Publications

A phase inversion process was used to co-extrude cerium–gadolinium oxide (Ce0.9Gd0.1O1.95)/NiO–CGO dual-layer hollow fibres (HF), which were then sintered to form, respectively, the electrolyte and high porosity anode precursor of a solid oxide fuel cell (SOFC) with anode inner diameter of 0.8mm. Graded CGO–lanthanum strontium cobalt ferrite (La0.6Sr0.4Fe0.8Co0.2O3) cathode layers were then painted onto the CGO electrolyte to form a micro-tubular HF-SOFC. With a carefully designed anode current collector, this produced maximum power densities of 1186–5864Wm−2 at 450–570°C. High magnification imaging analysis revealed large three-phase boundary regions within the anode, a dense electrolyte layer and clearly highlighted the multiple CGO–LSCF cermet and pure LSCF cathode layers. The performance of the HF-SOFC with a twenty millimetre active length showed no degradation after four thermal cycles between 300°C and 570°C.

The imidazolate framework-8 (ZIF-8) crystals were synthesized by in -situ growth techniques inside the pore of porous poly ether sulfone (PES) in order to fabricate a composite PES/ZIF-8 electrolyte membrane for direct methanol fuel cell (DMFC) applications. In situ techniques by adapting the filtration method was adhered in this study. It was found that the proton conductivity (17.9 × 10−3 Scm−1) was drastically increased for PES/ZIF-8 as compared to pristine PES membrane (0.21 × 10−3 Scm−1). However, the methanol barrier property was slightly decreased from 2.07 × 10−7 cm2s−1 to 3.88 × 10−7 cm2s−1 for PES and PES/ZIF-8 membranes, respectively. The introduction of ZIF-8 in PES membranes not only improve proton conductivity, but also positively affected the mechanical stability of PES/ZIF-8 with 1.73-fold lower of swelling ratio even though the water uptake increased by 2.08 folds. In spite of the increment in methanol permeability, selectivity of PES/ZIF-8 membrane was 6 folds and 2 folds higher than pristine PES and Nafion®, respectively which indicated that the potential for PES/ZIF-8 to be a good candidate for electrolyte in DMFC applications. Nonetheless, via scanning electron microscopy (SEM) showed a good distribution of ZIF-8 crystals inside the pore of PES membranes which proven that the effectiveness of filtration techniques for ZIF-8 crystals in-situ growth synthesized within the pores.

-mounted air supply diffusers in reducing BCPs. This paper aims to investigate the efficacy of both vertical downward (default) and horizontal air supply diffusers in mitigating BCPs within the surgical zone. By utilizing a renormalization group (RNG) k-􀄰􀀃 airflow model, the air distribution within the OR was simulated, while the transportation of particles was predicted utilising a Lagrangian technique. Five cases were analyzed, including the vertical air supply diffuser as the baseline case, two-sided wall-mounted diffuser on xy plane (case 2), single-sided wall-mounted diffuser on yz plane (case 3), and single-sided wall-mounted diffuser on xy plane (case 4). The findings indicate that the airflow supplied by all wall-mounted diffusers (case 1 – case 4) failed to minimise the number of particles within the surgical region. However, there was a notable increase in particle settlement on the patient. In cases 1, 2, 3, and 4, the particles adhere on the patient's body surface intensified by 8.5-fold, 2-fold, 13-fold, and 15.5-fold respectively.

The hydrophobicity of metal–organic frameworks (MOFs) is critical in enhancing the separation process in membrane distillation. Herein, a new superhydrophobic University of Oslo 66 (UiO-66) MOFs was successfully constructed on the top of alumina hollow fibre (AHF) membrane for desalination purposes. The fabrication methodology of the membrane involved in situ growth of pure crystalline UiO-66 on top of AHF and post-synthetic modification by fluorosilane grafting. The resultant membrane was characterised to study the physicochemical properties of the pristine and modified membrane. A superhydrophobic UiO-66 with a contact angle of 154° and high liquid entry pressure was obtained by introducing a highly branched fluorocarbon chain while maintaining its crystallinity. As a result, the modified membrane achieved 14.95 L/m2∙h water flux and 99.9% NaCl rejection with low energy consumption in the direct contact membrane distillation process. Furthermore, the high surface energy contributed by UiO-66 is maximised to produce the maximum number of accessible sites for the grafting process. The synergistic effect of surface hydrophobicity and porous UiO-66 membrane in trapping water vapour shows great potential for desalination application.

This chapter discusses various methods in characterizing porous ceramic membranes. The fundamental theory and calculation for every approach are given to relate the basic concept of each technique to the results obtained from experiments. A number of techniques are discussed, including gas adsorption/desorption isotherm, permporometry, mercury porosimetry, thermoporometry, bubble point method, and liquid displacement technique. This chapter includes some step-by-step methodologies in obtaining the results of pore properties for ceramic membranes. The view and comparisons that include the advantages and limitations are given in the end of this chapter.

Objective: Bisphenol A (BPA), a xenoestrogen chemical compound has wide range of harmful effects in the body. It is not clear whether BPA induced harmful effects in the body occurs through disrupting the intestinal barrier (IB). Objective of this review is to provide an up to date information about the effect of BPA on the IB. Materials and Methods: Literatures were searched in PubMed, Scopus and Google Scholar using the key words 'BPA' paired with 'intestinal barrier', 'intestinal barrier function', 'gut barrier function', 'gut' and 'intestinal permeability' from the year 1980 till early March 2018. Results: Only six animal studies were found. BPA was found to increase intestinal permeability, an indicator of compromised IB in one study. But it dose-dependently decreased intestinal permeability in ovariectomized animals. BPA has been reported to alter gut microbiota in five studies. Altered gut microbiota is proposed to be an important factor contributing to compromised IB. Conclusion: The effect of BPA on the IB varies on the species, gender, presence or absence of endogenous estrogen and maturity of the gut. However, five out of six studies are in agreement that BPA altered intestinal microbial flora.

No abstract is provided for this article.

This volume consists of 10 chapters focusing on the development and application of advanced and hybrid membranes in wastewater treatment using various conventional and advanced membrane technologies. This book aims to provide (1) better understanding of the mechanism of wastewater treatment from membrane technologies, (2) current information about technologies and limitations of wastewater treatment, (3) recent discovered solutions from experts for wastewater treatment, and finally (4) information on weaknesses of and solutions to membrane technologies for wastewater treatment. Topics covered in this book include overview of wastewater treatment, conventional technology process for wastewater treatment, recent advanced membrane technologies such as adsorptive, photocatalytic, forward osmosis, ceramic and metal organic framework membranes, and membrane distillation. The final chapter offers comprehensive discussion on the weaknesses of and solutions to advanced membranes for wastewater treatment. Materials presented in this book could be beneficial to wastewater management companies, research and development agencies, environment-related private and government agencies, researchers and students from the fields of science, engineering and the environment.

Microalgae dewatering using membrane technology has become feasible. The features of membrane are essential for achieving efficient dewatering performance. Thin-film nanocomposite membrane with layered double hydroxide (LDH) nanosheet incorporated substrate and its performance in microalgae dewatering were examined in this research. The membrane has been developed to address the drawbacks of FO in regards to concentration polarization, reverse draw solute diffusion, and antifouling. The morphology, wettability, permeability, fouling resistance, and long-term performance of the membranes was improved by incorporating exfoliated LDH within the polyethersulfone (PES) support layer of polyamide TFN membranes. Dewatering of Chlorella vulgaris by FO in active layer facing feed solution (AL-FS) and active layer facing draw solution (AL-DS) was evaluated with 2M NaCl as draw solution. The findings revealed the 0.5% LDH embedded within PES support, the water flux improved by 111.43% contrasted with neat membrane. The 0.5% LDH-TFN showed improved antifouling properties during the 4-cycle microalgae dewatering. In addition, the incorporation of LDH supressed internal concentration polarization of TFC membranes thus exhibiting good flux stability throughout the 72h operation. This research evidenced the intriguing prospect of exfoliated Zn-Al LDH as a promising additive to modify TFC membrane for high performance microalgae dewatering.

Metal-organic frameworks (MOFs) are emerging material class for the past few years due to its tailorability characteristics for various applications. However, the research and development (RD in conjunction with the properties, the synthesis and fabrication of ZIF-8 membrane as alternative proton conductor and methanol barrier for DMFC application have also been highlighted.

Photocatalytic membrane reactors have recently gained prominence as environmentally friendly and sustainable solutions for the treatment of contaminated water sources. Photocatalytic membranes (PMs) play an essential role in the separation and degradation of toxic compounds in aquatic environments. Hydrothermal and solvothermal (HST) methods displayed a superior technique in the development of the desired ceramic photocatalyst on a membrane substrate. This chapter presents the impact of HST methods on the recent advancement of PMs for versatile applications. The fundamental principles of the HST approaches for the synthesis of photocatalysts are discussed. The parametric effects on physicochemical properties were also studied. Recent improvements in PM-based HST methods have shown promising results for wastewater treatment. This chapter provides scope for the design of low-cost and efficient HST method-based PMs for water purification applications.

Combination of optical fiber and semiconductor metal oxide nanostructure provide a label-free refractive index (RI) sensor with an excellent limit of detection. ZnO NPs (nanoparticles) coated evanescent based multimode optical fiber sensor is established to detect different crude oil concentrations blended in diethyl ether. The efficacy of fabricated sensors with respect to wavelength shift and intensity changes is tested with different crude oil concentration from 0% (RI: 1.35) to 100% (RI: 1.47). By increasing the crude oil concentration, the maximum shift of ~10 nm towards lower wavelength is occurred. The signal in visible area originated from the electron–hole recombination at a deep level via singly ionized oxygen vacancies (VO +). Increasing the crude oil concentration leads to decreasing the transmission intensity up to 72% of its maximum value. Changes in refractive index of ZnO nanostructure from 2.671 to 2.726 with the change in oil concentration from 0% to 100% respectively, leads to different quantity of evanescent wave absorption taken placed. Different absorption rate and reflection angle in the cladding-ZnO interface are responsible for intensity modulation. The interaction of oxygen vacancies on ZnO surface, electron migration from donor media to the valance band and lowering the band-gap with decreasing the crude oil concentration are responsible for RI modification of ZnO. Therefore, an economic, high sensitive and multipurpose dual sensing scale has been proposed for crude oil detection.

The toxic and carcinogenic organic compounds discharge from industries, contaminate the natural reservoirs of water and air which eventually pose a global threat not only to the aquatic life but also to the humanity. Herein, ternary nanocomposites of silver-nanoparticle (AgNPs)-decorated on polyaniline (Pani)-wrapped zinc oxide nanorods (AgNPs@Pani/ZnO) were prepared via a facile approach. The nanocomposite degraded 97.91% phenol with an optimized dosage and concentration of H2O2. Moreover, the apparent rate constant for phenol degradation was 3.69 times higher than for pure ZnO nanorods. The hydrogen production from AgNPs@Pani/ZnO was 1.58 and 2.74 times higher than Pani/ZnO and ZnO, respectively. The enhanced phenol degradation and hydrogen production is attributed to the transfer of holes to the Pani, from which the electrons were transferred to the conduction band of ZnO and eventually to the conduction band of the AgNPs, where they accelerated the redox reactions for rapid photolysis of water and phenol. The concentration of the catalyst dosage affected the rate of phenol degradation. Further, response surface methodology was also applied in order to design 13 sets of random experiments in which the catalyst dosage and degradation time were varied to predict the phenol degradation.