Cellulose nanofibers are green nanomaterials because of their biodegradability and sustainability, they are also attractive structural materials because of their high mechanical performance. For further expansion of their application and acquisition of their reliability, mechanical reinforcement and functionalization of cellulose nanofiber materials are required. In this work, we focused on the mechanical properties and thermal conductivities of composites of cellulose nanofibers and a nanodiamond (ND). Compared with graphene oxides, which are conventional two-dimensional nanocarbon fillers in aqueous media, natural diamond possesses a much larger modulus. It also has the highest thermal conductivity among all the elemental substances. The ND possesses hydrophilic oxygen functional groups at the surface, following a high dispersion in aqueous media and the rigid diamond structure at the core. In this work, the ND resulted in an increased mechanical reinforcement and enhancement of the thermal conductivity of the cellulose nanofiber, while keeping the high visible light transmittance originating from the latter. In particular, 2,2,6,6-tetramethylpiperidine 1-oxyl-oxidized cellulose nanofibers were reinforced more effectively than quaternary ammonium cellulose nanofibers because of the stronger interaction with the ND and higher dispersibility of the ND. Accordingly, it was proved that the cellulose nanofiber/ND composite was a promising high-strength and high-thermal-conductive material.

纤维素纳米纤维由于其生物可降解性和可持续性而为绿色纳米材料，由于其较高的机械性能，它们也是有吸引力的结构材料。为了进一步扩展其应用并获得其可靠性，需要纤维素纳米纤维材料的机械增强和功能化。在这项工作中，我们专注于纤维素纳米纤维和纳米金刚石（ND）的复合材料的机械性能和热导率。与在水性介质中是传统的二维纳米碳填料的氧化石墨烯相比，天然金刚石具有更大的模量。在所有元素物质中，它的导热系数也最高。ND在表面具有亲水性氧官能团，在水性介质中具有高度分散性，并且在核心处具有刚性的金刚石结构。在这项工作中，ND增强了纤维素纳米纤维的机械强度并提高了其导热性，同时又保持了源自纤维素纳米纤维的高可见光透射率。特别地，由于2,2,6,6-四甲基哌啶1-氧基氧化的纤维素纳米纤维比季铵纤维素纳米纤维更有效地增强，因为与ND的相互作用更强并且ND的分散性更高。因此，证明了纤维素纳米纤维/ ND复合材料是有前途的高强度且高导热性的材料。ND增强了纤维素纳米纤维的机械强度并提高了其导热性，同时又保持了源自纤维素纳米纤维的高可见光透射率。特别地，由于2,2,6,6-四甲基哌啶1-氧基氧化的纤维素纳米纤维比季铵纤维素纳米纤维更有效地增强，因为与ND的相互作用更强并且ND的分散性更高。因此，证明了纤维素纳米纤维/ ND复合材料是有前途的高强度且高导热性的材料。ND增强了纤维素纳米纤维的机械强度并提高了其导热性，同时又保持了源自纤维素纳米纤维的高可见光透射率。特别地，由于2,2,6,6-四甲基哌啶1-氧基氧化的纤维素纳米纤维比季铵纤维素纳米纤维更有效地增强，因为与ND的相互作用更强并且ND的分散性更高。因此，证明了纤维素纳米纤维/ ND复合材料是有前途的高强度且高导热性的材料。6-四甲基哌啶1-氧基氧化纤维素纳米纤维比季铵纤维素纳米纤维更有效地增强，因为它与ND的相互作用更强，ND的分散性更高。因此，证明了纤维素纳米纤维/ ND复合材料是有前途的高强度且高导热性的材料。6-四甲基哌啶1-氧基氧化纤维素纳米纤维比季铵纤维素纳米纤维更有效地增强，因为它与ND的相互作用更强，ND的分散性更高。因此，证明了纤维素纳米纤维/ ND复合材料是有前途的高强度且高导热性的材料。