Responsive gel networks: Engineering smart hydrogels, nanogels and ionogels

Gelation chemistry, a dynamic and evolving field, is marked by recent advancements in the synthesis, characterization, and tuning of hydrogels, nanogels, and ionogels. This review delves into the mechanistic aspects of gel formation, offering novel insights into the synthesis methods, structural characteristics, and diverse properties of these gel systems. The three major classes (hydrogels, nanogels, and ionogels) have gained substantial attention due to their diverse applications in drug delivery, tissue engineering, and energy storage. The review begins with an in-depth discussion of the synthesis and fabrication techniques of these three gels, covering traditional techniques like free radical polymerization, click chemistry, and gelation, while also delving into emergent approaches such as microfluidics, radiation polymerization, and electrochemical polymerization. This is followed by the advanced instrumentation techniques like NMR, XRD, FTIR, FE-SEM, TEM, and TGA utilized for characterization. The design and properties of each gel type are discussed at the end, emphasizing properties such as swelling behavior, mechanical strength, and responsiveness to external stimuli. The paper concludes with challenges and future perspectives of advanced gels in various fields of science and research. Advances in hydrogel, nanogel, and ionogel synthesis and characterization.Synthesis methods: polymerization, microfluidics, and electrochemistry.Characterization: NMR, XRD, FTIR, SEM, TEM, TGA.Focus on swelling, mechanical strength, and stimulus responsiveness. Advances in hydrogel, nanogel, and ionogel synthesis and characterization. Synthesis methods: polymerization, microfluidics, and electrochemistry. Characterization: NMR, XRD, FTIR, SEM, TEM, TGA. Focus on swelling, mechanical strength, and stimulus responsiveness.