Opuntia-Ficus-Indica (Nopal) mucilage as a steel corrosion inhibitor in alkaline media

Abstract

This paper presents results on the corrosion performance of reinforcing steel in alkaline media when dehydrated Opuntia Ficus Indica (Nopal) was used as an admixture. The dehydrated Nopal material was mixed with saturated calcium hydroxide (SCH) at 0.5, 1.0, and 2.0% by weight. Half cell potentials and Linear Polarization Resistance (LPR) measurements were performed at different time periods to characterize the corrosion inhibiting effect of the admixture. Results showed good corrosion inhibiting effect of dehydrated Nopal on reinforcing steel. The polarization resistance (R P ) value increased from an average of 40 kW cm 2 for regular chloride-contaminated SCH solution, to an average of 150 kW cm 2 for Nopal-added chloride-contaminated SCH solutions. The addition of Nopal led to the formation of a denser and more packed oxide/hydroxide surface layer on the steel surface that decreased corrosion activity. This oxide/hydroxide layer growth was confirmed from microscopic evaluation of the metal surface layer performed at the end of the experiment.

Exploitation of Leuconostoc mesenteroides strains to improve shelf life, rheological, sensory and functional features of prickly pear (Opuntia ficus-indica L.) fruit puree

“…Processing prickly pear for making beverages requires strategies, which aimed to overcoming faint flavour and the presence of mucilage responsible for unpleasant rheological properties (Mobhammer et al, 2006). Cactus-pear mucilage is composed of complex polysaccharides mainly consisting of galactose, arabinose, rhamnose, and galacturonic acid, which are thick and slimy, and confer an unpleasant viscosity often rejected by consumers (S aenz and Sepúlveda, 2001;Piga, 2004;Torres-Acosta, 2007).…”

State of the Art on Cactus Additions in Alkaline Media as Corrosion Inhibitors

“…This oxide/hydroxide layer growth due to Nopal interaction with the reinforcing steel was further confirmed by microscopy evaluation of the metal surface layer performed at the end of the experiment in [7]. It was found also that dehydrated Nopal provides a good protection to steel against pitting corrosion in chloride-contaminated alkaline media.…”

“…This gradual change from high to intermediate humidity changed the half-cell potential to more positive values (∼ +0.05 V versus CSE). During few minutes after [7]. starting the first ponding, the rebar half-cell potential, closest to the ponding pool, decreased few mileivolts (∼0.05 V more negative), as compared to the rebar away from the ponding pool tha stayed in the same range of potential values.…”

“…Results obtained from SCH solutions are based on the results of a previous investigation performed by the authors [7] and are shown in Figure 1. As observed from the half-cell potential of the control rebar specimens, the values reached passive potentials during the first hours, as compared to the rebars immersed in Nopal-added solutions, which reached similar potential values after almost 20 days of being immersed in such solutions.…”

Magnolia Champaca- Flower Extracts As Corrosion Inhibitor For Mild Steel In Acid Medium

“…The inhibition effect of Zenthoxylum alatum extract on the corrosion of mild steel in aqueous Orthophosphonic acid was investigated. [19][20][21].In continuation of our work on development of green corrosion inhibitors [22][23], the present study investigates the inhibiting effect of Magnolia champaca flower extract on the corrosion of mild steel in 0.5 M H 2 SO 4 solution by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods.…”