Effective Construction of Functional Interfaces for <scp>CF</scp> Composites Based on In Situ Growth Technology

ABSTRACT Carbon fiber‐reinforced polymer (CFRP) has emerged as one of the most advanced composite materials due to its exceptional properties, including high specific strength and fatigue resistance. However, its performance is constrained by issues such as the chemical inertness of carbon fiber (CF) surfaces, poor interfacial compatibility, and insufficient electromagnetic wave absorption capabilities. To address these issues, researchers have pursued studies in both resin matrix modification and CF modification. Among these, the in situ surface growth technology for CF stands out as an emerging modification strategy. Its unique chemical bonding mechanism and structural controllability have garnered significant attention. This paper reviews in situ growth techniques on carbon fiber surfaces. First, it introduces the definition of in situ growth on carbon fiber surfaces and its advantages over surface modification. Subsequently, it categorizes and describes the primary reaction types involved in the mechanisms of carbon fiber in situ growth. These include in situ vapor‐phase processes, in situ liquid‐phase processes, in situ solid‐phase processes, and in situ gas–liquid–solid processes. Subsequently, based on the characteristic of controllably constructing multidimensional materials on carbon fiber surfaces through in situ growth, the substances formed are categorized by dimensionality: zero‐dimensional, one‐dimensional, two‐dimensional, and three‐dimensional. Finally, the underlying mechanisms of macroscopic properties resulting from alterations in microstructure are analyzed, including mechanical, electrical, and thermal performances.