α terpineol

The information of 60 EOs is listed in Table S1 of supporting information. Lemon eucalyptus EO was purchased from Jiangxi Hualong Plant Flavor Co., Ltd., Ji’an, China; and other EOs were purchased from Guangzhou Yuxitang Cosmetics Co., Ltd. Guangzhou, China. All were pure EOs with no additive.
Benzyl acetate (purity: 95%), 2,2,4,6,6-pentamethyl-heptane (98%), menthol (97%), terpinen-4-ol (95%), cinnamaldehyde (98%), citral (isomers of neral and geranial, 98%), p-menthone (cis-&trans-isomers, 98%) and diethyl phthalate (99%) were purchased from Bidepharm (Shanghai, China). p-Cymene (97%) was purchased from Energy Chemical (Shanghai, China). Limonene (95%), linalool (96%), thymol (99%), carvacrol (98%), eugenol (99%), and β-caryophyllene (90%) were purchased from TCI (Shanghai, China). γ-Terpinene (95%), PEG-40 (HLB value: 13-14; pH value: 5.0-7.0), 1,2-propanediol (99%) were purchased from Macklin (Shanghai, China). α-Terpineol (96%) was purchased from Alfa Aesar (UK). (E)-2-Hexyl- cinnamaldehyde (92%) and DEET (99%) were purchase from Aladdin (Shanghai, China). Diisobutyl phthalate (99%) was purchased from J&K Scientific (Beijing, China). Defibrinated sheep blood was purchased from Rigorous Scientific (Guangzhou, China).

Ultrapure 18.3 MΩ⋅cm water used for these experiments was produced from a Zeneer Power III TOC system (Human Corp., Seoul, Korea). All the following reagents were purchased from Sigma Aldrich, unless stated otherwise, and were standard grade: butyl acetate, hexanal (Alfa Aesar, Haverhill, MA, USA), butanol, 3-methyl-1-butanol (Alfa Aesar), (E)-hex-2-enal (Alfa Aesar), hexanol, (Z)-hex-3-en-1-ol (Alfa Aesar), nonanal, 2-ethyl-1-hexanol, acetophenone, α-terpineol, benzyl alcohol, 2-phenylethanol, ethyl tetradecanoate, ethyl dodecanoate, methyl 2-hydroxybenzoate (Alfa Aesar), citronellol, ethyl decanoate, benzaldehyde (Alfa Aesar), ethyl octanoate, ethyl heptanoate, isoamyl acetate, limonene, 2-methyl-1-butanol, ethyl hexanoate, ethyl acetate, ethyl butanoate, Saccharomyces cerevisiae (Franke, Italy), (NH₄)₂HPO₄ (Franke, Italy), K₂S₂O₅ (Franke, Italy), tartaric acid, polyvinylpolypyrrolidone (Alfa Aesar), sodium azide (Alfa Aesar), NaOH, Na₂PO₄(H₂O)₂, citric acid, HCl, 3-octanol, MeOH, CH₂Cl₂, β-glucosidase enzyme (Ecozim AROM, CRC Biotek, Roma, Italy), hydrocarbon mixture from C8–C23 (Sigma-Aldrich, St. Louis, MO, USA).

The corroded surface of steel specimens was characterized using (FTIR) spectroscopy (Nicolet iS50, Thermo Fisher Scientific, USA) and Raman spectroscopy. The surface of the specimens was polished until a mirror-like surface was obtained using SiC paper and 1 μm of Al₂O₃ paste, rinsed with distilled water in an ultrasonic cleaning bath, and then dried in the oven. The prepared specimens were immersed in 1 M HCl solution in the presence or absence of the inhibitor at 298 K. The specimens retrieved from the test solution were carefully washed with distilled water and dried in the oven at 40 ℃ for 1 h. Raman spectra were obtained using a 10 mW power and 532 nm wavelength laser as an excitation source. In order to prevent thermal degradations (e.g., phase transformation of Fe oxides or burning of organic materials), the laser power used in this study was optimized, as shown in the Supporting Information (Figure S1). The FTIR and Raman spectra of tea tree extract and its constituents (i.e., α-terpineol (96% purity, Alfa Aesar, Ward Hill, MA, USA), 1,8-cineole (99% purity, Alfa Aesar, Ward Hill, MA, USA) and terpinen-4-ol (≥95% purity, Sigma Aldrich, Burlington, MA, USA)) were obtained by analyzing their raw materials.