Effect of Egyptian Attapulgite Clay on the Properties of PVA-HES–Clay Nanocomposite Hydrogel Membranes for Wound Dressing Applications

Abstract

In this study, attapulgite clay was extracted from North Western desert of Borg El-Arab, Egypt. The pristine clay was purified and treated before further use. The mineralogical composition of pristine clay was investigated by TEM, SEM, XRD and EDX analyses. Moreover, the pristine clay was organically modified with hexadecyl trimethyl ammonium chloride before incorporating into PVA-HES membranes. The modification of clay was also verified by FTIR, SEM and XRD analyses. Meanwhile, PVA-hydroxyethyl starch (PVA-HES/modified attapulgite clay) composite hydrogel membranes were fabricated by solution-casting method, where citric acid was utilized as cross-linker for formation of cross-linked membranes. The influence of addition of Egyptian modified attapulgite clay in ratios (0, 1.0, 3.0, 5.0, 7.0 and 10 wt%) on properties of PVA-HES composite membranes was studied in detail. Results revealed that the incorporation of modified attapulgite clay into membranes increased significantly the swelling ability and mechanical stability of composed hydrogel membranes. Also, the increase in clay contents in membranes showed antimicrobial activity against tested six pathogen strains and adequate hemolytic behavior, compared to clay-free membranes. These findings are referring to the capability of using of PVA-HES–attapulgite composite membrane as a good candidate for the purpose of super-absorbent dermal wound dressings.