Solid State Phenomena Vol. 340

Abstract: The development of MWCNT mixed matrix membranes (MWCNT-MMMs) has shown good performance for gas separation. Interfacial interactions between the CNTs and the polymer and the dispersion of the MWCNTs in the polymeric matrix affects the overall performance of CNT mixed matrix membranes. Although CNTs properties are superior to other inorganic fillers but due to their chemically inert properties and inability to disperse in typical organic solvents, their applicability in industry is still uncertain. Typically, nanotubes are bound together by strong van der Waals interactions and form tight bundles. Therefore, MWCNTs tend to accumulate to each other in polymer matrix. This has been the biggest challenge in development of MWCNT-MMMs in producing defect free membranes. In this research, PES/Pebax-MWCNTs mixed matrix membraness were fabricated to capture carbon for natural gas. Sorbitol has been utilized in the fabrication of membranes to break the agglomeration of MWCNTs. In this study, the effect of MWCNTs loading and addition of sorbitol on the structure of synthesized membranes was analyzed using FESEM, DSC and FTIR. The incorporation of MWCNTs in the polymer matrix allows more active path for small molecules to flow across the membranes. The agglomeration of MWCNTs is more significant with the increase of fillers loading. Addition of sorbitol improved the morphology of membranes. Smooth surface of membranes with no agglomeration are observed for all MWCNTs loading (2-6 wt%). Glass transition temperature (T_g) was shifted to lower temperature with the addition of both MWCNTs and sorbitol.

Abstract: The hard capsule market growth is mainly driven by the demand for gelatin capsules made of animals. Plant-based hard capsules, such as hydroxypropyl methylcellulose are currently in high demand for drug delivery, but the manufacturing process is costly with limited reagent supply. As an alternative, carrageenan from seaweed was used as a film-forming agent in this work. Carrageenan film possesses low mechanical strength, thus gum Arabic is incorporated to strengthen the biocomposite film. The films and hard capsules were produced with different concentrations of gum Arabic, ranging from 0 to 2.0 w/v%. The tensile strength and elongation at break were enhanced to 56.8 MPa and 23.7%, respectively. The highest capsule loop strength is 32.5 N, which was achieved at 1.2 w/v% of gum Arabic. All biocomposite films were kept at a moisture content of 13%, which is comparable to gelatin hard capsules. These results demonstrate that gum Arabic can strengthen the carrageenan biocomposite to be an alternative to gelatin hard capsules.

Abstract: As the main-stream of the machining coating, nitrogen-based coatings have irreplaceable advantages, such as high hardness, high strength, and good oxidation resistance recently. This paper introduces common multiple nitrogen-based coatings which including TiAlN, CrAlN, TiAlSiN, CrAlSiN and CrTiAlN coatings for cemented carbide tools. The microstructure and property of coating is depended on its chemical composition. Generally, compounds of different structures are formed between the various elements of the coating, and these have different forms of existence and properties: titanium and chromium exist in nitrides (face-centered cubic structure), aluminium solubilizes in TiN/CrN, and amorphous Si₃N₄ can make difference in fine grain strengthening. The Al₂O₃ and SiO₂ can improve oxidation resistance.

Abstract: As the main process of carbide tool coating fabrication, cathodic arc ion plating plays an important role in modern industrial production. This paper introduces the influence of process parameter selection on the coating properties of tools by cathodic arc ion plating. The process parameters mainly include nitrogen partial pressure, negative bias pressure and arc current, and the coating properties are mainly characterized by deposition rate, phase composition, coating hardness and surface quality. It can optimize the selection of process parameters on modern industrial production.

Abstract: In this work, imidazoline-oleic derivative had been successfully synthesized by reacting ethylenediamine (EDA) with oleic acid (OA). The synthesis process was performed with MAOS (Microwave Assisted Organic Synthesis) and the conventional method (reflux with Dean-Stark) using xylene as a solvent was also performed as comparisons. The percentage yield of EDA-OA imidazoline was obtained from Reflux with Dean-Stark at 5 hours (90 %), and MAOS at 10 min (68,2 %). EDA-OA imidazoline then was identified by using thin-layer chromatography, and the separation method by KVC with eluent CHCl₃: MeOH (9:1) with ammonium solution followed by characterization using Fourier Transform Infrared (FTIR), UV-Vis, Proton Nuclear Magnetic Resonance (¹H-NMR). This study provides information regarding the comparison method for imidazoline derivative synthesis. For further research, EDA-OA imidazoline can be used as a corrosion inhibitor towards carbon steel.

Abstract: Tetra-Boron Carbide (B4C) are an excellent material for industrial applications in the nuclear, aerospace, and military. It is an excellent neutron absorber for use as a radiation shield. Using B4C as thermal barrier coating reduces the metal surface temperature, shields the substrate metal alloy from excessive heat, and increases system efficiency. In this degraded has been evaluated using non- destructive techniques that are appropriate for the predicament. To track the thermal barrier coating’s integrity over time, a microwave non-destructive technique was used to predict the porosity of the topcoat. Network analyzer (ENA5701C) in X-band (12–18 GHz) was utilized for this investigation. Detection was based on the changes in the electromagnetic properties, such as permittivity . A set of samples contained varied filler ranging of 5, 10, 15, 20 percent particle reinforcement. Most tested samples shows that porosities have maximum permittivity in the range of 15.4 – 16.7 GHz where some resonance occurred when real primitivity represent the capability of B4C to store and dissipate energy. This study suggesting that the proposed methodology could be a valuable aid technique for evaluating degraded on composite material systems in a non-destructive and accurate manner with complex pore morphology

Abstract: Natural fibers are increasingly used in the polymer industry as bio-composites for a wide range of applications, such as the interior part of the automobile, interior material boards, decking panels, and many others. The presence of cellulose, which is hydrophilic in nature, lessens the mechanical properties of the bio-composites by increasing water uptake into the composites or also may affect the interfacial bonding between the polymer matrix and the fibers because the matrix is hydrophobic. The former may occur due to the surface of the bio-composites being highly exposed to water sources, e.g., high humidity in the air, rainwater, and many more. Thus, an additional layer on the surface of the bio-composites needs to be applied to protect the surface from water sources. The coating may be used for decorative, protective, or both purposes. This study aims to investigate the performance of polymer coating on a bio-composite substrate. The coating solution, chitosan-pectin-calcium chloride (CPC) solution was prepared, and the compatibility and wettability of the coating solution with the polymer-based bio-composites substrate were evaluated. The substrate was dipped into the coating solution for two minutes and hung to allow the excess coating solution to drop while drying the substrate. The performance of coating on the bio-composite substrate is evaluated by measuring the contact angle θ and average maximum bond strength σ_b of the sample with the different numbers of coating layers. It is found that the wettability of the contact angle indicates a lower contact angle for two-layer compared to one layer of the CPC coating due to the hydrophilicity of the coating materials.

Abstract: Corrosion of mild steel has been attributed to the respiratory activity of microbes under different growth conditions. Under nitrate-reducing condition, nitrate-reducing bacteria were postulated to inhibit corrosion, yet existing literatures reported contradicting findings. Newly isolated Cronobacter sp. KP 19 from Kuantan Port is capable of reducing ferric iron (Fe³⁺) and nitrate (NO₃^-) as electron acceptors. To investigate the effect of Cronobacter sp. KP 19 on mild steel corrosion under nitrate-reducing condition, the Cronobacter sp. KP 19 was cultured as nitrate-reducing facultative bacteria in a defined growth M1 media amended with 15 mM of sodium nitrate as the sole electron acceptor. Mild steel coupons were immersed in growth media for 46 days. The deteriorations of the mild steel coupons were then evaluated by corrosion rate analysis and the morphology was characterized via scanning electron microscopy (SEM) followed by X-ray diffraction (XRD) analyses. Our results indicated that under nitrate-reducing condition, Cronobacter sp. KP 19 remarkably accelerates the corrosion rates of mild steel by approximately ten folds. XRD analysis confirmed the formation of magnetite (Fe₃O₄) and vivianite [Fe₃(PO₄)₂·8H₂O] as the corrosion products. Results from current study provide insight on how facultative anaerobes affect the corrosion processes under different respiratory growth conditions.

Abstract: Aluminum with –2.5wt.% Cu–2.5wt.% Mg – 5wt.% Zn alloy was synthesized by die cast and spray formed technique. The average density of die cast and spray formed Al alloy was measured by water displacement method. The compression strength, hardness and tribological properties of the Al alloy produced by die cast and spray formed technique was studied as per the ASTM test standards and recorded the average values. The surface morphology of die cast Al alloy depicts the dendritic structures and spray formed Al alloy contains the equiaxed grains, coarse grains and fine grains across the surface. The elemental analysis of both die cast and spray formed Al alloy was measured by using scanning electron microscope. Average percentage of porosity of die cast and spray formed aluminum alloy is 1.79 ± 0.23 and 1.10 ± 0.3 respectively. The hardness of spray formed Al alloy is 10.54 % lesser than that of die cast Al alloy. Average ultimate compression strength of spray formed and die cast Al alloys are 360.07 ± 9.58 MPa and 353.33 ± 5.56 MPa respectively. The study also recorded the wear rate and coefficient of friction of die cast and spray formed Al alloy at different load and speed conditions. The precipitation strengthening mechanism is found to be involved in spray formed alloy.