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Simplified search suggestions : Norhayati Hashim

Zinc/aluminium–quinclorac layered nanocomposite modified multi-walled carbon nanotube paste electrode for electrochemical determination of bisphenol A

Norhayati Hashim

Abstract

This paper presents the application of zinc/aluminium-layered double hydroxide-quinclorac (Zn/Al-LDH-QC) as a modifier of multiwalled carbon nanotubes (MWCNT) paste electrode for the determination of bisphenol A (BPA). The Zn/Al-LDH-QC/MWCNT morphology was examined by a transmission electron microscope and a scanning electron microscope. Electrochemical impedance spectroscopy was utilized to investigate the electrode interfacial properties. The electrochemical responses of the modified electrode towards BPA were thoroughly evaluated by using square-wave voltammetry technique. The electrode demonstrated three linear plots of BPA concentrations from 3.0 × 10−8–7.0 × 10−7 M (R2 = 0.9876), 1.0 × 10−6–1.0 × 10−5 M (R2 = 0.9836) and 3.0 × 10−5–3.0 × 10−4 M (R2 = 0.9827) with a limit of detection of 4.4 × 10−9 M. The electrode also demonstrated good reproducibility and stability up to one month. The presence of several metal ions and organic did not affect the elect.....

Article Published 2019 6196 hits Available

Synthesis and characterisation of Zinc/Aluminium-Layered Double Hydroxide-L-Phenylalanate Nanocomposites using ION exchange method

Mohd Sharif Sharifah Norain, Hashim Norhayati, Md Isa Illyas, Mohd Ali Noorshida, Muhamad Damanhuri Muhd Ibrahim,

Article Published 2017 3625 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 4038 hits Limited

Controlled release formulation of an anti-depression drug based on a L-phenylalanate-zinc layered hydroxide intercalation compound

Norhayati Hashim

Abstract

The intercalation of L-phenylalanate (LP) into the interlayer gallery of zinc layered hydroxide (ZLH) has been successfully executed using a simple direct reaction method. The synthesised intercalation compound, zinc layered hydroxide-L-phenylalanate (ZLH-LP), was characterised using PXRD, FTIR, CHNS, ICP-OES, TGA/ DTG, FESEM and TEM. The PXRD patterns of the intercalation compound demonstrate an intense and symmetrical peak, indicating a well-ordered crystalline layered structure. The appearance of an intercalation peak at a low angle of 2θ with a basal spacing of 16.3 Å, signifies the successful intercalation of the Lphenylalanate anion into the interlayer gallery of the host. The intercalation is also validated by FTIR spectroscopy and CHNS elemental analysis. Thermogravimetric analysis confirms that the ZLH-LP intercalation compound has higher thermal stability than the pristine L-phenylalanine. The observed percentage of Lphenylalanate accumulated release varies in each release .....

Article Published 2017 770 hits Limited

Preparation of zinc layered hydroxide-chloroacetate nanohybrid using direct reaction method

Norhayati Hashim

Abstract

The intercalation of chloroacetic acid (CAA) into the interlayer gallery of zinc layered hydroxide has been achieved via a facile direct reaction method. The nanohybrid synthesised, zinc layered hydroxide-chloroacetate was characterised using Powder X-ray diffraction patterns (PXRD), which demonstrated the progressive evolution of the nanohybrid structure, as the CAA molarity were increased from 0.05 to 0.3 M. Sharp and symmetrical peaks of 0.3 M CAA were observed in the PXRD pattern. The emergence of intercalation peak, with basal spacing of 14.3 Å signifying the success intercalation of chloroacetate anions into the interlayer space of the host.The intercalation was also validated by FTIR spectroscopy and CHNS elemental analyser. The increased thermal stability of zinc layered hydroxide-chloroacetate nanohybrid was confirmed by thermogravimetric analysis..

Article Published 2017 767 hits Limited

The effect of ion exchange and co-precipitation methods on the intercalation of 3-(4-methoxyphenyl)propionic acid into layered zinc hydroxide nitrate

Norhayati Hashim

Abstract

A new compound, namely zinc hydroxide nitrate-3-(4-methoxyphenyl)propionate (ZHN-MPP) nanocomposite, was prepared using the ion exchange and coprecipitation methods. The resulting nanocomposite was composed of the herbicide MPP sandwiched between ZHN inorganic layers. From PXRD results, the intercalation of MPP anions into the interlayer of ZHN was successful, leading to the expansion of the interlayer of ZHN at 26.9 and 26.1 Å with the ion exchange and co-precipitation methods respectively. The intercalation of layered material is confirmed by PXRD pattern. FTIR spectra for both nanocomposites revealed the presence of MPP in the interlayer of ZHN-MPP nanocomposites. Based on TGA/DTG analysis, the ZHN-MPP nanocomposite prepared by the ion exchange method was found to have greater thermal stability than the one synthesized by the co-precipitation method. The intercalation was also supported by ICP-OES and CHNO-S analysis, which confirmed the presence of C and Zn in the resultant nanoco.....

Article Published 2017 816 hits Limited

Controlled release formulation of zinc hydroxide nitrate intercalated with sodium dodecylsulphate and bispyribac anions: a novel herbicide nanocomposite for paddy cultivation

Norhayati Hashim

Abstract

Bispyribac (BP) anions have been successfully intercalated in the interlayer region of zinc hydroxide nitrate (ZHN) in the presence of sodium dodecylsulphate (SDS) surfactant. The physicochemical properties of the intercalation compound ZHN–SDS–BP have been characterised herein with different instrumental techniques. The intercalation of BP and SDS is clearly reflected in the PXRD analysis, based on the appearance of symmetrical, sharp and intense intercalation peaks at lower 2h with a basal spacing of 28.2–28.6 A? . The thermal studies show that the ZHN–SDS– BP nanocomposite has better thermal stability than the pristine BP. The intercalation of BP leads to significant changes in the surface area, porosity, and morphology. Nitrogen adsorption–desorption isotherms reveal that both ZHN–SDS and ZHN–SDS–BP are of Type IV. The release and kinetic studies were also carried out on the ZHN–SDS–BP, in aqueous solution of Na3PO4, Na2-SO4 and NaCl as the release media. The .....

Article Published 2019 1189 hits Available

Release behavior of dichlorprop from zn/al-ldh-dichlorprop nanocomposite into chloride, carbonate and phosphate solutions

Norhayati Hashim

Abstract

A release study of dichlorprop phenoxyherbicides from the interlayer of a Zn/Allayered double hydroxide-dichlorprop nanocomposite was performed with various concentrations of sodium chloride, sodium carbonate and sodium phosphate and a mixture of sodium chloride, sodium carbonate and sodium phosphate in aqueous solution. The release study of dichlorprop showed that release is dependent on the concentration of the aqueous solution. The accumulated release percentage of dichlorprop phenoxyherbicides into the solution was found to be higher in solutions containing carbonate, phosphate, and a mixture of carbonate or phosphate anions. Confirmation of the releaseprocess was confirmed by the PXRD pattern of the powder recovered from highly concentrated solutions of sodium chloride, sodium carbonate, and sodium phosphate with basal spacing of 7.8 Å, 7.6 Å and 7.4 Å, is due to chloride, carbonate, and phosphate intercalation, respectively. The kinetic study revealed that dichlorprop release .....

Article Published 2019 743 hits Available

Surfactant-assisted imidacloprid intercalation of layered zinc hydroxide nitrate:synthesis, characterisation and controlled resease formulation

Norhayati Hashim

Abstract

A neutrally charged insecticide, imidacloprid (IC), has been intercalated into zinc hydroxide nitrate (ZHN) with the assistance of sodium dodecylsulphate (SDS). The presence of SDS assists the intercalation of IC by forming a hydrophobic region in the interlayer gallery of ZHN. The intercalated compound, ZHN–SDS–IC, was characterised using powder X-ray difraction (PXRD), thermogravimetric analysis, Fourier transform infrared spectroscopy, elemental analysis, feld emission scanning electron microscopy, and gas sorption analysis. The PXRD studies demonstrated intercalation peaks at lower 2θ, which confrmed the intercalation of IC and SDS in the interlayer gallery of ZHN. The release and kinetic studies of ZHN–SDS–IC reveals that the IC were successfully released in controlled manner (with release time up to 1478 min), and were governed by pseudo second order kinetic model. The ZHN–SDS–IC synthesised is hopefully benefcial in overcoming the consequences of excessive usage of .....

Article Published 2019 802 hits Available

Carboxymethylcellulose-coated magnesium-layered hydroxide nanocomposite for controlled release of 3-(4-methoxyphenyl)propionic acid

Norhayati Hashim

Abstract

Carboxymethylcellulose (CMC) acts as a coating material for a magnesium-layered hydroxide-3-(4-methoxyphenyl)propionate (MLH-MPP) nanocomposite via spontaneous selfassembly. The resulting product is called a magnesium-layered hydroxide-3-(4-methoxyphenyl)pro pionate/carboxymethylcellulose (MLH-MPP/CMC) nanocomposite. The XRD pattern of the MLH-MPP/CMC nanocomposite showed that MPP was maintained in the interlayers of the MLH, thus confirming that CMC is only deposited on the surface of the MLH-MPP nanocomposite. These findings were also supported by FTIR spectra, SEM and TEM. TGA data showed that the thermal stability of the intercalated MPP was significantly enhanced compared to pure MPP and uncoated nanocomposite. The release of MPP from the interlayers of MLH-MPP/CMC nanocomposite showed slower release than did uncoated nanocomposite and followed pseudo– second-order kinetics. Since the herbicide, MPP was released from the synthesised nanocomposite in a sustained manner, thus, it .....

Article Published 2020 1419 hits Available

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