Ultralong carbon nanotubes (CNTs) are in huge demand in many cutting-edge fields due to their macroscale lengths, perfect structures, and extraordinary properties, while their practical application is limited by the difficulties in their mass production. Herein, we report the synthesis of ultralong CNTs with a dramatically increased yield by a simple but efficient substrate interception and direction strategy (SIDS), which couples the advantages of floatingcatalyst chemical vapor deposition with the flying-kite-like growth mechanism of ultralong CNTs. The SIDS-assisted approach prominently improves the catalyst utilization and significantly increases the yield. The areal density of the ultralong CNT arrays with length of over 1 cm reached a record-breaking value of ∼6700 CNTs mm −1 , which is 2−3 orders of magnitude higher than the previously reported values obtained by traditional methods. The SIDS provides a solution for synthesizing high-quality ultralong CNTs with high yields, laying the foundation for their mass production.

Carbon nanotube fibers (CNTFs) are endowed with excellent mechanical, electrical, and thermal properties and are considered promising candidates in numerous cutting-edge fields. However, the inherent black color of CNTFs hinders their practical application in fields with high aesthetic requirements such as wearable devices and smart textiles. Due to the smooth surface and chemical inertness, CNTFs are hard to be dyed by conventional chemical dyes or colorful inks. Herein, we realize a structural coloration of CNTFs by coating them with two metal oxide layers via atomic layer deposition. The three elements of color, that is, hue, saturation, and brightness, can be controlled by adjusting the types and thickness of each oxide layer. Colorful CNTFs with wide color gamut and high saturation are achieved through different combinations. A film interference model is also established to reveal the mechanism of the structural coloration, which is a comprehensive result of thin-film interference and surface roughness briefly. The calculated reflectance well fits the measured results by introducing surface roughness parameters. Moreover, the colored CNTFs are not iridescent because of retinal signal delay, which will further expand their applications.

The coloration of carbon nanotube (CNT) fibers (CNTFs) is a long-lasting challenge because of the intrinsic black color and chemically inert surfaces of CNTs, which cannot satisfy the aesthetic and fashion requirements and thus significantly restrict their performance in many cutting-edge fields. Recently, a structural coloration method of CNTFs was developed by our group using atomic layer deposition (ALD) technology. However, the ALD-based structural coloration method of CNTFs is expensive, time-consuming, and not suitable for the large-scale production of colorful CNTFs. Herein, we developed a very simple and scalable liquid-phase method to realize the structural coloration of CNTFs. A SiO 2 /ethanol dispersion containing SiO 2 nanospheres with controllable sizes was synthesized. The SiO 2 nanospheres could selfassemble into photonic crystal layers on the surface of CNTFs and exhibited brilliant colors. The colors of SiO 2 nanoparticle-coated CNTFs could be easily changed by tuning the sizes of SiO 2 nanospheres. This method provides a simple, effective, and promising way for the large-scale production of colorful CNTFs.

In orthopedics, developing functionalized biomaterials to enhance osteogenesis and bacterial resistance is crucial. Although poly­(ether ether ketone) (PEEK) is regarded as an important engineering plastic for biomedical material with excellent mechanical properties and biocompatibility, its biological inertness has greatly compromised its application in biomedical engineering. Inspired by the catecholamine chemistry of mussels, we propose a universal and versatile approach for enhancing the osteogenesis and antibacterial performances of PEEK based on surface functionalization of polydopamine-modified nanohydroxyapatite and lysozyme simultaneously. The characterizations of surface morphology and elemental composition revealed that the composite coating was successfully added to the PEEK surface. Additionally, the in vitro cell experiment and biomineralization assay indicated that the composite coating-modified PEEK was biocompatible with significantly improved bioactivity to promote osteogenesis and biomineralization compared with the untreated PEEK. Furthermore, the antibacterial test demonstrated that the composite coating had a strongly destructive effect on two bacteria (Staphylococcus aureus and Escherichia coli) with antibacterial ratios of 98.7% and 96.1%, respectively. In summary, the bioinspired method for surface functionalization can enhance the osteogenesis and bacterial resistance of biomedical materials, which may represent a potential approach for designing functionalized implants in orthopedics.

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