Molecular Dynamics Simulation Study on Two-Component Solubility Parameters of Carbon Nanotubes and Precisely Tailoring the Thermodynamic Compatibility between Carbon Nanotubes and Polymers

Abstract

Solubility parameters play an important role in predicting compatibility between components. The current study on solubility parameters of carbon materials (graphene, carbon nanotubes, and fullerene, etc.) is unsatisfactory and stagnant due to experimental limitations, especially the lack of a quantitative relationship between functional groups and solubility parameters. Fundamental understanding of the high-performance nanocomposites obtained by carbon material modification is scarce. Therefore, in the past, the trial and error method was often used for the modification of carbon materials, and no theory has been formed to guide the experiment. In this work, the effect of defects, size, and the number of walls on the Hildebrand solubility parameter (δ T ) of carbon nanotubes (CNTs) was investigated by molecular dynamics (MD) simulation. Besides, three-component Hansen solubility parameters (δ D , δ p , δ H ) were transformed into two-component solubility parameters (δ vdW , δ elec ). The quantitative relation between functional groups and two-component solubility parameters of single-walled carbon nanotubes (SWCNTs) was then given. An important finding is that the δ T and δ vdW of SWCNTs first decrease, reach a minimum, and then increase with increasing grafting ratio. The thermodynamic compatibility between functionalized SWCNTs and six typical polymers was investigated by the Flory−Huggins mixing model. Two-component solubility parameters were proven to be able to effectively predict their compatibility. Importantly, we theoretically gave the optimum grafting ratio at which the compatibility between functionalized SWCNTs and polymers is the best. The functionalization principle of SWCNTs toward good compatibility between SWCNTs and polymers was also given. This study gives a new insight into the solubility parameters of functionalized SWCNTs and provides theoretical guidance for the preparation of high-performance SWCNTs/polymers composites.

Hydroxyl-Enriched Core/Shell Carbon Nanotubes for Catalytic Hydrolysis of Regenerated Cellulose to Glucose

“…The increase of hydroxyl groups can also promote the dispersion of CNT/C-OHs (Figure S8). This result is consistent with the theory that the hydroxyl content on the surface of the CNT is directly related to the solubility parameters calculated by Luo et al 41 In addition, the formation of the shell layer on the surface of the CNT/C-OH by HTC does not damage the graphitization structure CNT (Figures S5 and S6). This result further shows the advantage of treating the CNT with concentrated nitric acid.…”

Asphaltene/polymer composites: Morphology, compatibility, and rheological properties

“…In another research, molecular dynamics was used to study the effect of carbon nanotube characteristics on the solubility parameters and, thus, its compatibility with polymers. [63] Additionally, Seo et al [5] calculated the solubility of polymers with group contribution methods and examined the compatibility of functionalized graphene nanosheets with polyethylene and its copolymers with optical microscopy. They suggested that when polymer and functionalized graphene nanosheets solubility parameters are similar, OM shows good dispersion and compatibility.…”

Fabrication of MWCNTS‐functionalized SA pervaporation composite membranes to enhance esterification

“…The serious aggregation of carbon nanotube makes it difficult to manipulate and combine with polymers 18 and the strong hydrophobicity affects membrane selectivity. Therefore, the hydrophilicity of multi‐walled carbon nanotubes should be improved 19,20 . The dispersibility of the functionalized carbon nanotubes obtained by carboxylation surface modification and ultrasonic interruption is significantly improved.…”

“…Therefore, the hydrophilicity of multi-walled carbon nanotubes should be improved. 19,20 The dispersibility of the functionalized carbon nanotubes obtained by carboxylation surface modification and ultrasonic interruption is significantly improved. Functional modification of carbon nanotubes can solve the problem of serious aggregation and strong hydrophobicity.…”