39-43
Author(s):  
M. A. Alaa ◽  
Kamal Yusoh ◽  
S.F. Hasany

Petroleum based polyurethanes are contributing major portions in the world requirement. To overcome the environmental issues and price adaptability, there is always a massive demand of utilization of renewable resources for polyurethane synthesis with comparable physico-chemical properties. Castor oil is the only major natural vegetable oil that contains a hydroxyl group (-OH) and unsaturated double bonds (C=C) in its organic chain and therefore can be employed with or without modification due to the excellent properties derived from the hydrophobic nature of triglycerides. In this study, physico-chemical properties of high performance polyurethane synthesized from Poly propylene glycol (PPG) in comparison with a combination of PPG and Castor oil (a renewable source), by in situ polymerization technique has been studied. The variations in properties of both types of polyurethanes are evaluated by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Thermogravimetric analysis technique (TGA). Tensile strength properties were investigated by Film Tensile testing equipment. Results indicated the presence of large-CH stretching in castor oil mixed polyurethane with a larger oxidative thermal stability, over a pure PPG polyurethanes. Tensile properties were found almost comparable in pure and mixed polymers, which signify the usage of mixed polymer in coming future, to overcome the environmental and economical crisis in polyurethanes synthesis.


2020 ◽  
Vol 4 (2) ◽  
pp. 42 ◽  
Author(s):  
Ignazio Blanco

Nowadays, all production, from the smallest ones to large companies, and research activities are affected by the use of 3D printing technology. The major limitation, in order to cover as many fields of application as possible, is represented by the set of 3D printable materials and their limited spectrum of physico-chemical properties. To expand this spectrum and employ the 3D-printed objects in areas such as biomedical, mechanical, electronical and so on, the introduction of fibers or particles in a polymer matrix has been widely studied and applied. In this review, all those studies that proposed modified polymer presenting advantages associated with rapid prototyping are reported.


2017 ◽  
Vol 10 (1) ◽  
pp. 30-40 ◽  
Author(s):  
Satveer Singh ◽  
Sartaj A. Bhat ◽  
Jaswinder Singh ◽  
Rajinder Kaur ◽  
Adarsh P. Vig

Aims and Objectives:The present study was conducted to utilize the Milk Processing Industry Sludge (MPIS) for the purpose of vermicomposting, in two sets of experimentsviz. with earthworms (ME) and without earthworms (MW).Methods and Materials:Twenty young non-clitellatedEisenia fetidawere released in each tray. The various parameters like growth, clitellum development, biomass, cocoon production and hatchlings ofE. fetidawere observed after every 15 days, during 90 days of vermicomposting.Results:The maximum growth and better responses were observed in ME25mixtures of MPIS which was the minimum ratio of the waste to CD. The physico-chemical analysis (pH, EC, TKN, TOC, C/N ratio, TAP, TK, TNa) and heavy metals (Cr, Cu, Mn, Pb) were also done before and after vermicomposting process. There was a significant increase in TKN (23-46%), and TAP (39-47%), and a decrease in pH (6.2-6.8%), EC (24.6-37.2%), TOC (16.8-37.9%), C/N ratio (23.8-97.9%), TK (26.6-40.6%), and TNa (31.3-53%) and heavy metals (Cr 30.9-40.6%, Cu 32.7-44.6%, Mn 23.9-36.3%, and Pb 32.6-42.9%) from initial to final feed mixtures with earthworms.Conclusion:Thus the final vermicompost had excellent physico-chemical properties with all nutrients in plant available forms. The study further strengthens that the vermicomposting is an efficient technique in converting MPIS into nutrient rich biomanure in a short period of timei.e. 90 days.


Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 89 ◽  
Author(s):  
Jian Li ◽  
Pablo Jiménez-Calvo ◽  
Erwan Paineau ◽  
Mohamed Nawfal Ghazzal

The photo-conversion efficiency is a key issue in the development of new photocatalysts for solar light driven water splitting applications. In recent years, different engineering strategies have been proposed to improve the photogeneration and the lifetime of charge carriers in nanostructured photocatalysts. In particular, the rational design of heterojunctions composites to obtain peculiar physico-chemical properties has achieved more efficient charge carriers formation and separation in comparison to their individual component materials. In this review, the recent progress of sulfide-based heterojunctions and novel nanostructures such as core-shell structure, periodical structure, and hollow cylinders is summarized. Some new perspectives of opportunities and challenges in fabricating high-performance photocatalysts are also discussed.


In previous communications on this subject (20, 21, 22) we described the results obtained when coloured indicators of known physico-chemical properties were injected into individual living cells. Using a modification of the micromanipulator of Chambers (4), we have worked with various unicellular protozoa and egg-cells, and have been able to draw definite conclusions as to the average hydrogen-ion concentration and the average oxidation-reduction potential of the cell interior. Our first communication dealt with the amœba, and we showed that its internal p H was probably in the neighbourhood of 7.6, while its internal r H (oxidation-reduction potential, 5) was between 17 and 19. Both values are near neutrality, so that this cell could be said to be slightly alkaline and slightly on the electronegative or reducing side of oxidation-reduction neutrality. We next extended our investigation to several types of marine egg-cells before and after fertilisation, and during the early cleavage stages. The changes which the internal p H and r H undergo during these ontogenetic events are very small indeed, and the phylogenetic differences, for example, as between the ovum of the polychsete worm and that of the starfish are correspondingly slight. The egg-cell, then, appeared to have a of about 6.6 and an r H of the order of 21 or 22. It was therefore a little on the acid side of acidbase neutrality and a little on the electropositive side of oxidation-reduction neutrality, differing on both these counts from the amœba. The amœba, therefore, has a higher intensity of reduction than the egg-cell.


ChemInform ◽  
2010 ◽  
Vol 24 (25) ◽  
pp. no-no
Author(s):  
N. V. ZHURAVLEVA ◽  
K. I. SAKODYNSKII ◽  
M. A. KUKLINA ◽  
V. M. KUKLIN ◽  
N. N. SUKHANOV

2019 ◽  
Vol 11 (2) ◽  
pp. 77
Author(s):  
Abba Paltahe ◽  
Tsamo Cornelius ◽  
Balkissou Sambo ◽  
Djaoyang Christian ◽  
Téri Téri ◽  
...  

This paper presents the variation in physico-chemical properties of a local Maroua tannery effluent before and after a flocculation treatment. Tanning is a process that consists of the transformation of the animal skin into leather by using different baths which contain many chemical reagents and produces high quantity of liquid and solid waste. The used water of traditional tannery of Maroua is directly thrown in nature without any pre-treatment posing a potential risk to the environment and human health. Physico-chemical parameters such as temperature, pH and conductivity, Total suspended solids, Total hardness, chlorides, sulfides, nitrates,COD, BOD5 , ammonium ion, dissolve oxygen, turbidity, colour and odour were determined before and after aluminum sulfate powder flocculation treatment for effluents collected from soaking, liming, deliming and vegetable tanning stages of the tannery process. The results obtained showed that most of the physico-chemical parameters are higher than the international standard. The results obtained made it possible to classify these four effluents in order of toxicity as follows: Liming water > vegetable tanning water > deliming water > soaking water. The treatment of these waste waters by flocculation reduces the concentrations of certain pollutant loads such as TSS, turbidity, hardness, COD, BOD5, sulfate; but remains less effective on others such as nitrate, chloride and ammonium ion (8%). There is also a decrease in pH, an increase in dissolved oxygen and conductivity. The flocculation treatment thus considerably reduced the toxicity of these effluents, especially its organic load.


Author(s):  
Dr. Shashikant Pardeshi

Oils and fats for commercial frying applications can lead the changes caused by oxidation, polymerization, or hydrolysis during high-temperature processing. Deep frying is one method which involves submerging the food in hot oil. During oxidation can lead to the formation of potentially toxic oxidation products. This lipid per oxidation products generates that may be harmful to human health and it is necessary to monitoring of the frying oil quality degradation, therefore, is an important issue for both food frying operators and food control/regulatory agencies. In this study, The changes in the physicochemical properties of eight different brands of sunflower oils were analysed (before and after frying) using standard procedures of AOAC and AOCS. The experimental results obtained that,RI and specific gravity and colour were in the range of 1.4658-1.4720,0.9018-0.8848 and1.82-16.6 before and after frying. AV and PV were ranged between 0.22-0.54 in fresh oils,0.85-1.21in after frying and 2.4-4.1and 8.18- 13.15 mg KOH/g before and after frying oil while SV and EV were ranged between 189.98-193.12 and 189.62- 192.67 mg KOH/g oil in fresh oils and in between 198.68- 202.18 and 197.71-200.97mg KOH/g oil in after frying oils respectively. P-AV and TV were in the range of 3.9- 5.01 and 8.79-13.21 in before frying while in case of after frying it is 9.16-13.15 and 25.52-38.55 meq/kg respectively. In general, after frying, RI, colour,AV,PV,P-anisidine and totox values were found higher and deviates codex standards and specific gravity and iodine values are lower than as compared with safety limit. The results showed degradation in the physico-chemical properties of the vegetable cooking oil after frying


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