Frontogenesis-inspired efficient synthesis of dense SWCNT fiber through in-situ boosting of catalyst re-nucleation

[Display omitted] •Purging cold gas inspired by frontogenesis enhanced catalyst re-nucleation.•Efficient production of SWCNT fiber (yield >20 %) due to better catalyst utilization.•In-situ densification eliminating the extra post-synthesis densification steps. The continuous synthesis of single-walled carbon nanotube fiber (SWCNT fiber) using the floating-catalyst chemical vapor deposition (FC-CVD) process is a promising route for industrial-scale production of this most sought-after fiber. However, the process poses three significant challenges, namely co-synthesis of amorphous carbon, a higher percentage of residual catalyst particles and lower densification. Managing these issues during synthesis often results in a lower yield. Due to these challenges, various post-synthesis treatments are required to realize their practical applications. Here, inspired by frontogenesis in temperate climatic region, flow engineering has been employed to achieve a highly selective synthesis of a dense network of SWCNT with a very high yield (>20 %), thereby making the process continuous and scalable in the true sense. The countercurrent flow of cold purge gas is used to enhance the re-nucleation of the catalyst in the growth zone causing a nearly four times increase in yield with very low defects (IG/ID > 100). The strategy used in this work employs in-situ densification of SWCNT aerogel resulting in the synthesis of fiber with high electrical conductivity (72 kS/m) and high tensile strength (more than 1.6 GPa) without using any post-synthesis chemical treatments. This accomplishment holds significant promise for various technological applications.