1
|
Chung DCK, Lin ES, Peng L, Jiang X, Ong JW, Abid HA, Song Z, Liew OW, Ng TW. Efficient drop reactor processing of methylene blue degradation with silver nanowire catalysts. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.125749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
2
|
Chung DK, Huynh SH, Ahmad Zahidi AA, Liew OW, Ng TW. Simultaneous Multidrop Creation with Superhydrophobic Wells for Field Environmental Sensing of Nanoparticles. ACS OMEGA 2018; 3:9310-9317. [PMID: 31459064 PMCID: PMC6644516 DOI: 10.1021/acsomega.8b00919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 08/02/2018] [Indexed: 06/10/2023]
Abstract
Facile creation of multiple drops at appropriate volumes on surfaces without the use of sophisticated instrumentation facilitates downstream evaporative preconcentration of liquid samples for analytical purposes. In this work, a superhydrophobic (SH) substrate comprising wells with a perforated mesh base was developed for simultaneous drop creation in a quick and convenient manner. In contrast to the method of pouring liquid directly over the SH wells, consistent liquid filling was readily achieved by a simple immersion approach. This method works well even for challenging situations where well diameters are smaller than 3.4 mm. Despite the poor liquid-retention properties of SH surfaces, inverting the wells did not result in liquid detachment under gravitational force, indicating strong pinning effects afforded by the well architecture. The perforated base of the well allowed the liquid to be completely removed from the well by compressed air. High-speed camera image processing was used to study the evolution of drop contact angle and displacement with time. It was found that the liquid body was able to undergo strong oscillations. Optical spectroscopy was used to confirm the ability of evaporative preconcentration of silver nanoparticles.
Collapse
Affiliation(s)
- Dwayne
Chung Kim Chung
- Laboratory
for Optics and Applied Mechanics, Department of Mechanical & Aerospace
Engineering, Monash University, Building 31, Clayton, Victoria 3800, Australia
| | - So Hung Huynh
- Laboratory
for Optics and Applied Mechanics, Department of Mechanical & Aerospace
Engineering, Monash University, Building 31, Clayton, Victoria 3800, Australia
| | - Alifa Afiah Ahmad Zahidi
- Laboratory
for Optics and Applied Mechanics, Department of Mechanical & Aerospace
Engineering, Monash University, Building 31, Clayton, Victoria 3800, Australia
| | - Oi Wah Liew
- Cardiovascular
Research Institute, Yong Loo Lin School of Medicine, Centre for Translational
Medicine, National University of Singapore,
National University Health System, 14 Medical Drive, 117599, Singapore
| | - Tuck Wah Ng
- Laboratory
for Optics and Applied Mechanics, Department of Mechanical & Aerospace
Engineering, Monash University, Building 31, Clayton, Victoria 3800, Australia
| |
Collapse
|
3
|
Chung DK, Huynh SH, Katariya M, Chan AYC, Wang S, Jiang X, Muradoglu M, Liew OW, Ng TW. Drops on a Superhydrophobic Hole Hanging On under Evaporation. ACS OMEGA 2017; 2:6211-6222. [PMID: 31457866 PMCID: PMC6644627 DOI: 10.1021/acsomega.7b01114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/15/2017] [Indexed: 05/04/2023]
Abstract
Drops with larger volumes placed over a superhydrophobic (SH) surface with a hole do not fall through unless they are evaporated to a size that is small enough. This feature offers the ability to preconcentrate samples for biochemical analysis. In this work, the influence of pinning on the behavior of drops placed on a 0.1 mm thick SH substrate with a 2 mm diameter hole as they evaporated was investigated. With 16 μL of water dispensed, the sessile drop component volume was initially higher than that of the overhanging drop component and maintained this until the later stages where almost identical shapes were attained and full evaporation was achieved without falling off the hole. With 15 μL of water dispensed, the volume of the sessile drop was initially higher than that of the overhanging drop component but the liquid body was able to squeeze through the hole after 180 s due to the contact line not having sufficient pinning strength when it encountered the edge of the hole. This resulted in the liquid body either falling through the hole or remaining pinned with an oval-like shape. When it did not fall-off, the liquid body had volume and contact angle characteristics for the sessile drop and overhanging drop components that were reversed. In the later stages, however, nearly identical shapes were again attained and full evaporation was achieved without falling off the hole. The effects of pinning, despite the substrate being SH, offer another path toward achieving practical outcomes with liquid bodies without the need for chemical surface functionalization. Similarities and differences could be seen in the behavior of a sessile drop on a SH plate that was inclined at 30° to the horizontal and evaporated.
Collapse
Affiliation(s)
- Dwayne
Chung Kim Chung
- Department of Mechanical &
Aerospace Engineering, Laboratory
for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
| | - So Hung Huynh
- Department of Mechanical &
Aerospace Engineering, Laboratory
for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Mayur Katariya
- Department of Mechanical &
Aerospace Engineering, Laboratory
for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Aaron Yin Chun Chan
- Department of Mechanical &
Aerospace Engineering, Laboratory
for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Shufen Wang
- Department of Mechanical &
Aerospace Engineering, Laboratory
for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Xuchuan Jiang
- Department of Mechanical &
Aerospace Engineering, Laboratory
for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Murat Muradoglu
- Department of Mechanical &
Aerospace Engineering, Laboratory
for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Oi Wah Liew
- Cardiovascular
Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System,
Centre for Translational Medicine, 14 Medical Drive, 117599 Singapore
| | - Tuck Wah Ng
- Department of Mechanical &
Aerospace Engineering, Laboratory
for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
- E-mail: . Tel: 61-3-99054647. Fax: 61-3-99051825
| |
Collapse
|
4
|
Zahidi AAA, Cheong BHP, Huynh SH, Vuong T, Liew OW, Ng TW. Glycerol–water sessile drop elongation on PTFE inclines in relation to biochemical applications. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|