Abstract
Exudates gums from Pachylobus edulis (PE) and Raphia hookeri (RH) were evaluated as corrosion inhibitors for aluminium in HCl using weight loss and thermometric measurements at 30-60 °C. The exudates were found to retard corrosion rate of aluminium. The inhibition efficiency (%1) increased with increase in concentration of the exudates. Increase in temperature increased the corrosion rate in the absence and presence of inhibitors but decreased the inhibition efficiency. Both PE and RH exudate gums were found to obey Temkin adsorption isotherm and Kinetic-Thermodynamic Model of El-Awady et al. at all the concentrations and temperatures studied. Phenomenon of physical adsorption is proposed from the activation parameters obtained. Thermodynamic parameters reveal that the adsorption process is spontaneous. Exudate gum from RH was found to be a better inhibitor than PE.
| Original language | English |
|---|---|
| Pages (from-to) | 267-282 |
| Number of pages | 16 |
| Journal | Portugaliae Electrochimica Acta |
| Volume | 26 |
| Issue number | 3 |
| State | Published - 2008 |
| Externally published | Yes |
Keywords
- Adsorption isotherm
- Aluminium
- Corrosion inhibition
- Pachylobus edulis
- Raphia hookeri
ASJC Scopus subject areas
- Electrochemistry