Biocompatible self-healing hydrogels based on boronic acid-functionalized polymer and laponite nanocomposite for water pollutant removal

Global water pollution by organic dyes and metals may be solved by adsorption. In particular, hydrogel adsorbents display unique advantages due to their three-dimensional porous structure. Here, a new type of self-healing hydrogels based on boronate and amide bonds were prepared. The precursor polymer, 2-aminophenylboronic acid-modified polyacrylic acid (PAA-2APBA), was firstly synthesized by amidation, then, the poly(vinyl alcohol) and laponite were mixed with PAA-2APBA to form a nanocomposite hydrogel. Results show that this hydrogel has good self-healing and injectable properties, as well as good biocompatibility. The introduction of laponite nanoparticles into the hydrogel improved the stability, mechanical strength, and the adsorption efficiency of metal ions and organic dyes. The maximum adsorption of copper ion, cadmium ion, lead ion, and iron ion was 259.1 mg/g, 243.4 mg/g, 217.4 mg/g, and 166.2 mg/g, respectively. For organic dyes, 71% of methylene blue and 81% of malachite green were removed in 28 h.