Papers by Keyword: Chemical Treatment

Abstract: Diesel vehicle emissions containing nitrogen oxides, volatile organic compounds, and soot pose significant health and environmental risks. Diesel particulate filters (DPFs) reduce soot emissions by capturing particulate matter through their porous structure, but are often made from costly materials like silicon carbide and cordierite. This study addresses this gap by developing a DPF using recycled carbon fibers (CF) coupled with bentonite-supported copper-manganese (Cu/Mn) catalysts. CFs were recovered from polymer composite wastes using two distinct approaches: a two-step pyrolysis involving thermal decomposition and oxidation of resin, and a chemical treatment via acid digestion and catalyzed separation. These processes yielded clean, structurally intact fibers suitable for filter fabrication. Sintering the filter produced a composite with enhanced structural cohesion, porosity, and thermal stability, which makes it suitable for particulate entrapment. Scanning electron microscopy (SEM) images revealed that sintered filters exhibit dispersed bentonite and carbon fibers, with pyrolyzed fibers providing a more compact structure. The resulting filter exhibited an average specific surface area of 56.58 m²/g and an average pore size of 3.36 nm, while analyses confirmed the presence of Cu and Mn oxides within the bentonite matrix with synergistic interactions between catalysts. Thermogravimetric analysis (TGA) showed that Cu/Mn-bentonite catalysts reduced soot oxidation onset temperatures to approximately 245.26°C and 471.89°C, providing efficient catalytic performance at lower temperatures while maintaining stability. These results effectively demonstrate the potential of recycled carbon fibers for integration with Cu/Mn catalysts to develop DPFs.

Abstract: Surface modifications of bio-filler and polymer matrix is critical in natural fiber reinforced composites to improve compatibility with the hosting polymer. The literature contains only a few studies on grafting bio-fillers to improve their reactivity with polymer matrix. This study focuses on introducing crosslinking between Date Palm Particles (DPP) and Polypropylene (PP) using new methods. The experimental setup starts with chemical modifications of PP that result in the formation of PP-g-mTMI. Following that, the two components are blended together, forming a urethane link between the filler and the polymer. Following the fabrication of bio-composite sheets based on the Taguchi design, various specimens were prepared and tested thoroughly to assess their chemical properties, thermal stability, and mechanical properties. The results of the experiments revealed an improvement in the interfacial adhesion of the filler/polymer, which was confirmed by experimental mechanical characterization and Scanning Electron Microscope (SEM) analysis. The new composite demonstrated improved strength, ductility, and overall durability, demonstrating its potential as a bio-based polymeric material.

Abstract: The application of nanocellulose has been adapted as fillers in composite bricks. Raw kenaf and oil palm empty fruit bunch were treated through chemical treatment and high intensity ultrasonication process to produce cellulose nanofibrils (CNF). One control brick without CNF and ten CNF composite bricks were fabricated. The composite bricks used different amount of CNF which were 40 - 200 ml mixed with filtered sand, portland cement and pebbles. Physical and mechanical characterization was done by using field emission scanning electron microscopy (FESEM) and universal testing machine (UTM) on CNF and composite bricks. FESEM showed the fibril diameter were ranges from 30 - 80 nm for kenaf and 20 - 60 nm for oil palm. The compression tests showed that control brick, 40 ml kenaf CNF composite brick and 40 ml oil palm CNF composite brick were cracked at force 39.01 kN, 50.46 kN and 42.16 kN respectively. Kenaf CNF composite brick has the highest value of Young’s Modulus which is 28.92 N/mm², followed by oil palm CNF composite brick with 27.8 N/mm² and control brick (Malaysia Standard) with 25.8 N/mm². Kenaf and oil palm CNF can increase the strength of the bricks because of enhancement in their mechanical properties.

Abstract: Coconut shell (CS) reinforced unsaturated polyester (UPE) composites have been prepared by using hand lay-up and compression molding techniques. To improve fiber matrix adhesion, the CS (30 wt%) was chemically treated by two chemical treatments which are alkaline (NaOH) and alkaline-silane with concentration NaOH (6%) and silane (2%). To enhance the performance of CS-UPE composites, graphene nanoplatelets (GNP) was also added as a nano filler. Scanning electron microscopy (SEM) was used to investigate the morphology of the composite samples. Mechanical properties such as tensile and flexural tests of untreated and chemical treated CS-UPE composites was also studied and compared. Overall, the use of alkalized treated CS-UPE composites showed the best mechanical (strength and modulus). Therefore, alkaline treated CS was selected to be re-prepared with graphene as nano filler in UPE composites at 0.5, 1.0 and 1.5 wt% filler loading, respectively. The presence of GNP in CS-UPE composites have demonstrated a significant enhancement in modulus properties but at the expense of tensile strength. The use of 1.0 wt% of GNP seems more optimize loading since the increment of GNP has reduced the tensile strength, which might be due to the agglomeration issue.

Abstract: The purpose of this research is to study the mechanical and morphology of sugarcane bagasse (SGB) reinforced unsaturated polyester resin (UPR) composites by utilizing a different percentage of fibre contents and different chemical treatments on fibres. Sugarcane bagasse reinforced unsaturated polyester resin composites have been prepared using the compression molding technique. To enhance better adhesion between fibre and matrix, the SGB was chemically treated with alkaline (NaOH) solution and silane solution for 2 hours. The characterization of mechanical properties such as tensile and flexural strength, and tensile and flexural modulus of SGB-UPR composites were studied and compared. The incorporation of the alkaline + silane treatment of SGB resulted in better tensile and flexural properties of composites than untreated or alkaline-only treated SGB composites. Overall, it can be seen that the 5 % of fibre treated with NaOH + silane treatment showed the best results for tensile and flexural properties. Surfaces of cracked composites were observed using SEM and treated SGB showed better interfacial adhesion with matrix rather than the untreated SGB. Chemical treatment plays an important in enhancing the interfacial adhesion of fibre and matrix in composites.

Abstract: Alfa plant presents a great ecological and socio-economic interest in the Maghreb countries. It is used in several fields of applications such as craft production and paper industry. However, a few research work has been realized on the valorisation of Alfa fibres in the construction sector. The main objective of this work is to develop an Alfa fibre-reinforced mortar with significant mechanical properties for the facade panel’s manufacturing. It was highlighted that Alfa fibres enhance the flexural strength of reinforced mortars. Therefore, a decrease in the flexural strength of the composite after 90 days of curing. In addition, the incorporation of Alfa fibres reduced the compressive strength of the composite. In this regard, to enhance the mechanical properties of the composite, various treatments were explored: alkaline treatment with sodium hydroxide, hydrothermal treatment by water boiling, and coating with sulfoaluminate cement. It was noted that the treatments could provide a partial elimination of the non-cellulosic components and enhance the Alfa fibre roughness. Raw and treated Alfa fibres were incorporated into cement mortars at different lengths of the (10 and 20 mm) with an addition ratio of 1 %vol.. Compared to untreated fibres, fibres treated chemically provide an improvement of 38 % of the flexural strength at 28 days for both fibres length. Unlike the coated fibres, the efficiency of treatment was noted at 90 days of curing. Otherwise, a slight increase in compressive strength was observed compared to the untreated fibres mortar. These results were approved by porosity accessible to water and calorimetric tests.

Abstract: The article is devoted to studying the effect of liquid melt treatment with a substance having high affinity with hydrogen – lead-base silumin. Taking into account that gases (hydrogen, nitrogen and oxygen) are present everywhere, including alloys, a series of experiments was carried out on treating melt of blast furnace iron with substances having great affinity with hydrogen. It is established: when treating melt with lead-base silumin in the low-temperature test interval, there is a slight increase in the linear expansion coefficient (LEC) at 100°C, compared with the initial one, to 8.210^-6, deg^-1. In the temperature range of 100-150°C LEC decreases to a minimum value of 7.210^-6, deg^-1. In the average temperature range of 150-300°C, a sharp, anomalous increase is noticeable, compared with the initial one up to 15.5210^-6, deg^-1. When studying the microstructure of cast iron after processing the melt with lead silumin, the formation of ledeburite structure is stated. Samples treated with lead-base silumin were subjected to cementation by feeding water steam at 900°C for 1-5 hours. It should be noted that, in the temperature range of 50-150°C, the values of the linear expansion coefficient lie almost in a straight line in the entire field of study. The coefficient varies from 10.810^-6, deg^-1 at 50°C to 13.710^-6, deg^-1 at 450°C. Preliminary heat treatment of cast iron in the carburizer made by the Bondyuzhsky plant with water steam smoothes anomalies of LEC and increases its initial values, and grinds perlite and cementite as well. Subsequent quenching in water with a temperature of 1000°C significantly changes the linear expansion coefficient of cast iron. Hardening of samples after cementation sharply reduces the linear expansion coefficient in the test range of 150-200°C, and in the temperature range of 350-450°C negative values of LEC are observed. Thus, it can be concluded, that treating the melt with lead-base silumin, cementation in the medium of the carburizer made by the Bondyuzhsky plant and subsequent hardening leads to sharp changes of the linear expansion coefficient up to negative values. The identified properties suggest the possibility of using cast iron where it is necessary to constancy of LEC and there are no requirements for the weight of the product.

Abstract: Using PMMA Polymer reinforced by Natural Fiber (N.F.) materials have established much consideration because of several advantages for example low cost, non-abrasive, lightweight, non-toxic and the properties of bio-degradable. many kinds of research have been done in the recent usage of the natural reinforcing material to the preparation of different types of composites. Chemically treated jute fiber can enhance the surface of the fiber, decrease the absorption technique, and improve the roughness surface.in this research, pre-chemical treated in different lengths of jute- fibers in PMMA polymer-composites has been considered. Also, the effect of chemical treatment on mechanical properties of jute, jute reinforcing composite has been conferred. The results showed that the tensile strength T.S. of the treated in benzoylate solutions (4 mm) length fiber had good indicate to better interlocking between composite contents.Flexural-Strength F.S. of the-alkaline. solution treated (12 mm) length of fiber was obtained-better-results by increasing (16.5 %) compared with (2 mm) fiber-length. The fracture of the samples has discussed the relationship between composite adhesion. Impact Strength I.S. of the alkaline-treated (8,12 mm) fiber- a length that is due to to.better mechanical - interlocking between composite materials. The 2 mm fiber – length was not suitable-PMMA/ Jute composite in these tested for treated and untreated chemicals

Abstract: The jute polyethylene composites were developed using the hot-press technique with different fiber weight ratios. Due to the hydrophilic nature of fiber, it exhibited poor interfacial interaction to hydrophobic polymer matrix. In order to enhance the interfacial interaction between fiber and polymer, the benzene diazonium salt (BDS), propionic anhydride (PA), and 3-isocyanatopropyl triethoxysilane (silane) treated jute were used for the manufacturing of composites in this study. The chemical resistance tests of prepared composites were performed in order to probe whether these are resistant to various chemicals such as: acids, alkalis, and solvents. The effect of chemical treatments of the composites have been investigated. It was observed that the fabricated composites were resistant to all chemicals except carbon tetrachloride. The treated jute composites showed higher chemical resistance than raw jute composite and silane treated jute composite yield the highest resistance which can be suggested for making the water and chemical storage tanks.

Abstract: The aim of this work is to study the feasibility of recycling the rejected fiber-cement composites as the filler in the fiber-cement mixture for producing the new fiber-cement composites. The rejected fiber-cement composites were ground and mixed with ordinary Portland cement (OPC), sand, cellulose fiber, and the dissolving agent which was a chemical prepared from the proprietary blend of citric acid together with thickening and wetting agent. The samples (75 mm × 200 mm × 7 mm) were prepared by mixing the raw materials, including 34.25 wt% OPC, 30 wt% sand, 5.5 wt% cellulose fiber, and 30.25 wt% recycled fiber-cement composites. Then, the dissolving agent was added in the amount of 0 to 4.5 % of the OPC weight in the mixture. The mixtures of raw materials were mixed with water to form the slurry. Then, the green samples were produced by the filter pressing method. After molding, the green samples were autoclaved at pressure 10 bars and temperature 180 °C for 16 hrs. After that, the microstructure of the autoclaved samples was examined by scanning electron microscope (SEM). The modulus of rupture (MOR) and modulus of elasticity (MOE) of the samples were measured by universal testing machine (UTM) based on ASTM C1186-08 standard. The results showed that properties of the samples passed the requirements of the industrial standard. In addition, the utilization of dissolving agent affects both the microstructure and the properties of the samples.