Effect of alkaline treatment on the fruit peel of Pachira aquatic Aubl.: Physico-chemical evaluation and characterization

Abstract

Due to their bioavailability, lignocellulosic materials have gained increasing attention, and several chemical treatments been performed to promote modifications in their structure. Alkaline treatment promotes modifications in native cellulose and adds alkaline groups to the surface of the material, potentiating its use as an adsorbent. In this study, the effect of alkaline treatment with 2‑aminopropane (C3H9N 10% m v−1) and sodium hydroxide (NaOH 10% m v−1) on the fruit peel of Pachira aquatic Aubl. was evaluated, generating PBO and PBI samples, respectively. The samples were characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electronic microscopy (SEM), thermal analysis, point of zero charge, crystallinity index, moisture content and the alkaline groups were determined using the Boehm's method. The results show that organic alkaline treatment decreased the crystallinity of the material, while the inorganic alkaline treatment added alkaline groups to the surface of the sample.