TY - JOUR
T1 - Surface Properties of Colloidal Particles Affect Colloidal Self-Assembly in Evaporating Self-Lubricating Ternary Droplets
AU - Koshkina, Olga
AU - Raju, Lijun Thayyil
AU - Kaltbeitzel, Anke
AU - Riedinger, Andreas
AU - Lohse, Detlef
AU - Zhang, Xuehua
AU - Landfester, Katharina
N1 - Funding Information:
Open access funded by Max Planck Society. We acknowledge the funding from Max Planck University of Twente Center for Complex Fluid Dynamics. D.L. also acknowledges the funding from ERC Advanced Grant DDD (No. 740479). X.H.Z. acknowledges the support by the Natural Sciences and Engineering Research Council of Canada (NSERC) and Future Energy Systems (Canada First Research Excellence Fund) and the funding from the Canada Research Chairs program. O.K. acknowledges the funding from the Alexander von Humboldt Foundation.
Publisher Copyright:
© 2021 The Authors. Published by American Chemical Society.
PY - 2022/1/12
Y1 - 2022/1/12
N2 - In this work, we unravel the role of surface properties of colloidal particles on the formation of supraparticles (clusters of colloidal particles) in a colloidal Ouzo droplet. Self-lubricating colloidal Ouzo droplets are an efficient and simple approach to form supraparticles, overcoming the challenge of the coffee stain effect in situ. Supraparticles are an efficient route to high-performance materials in various fields, from catalysis to carriers for therapeutics. Yet, the role of the surface of colloidal particles in the formation of supraparticles using Ouzo droplets remains unknown. Therefore, we used silica particles as a model system and compared sterically stabilized versus electrostatically stabilized silica particles─positively and negatively charged. Additionally, we studied the effect of hydration. Hydrated negatively charged silica particles and sterically stabilized silica particles form supraparticles. Conversely, dehydrated negatively charged silica particles and positively charged amine-coated particles form flat film-like deposits. Notably, the assembly process is different for all the four types of particles. The surface modifications alter (a) the contact line motion of the Ouzo droplet and (b) the particle-oil and particle-substrate interactions. These alterations modify the particle accumulation at the various interfaces, which ultimately determines the shape of the final deposit. Thus, by modulating the surface properties of the colloidal particles, we can tune the shape of the final deposit, from a spheroidal supraparticle to a flat deposit. In the future, this approach can be used to tailor the supraparticles for applications such as optics and catalysis, where the shape affects the functionality.
AB - In this work, we unravel the role of surface properties of colloidal particles on the formation of supraparticles (clusters of colloidal particles) in a colloidal Ouzo droplet. Self-lubricating colloidal Ouzo droplets are an efficient and simple approach to form supraparticles, overcoming the challenge of the coffee stain effect in situ. Supraparticles are an efficient route to high-performance materials in various fields, from catalysis to carriers for therapeutics. Yet, the role of the surface of colloidal particles in the formation of supraparticles using Ouzo droplets remains unknown. Therefore, we used silica particles as a model system and compared sterically stabilized versus electrostatically stabilized silica particles─positively and negatively charged. Additionally, we studied the effect of hydration. Hydrated negatively charged silica particles and sterically stabilized silica particles form supraparticles. Conversely, dehydrated negatively charged silica particles and positively charged amine-coated particles form flat film-like deposits. Notably, the assembly process is different for all the four types of particles. The surface modifications alter (a) the contact line motion of the Ouzo droplet and (b) the particle-oil and particle-substrate interactions. These alterations modify the particle accumulation at the various interfaces, which ultimately determines the shape of the final deposit. Thus, by modulating the surface properties of the colloidal particles, we can tune the shape of the final deposit, from a spheroidal supraparticle to a flat deposit. In the future, this approach can be used to tailor the supraparticles for applications such as optics and catalysis, where the shape affects the functionality.
KW - UT-Hybrid-D
KW - Silica particles
KW - Self-lubrication
KW - Ouzo effect
KW - Supraparticles
KW - Colloidal stabilization
KW - Colloidal self-assembly
KW - Evaporation induced self-assembly
UR - http://www.scopus.com/inward/record.url?scp=85121921312&partnerID=8YFLogxK
U2 - 10.1021/acsami.1c19241
DO - 10.1021/acsami.1c19241
M3 - Article
SN - 1944-8244
VL - 14
SP - 2275
EP - 2290
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 1
ER -