The Open UniversitySkip to content

Self-assembly of fluoride-encapsulated polyhedral oligomeric silsesquioxane (POSS) nanocrystals

Heeley, Ellen; El Aziz, Youssef; Ellingford, Christopher; Jetybayeva, Albina; Wan, Chaoying; Crabb, Eleanor; Taylor, Peter G. and Bassindale, Alan (2019). Self-assembly of fluoride-encapsulated polyhedral oligomeric silsesquioxane (POSS) nanocrystals. CrystEngComm, 21(4) pp. 710–723.

Full text available as:
PDF (Version of Record) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (8MB) | Preview
DOI (Digital Object Identifier) Link:
Google Scholar: Look up in Google Scholar


The self-assembly and crystal packing of a unique series of nanocrystalline fluoride ion-encapsulated polyhedral oligomeric silsesquioxane compounds (F-POSS), with substituted electron-withdrawing group (EWG) perfluorinated alkyl chain arms of varying lengths was investigated. The fluorine-encapsulated T8[(CH2)n-EWG]8F--18-crown-6-ether-M+ and T8[(CH2)n-EWG]8F--tetrabutyl ammonium TBA+ compounds with fluorinated alkyl chain arms, were synthesized and subsequently analyzed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and simultaneous small- and wide-angle X-ray scattering SAXS/WAXS techniques. DSC and TGA of the compounds showed that the melting temperatures occurred below 100 °C and were thermally stable above their melting temperatures. SAXS/WAXS data probed the crystalline structure and self-assembly of the nanocrystalline compounds. At ambient temperatures, the crystalline structures of the compounds were seen to be complex with triclinic unit cells. On cooling from the melt, the self-assembly of the compounds with shorter fluorinated alkyl chain arms is dominated by the ionic attraction between the cages such that the arms form a disordered state that only reorder on standing. In contrast, the self-assembly of the compounds with longer fluorinated alkyl chain arms is dominated by the alignment of the arms into rod-like morphologies such that a fully ordered solid is formed from the melt. Electrical characterization has revealed that the POSS cages exhibited an insulating behavior. The POSS cages with or without fluoride ion encapsulation had similar AC conductivities but cages without fluoride ion encapsulation have the highest relative permittivity. The results show that due to the inorganic-organic-ionic nature the F-POSS ion encapsulated compounds and nanocrystalline self-assembly, they have great potential as interfacial compatibilizers enhancing miscibility of polymer composites and aiding interactions between polar and non-polar solvents as ionic liquids.

Item Type: Journal Item
Copyright Holders: 2018 The Royal Society of Chemistry
ISSN: 1466-8033
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Life, Health and Chemical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Research Group: Smart Materials
Item ID: 58501
Depositing User: Ellen Heeley
Date Deposited: 04 Jan 2019 16:06
Last Modified: 02 May 2019 09:33
Share this page:


Altmetrics from Altmetric

Citations from Dimensions

Download history for this item

These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU