Catalytic vs. thermal Si - H crosslinking polydimethylsiloxane (PDMS) elastomers: Network heterogeneity drives...

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Science

Background:

• Network architecture in polydimethylsiloxane (PDMS) elastomers is crucial for interfacial performance.
• The influence of uniform versus heterogeneous networks on energy dissipation, adhesion, and ice detachment is not fully understood.

Purpose of the Study:

• To establish a direct link between crosslinking chemistry, network structure, and interfacial behavior in PDMS elastomers.
• To investigate how different network architectures affect adhesion and ice detachment.

Main Methods:

• Synthesized PDMS networks using two routes: platinum-catalyzed hydrosilylation and additive-free thermal curing.
• Characterized network structure via spectroscopy, rheology, and morphology.
• Evaluated interfacial performance using peeling tests, sliding angle measurements, and ice adhesion tests.

Main Results:

• Catalytic curing yielded uniform networks with tunable adhesion (70-550 mN/m) and moderate ice adhesion (~20 kPa at -30°C).
• Thermal curing produced heterogeneous networks with lower peeling strength (64 mN/m) and reduced ice adhesion (~15 kPa).
• Heterogeneous networks exhibited enhanced surface topography, chain mobility, and minimal contact line pinning, leading to distinct energy dissipation modes.

Conclusions:

• Crosslinking chemistry dictates PDMS network structure and subsequent interfacial properties.
• Heterogeneous PDMS networks demonstrate potential for sustainable anti-icing and antifouling applications due to reduced ice adhesion.
• Understanding network structure-property relationships is key for designing advanced soft-interface materials.