Abstract
The liquid structure of the commonly used solvents dimethylformamide (DMF) and dimethylacetamide (DMA)were measured using state-of-the-art state neutron diffraction augmented with isotopic substitution (NDIS) and interpreted with empirical potential structure refinement (EPSR). Both solvents are found to develop rich local ordering with similar local packing densities, though with differences related to their three-dimensional molecular structure. While DMF’s dipole preferentially orientates anti-parallel to maximise hydrogen bonding, DMA favours parallel arrangement maximising non-directional dispersive forces. The highly-developed local orientational structure found in these solvents rationalises their ability to solvate a range of charged and neutral nanomaterials and highlights that the understanding of nanomaterial dispersions is a multi-body problem in which the geometry of the molecule, as well its dipole moment, must be incorporated.
Highlights
Dimethylformamide (DMF) and dimethylacetamide (DMA), shown in Figure 1, are both widely used, polar, aprotic solvents with a particuarly useful combination of physicochemical properties
Neutron diffraction with isotopic substitution, analysed by empirical potential structure refinement (EPSR) has been successfully used to elucidate the spatial and orientation correlations found for two common solvents, DMF and DMA
Analysis of the orientational correlations reveals opposite preferences for orientations of dipole moments in the first solvation shell, with DMF showing a small preference for anti-parallel alignment and DMA a slight preference for parallel alignment
Summary
Dimethylformamide (DMF) and dimethylacetamide (DMA), shown in Figure 1, are both widely used, polar, aprotic solvents with a particuarly useful combination of physicochemical properties. Dimethylformamide (DMF) and dimethylacetamide (DMA), shown, are both widely used, polar, aprotic solvents with a particuarly useful combination of physicochemical properties. DMF is a high boiling point (153°C) liquid, miscible with most solvents, notably baring aliphatics, capable of dissolving the majority of organic compounds, infiltrating most polymers, and being available in bulk quantities at low cost. Major applications include as polymer-solvent for fibre (electro) spinning [2], solid-state peptide synthesis [3], and more recently, as a solvent for charged and uncharged nanomaterials processing [4,5,6,7,8,9,10] where it has shown among the best performances for neat-solvent dispersion of nanocarbons [11,12,13,14,15,16,17]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call