The Synthesis, Functionalisation And Characterisation Of Carbon Nanotubes Alumina Hybrid Compound And Its Nanocomposites

Dalam kajian ini, karbon nanotiub (CNT) dan alumina hybrid telah disintesis menggunakan proses pemendapan wap kimia (CVD). Sebatian hibrid CNT-alumina ini diteruskan penghasilannya dengan polydimethylsiloxane (PDMS) untuk menghasilkan komposit. Pada mulanya, analisis yang dilakukan semasa sintesis hibrid CNT-alumina adalah secara fizikal dan kimia untuk mengenalpasti penghasilan mana yang lebih baik dengan mengggunakan kepelbagaian pemangkin sokongan seperti nikel nitrat, ferik nitrat dan kobalt nitrat. Didapati nikel nitrat mempamerkan ciri-ciri yang dikehendaki dengan tahap pertumbuhan CNT yang lebih tinggi dan sifat-sifat yang agak baik berbanding pemangkin sokongan yang lain. Kemudian, kajian ke atas masa kitaran (0, 5, 10 dan 15 jam) mendakan pemangkin untuk menghasilkan hybrid CNT-alumina telah dikaji. Ia adalah untuk mengetahui kesan pengaktifan mekanokimika terhadap sifat-sifat bahan semasa sintesis hibrid CNT-alumina. Didapati pemilihan masa kisaran 15 jam adalah yang paling sesuai serta lebih baik untuk pertumbuhan CNT dari segi sifat-sifat fizikal, kimia dan terma. Seterusnya, hibrid CNT-alumina telah difungsikan dengan asid H2SO4: HNO3 (50 °C / 24 jam dan 100 °C / 2 jam) dan reagen asli (minyak zaitun dan minyak sawit) untuk pengubahsuaian dan pembaikan permukaan hybrid tersebut. Kefungsiaan ini ditunjukkan untuk membandingkan ciri dan sifat mana yang lebih baik daripada interaksi ikatan kimia yang terbentuk di permukaan hybrid CNT-alumina. Didapati permukaan hybrid CNT-alumina menunjukkan ikatan kimia telah dibentuk, tetapi didapati bahawa rawatan asid reagen pada suhu 50 °C selama 24 jamadalah lebih sesuai dengan ketetapan kumpulan ikatan yang baik. Terdapat lebih kumpulan karboksil berfungsi di dinding sisi hibrid CNT-alumina. Pada akhirnya, penghasilan hibrid CNT-alumina / PDMS komposit telah dicapai melalui pemprosesan ultrasonik. Kesan daripada ikatan hibrid CNT-alumina dalam pelbagai peratusan berat (0, 0.5, 1.0 dan 1.5 wt%) di PDMS telah dikaji. Jelas dilihat melalui keputusan kajian bahawa komposit 1.5 wt% hibrid CNT-alumina / PDMS telah menunjukkan lebih keberkesanan di mana ianya memiliki kekuatan tekanan yang lebih tinggi dengan daya terikan yang lebih rendah dan kekonduksian terma yang tinggi tetapi pengembangan haba serta kehilangan komposisi berat yang rendah. Secara kajiannya, pembuatan hibrid CNT-alumina / PDMS komposit ini telah menunjukkan sifat kefungsian dalam keadaan baik dengan ciri-ciri yang lebih baik serta boleh digunakan mengikut aplikasi yang diperlukan. __________________________________________________________________________________ In this study, CNT and alumina hybrid compound were synthesised using the chemical vapour deposition (CVD) process. The CNT-alumina hybrid compound was synthesised with polydimethylsiloxane (PDMS) to produce composites. Initially, the synthesised CNT-alumina hybrid was analysed physically and chemically to identify the best production route by using nickel nitrate, ferric nitrite and cobalt nitrate as the supported catalysts. Throughout the synthesis, nickel nitrate was verified as having the most desirable characteristics with a high level of CNT growth compared to the other supported catalysts. Then, investigations were carried out on the milling time (0, 5, 10 and 15 hours) of the precipitate catalyst in producing the CNT-alumina hybrid. The effects of mechanochemical activation by milling on the particular characteristics of the synthesised CNT-alumina hybrid were also studied. It was found that 15 hours of milling time of the catalyst produced the best physical, chemical and thermal properties for CNT growth. Thereupon the milled, CNT-alumina hybrid compound was functionalised with acids, namely H2SO4: HNO3 (50 °C for 24 hours and 100 °C for 2 hours), and natural reagents (olive oil and palm oil) for surface modifications. These functionalisations were exhibited to compare the possible characteristics and all the improved properties of interactions at the CNT-alumina hybrid surface in the form of the attached chemicals. The entire CNT-alumina hybrid functionalisation showed that chemical surface attachments had been formed, but it was found that most of the chemical attachments were specifically applicable to treatment with acid reagents at a temperature of 50°C for 24 hours. Thus, more carboxyl groups were found to be attached to the CNT-alumina hybrid on the sidewalls. Finally, CNT-alumina hybrid/ PDMS composites were fabricated using an ultrasonic processor. Furthermore, the effects of interactions of the various weight percentages (0, 0.5, 1.0 and 1.5 wt%) of CNT-alumina on PDMS were investigated. It was clearly seen that 1.5 wt% of the CNT-alumina hybrid/ PDMS composite presented effective results with higher strength and lower strain, high thermal properties but low thermal expansion and low weight loss. Experimentally, these CNT-alumina hybrid/ PDMS composites were fabricated and functionalised in good condition with better properties and can be applied in suitable applications

Studies On The Properties Of Pultruded Kenaf Fiber Reinforced Unsaturated Polyester Composites

Kenaf fiber reinforced unsaturated polyester composites (KFRPC) consisting of kenaf fiber (KF) and unsaturated polyester were produced by pultrusion machine, molded into rod specimens. KF and unsaturated polyester was being analyzed and characterized in terms of degradation, physical and mechanical properties, such as immersion, strength, elongation, absorbency and surface characteristic. In this research, KF and unsaturated polyester were immersed in distilled water (DW), seawater (SW) and acidic solution (AS) at room temperature to study the behavior of the specimen after long term immersion. KF immersed in SW exhibited the highest level of water absorption, whereas KF immersed in AS showed the lowest water absorption values. The tensile strength of the immersed KF decreased with increasing immersion time implying the degradation of the fiber. Investigation on the microstructure of immersed kenaf fibers using SEM reveal the degradation of the KF with presence of microcracks and increased in the surface roughness. Effect of water immersion on the bending behavior of the unsaturated polyester was also experimentally investigated. Water diffusion was observed more in DW than SW and AS, respectively. The unsaturated polyester experienced significant reduction of the flexural strength. These are attributed to the function of the water molecules absorbed in the unsaturated polyester. KFRPC were successfully produced with 50%, 60% and 70% of KF by volume, using pultrusion method. The various percent of KF volume were tested to identify the influence of KF volume (%) on the mechanical properties

Permeation Damage of Polymer Liner in Oil and Gas Pipelines: A Review

Non-metallic pipe (NMP) materials are used as an internal lining and standalone pipes in the oil and gas industry, constituting an emerging corrosion strategy. The NMP materials are inherently susceptible to gradual damage due to creep, fatigue, permeation, processing defects, and installation blunder. In the presence of acid gases (CO2, H2S), and hydrocarbons under high pressure and temperature, the main damage is due to permeation. The monitoring of possible damage due to permeation is not well defined, which leads to uncertainty in asset integrity management. Assessment of permeation damage is currently performed through mechanical, thermal, chemical, and structural properties, employing Tensile Test, Differential Scanning Calorimetry (DSC), Fourier-transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM)/Transmission Electron Microscopy (TEM), to evaluate the change in tensile strength, elongation, weight loss or gain, crystallinity, chemical properties, and molecular structure. Coupons are commonly used to analyze the degradation of polymers. They are point sensors and did not give real-time information. Polymers are dielectric materials, and this dielectric property can be studied using Impedance Analyzer and Dielectric Spectroscopy. This review presents a brief status report on the failure of polymer liners in pipelines due to the exposure of acid gases, hydrocarbons, and other contaminants. Permeation, liner failures, the importance of monitoring, and new exclusive (dielectric) property are briefly discussed. An inclusive perspective is provided, showing the challenges associated with the monitoring of the polymer liner material in the pipeline as it relates to the life-time prediction requirement

Structure property investigation of glass-carbon prepreg waste-polymer hybrid composites degradation in water condition

The limited shelf life of carbon prepreg waste (CPW) from component manufacturing restricts its use as a composite reinforcement fibre on its own. However, CPW can be recycled with glass fibre (GF) reinforcement to develop a unique remediate material. Therefore, this study fabricated (1) a glass fibre-carbon prepreg waste reinforced polymer hybrid composite (GF-CPW-PP), (2) a polypropylene composite (PP), (3) a carbon prepreg waste reinforced composite (CPW-PP), and (4) a glass fibre reinforced composite (GF-PP) and reported their degradation and residual tension properties after immersion in water. The polymer hybrid composites were fabricated via extrusion technique with minimum reinforce glass-carbon prepreg waste content of 10 wt%. The immersion test was conducted at room temperature using distilled water. Moisture content and diffusion coefficient (DC) were determined based on water adsorption values recorded at 24-h intervals over a one-week period. The results indicated that GF-PP reinforced composites retained the most moisture post-168 h of immersion. However, hardness and tensile strength were found to decrease with increased water adsorption. Tensile strength was found to be compromised since pores produced during hydrolysis reduced interfacial bonding between glass fibre and prepreg carbon reinforcements and the PP matrix

Temperature effect on pseudomonas aeruginosa growth and its presence on corrosion of steel wire rope

Bacterial can initiate, accelerate, and/or inhibit corrosion processes through a number of different ways, including modification of the localized environment at the metal/solution interface by causing pitting attack. In this work, the effect of temperature on bacteria (P.Aeruginosa sp) growth will be investigated the nature of bacteria before further investigated its corrosion effect on steel wire rope. It is found that the bacteria grew actively at 30 ºC. The pH value was also changed from 7 to 8. The corrosion rate with the presence of bacteria has been found increased from 9.95 x 10-7 mdy to 4.884 x 10-5 mdy. While corrosion pitting is found directly proportional to the bacterial activity

A Review on Recycling of Carbon Fibres: Methods to Reinforce and Expected Fibre Composite Degradations

Carbon fibres are widely used in modern industrial applications as they are high-strength, light in weight and more reliable than other materials. The increase in the usage of carbon fibres has led to the production of a significant amount of waste. This has become a global issue because valuable carbon fibre waste ends up in landfill. A few initiatives have been undertaken by several researchers to recycle carbon fibre waste; however, the properties of this recycled material are expected to be worse than those of virgin carbon fibre. The incorporation of polymers, nanoparticles and other hybrid materials could enhance the overall properties of recycled carbon fibre waste. However, the degradation of fibre composites is expected to occur when the material is exposed to certain conditions and environments. The study of fibre composite degradation is crucial to enhance their properties, strength, safety and durability for future applications

pH effect on microbial corrosion by pseudomonas aeruginosa sp. On galvanized JIS3502 steel

Microorganisms can initiate, accelerate, and/or inhibit corrosion processes through several different ways, including modification of the localized environment at the metal/solution interface causing pitting attack. In this work, the effect of pH on Pseudomonas growth was investigated in understanding the biodeterioration manganese steel rod due to bacteria attack. This study focused on identifying the effect of pH on the corrosion of galvanized steel. In artificial seawater containing Pseudomonas Aeruginosa. Galvanized steels were exposed to the medium for 7 days at 37°C at pH ranging from 5.0 to 9.0. Roles of different metallurgical, chemical and microbiological features on the surface will be reviewed to interpret this phenomenon. The results confirmed that the pits formed in this case are attributed to the Pseudomonas Aeruginosa sp under microbial corrosion