Development of Superhydrophobic Silica Based on Agricultural Biomass Waste as an Environmentally Friendly Corrosion Inhibitor Using Ultrasonic Dip-Coating Method on Metal Surfaces
Lisnawaty Simatupang 1)*, Ricky Andi Syahputra 2), Elfrida Ginting 3), Maryati Doloksaribu 4), Binsar Maruli Tua Pakpahan 5), Fransiskus Hottua Malau 6), Carlos Rewandes Sitorus 7),Winri Imanuella Sihombing 8)

1,2,3,4,6,7,8, Department of Chemistry, Universitas Negeri Medan, Medan 20221, Indonesia
* lisnawaty simatupang[at]unimed.ac.id
4, Department of Physics, Universitas Negeri Medan, Medan 20221, Indonesia
5, Department of Mechanical Engineering Education, Universitas Negeri Medan, Jl. Willem Iskandar Psr. V, Medan Sumatera Utara, 20221, Indonesia.

Abstract

Metal corrosion is a serious problem in the industrial world, causing material degradation, decreased efficiency, and increased operational costs. This study aims to develop a silica-based superhydrophobic coating from agricultural biomass waste as an environmentally friendly alternative to inhibit metal corrosion. Silica was extracted using the sol-gel method, modified using trimethylchlorosilane (TMCS), and formulated at a concentration of 1.0-5.0 percent in xylene solvent. The coating was applied to the surface of a metal plate using an ultrasonic dip-coating technique, then characterized using FTIR, XRD, and SEM. The FTIR spectrum demonstrated successful surface modification, characterized by the disappearance of the silanol group (SiOH) absorption band at 3420 cm-1 and the appearance of methyl groups (SiCH3) at 1260 cm-1 and Si-C groups at 840 cm-1. XRD indicated that the silica was amorphous, and SEM showed a fine particle morphology. The coating with a silica concentration of 3.0 percent demonstrated optimum performance with a water contact angle of 153.1 degrees and a shear angle of less than 10 degrees. Corrosion tests in 15 percent HCl and 3.5 percent NaCl media for 96 hours showed a decrease in the corrosion rate from 190.95 mpy to 37.42 mpy (HCl), and from 29.59 mpy to 2.13 mpy (NaCl), with inhibition efficiencies reaching 80.4 percent and 92.8 percent, respectively. These results indicate that the silica-TMCS coating from biomass waste is not only effective as a corrosion inhibitor but also has the potential to be developed as an environmentally friendly and sustainable functional coating.

Keywords: metal corrosion- biomass silica- superhydrophobic- green inhibitor- environmentally friendly coating

Topic: Applied Sciences and Information Technology