Effect of γ-Fe₂O₃ Nanoparticles on the Cross-Linking and Final Properties of PVA/Citric Acid-Based Nanocomposites

Abstract

In this research work, γ-Fe2O3 nanoparticle addition effect on final properties of citric acid-cross-linked poly­(vinyl alcohol) was studied. It was observed that citric acid, besides working as a cross-linking agent for poly­(vinyl alcohol), also acted as a dispersant agent for γ-Fe2O3 nanoparticles. This double role of citric acid has been proven to be very useful for preparing magnetically responsive nanocomposites with a proper filler dispersion. Infrared spectroscopy and thermogravimetric analysis showed that nanoparticle addition affected the chemical structure of cross-linked poly­(vinyl alcohol), while swelling tests demonstrated that for the highest 8 wt % nanoparticle content studied, the cross-linking degree remarkably decreased as it was corroborated by dielectric relaxation spectroscopy. Mechanical properties were improved by cross-linking with citric acid, and results obtained for nanocomposites reflected the reinforcing effect of γ-Fe2O3 nanoparticles together with that on diminishing the cross-linking degree for the highest nanoparticle content. Finally, γ-Fe2O3 nanoparticles transferred their magnetic properties to studied nanocomposites leading to hybrid materials with response to magnetic fields.

Multifunctional low temperature-cured PVA/PVP/citric acid-based hydrogel forming microarray patches: Physicochemical characteristics and hydrophilic drug interaction

“…The first position is where two terminal carboxylic groups form two ester bonds with different polymer chains, connecting those strands (A position). The second is when both terminal carboxylic acids form ester bonds with two different hydroxyl groups in the same PVA chain (B position), and the last is when only one terminal carboxylic group forms an ester bond and the other end is left unreacted (C position) [21,32,33]. On the other hand, PVP participates through the interaction of oxygen in the pyrrolidone ring and PVA hydroxyl groups, forming hydrogen bonds.…”

“…CA contains three carboxylic acid groups, where the two terminal groups are often involved in crosslinking reactions. It is relatively biocompatible compared to other alternatives, such as glutaraldehyde, and is often considered a green crosslinker due to its biological and environmental safety [18,21,22]. Heat treatment at 130 • C has been used in many studies involving PVA/PVP/CA HF-MAPs formulations [13,18,19].…”

Preparation and Tensile Properties of Citric Acid Crosslinked Poly(vinyl alcohol) films reinforced with Nano‐Alumina

“…It has several interesting properties such as biodegradability, ease of processability, non-toxicity, and good film forming properties. 1,2 In view of its interesting properties, the polymer is widely used in different applications such as in the field of packaging for making biodegradable packaging materials, as a membrane material, in opto-electronics and sensors, in biomedical and drug delivery applications, as vibration damper and so on. [3][4][5][6][7][8][9][10] However, the inherent water solubility of PVA may restrict its uses.…”

“…In many of the published studies, it has been used as a crosslinker for PVA systems owing to its nontoxic nature and low cost. 1,10,[12][13][14] Also, the citric acid has been listed as a food additive, preservative and emulsifier across many industries. 15 This is particularly helpful in PVA based packaging films for food packaging applications.…”

“…whereas the non-carbon based include a variety of metals like nano-silver, nanocopper, and so on 20,21 and metal oxides like silicon dioxide, zinc oxide, iron oxide to name a few. 1,22,23 Nano-alumina is another important metal oxide nanomaterial that has outstanding mechanical properties, good corrosion and abrasion resistance and is biocompatible as well. 16,24,25 Barring a few published studies on PVA-nano alumina, [25][26][27] there has not been much literature on the mechanical properties of PVA-alumina nanocomposites.…”