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קולוקוויום 25.10.2021

25/10/2021 - 13:00 - 12:00Add To Calendar 2021-10-25 12:00:00 2021-10-25 13:00:00 קולוקוויום 25.10.2021 Self-faceting of nano- to yocto- liter liquid droplets: from fundamental topology to nanotechnological applications Eli Sloutskin Physics Dept. and Institute of Nanotechnology & Advanced Materials, Bar-Ilan University   Contrary to everyday experience, where all liquid droplets assume rounded, near-spherical shapes, the temperature-tuning of liquid droplets to faceted polyhedral shapes and to spontaneous splitting has been recently demonstrated in oil-in-water and water-in-oil emulsions1-2. These effects occur in a wide range of oil:surfactant combinations, for broad temperature ranges, and in droplets of sizes spanning an incredible 13 decades in volume, from nano- to yocto- liters, suggesting that these phenomena may play a role in a wide range of industrial technologies, where emulsions are employed. Furthermore, droplets’ solidification enabled the formation of icosahedral (and other complex-shape) colloidal and nano- particles, unachievable by any other method. However, the mechanism driving these surprising self-faceting phenomena was recently subject to a significant scientific controversy2. Our recent experiments, employing simple linear n-alkanes and water-soluble ionic and non-ionic surfactants, have resolved the fundamental mechanism driving these phenomena1,3. In particular, we have demonstrated that the effect is driven by a few-nm thick monolayer interfacial crystal, self-assembled at the surface of the liquid droplets. This monolayer’s closed-surface topology controls the precise shapes adopted by the droplets. Similar mechanisms are suggested to play a fundamental role in shape formation in a wide range of biological systems: from viruses to living organisms. Furthermore, taking benefit of crystalline monolayers’ self-assembly on surfaces of these droplets, we decorate the droplets by precisely self-positioned micro- and nano- particles and molecules, opening new routes towards the self-assembly of complex higher-hierarchy structures. [1] S. R. Liber et al., JACS 142, 8672 (2020); Guttman et al., PNAS 113, 493 (2016). [2] N. Denkov et al., Nature 528, 392 (2015). [3] S. Guttman et al., Nano Lett. 19, 3161 (2019). Seminar Abstract (PDF)   חדר הסמינרים המחלקתי (חדר 112) Department of Chemistry chemistry.office@biu.ac.il Asia/Jerusalem public
מיקום
חדר הסמינרים המחלקתי (חדר 112)

Self-faceting of nano- to yocto- liter liquid droplets:

from fundamental topology to nanotechnological applications

Eli Sloutskin

Physics Dept. and Institute of Nanotechnology & Advanced Materials, Bar-Ilan University

 

Contrary to everyday experience, where all liquid droplets assume rounded, near-spherical shapes, the temperature-tuning of liquid droplets to faceted polyhedral shapes and to spontaneous splitting has been recently demonstrated in oil-in-water and water-in-oil emulsions1-2. These effects occur in a wide range of oil:surfactant combinations, for broad temperature ranges, and in droplets of sizes spanning an incredible 13 decades in volume, from nano- to yocto- liters, suggesting that these phenomena may play a role in a wide range of industrial technologies, where emulsions are employed. Furthermore, droplets’ solidification enabled the formation of icosahedral (and other complex-shape) colloidal and nano- particles, unachievable by any other method. However, the mechanism driving these surprising self-faceting phenomena was recently subject to a significant scientific controversy2.

Our recent experiments, employing simple linear n-alkanes and water-soluble ionic and non-ionic surfactants, have resolved the fundamental mechanism driving these phenomena1,3. In particular, we have demonstrated that the effect is driven by a few-nm thick monolayer interfacial crystal, self-assembled at the surface of the liquid droplets. This monolayer’s closed-surface topology controls the precise shapes adopted by the droplets. Similar mechanisms are suggested to play a fundamental role in shape formation in a wide range of biological systems: from viruses to living organisms.

Furthermore, taking benefit of crystalline monolayers’ self-assembly on surfaces of these droplets, we decorate the droplets by precisely self-positioned micro- and nano- particles and molecules, opening new routes towards the self-assembly of complex higher-hierarchy structures.

תמונת הפגישה

[1] S. R. Liber et al., JACS 142, 8672 (2020); Guttman et al., PNAS 113, 493 (2016).

[2] N. Denkov et al., Nature 528, 392 (2015).

[3] S. Guttman et al., Nano Lett. 19, 3161 (2019).

Seminar Abstract (PDF)

 

תאריך עדכון אחרון : 24/10/2021