Development of Acrylamide/Acrylic acid Superabsorbent Polymer (SAP) Particles for Water Applications

Water contamination, particularly from bacterial sources, poses significant risks to public health and environmental safety. Low bacterial concentrations in water samples often go undetected by conventional methods, increasing these risks and highlighting the need for efficient sample enrichment techniques. This research investigates the use of superabsorbent polymer microparticles (SAP-MPs) and their nanocomposites with MXene nanosheets for enriching bacterial samples. The study first focuses on developing innovative microfluidic platforms for real-time characterization of SAP-MPs. Subsequently, advanced MXene/SAP-MP nanocomposites are introduced for enhanced bacterial enrichment and water analysis.

The study is structured into four objectives. The first objective involves the design and fabrication of a novel microfluidic device for high-resolution, real-time characterization of SAP-MPs. This device enables detailed single particle analysis of swelling behaviors, including volume swelling ratio (VSR) and swelling rate (SR). The second objective investigates the effect of particle size, crosslinker concentration, acrylic acid concentration, and neutralization degree on the swelling behavior of SAP-MP. Results revealed a ~40% and ~300% reduction in equilibrium VSR (VSReq) and SR with increased crosslinker concentration, respectively, while increasing acrylic acid concentrations enhanced VSReq and SR by ~200%. A ~300% increase in VSReq was observed with smaller particle sizes, marking the first single-particle-scale study of this phenomenon. The third objective demonstrates the synthesis of MXene/SAP-MP nanocomposites using the Breathing-In-Breathing-Out (BI-BO) method, achieving successful integration of MXene nanosheets without compromising swelling behavior. Finally, the fourth objective evaluates bacterial enrichment performance, revealing a 10-fold enrichment efficiency and 90% recovery efficiency under optimized conditions.

This research advances the fundamental characterization of SAPs and their applications, including water treatment, biosensing, and environmental monitoring.