Macroscopically Self-Aligned and Chiralized Carbon Nanotubes: From Filtration to Innovation

Because of their natural 1D structure combined with intricate chiral variations, carbon nanotubes (CNTs) exhibit various exceptional physical properties, such as ultrahigh thermal conductivity and diameter-dependent electrical behavior, ranging from semiconducting to metallic. While CNTs excel individually at the nanoscale, their 1D and chiral nature can be lost on a macroscopic scale when they are randomly assembled. Therefore, the alignment and organization of CNTs in macroscopic structures is crucial for harnessing their full potential. In this Review, we explore recent advancements in understanding CNT alignment mechanisms, improving CNT aligning methods, focusing particularly on the controlled vacuum filtration technique, and demonstrating macroscopically 1D properties of ordered CNT assemblies. We also focus on a recently identified class of CNT architectures, combining CNT alignment and twisting mechanisms to create artificial radial and chiral CNT films at wafer scales. Finally, we summarize recent developments related to aligned and chiral CNT films in optoelectronics, highlighting their distinctive roles in nonlinear optics, thermal emission, and light modulation.