(354d) Anti-Icing Functionality in Novel Polymeric Composite Microcapsules

Anti-Icing Functionality in  Novel Polymeric Composite Microcapsules

Derya Aydın¹, Rıza. Kızılel², A. Levent Demirel³, Seda. Kızılel¹

¹College of Engineering, Chemical and Biological Engineering, Sariyer, Istanbul, Turkey, 34450

²KOÇ University- TUPRAS Energy Center, Sariyer, Istanbul, Turkey, 34450

³College of Sciences, Department of Chemistry 34450, Istanbul, Turkey

Presenting author: deryaaydin@ku.edu.tr

Encapsulation of functional agents within micro-capsules is an attractive approach for controlled release of anti-icing agents for surfaces, biomolecules or drugs for therapeutic applications, etc. The technique presented here involves incorporation of a hydrophilic agent in aqueous phase into hydrophobic styrene-butadiene-styrene (SBS) copolymer medium. The challenge of stabilizing immiscible droplets in the continuous medium is met by particle-stabilized emulsion system, known as Pickering emulsions. Partial wetting of the solid particles by the two immiscible liquids leads to self assembly of particles at the liquid-liquid interface during emulsification, providing stable water-in-oil emulsions with controlled permeability, mechanical strength and viscoelastic behavior. In this study, micron-sized aqueous capsules consisting functional anti-icing agents are embedded into hydrophobic SBS (Styrene-Butadiene-Styrene) copolymer medium, through particle stabilization in emulsion templating method. Partially hydrophobic silica nanoparticles are used to form Pickering emulsion. Gelation of the aqueous dispersed phase is further investigated for additional stability and controlled release of the anti-acing agent. The stable emulsion is casted as an anti-icing membrane upon drying. Rheological studies demonstrated that nanoparticle shells around functional beads enhanced mechanical strength. Dry or wet templated emulsion is characterized with respect to permeability to anti-icing agent, and water droplet freezing rate. The release of anti-icing agent from dry composite membranes was investigated by immersing samples in water. Dry composite membranes released 32 g/m² anti-icing agent within 4 hours. The amount of anti-icing agent released after 4 hours corresponds to about 50% of the initial content. Dry composite membrane delayed freezing of water droplets for about 70 minutes in a temperature and humidity controlled chamber. Hydrophobicity and thermoplastic nature of SBS copolymer allows for  incorporation of the composite into other mediums such as bitumen, thus opens up the possibility for the delivery of anti-icing agents through mediums which would otherwise not be compatible with polar agents.