Tariq Altalhi
Taif University
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Publication
Featured researches published by Tariq Altalhi.
Membranes | 2010
Tariq Altalhi; Milena Ginic-Markovic; Ninghui Han; Stephen Clarke; Dusan Losic
Carbon nanotubes are attractive approach for designing of new membranes for advanced molecular separation because of their unique transport properties and ability to mimic biological protein channels. In this work the synthetic approach for fabrication of carbon nanotubes (CNTs) composite membranes is presented. The method is based on growth of multi walled carbon nanotubes (MWCNT) using chemical vapour deposition (CVD) on the template of nanoporous alumina (PA) membranes. The influence of experimental conditions including carbon precursor, temperature, deposition time, and PA template on CNT growth process and quality of fabricated membranes was investigated. The synthesis of CNT/PA composites with controllable nanotube dimensions such as diameters (30–150 nm), and thickness (5–100 μm), was demonstrated. The chemical composition and morphological characteristics of fabricated CNT/PA composite membranes were investigated by various characterisation techniques including scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDXS), high resolution transmission electron microscopy (HRTEM) and x-ray diffraction (XRD). Transport properties of prepared membranes were explored by diffusion of dye (Rose Bengal) used as model of hydrophilic transport molecule.
Scientific Reports | 2016
Ali Aldalbahi; Eric Li; Manuel Rivera; Rafael Velazquez; Tariq Altalhi; Xiaoyan Peng; Peter Feng
We report on a new approach to quickly synthesize high-quality single crystalline wide band gap silicon carbide (SiC) films for development of high-performance deep ultraviolet (UV) photodetectors. The fabricated SiC based UV photodetectors exhibited high response while maintaining cost-effectiveness and size miniaturization. Focus of the experiments was on studies of electrical and electronic properties, as well as responsivity, response and recovery times, and repeatability of the deep UV photodetectors. Raman scattering spectroscopy and scanning electron microscope (SEM) were used to characterize the SiC materials. Analyses of the SEM data indicated that highly flat SiC thin films have been obtained. Based on the synthesized SiC, deep UV detectors are designed, fabricated, and tested with various UV wavelength lights at different radiation intensities. Temperature effect and bias effect on the photocurrent strength and signal-to-noise ratio, humidity effect on the response time and recovery time of the fabricated detectors have been carefully characterized and discussed. The detectors appear to have a very stable baseline and repeatability. The obtained responsivity is more than 40% higher compared to commercial detectors. The good performance of the photodetectors at operating temperature up to 300 °C remains nearly unchanged.
ACS Applied Materials & Interfaces | 2015
Mohammed Alsawat; Tariq Altalhi; Karan Gulati; Abel Santos; Dusan Losic
This work presents the synthesis of carbon nanotubes (CNTs) inside titania nanotube (TNTs) templates by a catalyst-free chemical vapor deposition (CVD) approach as composite platforms for photocatalytic applications. The nanotubular structure of TNTs prepared by electrochemical anodization provides a unique platform to grow CNTs with precisely controlled geometric features. The formation mechanism of carbon nanotubes inside nanotubular titania without using metal catalysts is explored and explained. The structural features, crystalline structures, and chemical composition of the resulting CNTs-TNTs composites were systematically characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The deposition time during CVD process was used to determine the formation mechanism of CNTs inside TNTs template. The photocatalytic properties of CNTs-TNTs composites were evaluated via the degradation of rhodamine B, an organic model molecule, in aqueous solution under mercury-xenon Hg (Xe) lamp irradiation monitored by UV-visible spectroscopy. The obtained results reveal that CNTs induces a synergestic effect on the photocatalytic activity of TNTs for rhodamine B degradation, opening new opportunities to develop advanced photocatalysts for environmental and energy applications.
Polymers | 2017
Mostafizur Rahaman; Ali Aldalbahi; Periyasami Govindasami; Noorunnisa Khanam; Subhendu Bhandari; Peter Feng; Tariq Altalhi
The electrical conductivity of extrinsically conducting polymer composite systems passes through a transition state known as percolation threshold. A discussion has been made on how different Sigmoidal models (S-models), such as Sigmoidal–Boltzmann (SB), Sigmoidal–Dose Response (SD), Sigmoidal–Hill (SH), Sigmoidal–Logistic (SL), and Sigmoidal–Logistic-1 (SL-1), can be applied to predict the percolation threshold of electrical conductivity for ethylene vinyl acetate copolymer (EVA) and acrylonitrile butadiene copolymer (NBR) conducting composite systems filled with different carbon fillers. An interesting finding that comes from these observations is that the percolation threshold for electrical conductivity determined by SB and SD models are similar, whereas, the other models give different result when estimated for a particular composite system. This similarity and discrepancy in the results of percolation threshold have been discussed by considering the strength, weakness, and limitation of the models. The percolation threshold value for the composites has also been determined using the classical percolation theory and compared with the sigmoidal models. Moreover, to check the universal applicability, these Sigmoidal models have also been tested on results from some published literature. Finally, it is revealed that, except SL-1 model, the remaining models can successfully be used to determine the percolation threshold of electrical conductivity for extrinsically conductive polymer composites.
Journal of Colloid and Interface Science | 2017
Amine Mezni; Tariq Altalhi; Nesrine Ben Saber; Ali Aldalbahi; Seifeddine Boulehmi; Abel Santos; Dusan Losic
This work aims at introducing the synthesis process of carbon nanotubes (CNTs) inside nanoporous anodic alumina (NAA) templates adopting a catalyst-free chemical vapor deposition (CVD) approach under different conditions. The nanotubular structure of NAA is prepared according to tow-step anodization process. This provides a unique platform to grow CNTs with precisely controlled geometric features. The structural features, crystalline structures and chemical composition of the resulting CNTs-NAA composites were systematically characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), High Resolution Transmission Electron Microscopy (HRTEM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR) as well as Raman spectroscopy. Preparing the CNTs according to this template technique allows us to obtain nanotubes which are open at one/both end(s) with a uniform diameter (10-200nm) along the pore length (1-100μm) without using any metal catalyst.
New Journal of Chemistry | 2017
Amine Mezni; Nesrine Ben Saber; Mohamed M. Ibrahim; Maged El-Kemary; Ali Aldalbahi; Peter Feng; Leila Samia Smiri; Tariq Altalhi
A new and facile method of synthesizing high-temperature stable titanium dioxide (TiO2) nanoparticles (NPs) is presented in this work. This novel approach allows the production of titanium dioxide nanoparticles owing to a modified solvothermal process that makes use of titanium(IV) butoxide as a titanium precursor and Dimethyl Sulfoxide (DMSO) as a solvent. The structure and morphology of the TiO2 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX) and high-resolution transmission electron microscopy (HRTEM). Based on FTIR and TDA/TGA measurements, a proposed mechanism for the formation of TiO2 NPs in DMSO (without adding any other reagents) is discussed in this contribution. Optical absorption measurements showed that the TiO2 nanoparticles exhibited a UV significant absorption peak clearly blue-shifted with respect to that of bulk TiO2. The results showed that monodisperse quasi-spherical TiO2 nanoparticles (with an average size of 11 nm) consisting of a pure anatase phase were formed. The titanium dioxide nanoparticles showed a high photocatalytic performance in the degradation of diuron pesticide (C9H10Cl2N2O) under illumination by UV light. The high crystalline quality, together with the easy synthesis process, makes TiO2 nanoparticles a promising candidate for many applications, such as optoelectronics and water photolysis for hydrogen production.
Chemistry and Ecology | 2018
Amine Mezni; Samir Alghool; Badreddine Sellami; Nesrine Ben Saber; Tariq Altalhi
ABSTRACT Little information is available on the potential ecotoxicity of nanomaterials in the marine environment. In particular, the aquatic ecotoxicity impact of titanium dioxide (TiO2) has been rarely reported. To carefully address this issue, we report on the synthesis of TiO2 NPs using solvothermal process. The structure and morphology of the prepared TiO2 nanoparticles were characterised using different techniques. To study the potential ecotoxicity effect of TiO2, antioxidant system of mediterranean bivalves (Mytilus galloprovincialis) was used, measuring three oxidative biomarkers (ROS production, SOD activity and GSH/GSSG level). No considerable effect was found in the digestive glands of any of the groups treated with TiO2 with concentration gradients ranging from 1 to 100 mg/L. Thus, the level of the superoxide anion, the activity of an antioxidant enzyme superoxide dismutase (SOD) and the GSH/GSSG ratio showed no significantly differences in digestive glands of all treated groups compared to the control. However, slight modifications were observed in the gills at high concentrations. These results demonstrated that TiO2 appears to exert little toxicity on marine mussels after a short-term exposure at high concentration. However, before considering the use of this nanomaterial in various applications, further complementary studies are required in order to ensure the environmental safety of these NPs.
Journal of Controlled Release | 2018
U. T. Uthappa; Varsha Brahmkhatri; Ganesan Sriram; Ho-Young Jung; Jingxian Yu; Nikita Kurkuri; Tejraj M. Aminabhavi; Tariq Altalhi; Gururaj M. Neelgund; Mahaveer D. Kurkuri
ABSTRACT Diatoms, unicellular photosynthetic algae covered with siliceous cell wall, are also called frustule. These are the most potential naturally available materials for the development of cost‐effective drug delivery systems because of their excellent biocompatibility, high surface area, low cost and ease of surface modification. Mesoporous silica materials such as MCM–41 and SBA–15 have been extensively used in drug delivery area. Their synthesis is challenging, time consuming, requires toxic chemicals and are energy intensive, making the entire process expensive and non‐viable. Therefore, it is necessary to explore alternative materials. Surprisingly, nature has provided some exciting materials called diatoms; biosilica is one such a material that can be potentially used as a drug delivery vehicle. The present review focuses on different types of diatom species used in drug delivery with respect to their structural properties, morphology, purification process and surface functionalization. In this review, recent advances along with their limitations as well as the future scope to develop them as potential drug delivery vehicles are discussed.
Materials | 2017
Ali Aldalbahi; Mostafizur Rahaman; Periyasami Govindasami; Mohammed Almoiqli; Tariq Altalhi; Amine Mezni
This article discusses the deposition of different amount of microstuctured poly(3,4-ethylenedioxythiophene) (PEDOT) on reticulated vitreous carbon (RVC) by electrochemical method to prepare three-dimensional (3D) PEDOT/RVC electrodes aimed to be used in capacitive deionization (CDI) technology. A CDI unit cell has been constructed here in this study. The performance of CDI cell in the ion removal of NaCl onto the sites of PEDOT/RVC electrode has been systematically investigated in terms of flow-rate, applied electrical voltage, and increasing PEDOT loading on PEDOT/RVC electrodes. It is observed that the increase in flow-rate, electric voltage, and PEDOT loading up to a certain level improve the ion removal performance of electrode in the CDI cell. The result shows that these electrodes can be used effectively for desalination technology, as the electrosorption capacity/desalination performance of these electrodes is quite high compared to carbon materials. Moreover, the stability of the electrodes has been tested and it is reported that these electrodes are regenerative. The effect of increasing NaCl concentration on the electrosorption capacity has also been investigated for these electrodes. Finally, it has been shown that 1 m3 PEDOT-120 min/RVC electrodes from 75 mg/L NaCl feed solution produce 421, 978 L water per day of 20 mg/L NaCl final concentration.
Journal of Nanomaterials | 2016
Ganesan Sriram; Pravin Patil; Mahesh P. Bhat; Raveendra M. Hegde; Kanalli V. Ajeya; Iranna Udachyan; M. B. Bhavya; Manasa G. Gatti; U. T. Uthappa; Gururaj M. Neelgund; Ho-Young Jung; Tariq Altalhi; Mahaveer D. Kurkuri
Pristine aluminum Al has received great deal of attention on fabrication of nanoporous anodized alumina NAA with arrays of nanosized uniform pores with controllable pore sizes and lengths by the anodization process. There are many applications of NAA in the field of biosensors due to its numerous key factors such as ease of fabrication, high surface area, chemical stability and detection of biomolecules through bioconjugation of active molecules, its rapidness, and real-time monitoring. Herein, we reviewed the recent trends on the fabrication of NAA for high sensitive biosensor platforms like bare sensors, gold coated sensors, multilayer sensors, and microfluidic device supported sensors for the detection of various biomolecules. In addition, we have discussed the future prospectus about the improvement of NAA based biosensors for the detection of biomolecules.