Reconstitution of cutin monomers on smectite surfaces: Adsorption and esterification

This paper focuses on the physico-chemical interactions of cutin monomers with clay smectites. Adsorption of cutin monomers was measured, and esterification and reconstitution were studied using Fourier transformed infrared spectrometry (FTIR), X-ray diffraction (XRD) and mass spectrometry (MS) analyses. Adsorption of a common cutin monomer, ω-dihydroxypalmitic acid (diHPA) to smectite was found to be affected by its interactions with exchangeable cations. Inner-sphere complexation was observed for Fe³⁺-montmorillonite, and nontronite. Outer-sphere complexes were observed for Ca²⁺- and Wyoming Na⁺-montmorillonite. XRD measurements showed that cutin monomers were intercalated between smectite layers, and MS results demonstrated their enhanced esterification on the smectite surfaces (as compared to monomer solution). This study suggests that cutin monomers can be reconstituted and esterified on the smectite surfaces to form stable organo-mineral complexes.