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Simplified search suggestions : Azmi Mohamed

Synthesis and characterisation of metallosurfactants as Carbon Dioxide viscosity modifier

R Abdosalam Khadega, Mohamed Azmi,

Article Published 2017 1054 hits Available

The synthesis of zinc oxide/carbon spheres nanocomposites and field electron emission properties

Abu Bakar Suriani, Alfarisa Suhufa, Mohamed Azmi, Hashim Norhayati,

Article Published 2017 4026 hits Limited

Magnetic and phase behavior of magnetic water-in-oil microemulsions

Brown Paul, Mohamed Azmi, Ardyani Tretya, Rogers Sarah E., Eastoe Julian,

Article Published 2017 1516 hits Limited

Fabrication and application of composite adsorbents made by one-pot electrochemical exfoliation of graphite in surfactant ionic liquid/nanocellulose mixtures

Azmi Mohamed

Abstract

Previously, surfactant-assisted exfoliated graphene oxide (sEGO) formed with the triple-chain surfactant TC14 (sodium 1,4-bis(neopentyloxy)-3-(neopentylcarbonyl)-1,4-dioxobutane-2-sulfonate) was applied in wastewater treatment. The extent of dye-removal and the adsorption capacity of the sEGO formed with this triple-chain surfactant outperformed those of two other systems, namely, the di-chain version of TC14 (AOT14; sodium 1,2-bis-(2,2-dimethyl-propoxycarbonyl)-ethanesulfonate) and the single-chain surfactant sodiumn-dodecylsulfate. In the present study, to further optimise the surfactant chemical structure, the sodium ion of TC14 was substituted with 1-butyl-3-methyl-imidazolium (BMIM) generating surfactant ionic liquids (SAILs; 1-butyl-3-imidazolium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulfonate), hereafter denoted as BMIM-TC14. This SAIL, together with nanofibrillated kenaf cellulose (NFC), was used to electrochemically exfoliate graphite, yielding BMIM-.....

Article Published 2021 1908 hits Available

Optimizing chemical structure of surfactant for graphene exfoliation method for nanoelectronic devices applications

Azmi Mohamed

Abstract

A facile electrochemical exfoliation method was established to efficiently prepare conductive paper containing reduced graphene oxide (RGO) with the help of dodecyl anionic and cationic surfactant. For the first time the combination of ionic surfactants and cellulose was used to directly exfoliate graphite. A thorough investigation using electron microscopy and Raman spectroscopy highlights the presence of uniform graphene incorporated inside the matrix. Studies into aqueous aggregation behavior between graphene and cellulose and is responsible for the enhanced exfoliation level and stabilization of the resulting dispersion. Interestingly, the cationic surfactant DTAB proved to be more efficient for stabilization of RGO in nanofibrillated kenaf cellulose than the anionic SDS. The simple and feasible process for producing conductive paper here is attractive for the possibility of scaling-up this technique for mass production of conductive composite containing graphene or other.....

Research Report Published 2019 998 hits Available

A facile surfactant-assisted synthesis of graphene oxide/zinc oxide catalyst for the degradation of methylene blue dye

Azmi Mohamed

Abstract

In this work, electrochemically exfoliated graphene oxide-based photocatalyst was synthesised with the help of single- (sodium dodecyl sulphate; SDS) and triple-chain (sodium 1,4-bis(neopentyloxy)-3-(neopentylcarbonyl)-1,4-dioxobutane-2-sulfonate; TC14) anionic surfactants. The hybrid photocatalyst is a system consisting of surfactant-assisted electrochemically exfoliated graphene oxide (sEGO) and zinc oxide (ZnO). The system was prepared by exfoliating graphite in the presence of surfactant and ZnO, and it was used for the removal of methylene blue (MB) dye. Of these different surfactants, the triple-chain TC14 exhibited 98.53% MB removal, which was significantly higher than the system with SDS surfactant (50.94%) or ZnO alone (42.33%). Observations through field-emission scanning electron microscopy suggested an enhanced exfoliation degree upon increasing the number of surfactant chains. Results from zeta potential measurement also revealed increased system stability along with a hig.....

Article Published 2024 587 hits Available

Thickening supercritical CO2 at high temperatures with rod-like reverse micelles

Azmi Mohamed

Abstract

Earlier studies demonstrated the ability of some fluorinated surfactants to form rod-like reverse micelles with the ability to thicken water/supercritical CO2 (scCO2) mixtures at temperatures below 45 ºC [Langmuir 26 (2010) 83–88. Soft Matter 8 (2012) 7044–7055. Colloids and Surfaces B, 168 (2018), 201–210.]. Such viscosity enhancement of scCO2 is known to increase sweep efficiency for oil recovery with CO2 flooding. However, temperatures of up to ∼100 ºC in conventional reservoirs are much higher than those employed in laboratory studies, and tend to weaken inter- and intra-molecular interactions between surfactant molecules, discouraging rod-like reverse micelle formation. With the aim of designing surfactants which form rod-like reverse micelles and thicken CO2 at high temperatures, this study examined phase behavior, nanostructures of reverse micelles and thickening ability of double ω-hydroperfluorocarbon-tail anionic surfactants in W/scCO2 mixtures at temperatures of 3.....

Article Published 2024 388 hits Available

Improved low concentration water content detection in biodiesel utilizing phase shift-based capacitive method

Azmi Mohamed

Abstract

Biodiesel has become an alternative fuel to substitute conventional fuel, yet challenges remain, particularly concerning water content. The presence of water in biodiesel can negatively impact engine spray and combustion properties and may lead to damage storage tanks. To address this issue, a phase-shift-based capacitive sensor was developed in this study to accurately measure water concentration in biodiesel. The sensor, designed with a semicylindrical electrode on a glass tube, is integrated with a signal conditioning circuit and the Digilent Analog Discovery module, allowing for real-time data analysis and enhanced sensitivity in detecting low concentrations of water concentration in biodiesel. The experimental results demonstrated a direct correlation between capacitance values and phase shift, with higher capacitance leading to more significant phase shifts. A Bode plot and simulation analysis, utilizing the transfer function, validated these experimental conditions, confirming t.....

Article Published 2024 582 hits Available

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