An Alignment Independent 3D-QSAR Modeling of Dispersibility of Single-walled Carbon Nanotubes in Different Organic Solvents

Abstract

An alignment free, three dimensional quantitative structure activity relationships (3D-QSAR) of dispersibility of single walled carbon nanotubes (SWNTs) in a diverse set of organic solvents was reported for the first time. GRIND methodology, where descriptors are derived from GRID molecular interaction fields (MIF), was used. Different variable selection procedures including: fractional factorial design (FFD), stepwise multiple linear regression (SW-MLR), successive projection algorithm (SPA), genetic algorithm (GA), and enhanced replacement method (ERM) were used to extract the more informative factors from exported GRIND descriptors and generate more predictive model. Partial least square (PLS) was applied to model construction and ERM-PLS based GRIND descriptors showed excellent performance in predicting of SWNTs dispersibility. ERM-PLS model satisfied a set of rigorous validation criteria and performed well in the prediction of an external test set. From the GRIND variables involved in ERM-PLS model the identification of some key molecular features and their position in solvent structure, which is crucial in SWNTs disperibility, would be possible. The obtained results confirmed the importance of hydrophobic interactions, size and steric hindrance of hydrophibic part of solvent molecule. Interestingly, the effect of presence of a hydrogen bond donor or polar group in structure of a solvent molecule with a large size couldn't be neglected.

Keywords:

• Single-walled carbon nanotubes (SWNTs)
• dispersibility
• 3D-QSPR
• GRIND
• enhanced replacement method

Notes

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