Supplementary information files for "Monodispersed biodegradable microparticles with wrinkled surface coated with silver nanoparticles for catalytic degradation of organic toxins"

<p dir="ltr">Supplementary files for article "Monodispersed biodegradable microparticles with wrinkled surface coated with silver nanoparticles for catalytic degradation of organic toxins"</p><p dir="ltr">Microfluidic fabrication of monodisperse microgels for biomedical, nanotechnological, environmental and catalytic applications has become the subject of growing interest. In this work, monodisperse polyethylene glycol diacrylate [P(EGDA)] microgel particles were fabricated using a CNC-milled microfluidic device with Lego-inspired interlocking mechanism. Silver nanoparticles (AgNPs) were synthesised and stabilised <i>in situ</i> on the wrinkled surface of the microgel particles using AgNO₃ as metal precursor and NaBH₄ as reductant. The loading of AgNPs (7.5 wt%) on microgel beads was confirmed by energy-dispersive X-ray spectroscopy, X-ray diffraction, and thermogravimetric analysis. Surface wrinkles were found to be a useful morphological feature acting as reservoirs for accumulation of AgNPs. Ag-P(EGDA) hybrid polymer particles were shown to be an efficient catalyst for the reduction of 4-nitrophenol (4NP) into 4-aminophenol (4AP) by sodium borohydride at room temperature. After 40 min, 0.08 M 4NP was completely converted into 4AP using 2.1 mg/mL of Ag-P(EGDA) catalytic particles and the reaction followed a pseudo first-order kinetics. The apparent rate constant increased from 0.0142 to 0.117 min^-1 when the loading of catalytic particles increased from 1.7 to 2.50 mg/mL indicating that the reduction is occurring on the catalyst surface according to Langmuir-Hinshelwood model. Ag-P(EGDA) hybrid microgel was a potent and recyclable catalyst for room-temperature degradation of methylene blue (MeB) by NaBH₄. At the Ag-P(EGDA) loading of 2.0 mg/mL, 25 µM of MeB was completely degraded in 6 min. Composite Ag-P(EGDA) microgel beads can be used as an ecofriendly and easily recoverable catalyst for the transformation of other organic pollutants into useful chemicals.</p><p dir="ltr">© The Authors, CC BY 4.0</p>