Microscale Experimental Study on the Mechanism of CO₂ Microbubble Rupture and Regeneration in Silicon Quantum Dots

In order to meet the needs of CO₂ geological storage technology in carbon capture, utilization and storage (CCUS), it constructs a reinforced foam system based on silicon quantum dots (SiQDs), and uses T-shaped microfluidic channels combined with high-speed camera technology to investigate the evolution of CO₂ microbubbles under different operating conditions, and explores the interface regulation mechanism of SiQDs on the dynamic behavior of CO₂ microbubbles. The results show that the flow parameters have a significant effect on the bubble dynamics: when the continuous phase flow velocity (0.05~2.00 mL/min) increases, the length of the CO₂ microbubble decreases, and the shear force gradually increases, replacing the interfacial tension as the dominant factor in the regulation of bubble size. An appropriate amount of SiQDs (0.05%) can be adsorbed to the bubble interface, improve the interfacial viscoelasticity, effectively inhibit the coalescence and rupture of CO₂ microbubbles, and enhance the stability of the foam. Under the synergistic effect of fluid shear force and SiQDs interfacial adsorption, the frequency of microbubble formation is increased by 20%~30% and the neck width change rate is increased by 5%~10% compared with that of pure surfactant foam system. Zero-dimensional SiQDs were introduced into the CO₂ foam strengthening system, and the CO₂ microbubbles with high stability and small size were successfully realized, which provided a theoretical and practical basis for the application of SiQDs in CO₂ geological storage technology.