Development of polydimethylsiloxane-microdiamond composite materials for application as sorptive devices

Area of Science:

• Materials Science
• Analytical Chemistry

Background:

• Development of novel sorptive materials is crucial for sensitive trace chemical analysis.
• Polydimethylsiloxane (PDMS) is a common sorbent but can lack mechanical and thermal stability.
• Incorporating microdiamond (MD) into PDMS offers potential improvements.

Purpose of the Study:

• To develop and characterize non-porous and porous polydimethylsiloxane-microdiamond (PDMS-MD) composite rods.
• To evaluate the performance of these rods as sorptive phases for trace chemical analysis in wine.
• To compare the efficacy of porous versus non-porous PDMS-MD rods.

Main Methods:

• PDMS-MD composites were fabricated using inorganic salt particles as dissolvable templates to create porosity.
• Composite rods were characterized for pore size, density, mechanical stability, and thermal properties.
• Sorbent extraction followed by gas chromatography-flame ionization detection (GC-FID) was used for analyzing test solutes in synthetic and real wine samples.

Main Results:

• Porous PDMS-MD rods with pore sizes from ~5 µm to ~40 µm were successfully produced.
• Incorporation of up to 60% microdiamond significantly increased density, mechanical stability, and thermal conductivity of PDMS.
• Porous PDMS-MD rods demonstrated improved analyte recovery (>10-20%) compared to non-porous rods and commercial sorbents.
• The method achieved low limits of detection (LOD) ranging from 0.60 to 27.30 µg L⁻¹ for target analytes.

Conclusions:

• PDMS-MD composite rods offer enhanced physical and thermal properties compared to pure PDMS.
• Porous PDMS-MD rods are robust and efficient sorptive phases for trace chemical analysis in complex matrices like wine.
• The developed material and method provide a viable alternative for sensitive and reliable chemical analysis.