Adenine derived reactive dispersant and the enhancement of graphene based composites

• Published in: Journal of colloid and interface science 2023-06, Vol.640, p.91-99
• Main Authors: Cui, Junshuo, Sun, Lanlan, Sun, Qian, Xiong, Ying
• Format: Article
• Language: English
• Subjects: Adenine; Coating; Composite; Cross-link; Graphene dispersion; Reactive dispersant
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2023.02.069

Graphene can be uniformly dispersed in water at high concentration (6 mg mL−1) with the assistance of the dispersant. The dispersion is highly reactive and can self-cross-link via dehydrate condensation after direct casting on a glass slide. The obtained graphene composite shows good mechanical strength and excellent solvent resistance due to the formation of cross-linked Si-O-Si network inside the composite. [Display omitted] Homogeneous dispersion of graphene is the precondition for constructing high performance graphene based composites. However, most of the current dispersants reported in literature still suffer excess usage to reach a desired graphene concentration. Residual of dispersant in composite may seriously affect its properties. Hence, it is expected to obtain effective dispersant with high reactivity to diminish its adverse impacts on graphene composites. A highly reactive graphene dispersant (DSiA) was synthesized by grafting silanol groups (Si-OH) onto adenine. Molecular structure and the performance of the dispersant were systematically characterized. Composites were fabricated by direct writing of the graphene dispersion on various substrates, and their features were evaluated by resistance, solvent erosion and tensile testing. Graphene concentration can reach up to 6 mg mL−1 in the presents of DSiA at the weight ratio of 1:1 (DSiA: graphene). DSiA also exhibited good performance for stabilizing multi-walled carbon nanotubes (MWCNTs). Moreover, the dispersant is highly reactive. The graphene based composites showed good mechanical strength and excellent solvent resistance. Overall, the new dispersant provides an ideal choice to uniformly disperse graphene and suitable for fabricating high performance nanocarbon based composites.