Thermodynamic Optimization Strategy Based on Entropy Regulation and Multi-Field Synergy: Efficient Continuous Preparation of Carbon Nanotube Fibers

Efficient and stable conversion of carbon sources within the reactor is a core prerequisite for the large-scale production and engineering application of carbon nanotube fibers (CNTFs). However, existing single-channel injection processes are limited by the thermodynamic constraint of low-entropy local concentration enrichment, leading to multi-field mismatch and catalyst sulfur poisoning, which in turn results in low carbon nanotube (CNT) yield and uneven CNTF diameter distribution. Based on the concept of entropy regulation, this study proposes a dual-channel multi-field synergistic matching strategy. By achieving spatial decoupling, thiophene is uniformly distributed locally within the reactor, thereby suppressing excessive catalyst poisoning, optimizing the matching conditions of concentration field, temperature field, and flow field during the preparation process, and effectively breaking through the technical bottleneck of CNTF growth. Experimental results show that, compared with the traditional single-channel injection process, this strategy can increase CNTF yield by approximately 80.1% under the Fe10S system constructed with an appropriate thiophene concentration, and improve the carbon conversion efficiency from 3.47% to 6.26%. Under higher catalyst precursor feed conditions, its advantages become even more significant, with a yield increase of up to 114.7% and a high production rate (6.2 mg/min). This study provides an innovative reactor engineering design approach for the continuous, stable, and large-scale preparation of high-performance CNTFs.