Speaker
Description
To develop sustainable functional polymer-lignin composites, the lignin was modified with zwitterionic (L)/3-[(2-methacryloyloxy)ethyl]dimethylammonio propane sulfonate (DMAPS) oligomers grafted in situ from its surface in different mass ratios (1:1, 1:2, and 1:3) via an UV-induced thiol–ene reaction. Successful surface functionalization was confirmed by FTIR, XPS, and colloidal analysis. The L/DMAPS hybrids were subsequently employed as stabilizer in the Pickering miniemulsion polymerization of methyl methacrylate/butyl methacrylate to prepare functional polymer composites. Compared with unmodified lignin, the L/DMAPS hybrids exhibited improved dispersion within the polymer matrix, enhanced filler–matrix interactions, and promoted the formation of a more homogeneous microstructure. The composites were then functionalized with 2,4-dimethylbenzoic acid (DMBA) to be make its surface sensitive to similar compounds. The influence of L/DMAPS on adsorption behaviour and sensing performance toward DMBA was evaluated. Quartz crystal microbalance (QCM) measurements were performed to monitor the adsorption and desorption of DMBA from aqueous solutions (0.01 and 0.02 mg/mL), revealing that the 1:1 L/DMAPS/polymer composite exhibited the highest adsorption capacity while maintaining reversible binding characteristics. In comparison with the L/polymer composite, the incorporation of L/DMAPS facilitated the formation of selective recognition sites through the synergistic contribution of ionic interactions, π–π interactions, and steric complementarity. These results demonstrate that the optimized L/DMAPS hybrid composite is a promising sustainable material for the selective recognition and detection of organic pollutants.
Keywords: lignin/dmaps hybrids, pickering miniemulsion polymerization, selective adsorption