One-Pot Assembly of Microfibrillated Cellulose Reinforced PVA–Borax Hydrogels with Self-Healing and pH-Responsive Properties

Abstract

A facile, environmentally benign approach has been developed for the preparation of dynamic, multiresponsive, and self-healing hydrogels from inexpensive bamboo pulp, poly(vinyl alcohol) (PVA), and borax. The microfibrillated cellulose (MFC) reinforced PVA−borax hydrogels were produced through a onepot route in conjunction with ball milling and physical blending in tandem in aqueous medium. In this way, MFC particles could be efficiently generated and well-dispersed in a polymer matrix, and they have been verified by scanning electron microscopy. The rheology analysis indicated a close relationship between the mechanical strength and the MFC loading and ball milling time. Due to the dynamic equilibrium of the didiol−borax linkages and the reinforcement of MFC fibers, the hydrogels showed enhanced self-healing behavior and mechanical stiffness, which was also supported by rheology analyses. In addition, the hydrogels were found to be sensitive to the pH value. The hydrogels present a solvent or gel state with the change of pH value, and this sol−gel transfer can be repeated while maintaining the shape, further demonstrating the dynamic reversible behavior of the hydrogels.

Self‐Healing Hydrogel of Poly (vinyl alcohol)/Agarose with Robust Mechanical Property

“…However, with the excessive cross‐linking, the network structure was so tight that the water molecules penetrated hardly, and the water content became less. Due to form more brittle polymer, the mechanical properties have declined . When the content of AG was 5%, the hydrogel has good tear resistance and ductility.…”

“…As the concentration of AG increased, the compressive modulus added accordingly (Figure c). It was possible that an increase in electrostatic repulsion resulted in chain expansion, and an increase in cross‐linking density and hydrogel concentration reduced the water content . Higher concentrations of AG reduced the ability of the PVA to dissipate stress, thereby reducing strength .…”

Characterization of polyvinyl alcohol-borax/agarose (PVA-B/AG) double network hydrogel utilized for the cleaning of works of art

“…10-a). Furthermore, the non-Newtonian feature of PVA-B hydrogels permits the mobility of PVA strands and free borate ions which facilitates the bonds formation across the contact interface [49][50][51].…”

Vortex fluidic mediated one-step fabrication of polyvinyl alcohol hydrogel films with tunable surface morphologies and enhanced self-healing properties

“…Cytotoxicity screening of borax using different cells has shown a non-toxic nature in several studies [23,24,29]. Clearly, among different methods for crosslinking PVA-based hydrogels, the employment of borax is a simple approach without the excessive imposition of controls over the final associated properties [30][31][32]. The approach effectively supports the fabrication of PVA hydrogel composites with different properties ranging from self-adhesion to high mechanical strength, with negligible side effects on biomedical properties [33][34][35].…”