TY - THES UR - https://eprints.untirta.ac.id/53832/ A1 - Siahaan, Nathanael Stevent Pahala M1 - sarjana TI - SINTESIS ULTRASONIKASI NANOPARTIKEL LIGNIN DARI LIMBAH TANDAN KOSONG KELAPA SAWIT DALAM SUASANA ALKALI UNTUK APLIKASI INHIBITOR KOROSI BAJA API 5L Y1 - 2025/06/23/ N2 - Lignin is a natural polymer compound with promising potential as an eco-friendly raw material for nanoparticle synthesis. This study aims to isolate lignin from oil palm empty fruit bunch (EFB) waste using the Ultrasonic Assisted Alkaline Method (UAAM), and to synthesize lignin nanoparticles (LNPs) for application as corrosion inhibitors for API 5L carbon steel. Extraction was carried out using a QSONICA Q500 sonicator at 80% amplitude for 30 minutes under alkaline conditions, followed by precipitation using HCl (pH 2), centrifugation, and drying. LNP synthesis was conducted by varying ultrasonic parameters (amplitude, probe-to-beaker volume ratio, and duration) at pH 10. Particle size characterization was performed using PSA, based on the best results from free settling tests. The results revealed that ultrasonic conditions significantly influenced lignin particle size and stability. The optimum parameters were identified at 70% amplitude, 40 minutes, and a 1.2:5 probe-to-beaker ratio. These optimum conditions were then applied for the synthesis of EFB-derived LNPs, which were further characterized by FTIR, SEM, and XRD analyses. Functional groups characteristic of lignin remained detectable after sonication, with noticeable changes in specific band intensities. Approximately 72.66% of the samples achieved the target particle size of less than 300 nm. Characterization showed that the synthesized LNPs were crystalline, exhibited irregular morphology, and retained key lignin functional groups. However, corrosion inhibition tests indicated that raw EFB lignin demonstrated higher effectiveness compared to its nanoparticle form. Therefore, EFB lignin can be directly utilized as a corrosion inhibitor without the need for nanoparticle synthesis.. ID - eprintuntirta53832 AV - restricted EP - 138 PB - Fakultas Teknik Universitas Sultan Ageng Tirtayasa ER -