Interaction of aerosil nanoparticles with networks of polyacrylamide, poly(acrylic acid), and poly(methacrylic acid) hydrogels

Adjusting Some Properties of Poly(methacrylic acid) (Nano)Composite Hydrogels by Means of Silicon-Containing Inorganic Fillers

“…A special class of fillers for hydrogels is represented by materials that contain Si-O groups within their structure. This category includes various types of silica-based nanoparticles [ 16 ], such as pyrogenic silica [ 17 , 18 , 19 , 20 ] and layered clays such as montmorillonite (Mt) [ 21 ] and Laponite (Lap) [ 22 ], which have the advantage of being cheaper than the agents listed above. Among them, clays have attracted more and more attention as fillers due to their remarkable properties, such as high specific surface area and adsorption capacity, optimal rheological properties, chemical inertia, and low toxicity, Lap and Mt being the most used for hydrogel reinforcement [ 6 , 21 , 22 , 23 , 24 ].…”

“…Pure pyrogenic silica is hydrophilic and has a high surface energy due to the presence of these groups [ 31 ]. Pyrogenic silica nanoparticles are stable in aqueous solutions [ 32 ], but unlike layered silicates, they do not dissociate with the formation of free ions [ 17 ].…”

“…Both clays [ 24 , 33 ] and pyrogenic silica nanoparticles [ 17 , 18 , 19 ] have proven their effect on hydrogels, especially by increasing their mechanical and/or thermal properties or changing the swelling degree, but silica nanoparticles are less studied as reinforcing agents for hydrogels as compared to clays. Incorporating clays into the hydrogel matrix is also a good way to increase the final absorption properties of the hydrogel because they can absorb positively-charged pollutants, such as heavy metals and cationic dyes [ 34 ].…”

Highly deformable hydrogels constructed by pH-triggered polyacid nanoparticle disassembly in aqueous dispersions

“…Such gels can exhibit strong pH-responsive or electrolyte-responsive swelling. [14][15][16][17][18][19][20] They also offer potential biomaterial applications, because the pH-triggered swelling transition can be tuned to correspond to physiological conditions, especially for gels based on methacrylic acid (MAA). [21][22][23][24] Whilst excellent mechanical properties have been reported for such gels, 25 one common limitation in the context of biomaterials applications is that gel construction methods rely on the use of small molecule monomers.…”

“…[21][22][23][24] Whilst excellent mechanical properties have been reported for such gels, 25 one common limitation in the context of biomaterials applications is that gel construction methods rely on the use of small molecule monomers. 14,[17][18][19][20][25][26][27][28][29][30][31][32] In this study we introduce a new generic approach that enables the rational design of highly deformable pH-responsive hydrogels using aqueous dispersions of pre-formed polyacid NPs as the only gel building blocks.…”