Control of Hydrogel Properties By Incorporation of Surfactants: Dynamics Interfacial Properties of Precursor

Hydrogels are characterized by their three-dimensional hydrophilic polymer networks and remarkable capacity to absorb and retain high amounts of water. Hydrogels have a wide range of applications, from wound dressings and contact lenses to drug delivery systems and tissue engineering. Their ability to retain water and provide a moist environment makes them valuable in biomedical applications, such as promoting wound healing and supporting cell growth for regenerative medicine, and environmental applications, such as water retention in soil. This research comprehensively explores the potential to modify network structure and bulk properties of hydrogels by manipulating the macromer assembly prior to crosslinking by incorporating surfactants. The initial phase of this study is an in-depth investigation of the interfacial properties of surfactants and macromer mixtures. We use sodium dodecyl sulfate (SDS) as surfactant and polyethylene glycol diacrylate (PEGDA) as macromer. The dynamic surface tension of precursor is studied to determine the interaction of SDS and PEGDA, providing valuable insights into the alterations in bulk properties initiated by surfactant incorporation. Hydrogel synthesis is achieved through UV irradiation of aqueous solutions containing PEGDA and SDS. Then, the hydrogels are washed to remove the surfactant and unreacted species. Extensive swelling kinetics tests are conducted to evaluate the effect of surfactant on macromer assembly and subsequently on the swelling kinetics and network architecture. Moreover, drying kinetics studies give insights into the kinetics of water loss from the hydrogel, further elucidating its structural characteristics. The results and insights from this research will have profound implications for advancing hydrogel materials across a diverse spectrum of applications. The potential applications are vast and transformative, from tissue engineering, where precise control over hydrogel properties is needed for biomimetic scaffolds, to the sphere of plant growth, where tailored hydrogel formulations may change irrigation and nutrient delivery systems. This study is essential in exploring the multifaceted world of macromer-surfactant interactions in hydrogel synthesis, opening new horizons for innovation and technological advancement in materials science.