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Zhu J, Fan H, Wan J. Solvent-Free and UV-Cured Epoxy Silicone Coating with Excellent Wear Resistance and Antismudge Properties. ACS APPLIED MATERIALS & INTERFACES 2024; 16:35494-35504. [PMID: 38924769 DOI: 10.1021/acsami.4c03775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
Transparent, hard, and flexible multifunctional coatings have a wide range of applications; however, most of them need organic solvents. Here, we present a solvent-free and UV-cured coating made from fluorinated epoxy MTQ silicone resin combined with branched triepoxy siloxane as the reactive diluent. After UV-initiated ring-opening polymerization in the presence of a triarylsulfonium hexafluoroantimonate catalyst, the resultant cured coating exhibits high transparency (∼92%, 550 nm), pencil hardness (7H), and flexibility (1 mm bending diameter) due to the formed organic-inorganic nanostructures in a highly cross-linked network. The triepoxy siloxane significantly reduces the viscosity before curing and increases cross-link density of the coating. The coating without any volatile content shows a smooth surface with low roughness (Rq = 0.46 nm) and delivers an anti-smudge ability owing to perfluorinated chains inherited from the MTQ resin. Furthermore, even after 3000 abrasion cycles, the coating still has a water contact angle greater than 90°, displaying excellent wear resistance. Our work provides a promising way to access high-performance multifunctional coatings in a more sustainable manner.
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Affiliation(s)
- Jialong Zhu
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, P. R. China
| | - Hong Fan
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, P. R. China
| | - Jintao Wan
- School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710062, China
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2
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Lee S, Cho Y, Heo S, Bae JH, Kang IM, Kim K, Lee WY, Jang J. UV/Ozone-Treated and Sol-Gel-Processed Y 2O 3 Insulators Prepared Using Gelation-Delaying Precursors. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:791. [PMID: 38727385 PMCID: PMC11085385 DOI: 10.3390/nano14090791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 04/23/2024] [Accepted: 04/30/2024] [Indexed: 05/12/2024]
Abstract
In this study, a Y2O3 insulator was fabricated via the sol-gel process and the effect of precursors and annealing processes on its electrical performance was studied. Yttrium(III) acetate hydrate, yttrium(III) nitrate tetrahydrate, yttrium isopropoxide oxide, and yttrium(III) tris (isopropoxide) were used as precursors, and UV/ozone treatment and high-temperature annealing were performed to obtain Y2O3 films from the precursors. The structure and surface morphologies of the films were characterized via grazing-incidence X-ray diffraction and scanning probe microscopy. Chemical component analysis was performed via X-ray spectroscopy. Electrical insulator characteristics were analyzed based on current density versus electrical field data and frequency-dependent dielectric constants. The Y2O3 films fabricated using the acetate precursor and subjected to the UV/ozone treatment showed a uniform and flat surface morphology with the lowest number of oxygen vacancy defects and unwanted byproducts. The corresponding fabricated capacitors showed the lowest current density (Jg) value of 10-8 A/cm2 at 1 MV/cm and a stable dielectric constant in a frequency range of 20 Hz-100 KHz. At 20 Hz, the dielectric constant was 12.28, which decreased to 10.5 at 105 Hz. The results indicate that high-quality, high-k insulators can be fabricated for flexible electronics using suitable precursors and the suggested low-temperature fabrication methods.
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Affiliation(s)
- Sangwoo Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (S.L.); (S.H.); (J.-H.B.); (I.-M.K.)
| | - Yoonjin Cho
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (S.L.); (S.H.); (J.-H.B.); (I.-M.K.)
| | - Seongwon Heo
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (S.L.); (S.H.); (J.-H.B.); (I.-M.K.)
| | - Jin-Hyuk Bae
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (S.L.); (S.H.); (J.-H.B.); (I.-M.K.)
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - In-Man Kang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (S.L.); (S.H.); (J.-H.B.); (I.-M.K.)
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Kwangeun Kim
- School of Electronics and Information Engineering, Korea Aerospace University, Goyang 10540, Republic of Korea;
| | - Won-Yong Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (S.L.); (S.H.); (J.-H.B.); (I.-M.K.)
- The Institute of Electronic Technology, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jaewon Jang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (S.L.); (S.H.); (J.-H.B.); (I.-M.K.)
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
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3
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Junisu BA, Sun YS. Hierarchical Surface Instability in Polymer Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:15249-15259. [PMID: 37862459 DOI: 10.1021/acs.langmuir.3c01936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
This study demonstrates hierarchical instabilities in thin films. The hierarchical instabilities display three morphological characteristics: (1) windmill-like patterns at the macroscale, (2) Bénard cells and striations at the microscale, and (3) holes at the mesoscale. Such hierarchical instabilities occurred when spin coating was performed on high-volatile solutions under a high relative humidity (RH) but were suppressed when spin coating was performed on low-volatile solutions regardless of the RH. The high-volatile solutions comprise poly(4-vinylpyridine) (P4VP) in methanol or ethanol. The low-volatility solutions comprise P4VP in propanol or butanol. P4VP molecular weights, P4VP concentrations, spin rates, and film thicknesses are not vital factors in forming hierarchical instability in spin-coated P4VP films. Instead, the formation of hierarchical instabilities depends on the RH and solvent types. Namely, the hierarchical instabilities are driven by Bénard-Marangoni convection, water vapor condensation, and disturbance of spin-up and spin-off stages during spin coating of highly volatile solutions under high RH. Mechanisms of hierarchical instabilities are interpreted in detail.
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Affiliation(s)
- Belda Amelia Junisu
- Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan
| | - Ya-Sen Sun
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
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4
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Pinky SK, Kwansa AL, Zhang B, Stiff-Roberts AD, Yingling YG. Effect of solvent on the emulsion and morphology of polyfluorene films: all-atom molecular dynamics approach. SOFT MATTER 2023; 19:1782-1790. [PMID: 36779927 DOI: 10.1039/d2sm01001a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The morphology of conjugated polymer thin films deposited by the resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) process is related to the emulsion characteristics. However, a fundamental understanding of how and why the emulsion characteristics control the film properties and device performance is yet unclear. We performed all-atom molecular dynamics simulations of emulsions containing a mixture of polyfluorene (PFO) polymer, various primary solvents, secondary solvent, and water. The emulsion properties were then examined as a function of variable primary solvent and correlated with the morphology of deposited PFO thin films. The examination of the explicit interactions between all components of the emulsion indicated that using a primary solvent with a lower solubility-in-water and a higher non-bonded interaction energy ratio, between the solvent, polymer, and water in the emulsion recipe, produced the best result with smoother and denser films. Additionally, our simulation results are consistent with the AFM experimental results, indicating that interactions driven by trichlorobenzene (TCB) primary solvent within the emulsion are responsible for high-quality, smooth, and continuous thin film surfaces. Overall, this study can support the choice of a suitable primary solvent and provides the computational framework for predictions of new recipes for polymeric emulsion systems.
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Affiliation(s)
- Sabila K Pinky
- Department of Materials Science and Engineering, North Carolina State university, Raleigh, NC, 27606, USA.
| | - Albert L Kwansa
- Department of Materials Science and Engineering, North Carolina State university, Raleigh, NC, 27606, USA.
| | - Buang Zhang
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA
| | - Adrienne D Stiff-Roberts
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA
- University Program in Materials Science and Engineering, Duke University, Durham, NC, 27708, USA
| | - Yaroslava G Yingling
- Department of Materials Science and Engineering, North Carolina State university, Raleigh, NC, 27606, USA.
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5
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Yunus Y, Mahadzir NA, Mohamed Ansari MN, Tg Abd Aziz TH, Mohd Afdzaluddin A, Anwar H, Wang M, Ismail AG. Review of the Common Deposition Methods of Thin-Film Pentacene, Its Derivatives, and Their Performance. Polymers (Basel) 2022; 14:polym14061112. [PMID: 35335442 PMCID: PMC8950127 DOI: 10.3390/polym14061112] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/09/2021] [Accepted: 11/09/2021] [Indexed: 02/02/2023] Open
Abstract
Pentacene is a well-known conjugated organic molecule with high mobility and a sensitive photo response. It is widely used in electronic devices, such as in organic thin-film transistors (OTFTs), organic light-emitting diodes (OLEDs), photodetectors, and smart sensors. With the development of flexible and wearable electronics, the deposition of good-quality pentacene films in large-scale organic electronics at the industrial level has drawn more research attention. Several methods are used to deposit pentacene thin films. The thermal evaporation technique is the most frequently used method for depositing thin films, as it has low contamination rates and a well-controlled deposition rate. Solution-processable methods such as spin coating, dip coating, and inkjet printing have also been widely studied because they enable large-scale deposition and low-cost fabrication of devices. This review summarizes the deposition principles and control parameters of each deposition method for pentacene and its derivatives. Each method is discussed in terms of experimentation and theory. Based on film quality and device performance, the review also provides a comparison of each method to provide recommendations for specific device applications.
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Affiliation(s)
- Yusniza Yunus
- Institute of Microengineering & Nanoelectronics, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (Y.Y.); (N.A.M.); (T.H.T.A.A.); (A.M.A.)
| | - Nurul Adlin Mahadzir
- Institute of Microengineering & Nanoelectronics, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (Y.Y.); (N.A.M.); (T.H.T.A.A.); (A.M.A.)
| | - Mohamed Nainar Mohamed Ansari
- Institute of Power Engineering, Universiti Tenaga Nasional, Bangi 43000, Malaysia
- Correspondence: (M.N.M.A.); (A.G.I.)
| | - Tg Hasnan Tg Abd Aziz
- Institute of Microengineering & Nanoelectronics, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (Y.Y.); (N.A.M.); (T.H.T.A.A.); (A.M.A.)
| | - Atiqah Mohd Afdzaluddin
- Institute of Microengineering & Nanoelectronics, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (Y.Y.); (N.A.M.); (T.H.T.A.A.); (A.M.A.)
| | - Hafeez Anwar
- Department of Physics, University of Agriculture, Faisalabad 38040, Pakistan;
| | - Mingqing Wang
- Institute for Materials Discovery, University College London, London WC1E 7JE, UK;
| | - Ahmad Ghadafi Ismail
- Institute of Microengineering & Nanoelectronics, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (Y.Y.); (N.A.M.); (T.H.T.A.A.); (A.M.A.)
- Correspondence: (M.N.M.A.); (A.G.I.)
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6
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Enhanced Switching Reliability of Sol–Gel-Processed Y2O3 RRAM Devices Based on Y2O3 Surface Roughness-Induced Local Electric Field. MATERIALS 2022; 15:ma15051943. [PMID: 35269170 PMCID: PMC8911950 DOI: 10.3390/ma15051943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/17/2022] [Accepted: 03/02/2022] [Indexed: 12/01/2022]
Abstract
Sol–gel-processed Y2O3 films were used as active channel layers for resistive random access memory (RRAM) devices. The fabricated ITO/Y2O3/Ag RRAM devices exhibited the properties of conventional bipolar memory devices. A triethylamine stabilizer with a high vapor pressure and low surface tension was added to realize the local electric field area. During drying and high-temperature post-annealing processes, the large convective flow enhanced the surface elevation, and the increased –OH groups accelerated the hydrolysis reaction and aggregation. These phenomena afforded Y2O3 films with an uneven surface morphology and an increased surface roughness. The increased roughness of the Y2O3 films attributable to the triethylamine stabilizer enhanced the local electrical field, improved device reliability, and achieved successful repetition of the switching properties over an extended period.
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7
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Large-scale patterning of π-conjugated materials by meniscus guided coating methods. Adv Colloid Interface Sci 2020; 275:102080. [PMID: 31809990 DOI: 10.1016/j.cis.2019.102080] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/30/2019] [Accepted: 11/20/2019] [Indexed: 11/21/2022]
Abstract
Printed organic electronics has attracted considerable interest in recent years as it enables the fabrication of large-scale, low-cost electronic devices, and thus offers significant possibilities in terms of developing new applications in various fields. Easy processing is a prerequisite for the development of low-cost, flexible and printed plastics electronics. Among processing techniques, meniscus guided coating methods are considered simple, efficient, and low-cost methods to fabricate electronic devices in industry. One of the major challenges is the control of thin film morphology, molecular orientations and directional alignment of polymer films during coating processes. Herein, the recent progress of emerging field of meniscus guided printing organic semiconductor materials is discussed. The first part of this report briefly summarizes recent advances in meniscus guided coating techniques. The second part discusses periodic deposits and patterned deposition at moving contact lines, where the mass-transport influences film morphology due to convection at the triple contact line. The last section summarizes our strategy to fabricate large-scale patterning of π-conjugated polymers using meniscus guided method.
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8
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Kitamura I, Oishi K, Hara M, Nagano S, Seki T. Photoinitiated Marangoni flow morphing in a liquid crystalline polymer film directed by super-inkjet printing patterns. Sci Rep 2019; 9:2556. [PMID: 30796238 PMCID: PMC6385296 DOI: 10.1038/s41598-019-38709-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/08/2019] [Indexed: 11/30/2022] Open
Abstract
Slight contaminations existing in a material lead to substantial defects in applied paint. Herein, we propose a strategy to convert this nuisance to a technologically useful process by using an azobenzene-containing side chain liquid crystalline (SCLCP) polymer. This method allows for a developer-free phototriggered surface fabrication. The mass migration is initiated by UV-light irradiation and directed by super-inkjet printed patterns using another polymer on the SCLCP film surface. UV irradiation results in a liquid crystal-to-isotropic phase transition, and this phase change immediately initiates a mass migration to form crater or trench structures due to the surface tension instability known as Marangoni flow. The transferred volume of the film reaches approximately 440-fold that of the polymer ink, and therefore, the printed ink pattern acts as a latent image towards the amplification of surface morphing. This printing-aided photoprocess for surface inscription is expected to provide a new platform of polymer microfabrication.
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Affiliation(s)
- Issei Kitamura
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8603, Japan
| | - Kazuaki Oishi
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8603, Japan
| | - Mitsuo Hara
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8603, Japan
| | - Shusaku Nagano
- Nagoya University Venture Business Laboratory, Furo-cho, Chikusa, Nagoya, 464-8603, Japan.
| | - Takahiro Seki
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8603, Japan.
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9
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Ravi B, Bhattacharjee M, Ghosh A, Bandyopadhyay D. Fabrication of pixelated liquid crystal nanostructures employing the contact line instabilities of droplets. NANOSCALE 2019; 11:1680-1691. [PMID: 30620017 DOI: 10.1039/c8nr08400a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A liquid crystal (LC) droplet resting on a poly-dimethylsiloxane substrate could rapidly spread upon solvent vapour annealing to form a non-uniform film. While the solvophobic surfaces restricted the spreading of the droplet to form a thicker film upon solvent annealing, the solvophilic substrates allowed the formation of a thinner film under similar conditions. Withdrawal of the solvent exposure caused rapid evaporation of the solvent molecules from the film, especially near the retracting contact-line to form microscale LC-droplets, which shrunk into nanoscopic ones after evaporation of the excess solvent. The thinner films on solvophilic surfaces allowed the formation of droplets with smaller size and periodicity as small as ∼100 nm and ∼200 nm, respectively. Furthermore, the use of a patterned substrate could impose a large-area ordering on the nanodroplets. A theoretical model for an evaporating film of LC-solution revealed that the spacing of nanodroplets could be decided by the interplay of stabilizing and destabilizing components of capillary force while van der Waals interaction played a supportive role when the film was ultrathin near the contact line. The micro/nanodroplets thus formed showed an anomalous oscillatory rotational motion originating from the difference in the Laplace pressure near contact lines under the influence of an external electric field. The application of the Lorenz force to these droplets showed translation and rotational motions followed by ejection of satellite droplets.
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Affiliation(s)
- Bolleddu Ravi
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, India.
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10
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Zhang H, Okamura Y. Elongated phase separation domains in spin-cast polymer blend thin films characterized using a panoramic image. SOFT MATTER 2018; 14:1050-1055. [PMID: 29335709 DOI: 10.1039/c7sm02144e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Polymer thin films with micro/nano-structures can be prepared by a solvent evaporation induced phase separation process via spin-casting a polymer blend, where the elongated phase separation domains are always inevitable. The striation defect, as a thickness nonunifomity in spin-cast films, is generally coexistent with the elongated domains. Herein, the morphologies of polymer blend thin films are recorded from the spin-cast center to the edge in a panoramic view. The elongated domains are inclined to appear at the ridge regions of striations with increasing radial distance and align radially, exhibiting a coupling between the phase separation morphology and the striation defect that may exist. We demonstrate that the formation of elongated domains is not attributed to shape deformation, but is accomplished in situ. A possible model to describe the initiation and evolution of the polymer blend phase separation morphology during spin-casting is proposed.
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Affiliation(s)
- Hong Zhang
- Micro/Nano Technology Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
| | - Yosuke Okamura
- Micro/Nano Technology Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan. and Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
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11
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Effect of the Ultrasonic Substrate Vibration on Nucleation and Crystallization of PbI2 Crystals and Thin Films. CRYSTALS 2018. [DOI: 10.3390/cryst8020060] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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12
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Li C, Zhao D, Wen J, Cheng J, Lu X. Evolution of entrained water film thickness and dynamics of Marangoni flow in Marangoni drying. RSC Adv 2018; 8:4995-5004. [PMID: 35539538 PMCID: PMC9078033 DOI: 10.1039/c7ra13533e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 01/21/2018] [Indexed: 12/29/2022] Open
Abstract
As an ultra-clean wafer drying technique, Marangoni drying has been widely applied in the integrated circuits manufacturing process. When the wafer is vertically withdrawn from a deionization water bath, Marangoni stress along the meniscus, which is induced by the organic vapour, strips off the water film entrained on the wafer surface, and the wafer drying is thereby realized. In this work, a numerical model is presented that is comprised of the film, meniscus, and bulk regions for Marangoni drying. The model combines the transfer of organic vapour from air to water and the withdrawal of the wafer from the bath. The evolution of the entrained water film thickness, the tangential velocity, and the stress at the air–water interface are quantitatively investigated. The results reveal that the thickness of the entrained water film is reduced by more than one order of magnitude compared with the wafer withdrawn process without the Marangoni effect. In addition, owing to the receding of the contact line, it is found that the capillary pressure gradient dramatically increases, which contributes to the sudden increase in the tangential velocity in the dynamic meniscus. Moreover, the tangential velocity decreases in the static meniscus adjacent to the dynamic meniscus, which results from the redistribution of the interfacial concentration of the organic species driven by the Marangoni flow. The receding contact line driven by Marangoni flow induces an immersed pressure gradient, and thus a sudden increase of tangential velocity in dynamic meniscus.![]()
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Affiliation(s)
- Changkun Li
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
| | - Dewen Zhao
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
| | - Jialin Wen
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
| | - Jie Cheng
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
| | - Xinchun Lu
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
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13
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Spray-cast multilayer perovskite solar cells with an active-area of 1.5 cm 2. Sci Rep 2017; 7:7962. [PMID: 28801601 PMCID: PMC5554192 DOI: 10.1038/s41598-017-08642-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/14/2017] [Indexed: 12/05/2022] Open
Abstract
We utilise spray-coating under ambient conditions to sequentially deposit compact-TiO2, mesoporous-TiO2, CH3NH3PbI(3−x)Clx perovskite and doped spiro-OMeTAD layers, creating a mesoporous standard architecture perovskite solar cell (PSC). The devices created had an average power conversion efficiency (PCE) of 9.2% and a peak PCE of 10.2%; values that compare favourably with control-devices fabricated by spin-casting that had an average efficiency of 11.4%. We show that our process can be used to create devices having an active-area of 1.5 cm2 having an independently verified efficiency of 6.6%. This work demonstrates the versatility of spray-coating as well as its potential as a method of manufacturing low-cost, large-area, efficient perovskite devices.
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14
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Singer JP. Thermocapillary approaches to the deliberate patterning of polymers. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/polb.24298] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jonathan Phillip Singer
- Department of Mechanical and Aerospace Engineering; Rutgers, the State University of New Jersey, 98 Brett Road; Piscataway New Jersey 08854
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15
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Pham T, Cheng X, Kumar S. Drying of multicomponent thin films on substrates with topography. ACTA ACUST UNITED AC 2016. [DOI: 10.1002/polb.24276] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Truong Pham
- Department of Chemical Engineering and Materials Science; University of Minnesota; Minneapolis Minnesota 55455
| | - Xiang Cheng
- Department of Chemical Engineering and Materials Science; University of Minnesota; Minneapolis Minnesota 55455
| | - Satish Kumar
- Department of Chemical Engineering and Materials Science; University of Minnesota; Minneapolis Minnesota 55455
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16
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Fowler PD, Ruscher C, McGraw JD, Forrest JA, Dalnoki-Veress K. Controlling Marangoni-induced instabilities in spin-cast polymer films: How to prepare uniform films. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2016; 39:90. [PMID: 27681887 DOI: 10.1140/epje/i2016-16090-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 09/07/2016] [Indexed: 05/27/2023]
Abstract
In both research and industrial settings spincoating is extensively used to prepare highly uniform thin polymer films. However, under certain conditions, spincoating results in films with non-uniform surface morphologies. Although the spincoating process has been extensively studied, the origin of these morphologies is not fully understood and the formation of non-uniform spin-cast films remains a practical problem. Here we report on experiments demonstrating that the formation of surface instabilities during spincoating is dependent on temperature. Our results suggest that non-uniform spin-cast films form as a result of the Marangoni effect, which describes flow due to surface tension gradients. We find that both the wavelength and amplitude of the pattern increase with temperature. Finally, and most important from a practical viewpoint, the non-uniformities in the film thickness can be entirely avoided simply by lowering the spin coating temperature.
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Affiliation(s)
- Paul D Fowler
- Department of Physics & Astronomy, McMaster University, L8S 4M1, Hamilton, Ontario, Canada
| | - Céline Ruscher
- Department of Physics & Astronomy, McMaster University, L8S 4M1, Hamilton, Ontario, Canada
- Institut Charles Sadron, Université de Strasbourg, Strasbourg, France
| | - Joshua D McGraw
- Département de Physique, Ecole Normale Supérieure / PSL Research University, CNRS, 24 rue Lhomond, 75005, Paris, France
| | - James A Forrest
- Department of Physics & Astronomy, University of Waterloo, N2L 3G1, Waterloo, Ontario, Canada
| | - Kari Dalnoki-Veress
- Department of Physics & Astronomy, McMaster University, L8S 4M1, Hamilton, Ontario, Canada.
- Laboratoire de Physico-Chimie Théorique, UMR CNRS 7083 Gulliver, ESPCI ParisTech, PSL Research University, Paris, France.
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Qi S, Craig D. Recent developments in micro- and nanofabrication techniques for the preparation of amorphous pharmaceutical dosage forms. Adv Drug Deliv Rev 2016; 100:67-84. [PMID: 26776230 DOI: 10.1016/j.addr.2016.01.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/03/2016] [Indexed: 12/27/2022]
Abstract
Nano- and microfabrication techniques have been widely explored in the textile, polymer and biomedical arenas, although more recently these systems have attracted considerable interest as drug delivery vehicles with concomitant considerations of physical characterization, scalability, stability and drug release. In this review, the current thinking with regards to the manufacture of solid amorphous pharmaceutical materials using electrohydrodynamic and gyration-based approaches, melt-spinning approaches, thermal moulding, inkjet printing and 3D printing will be examined in the context of their potential and actual viability as dosage forms. A series of practical examples will be discussed as to how these approaches have been used as means of producing drug delivery systems for a range of delivery systems and treatments.
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Affiliation(s)
- Sheng Qi
- School of Pharmacy, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - Duncan Craig
- UCL School of Pharmacy, 29-39 Brunswick Square, London, WC1N 1AX, UK
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Li N, Taylor LS. Nanoscale Infrared, Thermal, and Mechanical Characterization of Telaprevir-Polymer Miscibility in Amorphous Solid Dispersions Prepared by Solvent Evaporation. Mol Pharm 2016; 13:1123-36. [PMID: 26859046 DOI: 10.1021/acs.molpharmaceut.5b00925] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Miscibility is of great interest for pharmaceutical systems, in particular, for amorphous solid dispersions, as phase separation can lead to a higher tendency to crystallize, resulting in a loss in solubility, decreased dissolution rate, and compromised bioavailability. The purpose of this study was to investigate the miscibility behavior of a model poorly water-soluble drug, telaprevir (TPV), with three different polymers using atomic force microscopy-based infrared, thermal, and mechanical analysis. Standard atomic force microscopy (AFM) imaging together with nanoscale infrared spectroscopy (AFM-IR), nanoscale thermal analysis (nanoTA), and Lorentz contact resonance (LCR) measurements were used to evaluate the miscibility behavior of TPV with three polymers, hydroxypropyl methylcellulose (HPMC), HPMC acetate succinate (HPMCAS), and poly(vinylpyrrolidone-co-vinyl acetate) (PVPVA), at different drug to polymer ratios. Phase separation was observed with HPMC and PVPVA at drug loadings above 10%. For HPMCAS, a smaller miscibility gap was observed, with phase separation being observed at drug loadings higher than ∼30-40%. The domain size of phase-separated regions varied from below 50 nm to a few hundred nanometers. Localized infrared spectra, nano-TA measurements, images from AFM-based IR, and LCR measurements showed clear contrast between the continuous and discrete domains for these phase-separated systems, whereby the discrete domains were drug-rich. Fluorescence microscopy provided additional evidence for phase separation. These methods appear to be promising to evaluate miscibility in drug-polymer systems with similar Tgs and submicron domain sizes. Furthermore, such findings are of obvious importance in the context of contributing to a mechanistic understanding of amorphous solid dispersion phase behavior.
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Affiliation(s)
- Na Li
- Department of Industrial and Physical Pharmacy, Purdue University , 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Lynne S Taylor
- Department of Industrial and Physical Pharmacy, Purdue University , 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
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Uchiyama H, Matsui T, Kozuka H. Spontaneous Pattern Formation Induced by Bénard-Marangoni Convection for Sol-Gel-Derived Titania Dip-Coating Films: Effect of Co-solvents with a High Surface Tension and Low Volatility. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12497-504. [PMID: 26539840 DOI: 10.1021/acs.langmuir.5b02929] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Evaporation-driven surface tension gradient in the liquid layer often causes the convective flow, i.e., Bénard-Marangoni convection, resulting in the formation of cell-like patterns on the surface. Here, we prepared sol-gel-derived titania films from Ti(OC3H7(i))4 solutions by dip coating and discussed the effect of the addition of co-solvents with a high surface tension and low volatility on the spontaneous pattern formation induced by Bénard-Marangoni convection. Propylene glycol (PG, with a surface tension of 38.6 mN m(-1)) and dipropylene glycol (DPG, with a surface tension of 33.9 mN m(-1)) were added to the coating solutions containing 2-propanol (2-Pr, with a surface tension of 22.9 mN m(-1)) for controlling the evaporation-driven surface tension gradient in the coating layer on a substrate. During dip coating at a substrate withdrawal speed of 50 cm min(-1) in a thermostatic oven at 60 °C, linearly arranged cell-like patterns on a micrometer scale were spontaneously formed on the titania gel films, irrespective of the composition of coating solutions. Such surface patterns remained even after the heat treatment at 200 and 600 °C, where the densification and crystallization of the titania films progressed. The width and height of the cell-like patterns increased with increasing PG and DPG contents in the coating solutions, where the addition of PG resulted in the formation of cells with a larger height than DPG.
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Affiliation(s)
- Hiroaki Uchiyama
- Department of Chemistry and Materials Engineering, Kansai University , 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan
| | - Tadayuki Matsui
- Department of Chemistry and Materials Engineering, Kansai University , 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan
| | - Hiromitsu Kozuka
- Department of Chemistry and Materials Engineering, Kansai University , 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan
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