Utilization of freeze thaw process for polyvinyl alcohol/sodium alginate (PVA/SA) hydrogel composite

Abstract

Polyvinyl alcohol/sodium alginate (PVA/SA) hydrogel was successfully prepared by freeze thaw process. Without crosslinking agent, hydrogel was formed by using 3, 5 and 7 consecutive cycles of freeze thaw. Hydrogel can be formed by hydrogen bonding formation between OH-group of sodium alginate and polyvinyl alcohol throughout network. Scanning electron microscope reported that microstructure of hydrogel was well packed. The interconnect porosity was also observed. Differential scanning calorimetry exhibited that two exothermic peaks at temperature of 110℃ and 225℃ were observed due to evaporation of water molecule and melting temperature of hydrogel, respectively. The swelling behavior was rapidly increased within initial stage and then it was dimensionally stable. With low sodium alginate content, tensile strength was slightly superior, whereas low in vitro degradation behavior was observed. It was remarkable to note that polyvinyl alcohol/sodium alginate (PVA/SA) hydrogel exhibited outstanding properties for being as a medical material.

A Lignin Silver Nanoparticles/Polyvinyl Alcohol/Sodium Alginate Hybrid Hydrogel with Potent Mechanical Properties and Antibacterial Activity

“…FT-IR spectroscopy was employed to demonstrate the successful fabrication of PVA/SA/ Lig-Ag NPs composite hydrogel materials and the formation of hydrogen bonds within the hydrogel. As shown in Figure 2a,b, the characteristic absorption bands of SA at 3289 cm −1 , 1608 cm −1 , and 1420 cm −1 correspond to hydroxyl (-OH) peaks, asymmetric and symmetric stretching vibration peaks of the carbonyl group (C=O) bond of the carboxylic acid group [9,31], and the increase in intensity and area of these peaks with the percentage of SA confirmed the higher content of SA in the hydrogel. The peak at 1184cm −1 can be attributed to the presence of PhOH on Lig-Ag NPs, further indicating the successful bonding of Lig-Ag NPs with PVA/SA compound.…”

“…The water absorption capacity of a hydrogel was highly correlated with its p applications. We discussed the swelling behavior of hydrogels in deionized wa shown in Figure 8, the hydrogel rapidly absorbed water in a short period of tim gradually reached equilibrium over time, indicating the strong hydrophilicity inhe its porous structure [9]. The accelerated swelling rate observed in the hydrogel w escalating content of SA could be ascribed to the abundant presence of -OH and in SA.…”

“…PVA exhibits outstanding characteristics, including non-toxicity, biocompatibility, high hydrophilicity, and the ability to form fibers and films, as well as chemical and mechanical resistance [8]. On the other hand, SA is a naturally occurring polysaccharide polymer that is extensively utilized because of its exceptional biocompatibility, rapid degradability, and cost-effectiveness [9]. Additionally, SA demonstrates inadequate mechanical properties and stability, which limits its potential applications [10].…”

Exploring the Impact of Alginate—PVA Ratio and the Addition of Bioactive Substances on the Performance of Hybrid Hydrogel Membranes as Potential Wound Dressings

“…The number of crosslinked molecules forming an insoluble gel fraction is reflected by the gel content of a hydrogel, while the non-crosslinked portion of the hydrogel dissolves upon immersion in a solvent, leading to a reduction in the sample weight [ 116 ]. In addition to PVA crosslinking, freeze–thaw cycles have been demonstrated to promote the formation of intermolecular bonds in Alg [ 84 , 117 , 118 ], collagen [ 101 , 119 ] and hyaluronic acid [ 100 , 120 ]. The biohybrid hydrogel membranes were found to exhibit lower values for the gel fraction when compared to the corresponding hybrid hydrogel membranes, as expected from previous assays.…”

Humidity‐Responsive Polyvinyl Alcohol/Microcrystalline Cellulose Composites with Shape Memory Features for Hair‐Styling Applications

“…[ 32 ] Interestingly, the swelling of the film showed a small peak after 3 h, and the swelling rate tended to decrease slightly after 6 h. Similar reductions in the swelling rate upon moisture or water absorption have been reported for other PVA‐based materials. [ 38,39 ] On the other hand, pure PVA absorbed more water, with its moisture absorption rate reaching 1.55 after 24 h, in contrast to the saturated moisture absorption changes of the PVA/cellulose composites. In the pure PVA films, moisture absorption was driven by the hydroxyl groups of PVA attracting water molecules through hydrogen bonds, until reaching 100% equilibrium at 100% humidity.…”