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Effect of sonication to the stability properties of carboxymethyl cellulose/uncaria gambir extract water-based lubricant Rahmadiawan, Dieter; Ilhamsyah, Febrian; Abral, Hairul; Laghari, Imtiaz Ali; A, Yufrizal
Teknomekanik Vol. 5 No. 2 (2022): Regular Issue
Publisher : Universitas Negeri Padang

This study examined the effect of sonication on FTIR and stability at various temperatures in water-based lubricants with a mixture of Carboxymethyl Cellulose (1wt%) and Uncaria Gambir extract (1wt% and 2wt%). The sample was prepared by mixing the two materials into distilled water using a magnetic stirrer and sonicator with time variations of 5 and 10 minutes. Before mixing, the Uncaria Gambir extract solution with water is first centrifuged to remove the dregs in the Uncaria Gambir extract powder. Stability was carried out in an open room (28oC), drying oven (50oC), and refrigerator (5oC). The stability test results showed that the mixture of Carboxymethyl Cellulose and Uncaria Gambir had good stability at all temperatures after sonication for a short duration. The longer sonication duration could fuse the fibrils of Carboxymethyl Cellulose, leading to increasing particle size. FTIR results also show that there is no chemical reaction that occurs. After adding the gambier, there was a new peak at wave 800-1300 cm-1, corresponding to the gambier. The results of this study indicate that the Carboxymethyl Cellulose and Uncaria Gambir solution can be a potential lubricant additive. The Carboxymethyl Cellulose can be a viscosity modifier, while Uncaria Gambir extract for corrosion inhibitor.

Enhancing Current Density and Specific Capacitance of Nata de Coco, TEMPO, and MXene Composites through Boiling Time Variations Yunus, Syukri; Umah, Kuntum Khairah; Abral, Hairul; Ogah, Ogah Anselm; Aulia, Aulia
Andalasian International Journal of Applied Science, Engineering and Technology Vol. 3 No. 3 (2023): November 2023
Publisher : LPPM Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/aijaset.v3i3.110

This research aimed to enhance the current density and specific capacitance of electronic device materials to replace traditional metal materials. Composite materials that include Nata de Coco, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl), and MXene achieve this improvement. Composite materials that include Nata de Coco, TEMPO, and MXene accomplish this improvement. Initial testing has shown that these materials initially demonstrated lower electrical properties, particularly in current density and specific capacitance, than conventional metals. To enhance their electrical properties, we employed a boiling method with variations in boiling time. The time intervals chosen were 30, 300, and 480 minutes. In the manufacturing process, Nata de Coco, previously oxidized by TEMPO, was boiled in an MXene solution at a temperature of 70°C. We tested the electrical properties of the resulting composite film, focusing on current density and specific capacitance. The measured current density values, corresponding to the different boiling times, were as follows: 0.000239 A/cm² for 30 minutes, 0.000307 A/cm² for 300 minutes, and 0.000320 A/cm² for 480 minutes. The specific capacitance values were 1.7005 F/g for 30 minutes, 1.9707 F/g for 300 minutes, and 2.0364 F/g for 480 minutes. The percentage increase in current density and specific capacitance values from 30 minutes to 300 minutes of boiling was 22% and 13.7%, respectively. For boiling from 300 to 480 minutes, the increase was 4.06% for current density and 3.22% for specific capacitance. These findings suggest that longer boiling times result in improved electrical properties. Subsequently, characteristic tests were performed, including XRD (X-ray diffraction) and SEM (Scanning Electron Microscope) analyses. The XRD results indicated that longer boiling times caused a rightward shift of the diffraction peak with a narrower peak width, signifying increased crystallinity. The highest X-ray intensity was observed in the composite boiled for 480 minutes, with a power of 847.23 counts per second (cps) and a two-theta angle of 21.31°. Additionally, the smallest crystal size was achieved with a 480-minute boiling time, measuring 138.2851 Å. In the SEM analysis, it was evident that longer boiling times led to a higher fraction of MXene within the composite film.

Enhancing Current Density and Specific Capacitance of Nata de Coco, TEMPO, and MXene Composites through Boiling Time Variations Yunus, Syukri; Umah, Kuntum Khairah; Abral, Hairul; Ogah, Ogah Anselm; Aulia, Aulia
Andalasian International Journal of Applied Science, Engineering and Technology Vol. 3 No. 3 (2023): November 2023
Publisher : LPPM Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/aijaset.v3i3.110

This research aimed to enhance the current density and specific capacitance of electronic device materials to replace traditional metal materials. Composite materials that include Nata de Coco, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl), and MXene achieve this improvement. Composite materials that include Nata de Coco, TEMPO, and MXene accomplish this improvement. Initial testing has shown that these materials initially demonstrated lower electrical properties, particularly in current density and specific capacitance, than conventional metals. To enhance their electrical properties, we employed a boiling method with variations in boiling time. The time intervals chosen were 30, 300, and 480 minutes. In the manufacturing process, Nata de Coco, previously oxidized by TEMPO, was boiled in an MXene solution at a temperature of 70°C. We tested the electrical properties of the resulting composite film, focusing on current density and specific capacitance. The measured current density values, corresponding to the different boiling times, were as follows: 0.000239 A/cm² for 30 minutes, 0.000307 A/cm² for 300 minutes, and 0.000320 A/cm² for 480 minutes. The specific capacitance values were 1.7005 F/g for 30 minutes, 1.9707 F/g for 300 minutes, and 2.0364 F/g for 480 minutes. The percentage increase in current density and specific capacitance values from 30 minutes to 300 minutes of boiling was 22% and 13.7%, respectively. For boiling from 300 to 480 minutes, the increase was 4.06% for current density and 3.22% for specific capacitance. These findings suggest that longer boiling times result in improved electrical properties. Subsequently, characteristic tests were performed, including XRD (X-ray diffraction) and SEM (Scanning Electron Microscope) analyses. The XRD results indicated that longer boiling times caused a rightward shift of the diffraction peak with a narrower peak width, signifying increased crystallinity. The highest X-ray intensity was observed in the composite boiled for 480 minutes, with a power of 847.23 counts per second (cps) and a two-theta angle of 21.31°. Additionally, the smallest crystal size was achieved with a 480-minute boiling time, measuring 138.2851 Å. In the SEM analysis, it was evident that longer boiling times led to a higher fraction of MXene within the composite film.

Impact of Relative Humidity on Electrochemical Performance of MXene-Zn-CNC Composite Films Fernandez, Rudy; Abral, Hairul; Elfitri, Ikhwana
ASEAN Journal for Science and Engineering in Materials Vol 4, No 2 (2025): AJSEM: Volume 4, Issue 2, September 2025
Publisher : Bumi Publikasi Nusantara

Show Abstract | Download Original | Original Source | Check in Google Scholar

This study examines the influence of relative humidity (RH) on the electrochemical and structural properties of polyvinyl alcohol (PVA) composite films reinforced with MXene, zinc oxide (ZnO), and cellulose nanocrystals (CNC). Composite films were fabricated via solvent casting and conditioned at RH levels of 50%, 75%, and 94%. Cyclic voltammetry and four-point probe tests revealed substantial enhancements in current density, specific capacitance, and bulk conductivity with increasing RH, attributed to improved ionic mobility and interfacial polarization. X-ray diffraction indicated reduced crystallinity due to polymer swelling, while scanning electron microscopy showed enhanced MXene dispersion at higher RH. Fourier-transform infrared spectroscopy confirmed intensified hydroxyl interactions, reflecting increased hydrophilicity. These humidity-induced improvements suggest promising applications in humidity-responsive flexible electronics and sensors. However, potential trade-offs include reduced mechanical stability under prolonged exposure. The findings offer new insights for optimizing hydrophilic polymer composites to enhance environmental adaptability and advanced device performance.

Loading-dependent mechanical performance of alkali-treated areca nut husk fiber reinforced polyester composites modified with Uncaria gambir extract Nabawi, Rahmat Azis; Syahril, Syahril; Abral, Hairul
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.52472

Natural fiber-reinforced polymer composites often experience mechanical performance limitations due to weak interfacial bonds between hydrophilic fibers and hydrophobic matrices. This study experimentally examined the effect of alkali treatment and modification using Uncaria gambir extract (UGE) on the mechanical properties and interface morphology of polyester composites reinforced with areca nut husk fiber (ANHF). Four composite configurations were prepared with a constant fiber weight fraction of 40 wt.% after alkali treatment using 6% NaOH for 24 hours, while the remaining 2 wt.% UGE was selectively applied as a fiber surface treatment, matrix additive, or a combination of both. Tensile and flexural properties were evaluated in accordance with ASTM standards, while interface morphology was examined using scanning electron microscopy (SEM). The results showed that alkali-treated composites without UGE addition had the highest tensile strength, which was attributed to increased fiber surface roughness and mechanical interlocking mechanisms. Conversely, fiber surface modification using UGE significantly increased flexural strength, indicating better stress distribution under flexural loading due to increased interface continuity. However, the addition of UGE to the matrix caused a decrease in tensile strength, which was thought to be related to a reduction in matrix stiffness. SEM observations confirm the presence of distinct interface morphology differences according to the treatment applied. These findings indicate that UGE serves primarily as a bio-based interfacial modifier, enhancing flexural performance, while its effectiveness is strongly governed by the mechanical loading mode.

Harnessing Rotating Heat Pipes for Passive Electric Motor Cooling: Enhancing Electric Vehicle Efficiency Siregar, Yasmine Karenita; Rezqi, Khairu; Putra, Gerardo Janitra Puriadi; Fathoni, Andhy M; Putra, Nandy; Abral, Hairul
Journal of Engineering and Technological Sciences Vol. 58 No. 1 (2026): Vol. 58 No. 1(2026): February
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2028.58.1.7

Electric vehicles are equipped with electric motors that convert electrical energy into mechanical energy to propel the vehicle. The motor experiences an increase in temperature during operation due to various losses that cause the motor temperature to rise. The performance of the electric motor will be reduced or even damaged if the heat continues to increase and the temperature exceeds 60°C. Therefore, there is a need for a cooling system that can maintain the electric motor's temperature within its working range. This study aims to investigate and test the rotating heat pipe (RHP) as a passive cooling system for electric motors. The objective of this research is to examine the performance of the RHP. The study employs a RHP with installed thermocouples on its surface. Additionally, a slip ring is utilized to serve as interface between the data acquisition module and the thermocouple sensor. In this investigation, the Rotating Heat Pipe was equipped with two slip rings to measure temperature in rotary conditions. This study proves that using RHP can reduce thermal resistance by 30-66% compared to stationary heat pipes.

Modified PVA Film from Methanol-Soluble Phenolic Extracts of Spatholobus littoralis Hask as Active Pharmaceutical Packaging Kadriadi, Kadriadi; Abral, Hairul; Mahardika, Melbi; Ilhamdi, Ilhamdi; Akmal, Akmal; Handayani, Dian; Yulianis, Yulianis; Kassim, Mohamad Haafiz Mohamad; Ariksa, Jeri
Journal of Fibers and Polymer Composites Vol. 5 No. 1 (2026): Journal of Fibers and Polymer Composites
Publisher : Green Engineering Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55043/jfpc.v5i1.567

The development of active pharmaceutical packaging based on biodegradable materials is an important strategy to reduce dependence on single-use plastics and their environmental impact. Polyvinyl alcohol (PVA) is a potential biodegradable polymer, but it has limitations in terms of exposure to ultraviolet (UV) radiation and microbial contamination. This study aims to develop a modified PVA film with methanol-soluble phenolic extract of Spatholobus littoralis Hask as active pharmaceutical packaging with UV protection, antioxidant, and antibacterial functions. The phenolic extract was obtained through a maceration method using methanol as a solvent, while the PVA film was fabricated using the solution casting technique. The PVA film was modified with varying concentrations of phenolic extract of 0, 1.25, 2.5, and 5wt% (PPE0, PPE1.25, PPE2.5, and PPE5), then evaluated for its UV protection properties, antioxidant activity, and antibacterial activity. The results showed that the addition of S. littoralis phenolic extract was able to increase the ability of PVA films to block UV radiation completely (100%) in the 200–400 nm wavelength range. Antioxidant activity testing using the DPPH method showed an increase in free radical scavenging ability as the concentration of phenolic extract increased. In addition, the modified PVA film showed significant antibacterial activity against Staphylococcus aureus and Escherichia coli. These findings indicate that S. littoralis Hask phenolic extract has potential as a natural bioactive agent in the development of environmentally friendly and multifunctional active pharmaceutical packaging, with dual protection capabilities against UV degradation and microbial contamination. This research makes an important contribution to the development of sustainable pharmaceutical packaging materials based on renewable natural resources.

The Effect of Temperature on Manufacturing Process of Tannin Acid-Based Adhesive Materials on Mechanical and Physical Properties Perdana, Mastariyanto; Abral, Hairul; Son, Lovely; Masruchin, Nanang; Azmi, Muhammad; Kadriadi, Kadriadi
Journal of Fibers and Polymer Composites Vol. 5 No. 1 (2026): Journal of Fibers and Polymer Composites
Publisher : Green Engineering Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55043/jfpc.v5i1.570

This study focuses on the development and characterization of adhesives based on Polyvinyl Alcohol (PVA), Tannic Acid (TA), and Cellulose Nanofibre (CNF). The main objective is to optimize the temperature used in the production process. Phenol-formaldehyde and other synthetic adhesives frequently encounter environmental obstacles, necessitating the search for more ecologically sound alternatives. TA, a naturally occurring polyphenolic molecule, has significant potential as an eco-friendly glue ingredient. This study assesses the impact of temperature fluctuations (30, 45, 60, 75, and 90°C) during the glue manufacturing process on its mechanical characteristics, specifically emphasizing shear stress. Experiments were conducted at a rotational speed of 1500 revolutions per minute (RPM) for 30 minutes. The results indicated that the adhesive performed best at 90°C, achieving a maximum shear stress value of 3.41 MPa. The results demonstrated a significant enhancement in the shear strength of the bioadhesive, exhibiting an approximately sixfold increase as the processing temperature was elevated from 30°C to 90°C. Microstructural analysis reveals that the voids formed during the mixing process decrease at this specific temperature. The results indicate that elevated temperatures lead to a significant reduction in void formation. The FTIR measurement revealed the absorption of hydroxyl groups around 3305 cm⁻¹, suggesting the presence of robust crosslinking. Furthermore, elevated temperatures lead to a significant reduction of free OH- groups within the bioadhesive. The PVA/TA/CNF adhesive possesses extensive potential for application in industries that necessitate adhesives with exceptional strength. The study is anticipated to offer comprehensive understanding of how to improve the manufacturing process of TA-based adhesives, and its impact on the creation of adhesive materials that are more sustainable and environmentally friendly.

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