Abstract
Dispersing graphite nanpoflakes in aqueous suspension is essential both during their processing and to realise the high level of functionality they offer. In this study two types of chemical-free nanocelluloses were assessed as possible dispersing agent for graphite nanoflakes. Hydrothermally-produced nanocellulose (HTC) obtained by supercritical water treatment of microcrystalline cellulose, showed superior dispersing than the more conventional, mechanically-produced microfibrillated nanocellulose (MFC) alternative, effectively preventing nanoflake agglomeration. Thanks to the specific processing method, the HTC material displayed higher total surface energy and a favourable particle morphology. These properties resulted in a 2-fold reduction in the volume median colloidal particle size of nanographite in suspension upon addition of only 2 w/w% nanocellulose. The improved single particle dispersion within the suspension matrix could be observed microscopically and was reflected rheologically. The latter was achieved by parameterising the stress-shear rate response and fitting the linear segments displaying the suspension coupling response. Using chemical-free nanocellulose as dispersant in aqueous medium is a positive step toward the exfoliation of nanographite into graphene in a more affordable and environmentally-friendly way.
| Original language | English |
|---|---|
| Article number | 125668 |
| Number of pages | 14 |
| Journal | Colloids and Surfaces A: Physicochemical and Engineering Aspects |
| Volume | 610 |
| Early online date | 5 Oct 2020 |
| DOIs | |
| Publication status | Published - 5 Feb 2021 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- Green chemistry
- Nanocellulose
- Nanographite
- Nanoparticle dispersion
- Supercritical water