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1 – 4 of 4Faisal K. Algethami, Hadi M. Marwani, Abdullah M. Asiri and Mohammed M. Rahman
The purpose of this study is to prepare various CeO2-based carbon material (CNT, CB, GO) nanocomposites through a wet chemical process for the development of a sensor probe to…
Abstract
Purpose
The purpose of this study is to prepare various CeO2-based carbon material (CNT, CB, GO) nanocomposites through a wet chemical process for the development of a sensor probe to detect various environmental toxins by using an electrochemical approach under room temperature conditions. A comparative study on sensitive and selective phenolic sensor (4-methoxyphenol; 4-MP) has been fabricated by modifying a glassy carbon electrode (GCE) with various nanocomposites (NCs) such as CeO2, CeO2–CNT (carbon nanotubes), CeO2–CB (carbon black) and CeO2–GO (graphene oxide) NCs.
Design/methodology/approach
The CeO2–CNT NCs were prepared by the wet chemical method at low temperature. NCs were characterized by various methods such as transmission electron microscopy (TEM), Fourier-transform infra-red (FTIR), ultra-violet/visible (UV-Vis) spectroscopy and XRD (X-ray diffraction). CeO2–CNT NCs were immobilized as a film on the flat surface of the GCE by using binders (5% Nafion). The electrochemical measurements of the 4-MP detection with the CeO2–CNT NCs/Nafion/GCE sensor were studied by the current-voltage method.
Findings
In the optimal conditions, the sensitivity, detection limit and limit of quantification of 4-MP sensor probe were found to be 47.56 µAcm-2 µM−1, 12.0 ± 0.2 nM and 40.0 ± 0.5 nM (S/N of 3), respectively.
Research limitations/implications
This electrochemical sensor showed an acceptable analytical performance in the detection of 4-MP with higher sensitivity, lower detection limit, large dynamic concentration range, good reproducibility and fast response time.
Practical implications
This electrochemical approach can be applied practically for the determination of selective 4-MP in real environmental and extracted samples.
Social implications
CeO2–CNT NCs/Nafion/GCE sensor probe was used for the safety of environmental and health-care fields at larger scales.
Originality/value
This electrochemical approach is a significant achievement on the development of sensor probe. The results are indicated as being technically detailed with an up-to-date account of recent chemical sensor research studies.
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Emiliana Rose Jusoh Taib, Luqman Chuah Abdullah, Min Min Aung, Mahiran Basri, Mek Zah Salleh, Sariah Saalah, Suhaini Mamat, Ching Yern Chee and Jia Li Wong
This paper aims to demonstrate the synthesis of polyesterification reaction of non-edible jatropha seed oil (JO) and acrylic acid, which leads to the production of acrylated…
Abstract
Purpose
This paper aims to demonstrate the synthesis of polyesterification reaction of non-edible jatropha seed oil (JO) and acrylic acid, which leads to the production of acrylated epoxidised-based resin. To understand the physico-chemical characteristics when synthesis the JO-based epoxy acrylate, the effect of temperature on the reaction, concentration of acrylic acid and role of catalyst on reaction time and acid value were studied.
Design/methodology/approach
First, the double bond in JO was functionalised by epoxidation using the solvent-free performic method. The subsequent process was acrylation with acrylic acid using the base catalyst triethylamine and 4-methoxyphenol as an inhibitor respectively. The physico-chemical characteristics during the synthesis of the epoxy acrylate such as acid value was monitored and analysed. The formation of the epoxy and acrylate group was confirmed by a Fourier transform infrared spectroscopy spectra analysis and nuclear magnetic resonance analysis.
Findings
The optimum reaction condition was achieved at a ratio of epoxidised JO to acrylic acid of 1:1.5 and the reaction temperature of 110°C. This was indicated by the acid value reduction from 86 to 15 mg KOH/g sample at 6 hours.
Practical implications
The JO-based epoxy acrylate synthesised has a potential to be used in formulations the prepolymer resin for UV curable coating applications. The JO which is from natural resources and is sustainable raw materials that possible reduce the dependency on petroleum-based coating.
Originality/value
The epoxidised jatropha seed oil epoxy acrylate was synthesised, as a new type of oligomer resin that contains a reactive acrylate group, which can be alternative to petroleum-based coating and can used further in the formulation of the radiation curable coating.
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M. Bajpai, V. Shukla, D.K. Singh, M. Singh and R. Shukla
Development of new radiation‐curable materials for the application in radiation curing technology is of significant importance. Most of the commercially available…
Abstract
Development of new radiation‐curable materials for the application in radiation curing technology is of significant importance. Most of the commercially available radiation‐curable resins are derived from synthetic raw materials. The synthesis of acrylated, epoxidised soybean oil (ESO) from ESO had been carried out by reacting acrylic acid with the oxirane group in ESO. The acrylated ESO products were characterised using a variety of analytical techniques. Thus, the oxygen value, the iodine value, the acid value and the infrared spectra of the acrylated ESO products were obtained. Pigmented acrylated ESO systems were prepared and found to cure on exposure to UV radiation.
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Jyoti Srivastava and Padma S. Vankar
This paper aims to study carotenoids as a natural food colorant from Canna flowers. There is a growing demand for eco-friendly and non-toxic colorants, specifically for…
Abstract
Purpose
This paper aims to study carotenoids as a natural food colorant from Canna flowers. There is a growing demand for eco-friendly and non-toxic colorants, specifically for health-sensitive applications such as colours of food and textiles. Red Canna variety can be grown in normal garden situations and gives ample of flowers yielding good amount of natural colorant for both the purposes.
Design/methodology/approach
In the present work, ultrasound extraction of natural colorant from Canna indica flowers has been studied. The use of ultrasound is found to have a significant improvement in the extraction efficiency of colorants obtained from dry and fresh Canna flowers in different mediums. Ultrasonic cavitational processing has twofold advantages, it is an eco-friendly and cost-effective process.
Findings
The total carotenoid content in dry and fresh flower extract was found to be between 136.56 and 978.89 mg/kg. The assessment of antioxidant activity (AOA) in dry and fresh flower extract was found to be 5.78-78.33 per cent assayed by scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and identified by electron paramagnetic resonance (EPR) studies.
Research implications/limitations
The use of ultrasonication for the extraction of colorant has been the main feature and a step towards technological advancement in the area of finding newer method of efficient extraction of the colorant.
Practical implications
The ease of extraction due to ultrasound waves has been the highlight.
Originality/value
It is for the first time that the phytochemical data of red Canna flower and has been studied, the total carotenoid content and antioxidant activities of different extracts of Canna were measured. The extraction of natural dye from C. indica flowers using ultrasound has been found to have significant improvement in the extraction efficiency of the colorant obtained from flowers.
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