# Dielectric Response of Crosslinked Adenanthera pavonina L. Galactomannan in pH-Controlled Medium

**Authors:** Antônia Millena de Oliveira Lima, Fernando Mendes, Lincoln Almeida Cavalcante, Cristiane Carvalho Araújo, Beatriz da Silva Batista, João Pedro Lemos Morais, Filipe Miguel Borges Amaral, Ana Angélica Mathias Macêdo

PMC · DOI: 10.3390/polym17070954 · 2025-03-31

## TL;DR

This study explores how pH affects the dielectric properties of crosslinked galactomannan from Adenanthera pavonina L., revealing structural and electrical changes.

## Contribution

The novelty lies in analyzing the dielectric response of crosslinked galactomannan under varying pH conditions.

## Key findings

- Crosslinking with glutaraldehyde reduces water solubility of galactomannan.
- pH variations influence polymer chain interactions and dielectric responses.
- Crosslinked samples show lower dielectric constants due to restricted chain mobility.

## Abstract

This research investigates the production of galactomannan from Adenanthera pavonina L. in its crude form and its subsequent crosslinking with glutaraldehyde under various pH conditions. The study involved the creation of films and sponges from these materials, followed by a comprehensive analysis of their structural, thermal, swelling, and electrical properties. Galactomannan was crosslinked with a fixed concentration of 0.2 mol/L of glutaraldehyde, with pH levels ranging from 3 to 7. These films and sponges were prepared through a slow solvent evaporation process. The research encompassed multiple analytical techniques, including Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry, swelling profile assessments, and impedance spectroscopy. The findings from structural analysis indicated that variations in pH did not alter the amorphous nature of the samples but did influence the interactions between galactomannan molecules and restricted the mobility of polymeric chains, which resulted in different dielectric responses. Crosslinked samples exhibited reduced water solubility compared to unprocessed galactomannan. Crosslinking also decreases the ability of the material to polarize and align in response to the electric field, which justifies why crosslinked samples present a lower dielectric constant than the crude sample.

## Linked entities

- **Chemicals:** glutaraldehyde (PubChem CID 3485)

## Full-text entities

- **Chemicals:** glutaraldehyde (MESH:D005976), water (MESH:D014867), Galactomannan (MESH:C012990), Adenanthera pavonina L. Galactomannan (-)
- **Species:** Adenanthera pavonina (Barbados pride, species) [taxon 3811]

## Figures

8 figures with captions in the complete paper: https://tomesphere.com/paper/PMC11991530/full.md

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Source: https://tomesphere.com/paper/PMC11991530