Study on the inhibition mechanism of gastric mucus-mimetic inhibitors in coal spontaneous combustion

As a major safety hazard in coal mines, coal spontaneous combustion (CSC) necessitates continuous development of prevention and control technologies. Among various mitigation strategies, inhibitors have emerged as a key technology due to their high efficiency and controllability. Inspired by the gastric mucosal-mucus barrier, a composite inhibitor (GMA) was designed to integrate both physical barrier and chemical inhibition functions. The inhibition performance of GMA was evaluated using temperature-programmed desorption coupled with gas chromatography (TPD-GC) and Fourier transform infrared spectroscopy (FTIR).The physical oxygen-barrier properties of GMA were systematically characterized using scanning electron microscopy (SEM). Its inhibition mechanism was further investigated through quantum chemical calculations. It was found that GMA treatment lowered CO release by 92.7% relative to raw coal at 200℃ and induced a 31℃ lag in the self-ignition temperature. This inhibition effect was corroborated by FTIR, which indicated a substantial decrease in the peak intensities corresponding to key oxygen-containing and aliphatic functional groups. SEM analysis shows that sodium alginate (SA) alone can form a continuous and intact film, which effectively encapsulates coal particles. The addition of DL-malic acid(DL) further optimizes the microstructure of the film, making it denser and more uniform. Quantum chemical calculations reveal a dual role of DL. Structurally, it reinforces the SA-based barrier through hydrogen bonding and van der Waals forces. Reactively, it can act as a radical quencher via several pathways targeting species such as ·CH 3 and ·CHO. Specifically, the energy barrier for quenching ·CHO is low (15.43 kJ/mol), making this reaction readily accessible at low temperatures. In contrast, the barrier for quenching ·CH 3 is moderate (36.76 kJ/mol), yet remains kinetically viable. These exothermic pathways collectively establish the theoretical foundation for DL as an efficient radical scavenger. This paper proposes a bionic strategy that paves the way for developing a new generation of intelligent and efficient materials for mine safety prevention.