The excess electron in polymer nanocomposites. Issue 43 (29th October 2018)
- Record Type:
- Journal Article
- Title:
- The excess electron in polymer nanocomposites. Issue 43 (29th October 2018)
- Main Title:
- The excess electron in polymer nanocomposites
- Authors:
- Saiz, Fernan
Quirke, Nick - Abstract:
- Abstract : We have used ab initio molecular dynamics and density-functional theory (DFT) calculations at the B3LYP/6-31G** level of theory to evaluate the energy and localisation of excess electrons at a number of representative interfaces of polymer nanocomposites. Abstract : We have used ab initio molecular dynamics and density-functional theory (DFT) calculations at the B3LYP/6-31G** level of theory to evaluate the energy and localisation of excess electrons at a number of representative interfaces of polymer nanocomposites. These modelled interfaces are made by combining liquid water and amorphous slabs of polyethylene and silica. The walls of the amorphous silica slabs are built with two surface chemistries: Q 4 or fully-dehydroxylated and Q 3 /Q 4 or partially-hydroxylated with a silanol content between 1.62 and 6.86 groups per nm 2 . Our results indicate that in silica/polyethylene systems an excess electron would sit at the interface with energies between −1.75 eV with no hydroxylation and −0.99 eV with the highest silanol content. However, in the presence of a free water film, the chemistry of the silica surface has a negligible influence on the behaviour of the excess electron. The electron sits preferentially at the water/vapour interface with an energy of minus a few tenths of an eV. We conclude that the moisture content in a wet polymer nanocomposite has a profound influence on the electron trapping behaviour as it produces much lower trapping energies and aAbstract : We have used ab initio molecular dynamics and density-functional theory (DFT) calculations at the B3LYP/6-31G** level of theory to evaluate the energy and localisation of excess electrons at a number of representative interfaces of polymer nanocomposites. Abstract : We have used ab initio molecular dynamics and density-functional theory (DFT) calculations at the B3LYP/6-31G** level of theory to evaluate the energy and localisation of excess electrons at a number of representative interfaces of polymer nanocomposites. These modelled interfaces are made by combining liquid water and amorphous slabs of polyethylene and silica. The walls of the amorphous silica slabs are built with two surface chemistries: Q 4 or fully-dehydroxylated and Q 3 /Q 4 or partially-hydroxylated with a silanol content between 1.62 and 6.86 groups per nm 2 . Our results indicate that in silica/polyethylene systems an excess electron would sit at the interface with energies between −1.75 eV with no hydroxylation and −0.99 eV with the highest silanol content. However, in the presence of a free water film, the chemistry of the silica surface has a negligible influence on the behaviour of the excess electron. The electron sits preferentially at the water/vapour interface with an energy of minus a few tenths of an eV. We conclude that the moisture content in a wet polymer nanocomposite has a profound influence on the electron trapping behaviour as it produces much lower trapping energies and a higher excess-electron mobility compared to the dry material. … (more)
- Is Part Of:
- Physical chemistry chemical physics. Volume 20:Issue 43(2018)
- Journal:
- Physical chemistry chemical physics
- Issue:
- Volume 20:Issue 43(2018)
- Issue Display:
- Volume 20, Issue 43 (2018)
- Year:
- 2018
- Volume:
- 20
- Issue:
- 43
- Issue Sort Value:
- 2018-0020-0043-0000
- Page Start:
- 27528
- Page End:
- 27538
- Publication Date:
- 2018-10-29
- Subjects:
- Chemistry, Physical and theoretical -- Periodicals
541.3 - Journal URLs:
- http://pubs.rsc.org/en/journals/journalissues/cp#!issueid=cp016040&type=current&issnprint=1463-9076 ↗
http://www.rsc.org/ ↗ - DOI:
- 10.1039/c8cp04741c ↗
- Languages:
- English
- ISSNs:
- 1463-9076
- Deposit Type:
- Legaldeposit
- View Content:
- Available online (eLD content is only available in our Reading Rooms) ↗
- Physical Locations:
- British Library DSC - 6475.306000
British Library DSC - BLDSS-3PM
British Library STI - ELD Digital store - Ingest File:
- 8757.xml