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Xu J, Liu Z, Jing L, Chen J. Fabrication of PCDTBT Conductive Network via Phase Separation. MATERIALS (BASEL, SWITZERLAND) 2021; 14:5071. [PMID: 34501162 PMCID: PMC8433801 DOI: 10.3390/ma14175071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022]
Abstract
Poly[N-9'-hepta-decanyl-2,7-carbazole-alt-5-5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) is a stable semiconducting polymer with high rigidity in its molecular chains, which makes it difficult to organize into an ordered structure and affects the device performance. Here, a PCDTBT network consisting of aggregates and nanofibers in thin films was fabricated through the phase separation of mixed PCDTBT and polyethylene glycol (PEG). Using atomic force microscopy (AFM), the effect of the blending conditions (weight ratio, solution concentration, and molecular weight) and processing conditions (substrate temperature and solvent) on the resulting phase-separated morphologies of the blend films after a selective washing procedure was studied. It was found that the phase-separated structure's transition from an island to a continuous structure occurred when the weight ratio of PCDTBT/PEG changed from 2:8 to 7:3. Increasing the solution concentration from 0.1 to 3.0 wt% led to an increase in both the height of the PCDTBT aggregate and the width of the nanofiber. When the molecular weight of the PEG was increased, the film exhibited a larger PCDTBT aggregate size. Meanwhile, denser nanofibers were found in films prepared using PCDTBT with higher molecular weight. Furthermore, the electrical characteristics of the PCDTBT network were measured using conductive AFM. Our findings suggest that phase separation plays an important role in improving the molecular chain diffusion rate and fabricating the PCDTBT network.
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Affiliation(s)
- Jianwei Xu
- School of Materials Science & Engineering, Zhengzhou University, Zhengzhou 450002, China; (Z.L.); (L.J.)
| | | | | | - Jingbo Chen
- School of Materials Science & Engineering, Zhengzhou University, Zhengzhou 450002, China; (Z.L.); (L.J.)
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2
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Sequential binary protein patterning on surface domains of thermo-responsive polymer blends cast by horizontal-dipping. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 99:1477-1484. [DOI: 10.1016/j.msec.2019.02.087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 02/12/2019] [Accepted: 02/21/2019] [Indexed: 12/31/2022]
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3
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Liu X, Bhandaru N, Banik M, Wang X, Al-Enizi AM, Karim A, Mukherjee R. Capillary Force Lithography Pattern-Directed Self-Assembly (CFL-PDSA) of Phase-Separating Polymer Blend Thin Films. ACS OMEGA 2018; 3:2161-2168. [PMID: 31458520 PMCID: PMC6641379 DOI: 10.1021/acsomega.7b02078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 02/09/2018] [Indexed: 06/10/2023]
Abstract
We report capillary force lithography pattern-directed self-assembly (CFL-PDSA), a facile technique for patterning immiscible polymer blend films of polystyrene (PS)/poly(methyl methacrylate) (PMMA), resulting in a highly ordered phase-separated morphology. The pattern replication is achieved by capillary force lithography (CFL), by annealing the film beyond the glass transition temperature of both the constituent polymers, while confining it between a patterned cross-linked poly(dimethyl siloxane) (PDMS) stamp and the silicon substrate. As the pattern replication takes place because of rise of the polymer meniscus along the confining stamp walls, higher affinity of PMMA toward the oxide-coated silicon substrate and of PS toward cross-linked PDMS leads to well-controlled vertically patterned phase separation of the two constituent polymers during thermal annealing. Although a perfect negative replica of the stamp pattern is obtained in all cases, the phase-separated morphology of the films under pattern confinement is strongly influenced by the blend composition and annealing time. The phase-separated domains coarsen with time because of migration of the two components into specific areas, PS into an elevated mesa region and PMMA toward the substrate, because of preferential wetting. We show that a well-controlled, phase-separated morphology is achieved when the blend ratio matches the volume ratio of the elevated region to the base region in the patterned films. The proposed top-down imprint patterning of blends can be easily made roll-to-roll-compatible for industrial adoption.
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Affiliation(s)
- Xiangyu Liu
- Department
of Polymer Engineering, University
of Akron, Akron, Ohio 44325, United
States
| | - Nandini Bhandaru
- Instability
and Soft Patterning Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Meneka Banik
- Instability
and Soft Patterning Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Xiaoteng Wang
- Department
of Polymer Engineering, University
of Akron, Akron, Ohio 44325, United
States
| | - Abdullah M. Al-Enizi
- Chemistry
Department, Faculty of Science, King Saud
University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Alamgir Karim
- Department
of Polymer Engineering, University
of Akron, Akron, Ohio 44325, United
States
| | - Rabibrata Mukherjee
- Instability
and Soft Patterning Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
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4
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Bhandaru N, Karim A, Mukherjee R. Directed ordering of phase separated domains and dewetting of thin polymer blend films on a topographically patterned substrate. SOFT MATTER 2017; 13:4709-4719. [PMID: 28613314 DOI: 10.1039/c7sm00799j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Substrate pattern guided self-organization of ultrathin and confined polymeric films on a topographically patterned substrate is a useful approach for obtaining ordered meso and nano structures over large areas, particularly if the ordering is achieved during film preparation itself, eliminating any post-processing such as thermal or solvent vapor annealing. By casting a dilute solution of two immiscible polymers, polystyrene (PS) and polymethylmethacrylate (PMMA), from a common solvent (toluene) on a topographically patterned substrate with a grating geometry, we show the formation of self-organized meso patterns with various degrees of ordering. The morphology depends on both the concentration of the dispensed solution (Cn) and the blend composition (RB). Depending on the extent of dewetting during spin coating, the final morphologies can be classified into three distinct categories. At a very low Cn the solution dewets fully, resulting in isolated polymer droplets aligned along substrate grooves (Type 1). Type 2 structures comprising isolated threads with aligned phase separated domains along each substrate groove are observed at intermediate Cn. A continuous film (Type 3) is obtained above a critical concentration (Cn*) that depends on RB. While the extent of ordering of the domains gradually diminishes with an increase in film thickness for Type 3 patterns, the size of the domains remains much smaller than that on a flat substrate, resulting in significant downsizing of the features due to the lateral confinement imposed on the phase separation process by the topographic patterns. Finally, we show that some of these structures exhibit excellent broadband anti-reflection (AR) properties.
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Affiliation(s)
- Nandini Bhandaru
- Instability and Soft Patterning Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, West Bengal, Pin 721302, India.
| | - Alamgir Karim
- Department of Polymer Engineering and Akron Functional Materials Centre (AFMC), University of Akron, Akron, Ohio 44325, USA
| | - Rabibrata Mukherjee
- Instability and Soft Patterning Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, West Bengal, Pin 721302, India.
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5
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Li Y, Hao Y, Huang C, Chen X, Chen X, Cui Y, Yuan C, Qiu K, Ge H, Chen Y. Wafer Scale Fabrication of Dense and High Aspect Ratio Sub-50 nm Nanopillars from Phase Separation of Cross-Linkable Polysiloxane/Polystyrene Blend. ACS APPLIED MATERIALS & INTERFACES 2017; 9:13685-13693. [PMID: 28361542 DOI: 10.1021/acsami.7b00106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We demonstrated a simple and effective approach to fabricate dense and high aspect ratio sub-50 nm pillars based on phase separation of a polymer blend composed of a cross-linkable polysiloxane and polystyrene (PS). In order to obtain the phase-separated domains with nanoscale size, a liquid prepolymer of cross-linkable polysiloxane was employed as one moiety for increasing the miscibility of the polymer blend. After phase separation via spin-coating, the dispersed domains of liquid polysiloxane with sub-50 nm size could be solidified by UV exposure. The solidified polysiloxane domains took the role of etching mask for formation of high aspect ratio nanopillars by O2 reactive ion etching (RIE). The aspect ratio of the nanopillars could be further amplified by introduction of a polymer transfer layer underneath the polymer blend film. The effects of spin speeds, the weight ratio of the polysiloxane/PS blend, and the concentration of polysiloxane/PS blend in toluene on the characters of the nanopillars were investigated. The gold-coated nanopillar arrays exhibited a high Raman scattering enhancement factor in the range of 108-109 with high uniformity across over the wafer scale sample. A superhydrophobic surface could be realized by coating a self-assembled monolayers (SAM) of fluoroalkyltrichlorosilane on the nanopillar arrays. Sub-50 nm silicon nanowires (SiNWs) with high aspect ratio of about 1000 were achieved by using the nanopillars as etching mask through a metal-assisted chemical etching process. They showed an ultralow reflectance of approximately 0.1% for wavelengths ranging from 200 to 800 nm.
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Affiliation(s)
- Yang Li
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Yuli Hao
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Chunyu Huang
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Xingyao Chen
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Xinyu Chen
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Yushuang Cui
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Changsheng Yuan
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Kai Qiu
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Haixiong Ge
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Yanfeng Chen
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
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6
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Li Y, Hu K, Han X, Yang Q, Xiong Y, Bai Y, Guo X, Cui Y, Yuan C, Ge H, Chen Y. Phase Separation of Silicon-Containing Polymer/Polystyrene Blends in Spin-Coated Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3670-3678. [PMID: 27052643 DOI: 10.1021/acs.langmuir.6b00447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this Article, two readily available polymers that contain silicon and have different surface tensions, polydimethylsiloxane (PDMS) and polyphenylsilsequioxane (PPSQ), were used to produce polymer blends with polystyrene (PS). Spin-coated thin films of the polymer blends were treated by O2 reactive-ion etching (RIE). The PS constituent was selectively removed by O2 RIE, whereas the silicon-containing phase remained because of the high etching resistance of silicon. This selective removal of PS substantially enhanced the contrast of the phase separation morphologies for better scanning electron microscope (SEM) and atomic force microscope (AFM) measurements. We investigated the effects of the silicon-containing constituents, polymer blend composition, concentration of the polymer blend solution, surface tension of the substrate, and the spin-coating speed on the ultimate morphologies of phase separation. The average domain size, ranging from 100 nm to 10 μm, was tuned through an interplay of these factors. In addition, the polymer blend film was formed on a pure organic layer, through which the aspect ratio of the phase separation morphologies was further amplified by a selective etching process. The formed nanostructures are compatible with existing nanofabrication techniques for pattern transfer onto substrates.
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Affiliation(s)
- Yang Li
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Kai Hu
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Xiao Han
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Qinyu Yang
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Yifeng Xiong
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Yuhang Bai
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Xu Guo
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Yushuang Cui
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Changsheng Yuan
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Haixiong Ge
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Yanfeng Chen
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
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7
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Rodrigues R, Meira R, Ferreira Q, Charas A, Morgado J. Improving the Efficiency of Organic Solar Cells upon Addition of Polyvinylpyridine. MATERIALS 2014; 7:8189-8196. [PMID: 28788297 PMCID: PMC5456427 DOI: 10.3390/ma7128189] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 12/12/2014] [Indexed: 11/16/2022]
Abstract
We report on the efficiency improvement of organic solar cells (OPVs) based on the low energy gap polyfluorene derivative, APFO-3, and the soluble C60 fullerene PCBM, upon addition of a residual amount of poly (4-vinylpyridine) (PVP). We find that the addition of 1% by weight of PVP with respect to the APFO-3 content leads to an increase of efficiency from 2.4% to 2.9%. Modifications in the phase separation details of the active layer were investigated as a possible origin of the efficiency increase. At high concentrations of PVP, the blend morphology is radically altered as observed by Atomic Force Microscopy. Although the use of low molecular weight additives is a routine method to improve OPVs efficiency, this report shows that inert polymers, in terms of optical and charge transport properties, may also improve the performance of polymer-based solar cells.
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Affiliation(s)
- Rita Rodrigues
- Instituto de Telecomunicações, Avenida Rovisco Pais, P-1049-001 Lisboa, Portugal.
| | - Rui Meira
- Instituto de Telecomunicações, Avenida Rovisco Pais, P-1049-001 Lisboa, Portugal.
| | - Quirina Ferreira
- Instituto de Telecomunicações, Avenida Rovisco Pais, P-1049-001 Lisboa, Portugal.
| | - Ana Charas
- Instituto de Telecomunicações, Avenida Rovisco Pais, P-1049-001 Lisboa, Portugal.
| | - Jorge Morgado
- Instituto de Telecomunicações, Avenida Rovisco Pais, P-1049-001 Lisboa, Portugal.
- Department of Bioengineering, Instituto Superior Técnico, UL, Avenida Rovisco Pais, P-1049-001 Lisboa, Portugal.
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8
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Harirchian-Saei S, Wang MCP, Gates BD, Moffitt MG. Simultaneous patterning of two different types of nanoparticles into alternating domains of a striped array of a polymer blend in a single spin-casting step. J Colloid Interface Sci 2014; 433:123-132. [PMID: 25128863 DOI: 10.1016/j.jcis.2014.07.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/14/2014] [Accepted: 07/18/2014] [Indexed: 11/28/2022]
Abstract
A fast and convenient method is developed for simultaneously patterning inorganic nanoparticles with different optical, electronic or magnetic functionality to specific surface regions, by spin-casting onto microcontact printed substrates blend solutions in which the two nanoparticle types are functionalized with surface polymer brush layers of different surface energies. The process is based on phase separation of different nanoparticles based on their immiscible brush layers during spin-casting, with the underlying surface energy heterogeneity of the patterned substrate directing the different NP types to domains of different surface energies. Here, we specifically demonstrate the simultaneous localization of cadmium sulfide quantum dots (CdS QDs), addressed with a surface layer of polystyrene (PS), and silver nanoparticles (Ag NPs), addressed with a surface layer of poly(methyl methacrylate) (PMMA), onto the non-polar and polar surface domains, respectively, of hydrophilic glass patterned with hydrophobic octadecyltrichlorosilane (OTS) stripe arrays with micron-scale periodicities. In order to prevent gelation of solvent-swollen polymer-brush coated NPs during spin casting, which effects strong kinetic constraints on phase separation and localization, PS, PMMA or PS/PMMA homopolymer blends of sufficiently high Mw were added to the NP blends to increase the free volume between approaching NPs. The process parameters were fine-tuned to obtain control over defects in the obtained patterns.
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Affiliation(s)
- Saman Harirchian-Saei
- Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC V8W 3V6, Canada
| | - Michael C P Wang
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Byron D Gates
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Matthew G Moffitt
- Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC V8W 3V6, Canada.
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9
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Examination of polymer/metal interface modified by self-assembled monolayer by Kelvin probe force microscopy and secondary ion mass spectrometry. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.02.128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Harirchian-Saei S, Wang MCP, Gates BD, Moffitt MG. Directed polystyrene/poly(methyl methacrylate) phase separation and nanoparticle ordering on transparent chemically patterned substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:10838-10848. [PMID: 22738388 DOI: 10.1021/la301298p] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We investigate the surface-directed phase separation of spin-coated polystyrene/poly(methyl methacrylate) (PS/PMMA) blends on prepatterned octadecyltrichlorosilane (OTS)-glass substrates under various experimental conditions. As a result of tandem processes of spinodal decomposition and selective wetting of polymer components during spin-coating, low-energy OTS stripes and high-energy glass surfaces laterally arrange the phase-separated polymers according to the chemical pattern on the substrate. Optimal pattern replication was achieved when the length scale of phase separation, controlled via the polymer concentration of the spin-coating solution, matched the smallest feature dimension in a striped chemical pattern possessing two alternating distances between stripes. It was also shown that polymer blend patterns were most closely registered with the underlying substrate when the PS/PMMA composition ratio (30/70, w/w) matched the areal fraction of OTS on the glass surface (∼30%). The influence of solvents demonstrated that a solvent with a relatively low volatility, such toluene, was required for patterning so that domain feature sizes were able to coarsen to the size of the patterned features before film vitrification. As well, we showed that the technique and optimized conditions developed in this study could be applied to pattern photoluminescent CdS quantum dots into microscale arrays of parallel lines via spin-coating onto transparent OTS-glass substrates.
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Affiliation(s)
- Saman Harirchian-Saei
- Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC V8W 3V6, Canada
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Fang L, Wei M, Shang Y, Kazmer D, Barry C, Mead J. Precise pattern replication of polymer blends into nonuniform geometries via reducing interfacial tension between two polymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:10238-10245. [PMID: 22651098 DOI: 10.1021/la3008409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Patterned polymer structures with different functionalities have many potential applications. Directed assembly of polymer blends using chemically functionalized patterns during spin-coating has been used to fabricate the patterned polymer structures. For bridging the gap between laboratorial experiments and manufacturing of nanodevices, the polymer blends structures are required to be precisely patterned into nonuniform geometries in a high-rate process, which still is a challenge. In this Article, we demonstrated for the first time that by decreasing the interfacial tension between two polymers polystyrene and poly(acrylic acid) via adding a compatibilizer (polystyrene-b-poly(acrylic acid) ), a polystyrene/poly(acrylic acid) blend was precisely patterned into nonuniform geometries in a high-rate fashion. The patterned nonuniform geometries included angled lines with angles varied from 30° to 150°, T-junctions, square arrays, circle arrays, and arbitrary letter-shaped geometries. The reduction in the interfacial tension improved the line edge roughness and the patterning efficiency of the patterned polymer blends. In addition, the commensurability between characteristic length and pattern periodicity for well-ordered morphologies was also expanded with decreasing interfacial tension. This approach can be easily extended to other functional polymers in a blend and facilitate the applications of patterned polymer structures in biosensors, organic thin-film electronics, and polymer solar cells.
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Affiliation(s)
- Liang Fang
- NSF Center for High-rate Nanomanufacturing, Department of Plastics Engineering, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
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13
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Budkowski A, Zemła J, Moons E, Awsiuk K, Rysz J, Bernasik A, Björström-Svanström CM, Lekka M, Jaczewska J. Polymer blends spin-cast into films with complementary elements for electronics and biotechnology. J Appl Polym Sci 2012. [DOI: 10.1002/app.36574] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Fang L, Wei M, Barry C, Mead J. Effect of Spin Speed and Solution Concentration on the Directed Assembly of Polymer Blends. Macromolecules 2010. [DOI: 10.1021/ma1017082] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Liang Fang
- NSF Nanoscale Science and Engineering Center for High-Rate Nanomanufactuing, Department of Plastics Engineering, University of Massachusetts Lowell, One University Avenue, Lowell, Massachusetts 01854, United States
| | - Ming Wei
- NSF Nanoscale Science and Engineering Center for High-Rate Nanomanufactuing, Department of Plastics Engineering, University of Massachusetts Lowell, One University Avenue, Lowell, Massachusetts 01854, United States
| | - Carol Barry
- NSF Nanoscale Science and Engineering Center for High-Rate Nanomanufactuing, Department of Plastics Engineering, University of Massachusetts Lowell, One University Avenue, Lowell, Massachusetts 01854, United States
| | - Joey Mead
- NSF Nanoscale Science and Engineering Center for High-Rate Nanomanufactuing, Department of Plastics Engineering, University of Massachusetts Lowell, One University Avenue, Lowell, Massachusetts 01854, United States
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15
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Harirchian-Saei S, Wang MCP, Gates BD, Moffitt MG. Patterning block copolymer aggregates via Langmuir-Blodgett transfer to microcontact-printed substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:5998-6008. [PMID: 20334416 DOI: 10.1021/la904561b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate a new strategy for producing hierarchical polymer nanostructures, which combines nanoscale self-assembly of amphiphilic block copolymers at the air-water interface with microscale templated assembly of the resulting aggregates on chemically patterned substrates. Aggregates are formed via interfacial self-assembly of 141k polystyrene-b-poly(ethylene oxide) (PS-b-PEO, MW = 141k, 11.4 wt % PEO) or a blend of 185k PS-b-PEO (MW = 185k, 18.9 wt % PEO) and PS-coated CdS nanoparticles to form strandlike copolymer or copolymer-nanoparticle aggregates. Using Langmuir-Blodgett (LB) techniques, the aggregates are then transferred to patterned substrates possessing alternating hydrophilic/hydrophobic stripes, obtained by microcontact printing octadecyltrichlorosilane (OTS) on glass. The aggregates are transferred under various conditions of surface pressure, orientation of the patterned substrate, and withdrawal speed. Templated assembly of aggregates into the hydrophilic substrate domains is achieved when the hydrophilic/hydrophobic stripes are oriented perpendicular to the water surface during LB transfer; this is explained by surface energy heterogeneities along the subphase-substrate contact line, which induce selective dewetting and concomitant monolayer rearrangement at the drying front. In contrast, parallel orientation of stripes results in nonselective transfer of the monolayer without registration to the underlying surface pattern. By studying the effect of surface pressure, we show that packing constraints imposed by compression of aggregates to high surface densities prevent the formation of patterned LB films that match the established periodicity of the OTS-patterned glass. As well, it is shown that efficient transfer of aggregates to the patterned glass requires slower substrate withdrawal speeds compared to transfer to unpatterned hydrophilic glass.
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Affiliation(s)
- Saman Harirchian-Saei
- Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC, V8W 3V6 Canada
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16
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Chiota J, Shearer J, Wei M, Barry C, Mead J. Multiscale directed assembly of polymer blends using chemically functionalized nanoscale-patterned templates. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2009; 5:2788-2791. [PMID: 19924739 DOI: 10.1002/smll.200901530] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- Jason Chiota
- NSF Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, Department of Plastics Engineering, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA
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18
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Charas A, Ferreira Q, Farinhas J, Matos M, Alcácer L, Morgado J. Insoluble Patterns of Cross-Linkable Conjugated Polymers from Blend Demixing in Spin Cast Films. Macromolecules 2009. [DOI: 10.1021/ma901329n] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Ana Charas
- Instituto de Telecomunicações, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001, Lisbon, Portugal
| | - Quirina Ferreira
- Instituto de Telecomunicações, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001, Lisbon, Portugal
| | - Joana Farinhas
- Instituto de Telecomunicações, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001, Lisbon, Portugal
- Dep. Eng. Química, Instituto Superior de Engenharia de Lisboa, Lisbon, Portugal
| | - Manuel Matos
- Instituto de Telecomunicações, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001, Lisbon, Portugal
- Dep. Eng. Química, Instituto Superior de Engenharia de Lisboa, Lisbon, Portugal
| | - Luís Alcácer
- Instituto de Telecomunicações, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001, Lisbon, Portugal
- Dep. Eng. Química e Biológica, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001, Lisbon, Portugal
| | - Jorge Morgado
- Instituto de Telecomunicações, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001, Lisbon, Portugal
- Dep. Eng. Química e Biológica, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001, Lisbon, Portugal
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19
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Park LY, Munro AM, Ginger DS. Controlling film morphology in conjugated polymer:fullerene blends with surface patterning. J Am Chem Soc 2009; 130:15916-26. [PMID: 18983150 DOI: 10.1021/ja804088j] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We study the effects of patterned surface chemistry on the microscale and nanoscale morphology of solution-processed donor/acceptor polymer-blend films. Focusing on combinations of interest in polymer solar cells, we demonstrate that patterned surface chemistry can be used to tailor the film morphology of blends of semiconducting polymers such as poly-[2-(3,7-dimethyloctyloxy)-5-methoxy-p-phenylenevinylene] (MDMO-PPV), poly-3-hexylthiophene (P3HT), poly[(9,9-dioctylflorenyl-2,7-diyl)-co-benzothiadiazole)] (F8BT), and poly(9,9-dioctylfluorene-co-bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-1,4-phenylendiamine) (PFB) with the fullerene derivative, [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM). We present a method for generating patterned, fullerene-terminated monolayers on gold surfaces and use microcontact printing and Dip-Pen Nanolithography (DPN) to pattern alkanethiols with both micro- and nanoscale features. After patterning with fullerenes and other functional groups, we backfill the rest of the surface with a variety of thiols to prepare substrates with periodic variations in surface chemistry. Spin coating polymer:PCBM films onto these substrates, followed by thermal annealing under nitrogen, leads to the formation of structured polymer films. We characterize these films with Atomic Force Microscopy (AFM), Raman spectroscopy, and fluorescence microscopy. The surface patterns are effective in guiding phase separation in all of the polymer:PCBM systems investigated and lead to a rich variety of film morphologies that are inaccessible with unpatterned substrates. We demonstrate our ability to guide pattern formation in films thick enough to be of interest for actual device applications (up to 200 nm in thickness) using feature sizes as small as 100 nm. Finally, we show that the surface chemistry can lead to variations in film morphology on length scales significantly smaller than those used in generating the original surface patterns. The variety of behaviors observed and the wide range of control over polymer morphology achieved at a variety of different length scales have important implications for the development of bulk heterojunction solar cells.
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Affiliation(s)
- Lee Y Park
- Department of Chemistry, Williams College, Williamstown, Massachusetts 01267, USA.
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20
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Rehse S, Mecke K, Magerle R. Characterization of the dynamics of block copolymer microdomains with local morphological measures. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 77:051805. [PMID: 18643095 DOI: 10.1103/physreve.77.051805] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Revised: 02/15/2008] [Indexed: 05/26/2023]
Abstract
We investigate the structure formation in thin films of cylinder forming block copolymers. With in situ scanning probe microscopy image sequences can be recorded with high temporal (2 min per frame) and spatial (10 nm) resolution. We compare different image processing methods for quantitative analysis of the large amount of data. Computing local Minkowski functionals yields local geometrical and morphological information about the observed structures and enables us to track their evolution with time. An alternative characterization method is to reduce the gray scale images to their skeleton and to classify and count the branching points of the skeletonized structure. We tracked the temporal evolution of these measures and computed correlation functions.
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Affiliation(s)
- S Rehse
- Chemische Physik, Technische Universität Chemnitz, Reichenhainer Strasse 70, D-09126 Chemnitz, Germany.
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21
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Yan LT, Li J, Li Y, Xie XM. Kinetic Pathway of Pattern-Directed Phase Separation in Binary Polymer Mixture Films. Macromolecules 2008. [DOI: 10.1021/ma702616s] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Li-Tang Yan
- Advanced Materials Laboratory, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Jialin Li
- Advanced Materials Laboratory, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Yao Li
- Advanced Materials Laboratory, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Xu-Ming Xie
- Advanced Materials Laboratory, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China
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22
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Madej W, Budkowski A, Raczkowska J, Rysz J. Breath figures in polymer and polymer blend films spin-coated in dry and humid ambience. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:3517-3524. [PMID: 18294016 DOI: 10.1021/la703363a] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We investigate effects of two spin-coating parameters, relative humidity (5% < or = RH < or = 80%) in ambient atmosphere and water content (3 wt % < or = f(H2O) < or = 20 wt %) in solution (rich in tetrahydrofuran), on the structure of breath figures (BF) formed in spin-cast films of polar poly(methyl methacrylate) (PMMA) and PMMA mixed with nonpolar polystyrene (PS). Film morphologies, examined with atomic and lateral force microscopy, are analyzed with integral geometry analysis to yield morphological BF measures. In PMMA, water added to solution has much stronger impact than that from moisture on formed BFs, which could be ordered (with conformational entropy S approximately 0.9-1.0). In PMMA/PS, BFs decorate exclusively polar PMMA domains, resulting in morphologies with two length scales (sub-micrometer BFs and domains >10 microm). This suggests a novel strategy for herarchic structure formation in multicomponent polymer films. In PS/PMMA, BFs are better developed than in pure PMMA spin-coated in identical conditions. These observations show that the air boundary layer facing the spin-cast polymer film (region) is more important than the ambient atmosphere.
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Affiliation(s)
- Wojciech Madej
- Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland
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23
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Raczkowska J, Bernasik A, Budkowski A, Rysz J, Gao B, Lieberman M. Compositional Mismatch between Chemical Patterns on a Substrate and Polymer Blends Yielding Spin-Cast Films with Subpattern Periodicity. Macromolecules 2007. [DOI: 10.1021/ma062614f] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Raczkowska
- M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Nuclear Techniques, AGH - University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - A. Bernasik
- M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Nuclear Techniques, AGH - University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - A. Budkowski
- M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Nuclear Techniques, AGH - University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - J. Rysz
- M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Nuclear Techniques, AGH - University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - B. Gao
- M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Nuclear Techniques, AGH - University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - M. Lieberman
- M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Nuclear Techniques, AGH - University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
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24
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Andrew P, Huck WTS. Polymer phase separation on lattice patterned surfaces. SOFT MATTER 2007; 3:230-237. [PMID: 32680270 DOI: 10.1039/b613593e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We demonstrate the self-organization of phase-separated polymer microstructures on two-dimensionally chemically patterned surfaces. Pattern replication is expected when both the blend composition ratio matches the surface patterning area ratio, and the pattern periodicity matches the natural phase separation length scale. By varying film thickness and blend composition, we show that ordered morphologies also result for contrary situations, resulting in the formation of a rich variety of hierarchically-ordered microstructures. This hierarchy suggests that non-equilibrium structures generated by incomplete phase separation of blend components are locked in by rapid solvent quenching during casting.
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Affiliation(s)
- Piers Andrew
- The Nanoscience Centre, University of Cambridge, 11 J. J. Thomson Avenue, Cambridge, UKCB3 0FF.
| | - Wilhelm T S Huck
- The Nanoscience Centre, University of Cambridge, 11 J. J. Thomson Avenue, Cambridge, UKCB3 0FF. and Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UKCB2 1EW.
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25
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Jaczewska J, Budkowski A, Bernasik A, Raptis I, Raczkowska J, Goustouridis D, Rysz J, Sanopoulou M. Humidity and solvent effects in spin-coated polythiophene–polystyrene blends. J Appl Polym Sci 2007. [DOI: 10.1002/app.26012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Wei JH, Coffey DC, Ginger DS. Nucleating Pattern Formation in Spin-Coated Polymer Blend Films with Nanoscale Surface Templates. J Phys Chem B 2006; 110:24324-30. [PMID: 17134183 DOI: 10.1021/jp065409a] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We use Dip-Pen Nanolithography (DPN) to generate monolayer surface templates for guiding pattern formation in spin-coated polymer blend films. We study template-directed pattern formation in blends of polystyrene/poly(2-vinylpyridine) (PS/P2VP) as well as blends of PS and the semiconducting conjugated polymer poly(3-hexylthiophene) (P3HT). We show that acid-terminated monolayers can be used to template pattern formation in PS/P3HT blends, while hydrophobic monolayers can be used to template pattern formation in PS/P2VP blends. In both blends, the polymer patterns comprise laterally-phase separated regions surrounded by vertically separated bilayers. We hypothesize that the observed patterns are formed by template-induced dewetting of the bottom layer of a polymer bilayer during the spin-coating process. We compare the effects of template feature size and spacing on the resulting polymer patterns with predictions from published models of template-directed dewetting in thin films and find the data in good agreement. For both blends we observe that a minimum feature size is required to nucleate dewetting/phase separation. We find this minimum template diameter to be approximately 180 nm in 50/50 PS/P2VP blends, and approximately 100 nm in 50/50 PS/P3HT blends. For larger template diameters, PS/P2VP blends show evidence for pattern formation beginning at the template boundaries, while PS/P3HT blends rupture randomly across the template features.
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Affiliation(s)
- Joseph H Wei
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195-1750, USA
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