ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Chemical stability of sorbitan monolaurate under highly oxidative electrochemical environments

Wang Zonghao, Nie Yanyan, Shang Peiyuan, Chen Zheng, and Cheng Bin

Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing, China

E-mail: chengb@mail.buct.edu.cn

Received: 2 May 2023  Accepted: 24 February 2024

Abstract:

The primary objective of this investigation was to explore the electrochemical oxidation behavior of Sorbitan monolaurate (Span 20) under high-voltage environments. We designed and prepared working electrodes using a mixture containing Span 20 and conductive carbon black as an electron transport material. Linear sweep voltammetry (LSV) served as the technique to monitor the reactions undergone by Span 20. The oxidative products were subjected to analysis using X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance hydrogen spectrum (¹H NMR). LSV reveals the decomposition of Span 20 occurring at voltages exceeding 4.2 V, involving two distinct reactions. Further insights from XPS and ¹H NMR demonstrated that Span 20 underwent a two-electron-two-proton electrochemical reaction, producing triketone and 1, 3-diketone with a hydroxyl group positioned at the 2 position. To elucidate these results, a reasoning mechanism was proposed.

Keywords: Dispersant; Sorbitan monolaurate; Electrochemical oxidation; XPS; Linear voltammetry; 1H NMR

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03388-4

Chemical Papers 78 (7) 4277–4283 (2024)