Thursday, 6 February 2020 – 11:00 am in LT1, Level 1, School of Chemistry [Map].  (Special seminar)

Prof Elena Besley , School of Chemistry, University of Nottingham [Email: Elena.Besley@nottingham.ac.uk ]

Host:  Prof Peter Gill

Abstract:

The notion “like charges repel and opposite charges attract” is familiar to everyone, but electrostatic attraction between like-charged objects is also possible due to their mutual polarisation. We overview a comprehensive theory developed in our group over the past decade,¹ with universal relevance to the electrostatic properties of closely interacting particles of arbitrary size and charge,² which has been extended recently to modelling electrostatic interactions in solvents and ionized medium. The new formalism has been used to gain a comprehensive understanding of electrostatic particle-particle interactions in many areas of science, ranging from Coulomb fission of multiply charged clusters³ to aerosol growth in planetary atmospheres.⁴

This theory development also contributes to the design of thin films and surface assemblies with novel properties by providing insight into the effect of solvent on electrostatic self-assembly.⁵ The electrostatic deposition of particles has become an effective route to the assembly of many nanoscale materials. However, fundamental limitations to the process are presented by the choice of solvent, which can either suppress or promote self-assembly depending on specific combinations of nanoparticle/surface/solvent properties. Critical to assembly is the requirement for a minimum charge on a surface of an object, below which a solvent can suppress electrostatic attraction. Examples drawn from the literature are used to illustrate how a switch in electrostatic behaviour is mediated by the solvent.

Finally, experimental studies undertaken by Whitesides et al.⁶ relating to electrostatic self-assembly of polymer particles on a surface have been the subject of our dynamic computer simulations,⁷ where the consequences of changing the charge and the dielectric constant of the materials concerned have been explored. Our simulations successfully reproduce many of the observed patterns of behaviour.

1. J. Chem. Phys. 152, 024121 (2020); J. Comp. Phys. 371, 712 (2018); Soft Matter 14, 5480 (2018); J. Chem. Phys. 145, 084103 (2016); J. Chem. Phys.140, 074107 (2014); J. Chem. Phys. 133, 024105 (2010)
2. Perspective Article, Phys. Chem. Chem. Phys. 18, 5883 (2016)

1. J. Chem. Phys. 146, 164302 (2017); J. Phys. Chem. A 117, 3877 (2013); J. Chem. Phys. 151, 154113 (2019)
2. Icarus 291, 245 (2017)
3. J. Chem. Theory and Comp. 14, 905 (2018)
4. Nat. Mater. 2, 241 (2003); Soft Matter 8, 9771 (2012); JACS 136, 13348 (2014)
5. Phil. Trans. Roy. Soc. A 376, 20170143 (2018)