Papers by Keyword: Oleic Acid

Abstract: Oil contamination from petroleum hydrocarbons and other sources poses significant environmental and health risks due to its persistence and toxicity. This study developed polyethylene-calcium carbonate (PE-CC) composites with tailored structural and surface properties to enhance oil adsorption. The composites were fabricated through melt blending (PE:CC = 40:60), with the calcium carbonate (CC) filler first modified using oleic acid (OA) (0, 0.5, and 1.5 wt.%) to improve hydrophobicity and dispersion, followed by citric acid (1 M) treatment of the composites to induce porosity and optimize oil adsorption. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed successful surface modification of CC, as evidenced by reduced diffraction peak intensities and the emergence of new functional groups at 2970 cm^-1 and 1395.12 cm^-1. Citric acid treatment led to partial CC dissolution, resulting in up to 8.96 % weight loss, as confirmed by XRD and energy-dispersive spectroscopy (EDS). Scanning electron microscopy (SEM) revealed increased porosity (up to 40 μm) and enhanced surface roughness, particularly in TE 3. Wettability analysis demonstrated a maximum contact angle of 160.80° following OA modification of CC, while oil adsorption tests of the PE-CC composites showed substantial improvements in oil uptake, with vegetable oil adsorption increasing from 5.21 % (NE) to 18.75 % (TE 3), and hexane and diesel reaching 18.4 % and 12.5 % respectively, in TE 3. Photoluminescence analysis revealed wavelength-dependent blue-violet emissions with broad peaks at 405 and 570 nm when excited at 255 and 405 nm, respectively, indicating potential optical applications. These findings show the potential of OA and citric acid modifications in enhancing the surface properties, photoluminescence, and adsorption efficiency of PE-CC composites, positioning them as promising candidates for oil remediation and multifunctional industrial applications.

Abstract: Polystyrene (PS) is widely used in industries like packaging and insulation, but its performance can be enhanced by incorporating calcium carbonate as a filler. To improve polymer-filler compatibility, calcium carbonate was surface-modified with oleic acid, and PS-calcium carbonate composites were synthesized using the melt blending method, followed by citric acid treatment. X-ray diffraction (XRD) and FTIR analyses revealed no chemical interaction between the phases, with a reduction in calcium carbonate content due to citric acid treatment, suggesting partial dissolution of the filler. Scanning electron microscopy (SEM) images showed the formation of cavities in the matrix, especially in TPS3. Hardness testing indicated a decrease in hardness with increasing oleic acid concentration, with TPS3 exhibiting the lowest hardness (63.4 Shore D). Photoluminescence measurements showed a blue shift at lower oleic acid concentrations, while higher concentrations caused a red shift and broader emission, which was stabilized by citric acid treatment. Solvent absorption tests indicated that citric acid-treated composites had an enhanced absorption capacity, with TPS3 showing 38.3 % absorption in vegetable oil, suggesting potential for adsorption applications. Overall, the oleic acid and citric acid treatments significantly modified the mechanical, morphological, and optical properties of PS-calcium carbonate composites, creating tunable materials with potential for sensing applications.

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: Molecularly Imprinted Polymer-Oleic Acid (MIPOA) and Molecularly Imprinted Polymer-Palmitic Acid (MIPPA) were synthesized using oleic acid and palmitic acid as the templates; acetonitrile as the porogenic solvent; and allylthiourea as the monomer; and EDGMA as a cross-linker via bulk polymerization. The non-imprinted polymers (NIP) as a control were prepared with the same procedure, but with the absence of template molecule. The synthesized MIPs and NIP were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and the results showed the narrowing of –OH peak which shows that crosslinking has occurred. Field Emission Scanning Electron Microscope-Energy Dispersive X-Ray (FESEM-EDX) was used to analyze the composition of in both MIPs and NIP. The results yielded a composition of C, O, and S. This analysis corresponds to the composition of oleic acid and sulfuric acid as both templates contain -COOH group. These results suggested that the molecularly imprinted polymers can be employed as a potential adsorbent for the removal of oleic acid and palmitic acid from palm fatty acid distillate (PFAD) waste.

Abstract: Palm Fatty Acid Distillate (PFAD) consists of more than 80% of free fatty acids, primarily palmitic acid and oleic acid, which can be esterified and added to the biofuel and oleo-chemical industries as feedstock. Oleic Acid is also known as cis-9-octadecenoic acid has the chemical formula C₁₈H₃₄O₂ or (CH₃(CH₂)₇CHCH(CH₂)₇COOH). There have been numerous studies that demonstrate the nutritional value of oleic acid. The objectives of this research were to simulate the mechanism reaction design for Molecularly Imprinted Polymer (MIP) synthesis and to predict the bonding formed after synthesis by comparing the monomers and template. The mechanism and complexes formed were drawn according to the theoretical mechanism of MIP. The chemicals involved were allylthiourea as the monomer, oleic acid as the template, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,2-azobisisobutyronitrile (AIBN) as the initiator, and acetonitrile as porogenic solvent. The monomer, allylthiourea was compared with the other two monomers which are vinylpyridine and acrylamide in MIP synthesis prediction. On average, when the allylthiourea was used as the monomer, the bond length was quite similar for each connection of atoms (1.316 Angstrom). However, when the vinylpyridine and acrylamide were used as the monomers, the length of the bonds was not similar to each other. On top of that, the bond angles prediction for allylthiourea-oleic acid complex agreed with the molecular geometry shape was tetrahedral due to the average angle was 109.5^o. Next, two different templates; oleic acid and palmitic acid; were compared in MIP synthesis prediction. The bond length for oleic acid was on average quite similar to each other (1.316 Angstrom) whereas for palmitic acid as the template the bond length was not similar. The palmitic acid-allylthiourea complex showed the angles reading was not synchronized to each other and quite unstable, unlike the oleic acid-allylthiourea complex. The results agree that oleic acid as the template was the best in this setting parameter for MIP synthesis.

Abstract: Nitrogen-doped TiO₂ (N-TiO₂)/polytetrafluoroethylene (PTFE) has been prepared by optimization of nitrogen and polytetrafluoroethylene. N-TiO₂ has been modified by optimizing doping concentration in two-step process synthesis via solvothermal treatment, by mixing TiO₂ and variation ammonium carbonate as a nitrogen source at 0.5 M, 1.0 M, 1.5 M. Synthesized materials denoted as N-TiO₂, were characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared ( FTIR), Scanning Electron microscopy (SEM), and spectrophotometer UV Vis. Based on the XRD pattern, a shift diffraction pattern was assigned to [101] that indicated the nitrogen successfully doped. The functional group identified by FTIR shown an O-Ti-N bond seems to influence the energy gap of TiO₂. The presence of nitrogen as an impurity in semiconductor TiO₂ was decreased the amount of bandgap energy from 3.10 eV to 2.95 eV. Synthesized N-TiO₂ is a nanosphere morphology. Glass substrate containing N-TiO₂/PTFE has excellent self-cleaning in a ratio N-TiO₂/PTFE (1:3) and based on optical properties, show that each coating on the glass substrate has high transmittance for composition N-TiO₂/PTFE (1:3) > 90%. The contact angle before and after oleic acid contaminant under visible light are 97.68 and 94.16º, respectively. The discoloration of methylene blue (MB) coated on the glass performed under visible light shown 60.32% degradation.

Abstract: The purpose of this study was to investigate the influence of oleic acid as an additive in palm and coconut oils on tribological properties. Palm and coconut oils are vegetable oils that are consisted of free fatty acid, which one of the materials used as a source of environmental lubricant. Fatty acids in vegetable oil consist of saturated fatty acids and unsaturated fatty acids. Palm and coconut oils are rich in palmitic acid, which is categorized as saturated fatty acids. Whereas oleic acid is unsaturated fatty acids, and it has good lubricity as a lubricant. The effect of variation of oleic acid (10wt%, 20wt%, and 30wt%) in palm and coconut oils was investigated on tribological properties. The tribological properties were investigated by using a pin on disc apparatus and a ball bearing test rig. The results show that the effect of 10%wt oleic acids in coconut oil significantly increased its tribological properties with Δ scar width around 96 μm and 154 μm for the inner race and outer race, respectively.

Abstract: Nanofibers have high cell affinity due to their fine structure and surface roughness, and are expected to be used as biomaterials. In particular, magnetic nanofibers containing magnetic particles are expected to be used for magnetically induced drug delivery systems and hyperthermia. However, due to the aggregation of the magnetic particles contained in the nanofibers, there is a problem that the aggregation location becomes a starting point of fracture and causes a decrease in tensile strength. In this study, to improve the dispersibility of magnetic particles in Magnetite/PLA nanofiber nonwoven fabrics for suppressing the decrease in tensile strength, magnetite is subjected to surface treatment with oleic acid or stearic acid and ultrasonic agitation. Magnetite/PLA nanofiber nonwoven fabric was prepared by the electrospinning method, and dispersion of magnetite in PLA nanofiber nonwoven fabric and tensile strength were evaluated. Magnetite dispersion was improved by the surface treatment and increasing the ultrasonic agitation time. In particular, by performing the stearic acid treatment and prolonging the ultrasonic agitation time, the magnetite dispersion tended to be improved. This treated Magnetite/PLA nanofiber nonwoven fabric showed higher tensile strength.

Abstract: Starch-based hydrogels are biodegradable and biocompatible materials which have large surface area and are able to absorb a large amount of water. Hydrogels can be made of inclusion complexes between starch and hydrophobic guest molecules, such as starch-oleic acid complexes. The resulting hydrogels have advantages as the inclusion complexes can prevent the starch retrogradation in the hydrogel. For this purpose, inclusion complexes between starch and oleic acid were prepared by mixing cassava starch and oleic acid at 85 °C with varying complexation times(1 hour, 2 hours and 5 hours). Optimum result (product yield ~67%) was obtained by heating the reaction for 5 hours at 85 °C. In addition, the concentrations of oleic acid for complexation were varied at 10%, 20% and 50% (v/w) (calculated based on the weight of starch). The results showed that the maximum amount of oleic acid which could be complexed with starch was around 10% (v/w). The resulting products were characterized by Fourier Transform Infra Red (FTIR) spectroscopy, X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). FTIR results of the complexes showed vibration peaks at around 3600-3000 cm^-1 (-OH), 2900-2800 cm^-1 (-CH₂), 1300-1200 cm^-1 (C-O-C glycosidic bonds) and 1100-1000 cm^-1 (C-C and C­-O). The XRD results showed that the resulting complexes were crystalline and constructed of V₆-amylose, which was evidenced by the appearance of peaks at 2θ of 13.06° and 20.38°. Some complexes also showed interesting diffractions at 2θ of 17.07° and 30.26°. TGA results showed that the complexes started to decompose at either around 277 °C or 285 °C compared to starch which started to decompose at around 303 °C. SEM studies showed that the resulting complexes formed spheres with concave centers close to the shape of doughnuts. The complexes offered great potential to be applied as hydrogel materials, such as round hydrogels with initial average diameters of around 2.6 mm and 8.3 mm.

Abstract: In this paper, the mechanical properties of carboxymethyl cellulose-oleic acid (CMC-OA) solid bio-polymer electrolyte (SBE) were examined. The host, CMC was doped with different weight percentage (wt. %) of OA in the CMC-OA solution. The SBEs were tested by using the Universal Material Testing Machine where the readings of tensile strength and Young’s modulus can be obtained from the stress-strain curve produced by the software during the tension test. The sample of CMC doped with 20% wt. of OA was found to obtain the highest value of tensile strength and Young’s modulus which is 0.2069 MPa and 4.615 MPa respectively.