Characterization of PVA-IDA Hydrogel Crosslinked with 1.25%, 2.5% and 5% Glutaraldehyde

Abstract

Hydrogel membranes continue to be investigated for
potential use in a number of applications including
bioseparations, water purification, controlled drug release, to
name a few. The potential of hydrogels to overcome
disadvantages typically associated with packed bed
chromatography such as low protein loading, elution conditions
and regeneration increase their potential applicability and use for
biological separations. However, these materials typically provide
limited selectivity between proteins of similar size, low protein
loading and durability. To overcome these limitations, poly vinyl
alcohol (PVA) hydrogels were functionalized with metal affinity
ligand to provide a selective means to enhance protein loading
and improve protein separation characteristics. Additionally, the
crosslink ratio was varied from 1.25 % (v/v) to 5.0 % (v/v) to
further enhance membrane selectivity while also increasing
membrane durability. Characterization and comparison of
membranes with varied degrees of crosslinking and examination
of structural properties and behaviors of membranes were
determined for this study. Atomic Absorption Spectroscopy
(AAS), Fourier Transform Infrared spectroscopy (FTIR), and
Scanning Electron Microscopy (SEM) were used to characterize
and to examine IMAH membranes after functionalization.
Results demonstrate successful functionalization of the poly vinyl
alcohol membrane with metal affinity ligands. The FTIR results
showed different band frequencies for specific groups associated
with PVA cross-linked with glutaraldehyde. The presence of the
chelator did not impact the swelling properties of the membrane;
however, the Bound Copper Content (BCC) was increased by
50%
for the IDA-Me2+ membranes as the crosslinking ratio increased
from 1.25% to 5% GA (v/v).

Moreover, an increase in cross-linking ratio resulted in structural
changes that enhanced copper attachment which increased
protein solubility.