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Wang Y, Zhang S, Xu Y, Li H, Zhang R, Chen D, Xu J, Wu X. Different Size Formulations of Fluopyram: Preparation, Antifungal Activity, and Accumulation in the Fungal Pathogen Botrytis cinerea. Molecules 2023; 28:6099. [PMID: 37630351 PMCID: PMC10459100 DOI: 10.3390/molecules28166099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/10/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Nanotechnology is revolutionizing the efficient production and sustainable development of modern agriculture. Understanding the pesticide activity of both nano- and conventional methods is useful for developing new pesticide formulations. In this study, three solid fluopyram formulations with varying particle sizes were developed, and the mechanisms underlying the difference in the antifungal activity among these formulations were investigated. Wet media milling combined with freeze drying was used to prepare fluopyram nanoparticles (FLU-NS) and a micron-sized solid formulation (FLU-MS), and a jet grinding mill was employed to fabricate fluopyram wettable powder (FLU-WP). The mean particle sizes of FLU-NS, FLU-MS, and FLU-WP were 366.8 nm, 2.99 μm, and 10.16 μm, respectively. Notably, FLU-NS displayed a toxicity index against Botrytis cinerea (gray mold) that was approximately double those of FLU-MS and FLU-WP. Similar trends were noticed in the antifungal tests on Alternaria solani. The uptake of FLU-NS by B. cinerea was approximately twice that of FLU-MS and FLU-WP, indicating that fluopyram nanoparticles are more easily taken up by the pathogen (B. cinerea), and display better bioactivity than the larger fluopyram particles. Therefore, the nanosizing of pesticides appears to be a viable strategy to enhance efficiency without increasing the amount of pesticide used.
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Affiliation(s)
- Yinmin Wang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China; (Y.W.)
- Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing 100193, China
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; (S.Z.)
| | - Sida Zhang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; (S.Z.)
| | - Yong Xu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China; (Y.W.)
- Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing 100193, China
| | - Haiyun Li
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; (S.Z.)
| | - Ruihua Zhang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; (S.Z.)
| | - Dong Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; (S.Z.)
| | - Jianfu Xu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; (S.Z.)
| | - Xuemin Wu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China; (Y.W.)
- Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing 100193, China
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2
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Khawas S, Srivastava S. Anisotropic nanocluster arrays to a diminished zone: different regimes of surface deposition of gold nanocolloids. SOFT MATTER 2023; 19:3580-3589. [PMID: 37161512 DOI: 10.1039/d2sm01625g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Evaporation-induced assembly of nanoparticles has emerged as a versatile technique for the production of large-scale ordered structures and materials with complex features. In this study, we show that a dried particulate of an anisotropic nanocolloid undergoes non-ubiquitous surface morphological transitions at varying particle concentrations. Below 5 nM, deposits reveal the formation of linear arrays of AuNR clusters outside of the coffee ring and an annular CTAB-rich depletion zone in the inner vicinity of the coffee ring. For nanoparticle concentrations ≥5 nM, the outer cluster deposits disappear and a region of reduced AuNR density, sandwiched between the coffee ring and the depletion zone, analogous to the diminished zone, is observed. Within the coffee-ring deposits, nanoscale smectic AuNR assembly occurs via the expulsion of the cetyltrimethyl ammonium bromide (CTAB) bilayer, which contributes to the inward solutal Marangoni flow. An enhanced inward solutal Marangoni flow at high particle concentrations assists in the formation of a wider depletion zone, the emergence of the diminished zone and suppression of the width of the coffee-ring deposits. Through detailed analysis of data from ex situ (scanning electron microscopy, SEM) and in situ (contact angle and confocal imaging) measurements, we establish a direct correlation between the different evaporation modes and the various deposition regimes. A detailed mechanism for the surface morphology modulation of AuNR deposits by tuning the nanoparticle concentration in the drying sessile drop is discussed.
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Affiliation(s)
- Sanjoy Khawas
- Department of Physics, Indian Institute of Technology Bombay, Powai, Maharashtra-400076, India.
| | - Sunita Srivastava
- Department of Physics, Indian Institute of Technology Bombay, Powai, Maharashtra-400076, India.
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3
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Yang XY, Li GH, Huang X, Yu YS. Wetting of aqueous sodium dodecyl sulfate droplets on polydimethylsiloxane surfaces during evaporation. Colloids Surf A Physicochem Eng Asp 2023. [DOI: 10.1016/j.colsurfa.2022.130342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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4
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Ye L, Li S, Huang X. Effect of Nanoparticle Addition on Evaporation of Jet Fuel Liquid Films and Nanoparticle Deposition Patterns during Evaporation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:15973-15983. [PMID: 36521023 DOI: 10.1021/acs.langmuir.2c02306] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Jet fuel-based nanofluid fuel has been proposed for improving the energy density and utilization efficiency of jet fuel that is widely applied in aircraft powered by aviation turbine engines. To recognize the evaporation behavior of the formed liquid film as a jet fuel-based nanofluid sprayed onto the engine wall or blades, this paper presents the evaporation and deposition characteristics of the jet fuel-based nanofluid liquid film adhering on the hydrophilic substrate. The changes in contact line, contact angle, volume, and deposition pattern during liquid film evaporation under different substrate temperatures, different nanoparticle concentrations, and different kinds of nanoparticle additions were investigated. The effect of nano-Al addition on the evaporation kinetics and deposition pattern of the nano-Al/jet fuel (nAl/JF) nanofluid fuel liquid film was explored. Repeated pinning and de-pinning of contact lines during evaporation occurred, resulting in the formation of concentric multi-ring deposition patterns. The addition of nano-Al increased the evaporation rate and shortened the evaporation lifetime, demonstrating a promotion effect on jet fuel liquid film evaporation. The existence of an energy barrier shows that the movement of three-phase contact lines on the hydrophilic solid surface presented not a continuous sliding behavior but a "stick-slip" behavior, and there were multiple jumps in contact lines and contact angles. Finally, a comparison was made with the deposition pattern of jet fuel liquid films with different graphite and Fe nanoparticle additions during evaporation. The mechanism of deposition phenomena was deeply revealed by the analysis of capillary flow and Marangoni recirculation.
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Affiliation(s)
- Linhui Ye
- Institute of Energy, Department of Physics, Hangzhou Dianzi University, Hangzhou310018, China
| | - Shengji Li
- College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou310018, China
| | - Xuefeng Huang
- Institute of Energy, Department of Physics, Hangzhou Dianzi University, Hangzhou310018, China
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5
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Formation and development of distinct deposit patterns by drying Polyelectrolyte-stabilized colloidal droplets at different surfactant concentrations. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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6
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Zaibudeen A, Bandyopadhyay R. Correlating the drying kinetics and dried morphologies of aqueous colloidal gold droplets of different particle concentrations. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128982] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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7
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Zaibudeen AW, Bandyopadhyay R. DC field coupled evaporation of a sessile gold nanofluid droplet. SOFT MATTER 2021; 17:10294-10300. [PMID: 34782898 DOI: 10.1039/d1sm00820j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The coffee stain formed when a sessile nanofluid colloidal droplet dries on a substrate displays distinct nanoparticle aggregation regimes. We employ scanning electron microscopy to study the coffee stain morphologies when DC electric fields are applied to drying aqueous suspension droplets of CTAB capped gold nanorods (Au-NRs) on a hydrophilic substrate. We observe a typical coffee ring edge with several Au-NR domains due to outward capillary flow both in the absence and presence of the electric field. The Au-NRs at the coffee ring edge assemble in a smectic-like phase with homogeneous alignment in a zero DC field. Despite the presence of strong evaporation-induced flows, application of a DC electric field perpendicular to the substrate results in homeotropic alignment of the Au-NRs at the coffee ring edge. Clusters of Au-NRs with short-range order form at the inner coffee ring edge which we attribute to Marangoni eddies. Moving towards the centre of the coffee stain, we note a depletion region lacking particles, followed by non-uniform deposition of Au-NRs. Au-NR arrays are also found to deposit outside the coffee ring, presumably due to depinning of the evaporating droplet during the initial stages of droplet drying. In contrast to the outer coffee ring edge, we note no change in Au-NR orientation in other regions of the stain due to the extremely low particle concentrations. We believe that our results are applicable to assemblies of a variety of surfactant capped metal nanorods.
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Affiliation(s)
- A W Zaibudeen
- Soft Condensed Matter Group, Raman Research Institute, Bangalore - 560 080, India.
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8
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Tanis-Kanbur MB, Kumtepeli V, Kanbur BB, Ren J, Duan F. Transient Prediction of Nanoparticle-Laden Droplet Drying Patterns through Dynamic Mode Decomposition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:2787-2799. [PMID: 33577318 DOI: 10.1021/acs.langmuir.0c03546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nanoparticle-laden sessile droplet drying has a wide impact on applications. However, the complexity affected by the droplet evaporation dynamics and particle self-assembly behavior leads to challenges in the accurate prediction of the drying patterns. We initiate a data-driven machine learning algorithm by using a single data collection point via a top-view camera to predict the transient drying patterns of aluminum oxide (Al2O3) nanoparticle-laden sessile droplets with three cases according to particle sizes of 5 and 40 nm and Al2O3 concentrations of 0.1 and 0.2 wt %. Dynamic mode decomposition is used as the data-driven learning model to recognize each nanoparticle-laden droplet as an individual system and then apply the transfer learning procedure. Along 270 s of droplet drying experiments, the training period of the first 100 s is selected, and then the rest of the 170 s is predicted with less than a 10% error between the predicted and the actual droplet images. The developed data-driven approach has also achieved the acceptable prediction for the droplet diameter with less than 0.13% error and a coffee-ring thickness over a range of 2.0 to 6.7 μm. Moreover, the proposed machine learning algorithm can recognize the volume of the droplet liquid and the transition of the drying regime from one to another according to the predicted contact line and the droplet height.
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Affiliation(s)
| | - Volkan Kumtepeli
- Energy Research Institute, Nanyang Technological University, Singapore 637371
| | - Baris Burak Kanbur
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798
| | - Junheng Ren
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798
| | - Fei Duan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798
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9
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Kim J, Shim W, Jo SM, Wooh S. Evaporation driven synthesis of supraparticles on liquid repellent surfaces. J IND ENG CHEM 2021. [DOI: 10.1016/j.jiec.2020.12.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Whitby CP, Hermant A. Concentration of deposit patterns by nanoparticles modified with short amphiphiles. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.124648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Role of surfactant in controlling the deposition pattern of a particle-laden droplet: Fundamentals and strategies. Adv Colloid Interface Sci 2020; 275:102049. [PMID: 31757386 DOI: 10.1016/j.cis.2019.102049] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/21/2019] [Accepted: 10/15/2019] [Indexed: 11/24/2022]
Abstract
Evaporation of particle-laden droplets has attracted wide attention propelled by the vast applications from disease diagnostics, bio-medicines, agriculture, inkjet printing to coating. Surfactant plays a vital role in controlling the deposition patterns of dried droplets, thanks to its extensive influences on particle transport through adsorbing at particle surface and droplet interfaces as well as suppressing or facilitating multiple flows. In order to accurately control the subtle morphology of a deposition, it is of significance to systematically elaborate the microscopic functions of surfactant, and bridge them to the various phenomena of a droplet. In this review, we first elucidate the effects of surfactant on the flow paradigms of capillary flow, solutal Marangoni flow, thermal Marangoni flow, and the mixed flow patterns as capillary force, thermal and solutal surface tensions are in competence or collaboration. Second, surfactant adsorption at particle surface and droplet interfaces modifying short-range and long-range forces such as electrostatic force, van der Waals force, capillary attraction, and hydrophobic bonding among particles and between particles and interfaces are introduced by the underlying mechanisms and approaches. Two phase diagrams are developed to respectively illustrate the roles of capillary force among particles, and the electrostatic interaction between particles and solid-liquid interface in modifying the deposition profiles. This review could build a fundamental framework of knowledge for evaporating particle-laden surfactant solution droplets, and may shed light on strategies to manipulate particle deposition in abundant fluidic-based techniques.
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12
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Wu M, Di Y, Man X, Doi M. Drying Droplets with Soluble Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14734-14741. [PMID: 31604016 DOI: 10.1021/acs.langmuir.9b02229] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We propose a theory for the drying of liquid droplets of surfactant solutions. We show that the added surfactant hinders droplet receding and facilitates droplet spreading, causing a complex behavior of the contact line of an evaporating droplet: the contact line first recedes, then advances, and finally recedes again. We also show that the surfactant can change the deposition pattern from mountain-like to volcano-like and then to coffee-ring-like. Specially, when the contact line motion undergoes a clear receding-advancing transition, a two-ring pattern is formed. The mechanism of the two-ring formation is different from the stick-slip mechanism proposed previously and may be tested experimentally.
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Affiliation(s)
| | - Yana Di
- State Key Laboratory of Scientific and Engineering Computing (LSEC), Institute of Computational Mathematics and Scientific/Engineering Computing (ICMSEC), Academy of Mathematics and Systems Science , Chinese Academy of Sciences , Beijing 100190 , China
- School of Mathematical Sciences , University of Chinese Academy of Sciences , Beijing 100049 , China
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13
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Chu KC, Hu SW, Tsao HK, Sheng YJ. Strong competition between adsorption and aggregation of surfactant in nanoscale systems. J Colloid Interface Sci 2019; 553:674-681. [DOI: 10.1016/j.jcis.2019.06.075] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 06/21/2019] [Accepted: 06/23/2019] [Indexed: 10/26/2022]
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14
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Harikrishnan AR, Dhar P, Gedupudi S, Das SK. Effect of Interaction of Nanoparticles and Surfactants on the Spreading Dynamics of Sessile Droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12180-12192. [PMID: 28982242 DOI: 10.1021/acs.langmuir.7b02123] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
While a body of literature on the spreading dynamics of surfactants and a few studies on the spreading dynamics of nanocolloids exist, to the best of the authors' knowledge, there are no reports on the effect of presence of surfactants on the spreading dynamics of nanocolloidal suspensions. For the first time the present study reports an extensive experimental and theoretical study on the effect of surfactant impregnated nanocolloidal complex fluids in modulating the spreading dynamics. A segregation analysis of the effect of surfactants alone, nanoparticle alone, and the combined effect of nanoparticle and surfactants in altering the spreading dynamics have been studied in detail. The spreading dynamics of nanocolloidal solutions alone and of the surfactant impregnated nanocolloidal solutions are found to be grossly different, and particle morphology is found to play a predominant role. For the first time the present study experimentally proves that the classical Tanner's law is disobeyed by the complex fluids in the case of particle alone and combined particle and surfactant case. We also discuss the role of imbibitions across the particle wedge in the precursor film in tuning spreading dynamics. We propose an analytical model to predict the nature of dependency of contact radius on time for the complex colloids. A detailed theoretical examination of the governing factors, the interacting forces at the three phase contact line, and the effects of interplay of surfactants and the nanoparticles at the precursor film in modulating the spreading dynamics has been presented for such complex colloids.
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Affiliation(s)
- A R Harikrishnan
- Department of Mechanical Engineering, Indian Institute of Technology Madras , Chennai-600036, India
| | - Purbarun Dhar
- Department of Mechanical Engineering, Indian Institute of Technology Ropar , Rupnagar-140001, India
| | - Sateesh Gedupudi
- Department of Mechanical Engineering, Indian Institute of Technology Madras , Chennai-600036, India
| | - Sarit K Das
- Department of Mechanical Engineering, Indian Institute of Technology Madras , Chennai-600036, India
- Department of Mechanical Engineering, Indian Institute of Technology Ropar , Rupnagar-140001, India
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15
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Choi S, Birarda G. Protein Mixture Segregation at Coffee-Ring: Real-Time Imaging of Protein Ring Precipitation by FTIR Spectromicroscopy. J Phys Chem B 2017; 121:7359-7365. [DOI: 10.1021/acs.jpcb.7b05131] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Sun Choi
- Center
for Urban Energy Research, Korea Institutes of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Giovanni Birarda
- Elettra - Sincrotrone Trieste, Strada Statale 14 - km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
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16
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Mae K, Toyama H, Nawa-Okita E, Yamamoto D, Chen YJ, Yoshikawa K, Toshimitsu F, Nakashima N, Matsuda K, Shioi A. Self-Organized Micro-Spiral of Single-Walled Carbon Nanotubes. Sci Rep 2017; 7:5267. [PMID: 28706232 PMCID: PMC5509688 DOI: 10.1038/s41598-017-05558-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/31/2017] [Indexed: 11/09/2022] Open
Abstract
Single-walled carbon nanotubes (SWCNTs) are reported to spontaneously align in a rotational pattern by drying a liquid droplet of toluene containing polyfluorene as a dispersant. By situating a droplet of an SWCNT solution around a glass bead, spiral patterns are generated. The parallel alignment of SWCNTs along one stripe of such a pattern is confirmed using scanning electron microscopy and polarized optical microscopy. The orientation order increases toward the outer edge of a stripe. The stripe width in the pattern is proportional to the solute concentration, and the width and position of the stripes follow geometric sequences. The growth of the rotational pattern is also observed in real time. The process of spiral pattern formation is visualized, indicating the role of the annihilation of counter-traveling accompanied by continuous depinning. The geometric sequences for the stripe width and position are explained by the near-constant traveling speed and solute enrichment at the droplet periphery.
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Affiliation(s)
- Keisuke Mae
- Department of Chemical Engineering & Materials Science, Doshisha University, Kyoto, 610-0321, Japan
| | - Hidetoshi Toyama
- Department of Chemical Engineering & Materials Science, Doshisha University, Kyoto, 610-0321, Japan
| | - Erika Nawa-Okita
- Organization for Research Initiatives and Development, Department of Chemical Engineering & Materials Science, Doshisha University, Kyoto, 610-0321, Japan
| | - Daigo Yamamoto
- Department of Chemical Engineering & Materials Science, Doshisha University, Kyoto, 610-0321, Japan
| | - Yong-Jun Chen
- Department of Physics, Shaoxing University, Shaoxing, Zhejiang Province, 312000, China
| | - Kenichi Yoshikawa
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan
| | - Fumiyuki Toshimitsu
- Department of Applied Chemistry, Kyushu University, Fukuoka, 819-0395, Japan
| | - Naotoshi Nakashima
- International Institute for Carbon-Neutral Energy Research, Kyushu University, Fukuoka, 819-0395, Japan
| | - Kazunari Matsuda
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Akihisa Shioi
- Department of Chemical Engineering & Materials Science, Doshisha University, Kyoto, 610-0321, Japan.
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17
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Feng H, Chong KSL, Ong KS, Duan F. Octagon to Square Wetting Area Transition of Water-Ethanol Droplets on a Micropyramid Substrate by Increasing Ethanol Concentration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1147-1154. [PMID: 28094970 DOI: 10.1021/acs.langmuir.6b04195] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The wettability and evaporation of water-ethanol binary droplets on the substrate with micropyramid cavities are studied by controlling the initial ethanol concentrations. The droplets form octagonal initial wetting areas on the substrate. As the ethanol concentration increases, the side ratio of the initial wetting octagon increases from 1.5 at 0% ethanol concentration to 3.5 at 30% ethanol concentration. The increasing side ratio indicates that the wetting area transforms from an octagon to a square if we consider the octagon to be a square with its four corners cut. The droplets experience a pinning-depinning transition during evaporation. The pure water sessile droplet evaporation demonstrates three stages from the constant contact line (CCL) stage, and then the constant contact angle (CCA) stage, to the mixed stage. An additional mixed stage is found between the CCL and CCA stages in the evaporation of water-ethanol binary droplets due to the anisotropic depinning along the two different axes of symmetry of the octagonal wetting area. Droplet depinning occurs earlier on the patterned surface as the ethanol concentration increases.
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Affiliation(s)
- Huicheng Feng
- School of Mechanical and Aerospace Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Karen Siew-Ling Chong
- Institute of Materials Research and Engineering , A*Star, 2 Fusionopolis Way, Innovis, Level 9, Singapore 138634, Singapore
| | - Kian-Soo Ong
- Institute of Materials Research and Engineering , A*Star, 2 Fusionopolis Way, Innovis, Level 9, Singapore 138634, Singapore
| | - Fei Duan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore
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18
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Zhong X, Duan F. Flow regime and deposition pattern of evaporating binary mixture droplet suspended with particles. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2016; 39:18. [PMID: 26920521 DOI: 10.1140/epje/i2016-16018-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 10/12/2015] [Accepted: 11/04/2015] [Indexed: 06/05/2023]
Abstract
The flow regimes and the deposition pattern have been investigated by changing the ethanol concentration in a water-based binary mixture droplet suspended with alumina nanoparticles. To visualize the flow patterns, Particle Image Velocimetry (PIV) has been applied in the binary liquid droplet containing the fluorescent microspheres. Three distinct flow regimes have been revealed in the evaporation. In Regime I, the vortices and chaotic flows are found to carry the particles to the liquid-vapor interface and to promote the formation of particle aggregation. The aggregates move inwards in Regime II as induced by the Marangoni flow along the droplet free surface. Regime III is dominated by the drying of the left water and the capillary flow driving particles radially outward is observed. The relative weightings of Regimes I and II, which are enhanced with an increasing load of ethanol, determine the motion of the nanoparticles and the formation of the final drying pattern.
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Affiliation(s)
- Xin Zhong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 639798, Singapore, Singapore
| | - Fei Duan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 639798, Singapore, Singapore.
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Zhong X, Duan F. Dewetting transition induced by surfactants in sessile droplets at the early evaporation stage. SOFT MATTER 2016; 12:508-513. [PMID: 26482037 DOI: 10.1039/c5sm01976a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
As surfactants are employed to control the wettability of solutions, we observe that the sessile droplet dewetting induced by autophobing exhibits a unique relation with the surfactant concentration. Below the critical micelle concentration (cmc) of the surfactant, the autophobic effect makes the droplet go through a rapid depinning at first (Phase 1) and then a relatively slower shrinkage (Phase 2). Unexpectedly, the rapid velocity of the three-phase contact line in Phase 1 shows a transition as the surfactant concentration increases above 0.043 cmc, while such a transition is absent for the velocity in Phase 2. The spreading of the sessile droplets as they form before retraction, the maximum contact angle led by dewetting, and the droplet lifetime are regularly sensitive to the surfactant concentration as well. These phenomena are correlated with the assembling structure and the adsorbed amount at different interfaces with the loading of surfactant inventory.
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Affiliation(s)
- Xin Zhong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
| | - Fei Duan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
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20
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Zhong X, Duan F. Disk to dual ring deposition transformation in evaporating nanofluid droplets from substrate cooling to heating. Phys Chem Chem Phys 2016; 18:20664-71. [DOI: 10.1039/c6cp03231a] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Substrate temperature strongly influences the nanoparticle deposition patterns changing from a disk to a dual ring in sessile droplet evaporation.
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Affiliation(s)
- Xin Zhong
- School of Mechanical and Aerospace Engineering
- Nanyang Technological University
- Singapore 639798
- Singapore
| | - Fei Duan
- School of Mechanical and Aerospace Engineering
- Nanyang Technological University
- Singapore 639798
- Singapore
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