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Pei HW, Zhang J, Sun ZY. Deposition patterns formed by the evaporation of linear diblock copolymer solution nanodroplets on solid surfaces. J Chem Phys 2024; 161:014711. [PMID: 38958161 DOI: 10.1063/5.0216966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 06/17/2024] [Indexed: 07/04/2024] Open
Abstract
The evaporation-induced deposition pattern of the linear diblock copolymer solution has attracted attention in recent years. Given its critical applications, we study deposition patterns of the linear diblock copolymer solution nanodroplet on a solid surface (the wall) by molecular dynamics simulations. This study focuses on the influence of the nonbonded interaction strength, including the interaction between the wall and polymer blocks (ɛAW and ɛBW), the interaction between the solvent and the wall (ɛSW), and the interaction between polymer blocks (ɛAB). Conditions leading to diverse deposition patterns are explored, including the coffee-ring and the volcano-like structures. The formation of the coffee-ring structure is attributed to receding interfaces, the heterogeneity inside the droplet, and the self-assembly of polymer chains. This study contributes to the establishment of guidelines for designing deposition patterns of the linear diblock copolymer solution nanodroplet, which facilitates practical applications such as inkjet printing.
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Affiliation(s)
- Han-Wen Pei
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Jun Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Zhao-Yan Sun
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
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Erdem AK, Denner F, Biancofiore L. Numerical Analysis of the Dispersion and Deposition of Particles in Evaporating Sessile Droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:13428-13445. [PMID: 38901041 DOI: 10.1021/acs.langmuir.4c00680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Evaporating sessile droplets containing dispersed particles are used in different technological applications, such as 3D printing, biomedicine, and micromanufacturing, where an accurate prediction of both the dispersion and deposition of the particles is important. Furthermore, the interaction between the droplet and the substrate must be taken into account: the motion of the contact line, in particular, must be modeled carefully. To this end, studies have typically been limited to either pinned or moving contact lines to simplify the underlying mathematical models and numerical methods, neglecting the fact that both scenarios are observed during the evaporation process. Here, a numerical algorithm considering both contact line regimes is proposed whereby the regimes are distinguished by predefined threshold contact angles. After a detailed validation, this new algorithm is applied to study the influence of both regimes on the dispersion and deposition of particles in an evaporating sessile droplet. In particular, the presented analysis focuses on the influence of (i) the contact line motion characteristics by varying the limiting contact angle and spreading speed, (ii) the Marangoni number, characterizing the importance of thermocapillarity, (iii) the evaporation number, which quantifies the importance of evaporation, (iv) the Damköhler number, a measure of the particle deposition rate, and (v) the Peclet number, which compares the convection and diffusion of the particle concentration. When thermocapillarity becomes dominant or the limiting contact angle is larger, the particle accumulation near the contact line decreases, which, in turn, means that more particles are deposited near the center of the droplet. In contrast, increasing the evaporation number supports particle accumulation near the contact line, while a larger Damköhler number and/or smaller Peclet number yield more uniform final deposition patterns. Finally, a larger characteristic speed of spreading results in fewer particles being deposited at the center of the droplet.
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Affiliation(s)
- Ali Kerem Erdem
- Department of Mechanical Engineering, Bilkent University, Bilkent, Ankara 06800, Turkey
| | - Fabian Denner
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal H3T 1J4, QC, Canada
| | - Luca Biancofiore
- Department of Mechanical Engineering, Bilkent University, Bilkent, Ankara 06800, Turkey
- Department of Industrial Engineering Information and Economics, University of L'Aquila, Piazzale Ernesto Pontieri Monteluco di Roio, L'Aquila 67100, Italy
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Song T, Jiang Z, Man X, Shi W. Joint Experimental and Theoretical Study on Deposition Morphologies in Polymer Sessile Droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:860-870. [PMID: 38109327 DOI: 10.1021/acs.langmuir.3c03038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Although past experimental and theoretical research has made substantial progress in understanding evaporation behaviors in various suspensions, the fundamental mechanism for polymer sessile droplets is still lacking. One critical effect is the molecular weight on the evaporation behaviors. Here, systematic experiments are carried out to investigate the evaporation behavior of polymer droplets under the effects of polymer concentration, evaporation rate, and especially molecular weight. We obtain polymer films with various morphologies with molecular weights ranging from 2 orders of magnitude to 4 orders of magnitude and polymer concentration across 4 orders of magnitude. We further develop a theoretical model based on the Onsager principle to explain the evaporation mechanism from a dynamic perspective. Analysis indicates that increasing molecular weight or polymer concentration enhances the contact angle hysteresis and slows down the evaporation, resulting in the transition from multiring to coffee ring and eventually to uniform films. The findings offer a guideline for achieving the desired deposition patterns via droplet processing techniques.
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Affiliation(s)
- Tiantian Song
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Tianjin Key Laboratory of Functional Polymer Materials, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Zechao Jiang
- School of Physics, Beihang University, Beijing 100191, China
| | - Xingkun Man
- School of Physics, Beihang University, Beijing 100191, China
- Peng Huanwu Collaborative Center for Research and Education, Beihang University, Beijing 100191, China
| | - Weichao Shi
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Tianjin Key Laboratory of Functional Polymer Materials, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300071, China
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Wang F, Yuan Q. Evaporation-induced fractal patterns: A bridge between uniform pattern and coffee ring. J Colloid Interface Sci 2023; 637:522-532. [PMID: 36724666 DOI: 10.1016/j.jcis.2023.01.102] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/25/2023]
Abstract
HYPOTHESIS The rich variety of patterns induced by evaporating drops containing particles has significant guidance for coating processes, inkjet printing, and nanosemiconductors. However, most existing works construct a uniform pattern by suppressing the coffee ring effect, and establishing the connection between them is still an academic challenge. EXPERIMENTS We report uniform, polygonal, and coffee ring patterns obtained by adjusting the solute concentration that sets in when an ethanol drop with dissolved ibuprofen is deposited on a silicon wafer. FINDINGS Pattern formation involves rich hydrodynamic events: spreading, evaporative instability, dewetting, film formation, and particle deposition. Based on the distinct multiscale properties, this series of patterns is directly connected from the perspective of fractal geometry, which allows us to name them "fractal deposition patterns". A theoretical model considering film stability is established to explain the mechanism behind pattern formation, which is well verified by experiments. This work has presented a unique strategy that can directly connect uniform, polygonal, and coffee ring patterns under the same physics, hoping to provide instructive guidance for practical applications.
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Affiliation(s)
- Fushuai Wang
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China; School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Quanzi Yuan
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China; School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
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Tang J, Shan Y, Jiang Y. The control of dry-out patterns using bubble-containing droplets. J Colloid Interface Sci 2023; 645:12-21. [PMID: 37130484 DOI: 10.1016/j.jcis.2023.04.077] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 04/11/2023] [Accepted: 04/18/2023] [Indexed: 05/04/2023]
Abstract
HYPOTHESIS For an evaporating nanofluid droplet that contains a bubble inside, we suspect the bubble boundary remains pinned during evaporation whereas the droplet perimeter recedes. Thus, the dry-out patterns are mainly determined by the presence of the bubble and their morphology can be tuned by the size and location of the added bubble. EXPERIMENTS Bubbles with varying base diameters and lifetimes are added into evaporating droplets that contain nanoparticles with different types, sizes, concentrations, shapes, and wettability. The geometric dimensions of the dry-out patterns are measured. FINDINGS For a droplet containing a long-lifetime bubble, a complete ring-like deposit forms, and its diameter and thickness increases and decreases with the bubble base diameter, respectively. The ring completeness, i.e., the ratio of actual ring length to its imaginary perimeter, decreases with the decrease in bubble lifetime. The pinning of droplet receding contact line by particles near the bubble perimeter has been found to be the key factor leading to ring-like deposits. This study introduces a strategy of producing ring-like deposit and allows a control of the ring morphology in a simple, cheap, and impurity-free fashion, which is applicable to various applications associated with evaporative self-assembly.
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Affiliation(s)
- Jiaxin Tang
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; Department of Mechanical Engineering, Guangdong Technion - Israel Institute of Technology, Shantou, Guangdong 515063, China
| | - Yanguang Shan
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Youhua Jiang
- Department of Mechanical Engineering, Guangdong Technion - Israel Institute of Technology, Shantou, Guangdong 515063, China; Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
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Cheng C, Jae Moon Y, Hwang JY, Chiu GTC, Han B. A scaling law of particle transport in inkjet-printed particle-laden polymeric drops. INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2022; 191:122840. [PMID: 35444343 PMCID: PMC9015692 DOI: 10.1016/j.ijheatmasstransfer.2022.122840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Hydrogels with embedded functional particulates are widely used to create soft materials with innovative functionalities. In order to advance these soft materials to functional devices and machines, critical technical challenges are the precise positioning of particulates within the hydrogels and the construction of the hydrogels into a complex geometry. Inkjet printing is a promising method for addressing these challenges and ultimately achieving hydrogels with voxelized functionalities, so-called digital hydrogels. However, the development of the inkjet printing process primarily relies on empirical optimization of its printing and curing protocol. In this study, a general scaling law is proposed to predict the transport of particulates within the hydrogel during inkjet printing. This scaling law is based on a hypothesis that water-matrix interaction during the curing of inkjet-printed particle-laden polymeric drops determines the intra-drop particle distribution. Based on the hypothesis, a dimensionless similarity parameter of the water-matrix interaction is proposed, determined by the hydrogel's water evaporation coefficient, particle size, and mechanical properties. The hypothesis was tested by correlating the intra-drop particle distribution to the similarity parameter. The results confirmed the scaling law capable of guiding ink formulation and printing and curing protocol.
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Affiliation(s)
- Cih Cheng
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - Yoon Jae Moon
- Korea Institute of Industrial Technology, Ansan, Gyeonggi Do, Republic of Korea
| | - Jun Young Hwang
- Korea Institute of Industrial Technology, Ansan, Gyeonggi Do, Republic of Korea
| | - George T.-C. Chiu
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
| | - Bumsoo Han
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
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Wang F, Tian S, Yuan Q. Evaporation-induced crystal self-assembly (EICSA) of salt drops regulated by trace of polyacrylamide. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Bournigault-Nuquet A, Couderc S, Bibette J, Baudry J. Patterning of a Drying Emulsion Film. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:8924-8928. [PMID: 34279958 DOI: 10.1021/acs.langmuir.1c00246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Stabilizing layers of colloidal dispersions or emulsions to obtain homogeneous films is a real challenge. We describe here a new kind of instability in drying films of emulsions: during evaporation of the internal phase, cracks appear between the droplets that create aggregates according to a regular pattern. We show that this pattern only appears if the emulsion is adhesive, i.e., if droplets stick together. The pattern exhibits a characteristic length which depends on the adhesion strength and film thickness. These experimental results support a model where this instability is due to the gel structure and elastic properties of adhesive emulsions. Understanding this phenomenon will allow us to get a homogeneous film or to control it to get structured materials.
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Affiliation(s)
- Aurore Bournigault-Nuquet
- Laboratoire Colloïdes et Matériaux Divisés, CBI, ESPCI Paris, Université PSL, CNRS, 75005 Paris, France
- CHANEL Parfums Beauté, 8 rue du Cheval Blanc, 93500 Pantin, France
| | - Sandrine Couderc
- CHANEL Parfums Beauté, 8 rue du Cheval Blanc, 93500 Pantin, France
| | - Jérôme Bibette
- Laboratoire Colloïdes et Matériaux Divisés, CBI, ESPCI Paris, Université PSL, CNRS, 75005 Paris, France
| | - Jean Baudry
- Laboratoire Colloïdes et Matériaux Divisés, CBI, ESPCI Paris, Université PSL, CNRS, 75005 Paris, France
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Misyura S, Egorov R, Morozov V, Zaitsev A. Emergence and breakup of a cluster of ordered microparticles during the interaction of thermocapillary and thermogravitational convection. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2020.10.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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