Effect of gamma- irradiation on fully aromatic high performance novel thermosets and study of their physico-chemical properties

2020 ◽  
Vol 168 ◽  
pp. 108533
Author(s):  
Balakrishna Kalluraya ◽  
B.R. Kaushik ◽  
H.M. Somashekarappa
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.


2018 ◽  
Vol 316 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Érica Amanda de Barros ◽  
Vladimir Eliodoro Costa ◽  
Dayanne Fabrício Bressan ◽  
Renata Bruna dos Santos Coscolin ◽  
Rogério Lopes Vieites ◽  
...  

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.


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.


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 32 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Huynh Cang Mai ◽  
Duy Chinh Nguyen ◽  
Nguyen Phu Thuong Nhan ◽  
Long Giang Bach

Sacha inchi (Plukenetia volubilis L.) seed oil was studied for physico-chemical characteristics and chemical composition. Through gas chromatography-flame ionization (GC-FID) process, the fatty acid composition in the oil was analyzed, revealing that the oil is rich in linoleic acid (42.62 %), linolenic acid (36.32 %) and oleic acid (11.64 %). The tocopherol level in the oil was also high (7.7 ± 0.005 mg/Kg), revealed by high-performance liquid chromatography/ultraviolet-visible detector (HPLC/UV-VIS). The physico-chemical properties of the oil were also examined, including viscosity (88-92 cP), acid value (2.05 ± 0.005 mg KOH/g), saponification content (183.5 ± 1.45 mg KOH/g) and iodine value (192.4 ± 1.55 g I2/100 g). The results also indicated that sacha inchi is a health beneficial oil due to the high contents of essential fatty acids (ω-3, ω-6 and ω-9).


2020 ◽  
Vol 32 (7) ◽  
pp. 1799-1805
Author(s):  
Sheikha A. Alkhursani ◽  
Mohamed Mohamady Ghobashy ◽  
Mohamed Madani

Fluorescence label preparation, being the core of sensing and imaging, is the most interesting aspect of label technology. Using the gamma irradiation technique, a facial method is proposed to prepare organostarch consisting of polyaniline and starch. Polyaniline was introduced into starch molecules to form an inclusion complex between V-type starch and aniline monomer. The inclusion complex thus formed consisted of starch-aniline crosslink caused by gamma irradiation through organostarch crosslinks. Thus, organostarch develops fluorescence property at 470 nm possibly through the interaction of aniline and starch, which are both fluorophores. A comparative analysis of variations is performed in common fluorescent labels of starch and organostarch based on their physico-chemical properties. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectrometry were utilized to confirm the inclusion of polyaniline into starch molecules. Furthermore, using a fluorescence microscope, the positive implementation of fluorescent organostarch was verified. Fluorescent organostarch can be synthesized through this simple method and can be widely used for developing biomarkers and biosensors in food and biomedical industries. Organostarch produces florescence under mild conditions even without complicated preparations, such as additives for labelling with dye fluorescence. The intensity of fluorescence of organostarch was 17,000 times that of natural starch.


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