Facile access to poly(DMAEMA-co-AA) hydrogels via infrared laser-ignited frontal polymerization and their polymerization in the horizontal direction

A series of poly(DMAEMA-co-AA) hydrogels (DMAEMA = dimethylaminoethyl methacrylate, AA = acrylic acid) were quickly produced via infrared laser ignited frontal polymerization (LIFP), and LIFP in the horizontal direction was performed successfully for the first time. The dependence of the front velocity and front temperature of LIFP on the molar ratios of AA/DMAEMA and the concentrations of initiator was investigated, along with the characterization of the swelling capacity and morphology properties of the as-prepared hydrogels. The as-prepared hydrogels are sensitive to pH values ranging from 2 to 12, and their maximum equilibrium swelling ratio can reach 2497% in pH = 7. Moreover, the hydrogels are able to absorb an anionic dye (orange G) and a cationic dye (methylene blue) through electrostatic interaction, offering potential as dye adsorbents for water purification. Additionally, LIFP was employed horizontally to seal dyestuff solutions, expanding the scope of LIFP applications on spilled toxic substances without touching the location of the reaction.