Anomalously Shaped Functional Particles Prepared by Thiol-Isocyanate Off-Stoichiometric Click Dispersion...

Area of Science:

• Polymer Chemistry
• Materials Science
• Nanotechnology

Background:

• Anomalously shaped microparticles offer unique advantages in various applications.
• Traditional synthesis methods often rely on chain-growth polymerization.
• Thiol-X step-growth polymerizations typically yield regular particle shapes, limiting access to anomalous morphologies.

Purpose of the Study:

• To develop a novel method for synthesizing anomalously shaped microparticles.
• To explore the use of thiol-isocyanate dispersion polymerization for particle fabrication.
• To create functional microparticles for sensing applications.

Main Methods:

• Thiol-isocyanate dispersion polymerization in ethanol using polyvinylpyrrolidone (PVP) as a stabilizer and catalyst.
• Tuning monomer combinations, contents, and feed ratios to control particle morphology.
• Scanning electron microscopy (SEM) for observing morphology evolution.
• Fourier transform infrared spectroscopy (FT-IR) and fluorescent probe detection for confirming residual thiol groups.
• Functionalization with fluorescein isothiocyanate isomer I (FITC) and dithioacetal-functionalized perylenediimide (DTPDI) for probe development.

Main Results:

• Successfully synthesized anomalously shaped particles, including papillae-shaped, raspberry-like, and multibulged morphologies.
• Achieved particles with residual thiol (-SH) groups, even with equimolar monomer ratios, a deviation from previous studies.
• Developed fluorescent particle probes capable of detecting glutathione (GSH) and mercury ions (Hg2+).
• Demonstrated sensitive detection of Hg2+ down to 0.1-1 ppb using raspberry-like particle probes functionalized with DTPDI.

Conclusions:

• Thiol-isocyanate dispersion polymerization is an effective method for producing anomalously shaped microparticles.
• The synthesized particles possess residual thiol groups, enabling further functionalization.
• The developed fluorescent particle probes show high sensitivity and potential for detecting specific analytes like Hg2+ and GSH in aqueous solutions.