TY - JOUR
T1 - Tuning Contact Line Dynamics on Slippery Silicone Oil Grafted Surfaces for Sessile Droplet Evaporation
AU - Raynard, Astrid
AU - Abbas, Anam
AU - Armstrong, Steven
AU - Wells, Gary
AU - McHale, Glen
AU - Sefiane, Khellil
AU - Orejon Mantecon, Dani
N1 - Funding Information:
A.A. and D.O. acknowledges the support received from the Higher Education Commission of Pakistan. D.O. and K.S. additionally acknowledge the support of the European Space Agency (ESA) through the project Convection and Interfacial Mass Exchange (EVAPORATION) with ESA Contract Number 4000129506/20/NL/PG; and the support from the International Institute for Carbon-Neutral Energy Research (WPI-I2CNER) sponsored by the Japanese Ministry of Education, Culture, Sports, Science and Technology. D.O. further acknowledges The Royal Society and The Royal Society Research Grant 2020 Round 2 with reference code RGS/R2/202041. S.A. would like to acknowledge the support of the Engineering and Physical Sciences Research Council EPSRC (Grant Number EP/T025158/1). A.R., A.A. and D.O. acknowledge Khaloud Moosa Al Balushi for the support and discussion on the evaporation on smooth silicon and Teflon substrates. The authors additionally acknowledge Mr. Alex Jenkins for his help and support on the experimental setup. For the purpose of open access, the authors have applied a Creative Commons Attribution (CC BY) license to any Author Accepted Manuscript version arising from this submission.
Funding Information:
A.A. and D.O. acknowledges the support received from the Higher Education Commission of Pakistan. D.O. and K.S. additionally acknowledge the support of the European Space Agency (ESA) through the project Convection and Interfacial Mass Exchange (EVAPORATION) with ESA Contract Number 4000129506/20/NL/PG; and the support from the International Institute for Carbon-Neutral Energy Research (WPI-I2CNER) sponsored by the Japanese Ministry of Education, Culture, Sports, Science and Technology. D.O. further acknowledges The Royal Society and The Royal Society Research Grant 2020 Round 2 with reference code RGS/R2/202041. S.A. would like to acknowledge the support of the Engineering and Physical Sciences Research Council EPSRC (Grant Number EP/T025158/1). A.R., A.A. and D.O. acknowledge Khaloud Moosa Al Balushi for the support and discussion on the evaporation on smooth silicon and Teflon substrates. The authors additionally acknowledge Mr. Alex Jenkins for his help and support on the experimental setup. For the purpose of open access, the authors have applied a Creative Commons Attribution (CC BY) license to any Author Accepted Manuscript version arising from this submission.
Publisher Copyright:
© 2024, The Author(s).
PY - 2024/1/19
Y1 - 2024/1/19
N2 - Controlling the dynamics of droplet evaporation is critical to numerous fundamental and industrial applications. The three main modes of evaporation so far reported on smooth surfaces are the constant contact radius (CCR), constant contact angle (CCA), and mixed mode. Previously reported methods for controlling droplet evaporation include chemical or physical modifications of the surfaces via surface coating. These often require complex multiple stage processing, which eventually enables similar droplet-surface interactions. By leveraging the change in the physicochemical properties of the outermost surface by different silicone oil grafting fabrication parameters, the evaporation dynamics and the duration of the different evaporation modes can be controlled. After grafting one layer of oil, the intrinsic hydrophilic silicon surface (contact angle (CA) ≈ 60°) is transformed into a hydrophobic surface (CA ≈ 108°) with low contact angle hysteresis (CAH). The CAH can be tuned between 1° and 20° depending on the fabrication parameters such as oil viscosity, volume, deposition method as well as the number of layers, which in turn control the duration of the different evaporation modes. In addition, the occurrence and strength of stick-slip behaviour during evaporation can be additionally controlled by the silicone oil grafting procedure adopted. These findings provide guidelines for controlling the droplet-surface interactions by either minimizing or maximising contact line initial pinning, stick-slip and/or constant contact angle modes of evaporation. We conclude that the simple and scalable silicone oil grafted coatings reported here provide similar functionalities to slippery liquid infused porous surfaces (SLIPSs), quasi-liquid surfaces (QLS), and/or slippery omniphobic covalently attached liquid (SOCAL) surfaces, by empowering pinning-free surfaces, and have great potential for use in self-cleaning surfaces or uniform particle deposition.
AB - Controlling the dynamics of droplet evaporation is critical to numerous fundamental and industrial applications. The three main modes of evaporation so far reported on smooth surfaces are the constant contact radius (CCR), constant contact angle (CCA), and mixed mode. Previously reported methods for controlling droplet evaporation include chemical or physical modifications of the surfaces via surface coating. These often require complex multiple stage processing, which eventually enables similar droplet-surface interactions. By leveraging the change in the physicochemical properties of the outermost surface by different silicone oil grafting fabrication parameters, the evaporation dynamics and the duration of the different evaporation modes can be controlled. After grafting one layer of oil, the intrinsic hydrophilic silicon surface (contact angle (CA) ≈ 60°) is transformed into a hydrophobic surface (CA ≈ 108°) with low contact angle hysteresis (CAH). The CAH can be tuned between 1° and 20° depending on the fabrication parameters such as oil viscosity, volume, deposition method as well as the number of layers, which in turn control the duration of the different evaporation modes. In addition, the occurrence and strength of stick-slip behaviour during evaporation can be additionally controlled by the silicone oil grafting procedure adopted. These findings provide guidelines for controlling the droplet-surface interactions by either minimizing or maximising contact line initial pinning, stick-slip and/or constant contact angle modes of evaporation. We conclude that the simple and scalable silicone oil grafted coatings reported here provide similar functionalities to slippery liquid infused porous surfaces (SLIPSs), quasi-liquid surfaces (QLS), and/or slippery omniphobic covalently attached liquid (SOCAL) surfaces, by empowering pinning-free surfaces, and have great potential for use in self-cleaning surfaces or uniform particle deposition.
KW - Droplet evaporation
KW - Contact line dynamics
KW - Slippery oil grafted surfaces
KW - Pinning/Depinning
KW - Pinning suppression
U2 - 10.1038/s41598-023-50579-2
DO - 10.1038/s41598-023-50579-2
M3 - Article
C2 - 38242933
SN - 2045-2322
VL - 14
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 1750
ER -