Hollow mesoporous carbon nanospheres from self-generating dual template synergetic assembly for enhanced curcumin release

Hollow mesoporous carbon nanospheres with accessible interior cavity, short diffusion length, and abundant mesopore channels can favor guest encapsulation and facilitate mass diffusion and transfer. However, there still remains great challenge in controllable synthesizing mesoporous carbons with uniform hollow architectures and relatively large mesopores by a straightforward method. Herein, a self-generating dual template synergetic assembly strategy was developed to construct hollow structured nitrogen-doped mesoporous carbon nanospheres (NMCNs) for the first time. Differentiating from conventional emulsion template methods, this synthesis involved the generation of nanoemulsion, which was driven by the interaction between oleic acid and triethanolamine based on the newborn soap effect. The process from alkalic to acidic environment induced the polymerization of the 3D cross-linking framework and established coulomb forces for dual template synergetic assembly. Significantly, the inner-cavity size of NMCNs could be facilely changed by simply varying the addition of oleic acid. Furthermore, varying the ethanol/water volume ratio would regulate the surface roughness of the NMCNs by directing the polymerization mode. This method innovatively coupled the dual template strategy and emulsion polymerization system, providing new insight into the construction of hollow mesoporous materials. Impressively, the hollow NMCNs featured dual pore size (5.2, 8.6 nm), high surface area (≈ 723.48 m 2 /g), and high nitrogen content (12.24 wt%), which delivered enhanced release rate and in vitro bioactivity of insoluble drug curcumin.