Engineering, Chemical Engineering, Polymers and Plastics, Environmental Engineering
10
Scopus Publications
Scopus Publications
Three different types of tea as surfactant in liquid exfoliation of graphite: Green tea, black tea and oolong tea F S Ismail, K Yusoh, A S Zainal Abidin, A H Abdullah, Z Ismail Iop Conference Series Materials Science and Engineering, 2019 Liquid phase exfoliation (LPE) with surfactant-assisted is a method to produce graphene that used water and surfactant as solvent. Tea is one of possible surfactants that can be used in LPE of graphite as it reduced the surface tension energy of water (72.75 mJ m−2) to ~40 – 50 mJ m−2which is suitable level to exfoliate graphite. Three different types of tea were used as surfactant through one-step production of graphene which were green tea (GT), black tea (BT) and oolong tea (OT). The exfoliation of graphite in each tea solutions were successful as the UV spectra of supernatant samples show peak at 270 nm which indicates the C – C bond of graphene flakes. Morphology analysis (AFM) of resulted graphene samples show that graphene sheets have sharp edges caused by sonication process. The effect of sonication time was being investigated in this work. Green tea has higher exponent factor of time (1.715) compare to black tea (1.033) and oolong tea (0.762) due to high quantity of small molecules of polyphenols present in green tea solution. Thus, it is better to used GT as surfactant in LPE of graphite compare to BT and OT.
PVA/Graphene Nanocomposite: Morphology and its Thermal Properties Abu Hannifa Abdullah, Zulhelmi Ismail, Anis Sakinah Zainal Abidin, Fadwa Sameeha Ismail, Kamal Yusoh Iop Conference Series Materials Science and Engineering, 2018 Graphene is known as a wonder materials that can be used to enhance the properties of nanocomposites. In this work, PVA/Graphene nanocomposite was fabricated using simple solution method. The photograph of the nanocomposite samples shown the transparency of the sample reduced as the graphene content increase. The photograph also shown the PVA and the modified graphene are miscible and compatible. The XRD of the samples proved the exfoliation of graphene in the nanocomposite and the result of the thermal property improvement for the sample is confirmed by the TGA.
Production of functional graphene by kitchen mixer: mechanism and metric development for in situ measurement of sheet size Zulhelmi Ismail, Abu Hannifa Abdullah, Anis Sakinah Zainal Abidin, Kamal Yusoh Journal of Nanostructure in Chemistry, 2017 It has been reported that the production of defect free graphene is possible by the application of a kitchen mixer. Yet, we note that the natural-surfactant role in the exfoliation mechanism by a kitchen mixer has rarely been discussed. To investigate the possibility of graphene exfoliation in a bio-surfactant medium, we have produced graphene from the co-mixing of graphite and gum Arabic. Through the modelling of bulky graphite as a single composite disc, we have shown that the exfoliation of graphite crystal may be possible through rotational motion of graphite surface. In this paper, we also have developed two simple metric systems that were designed from the application of UV spectroscopy for in situ measurement of graphene sheet size after exfoliation step.
Application of graphene from exfoliation in kitchen mixer allows mechanical reinforcement of PVA/graphene film Zulhelmi Ismail, Abu Hannifa Abdullah, Anis Sakinah Zainal Abidin, Kamal Yusoh Applied Nanoscience Switzerland, 2017 Mechanical properties of polyvinyl alcohol (PVA) can be reinforced from the addition of graphene into its matrix. However, pristine graphene lacks solubility in water and thus makes dispersion a challenging task. Notably, functionalisation of graphene is required to accommodate graphene presence in the water. In this work, we have used a kitchen mixer to produce gum Arabic–graphene (GGA) for the first time as filler for mechanical reinforcement of PVA. For the characterisation of exfoliated graphene, mean lateral size of GGA was measured from the imaging by transmission electron microscopy while the mean thickness of graphene was predicted from the obtained spectra by Raman spectroscopy. During the preparation of PVA/graphene film by solution casting, GGA was varied between 0, 0.05, 0.075, 0.10 and 0.15 wt% in concentration. We found that the presence of GGA in PVA improves the tensile stress and elastic modulus about 72–200 and 19–187% from the original values. The data from Halpin–Tsai meanwhile suggested that the mechanical reinforcement of PVA/graphene film is due to the random distribution network of GGA in PVA.
Black tea assisted exfoliation using a kitchen mixer allowing one-step production of graphene Zulhelmi Ismail, Nurul Farhana Abu Kassim, Abu Hannifa Abdullah, Anis Sakinah Zainal Abidin, Fadwa Sameha Ismail, Kamal Yusoh Materials Research Express, 2017 A kitchen mixer is one of the possible tools for the exfoliation of graphene. While organic solvents such as NMP or DMF are suitable for the exfoliation of graphite, the majority are toxic and dangerously harmful when exposed to humans and the environment. Therefore, an alternative solvent must be proposed for green and sustainable production of graphene. In this initial work, we have developed a new synthesis method for graphene through the direct exfoliation of graphite in commercial black tea. We found that our maximum yield concentration of graphene is Y = 0.032 mg ml−l after 15 min of mixing. From the data of Raman, the level of defects in our produced graphene is suggested as being very minor (ID/IG = 0.17), despite possible graphene functionalization by oxygen groups in tea. Incorporation of our graphene into PMMA results in shifting the onset temperature from 300 °C to 326 °C, which impressively validates the potential of the produced graphene as a thermal reinforcement material for polymer composites.
Enhanced performance of alkylated graphene reinforced polybutylene succinate nanocomposite A. S. Zainal Abidin, K. Yusoh, S. S. Jamari, A. H. Abdullah, Z. Ismail Aip Conference Proceedings, 2016 Polybutylene succinate (PBS) was being grafted with octadecylamine-functionalized graphene oxide (GO-ODA) to produce novel PBS/GO-ODA nanocomposites by solution blending technique. Alkylated graphene oxide has superhydrophobic surface thus improved the affinity of the filler with low polar polymer such as PBS. The structure and compatibility of the filler and nanocomposites were being characterized using Fourier transform infrared spectroscopy (FTIR), Universal tensile machine (UTM) and thermogravimetric analysis (TGA). Enhancement of tensile strength and Young’s modulus by 30% and 165% respectively was achieved with cooperation of 0.5% GO-ODA loading. The functionalization of GO-ODA in PBS matrix leads to the improvement in the nanocomposites properties.
Irradiation cross-linking of ethylene vinyl acetate/waste tire dust: Effect of multifunctional acrylates Chantara Thevy Ratnam, Suganti Ramarad, Mohd Khalid Siddiqui, Anis Sakinah Zainal Abidin, Luqman TG Chuah Journal of Thermoplastic Composite Materials, 2016 In an attempt to maximize the beneficial effect of irradiation, the influence of multifunctional acrylates (MFAs) such as trimethylol propane triacrylate, ethylene glycol dimethacrylate, trimethylol propane trimethacrylate, and tripropylene glycol diacrylate on the 90/10 ethylene vinyl acetate/waste tire dust (EVA/WTD) were studied. The 90/10 EVA/WTD and EVA-containing 4 phr MFA prepared using a Haake mixer at 140°C and 50 r min−1 rotor speed. The blends were then irradiated using a 3.0-MeV electron beam machine. Results on gel fraction revealed that EVA/WTD blends were cross-linked by electron beam irradiation. Among the MFA employed in this studies, TPGDA was found to render highest tensile strength with the best retention in elongation at break and increased heat of fusion and crystallinity of blends upon irradiation. The changes in the properties of EVA/WTD blends upon irradiation are attributed to the cross-linking of the EVA matrix. The changes in crystallinity and crystalline melting temperatures of EVA/WTD blends upon irradiation are discussed in detail.
Effect of multifunctional acrylates (MFA) on the electron beam irradiated ethylene vinyl acetate/waste tyre dust 8th Asian Australasian Conference on Composite Materials 2012 Accm 2012 Composites Enabling Tomorrow S Industry Today, 2012
