1
|
Nguyen H, Lima RLS, Neto NMB, Araujo PT. What is the significance of the chloroform stabilizer C 5H 10 and its association with MeOH in concentration-dependent polymeric solutions? SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 310:123886. [PMID: 38245968 DOI: 10.1016/j.saa.2024.123886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/10/2023] [Accepted: 01/10/2024] [Indexed: 01/23/2024]
Abstract
The understanding of excitonic transitions associated with polymeric aggregates is fundamental, as such transitions have implications on coherence lengths, coherence numbers and inter- and intra-chain binding parameters. In this context, the investigation of efficient solvents and other ways to control polymer aggregate formation is key for their consolidation as materials for new technologies. In this manuscript, we use Poly(3-hexothiophene) (P3HT) as a probe to investigate the significance of amylene (C5H10) and its association with methanol (MeOH) in both pure and C5H10-stabilized chloroform (CHCl3)-based polymeric solutions. Using the intensity ratio between the first and second vibronic transitions of the P3HT H-aggregates formed, values for their exciton bandwidths and interchain interactions are obtained and correlated with the presence of C5H10 and MeOH as agents determining the CHCl3 quality.
Collapse
Affiliation(s)
- Huan Nguyen
- Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL, USA
| | - Ruan L S Lima
- Institute of Natural Sciences, Federal University of Para, Belem, PA, Brazil
| | | | - Paulo T Araujo
- Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL, USA.
| |
Collapse
|
2
|
Sakata T, Saitow KI. 4D Microspectroscopy Explores Orientation and Aggregations in π-Conjugated Polymer Films Prepared by Brush Printing. J Phys Chem Lett 2022; 13:653-660. [PMID: 35023754 DOI: 10.1021/acs.jpclett.1c03283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The orientation of polymers improves their mechanical, electrical, and optical properties, but aggregates alter these properties. Unfortunately, there is no definitive way to control aggregates and quantify orientations by distinguishing between polymer chains and aggregates. Herein, we show 4D microspectroscopy to examine brush-printed oriented films of π-conjugated polymers. Three-dimensional (x-y-z) and 1D (photon energy) components based on polarized-fluorescence spectra and film thickness at identical positions were measured. Stochastic analysis of 4D data for a brush-printed OLED film (30 × 30 μm2, 900 pixels) distinguished orientations of polymer chains and their aggregates with a 1 μm x-y resolution and a z-range of 20-1800 nm. Polymer chains in thin regions (t < 50 nm) were oriented parallel to the brush-printing direction, whereas aggregates were oriented perpendicularly in thicker regions (t > 1000 nm). This difference was attributed to shear stress, uneven thickness, and capillary forces. The generality of the 4D method was also examined using conventional drop casting.
Collapse
Affiliation(s)
- Toshiki Sakata
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Ken-Ichi Saitow
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| |
Collapse
|
3
|
Persson NE, Chu PH, McBride M, Grover M, Reichmanis E. Nucleation, Growth, and Alignment of Poly(3-hexylthiophene) Nanofibers for High-Performance OFETs. Acc Chem Res 2017; 50:932-942. [PMID: 28234458 DOI: 10.1021/acs.accounts.6b00639] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Conjugated semiconducting polymers have been the subject of intense study for over two decades with promising advances toward a printable electronics manufacturing ecosystem. These materials will deliver functional electronic devices that are lightweight, flexible, large-area, and cost-effective, with applications ranging from biomedical sensors to solar cells. Synthesis of novel molecules has led to significant improvements in charge carrier mobility, a defining electrical performance metric for many applications. However, the solution processing and thin film deposition of conjugated polymers must also be properly controlled to obtain reproducible device performance. This has led to an abundance of research on the process-structure-property relationships governing the microstructural evolution of the model semicrystalline poly(3-hexylthiophene) (P3HT) as applied to organic field effect transistor (OFET) fabrication. What followed was the production of an expansive body of work on the crystallization, self-assembly, and charge transport behavior of this semiflexible polymer whose strong π-π stacking interactions allow for highly creative methods of structural control, including the modulation of solvent and solution properties, flow-induced crystallization and alignment techniques, structural templating, and solid-state thermal and mechanical processing. This Account relates recent progress in the microstructural control of P3HT thin films through the nucleation, growth, and alignment of P3HT nanofibers. Solution-based nanofiber formation allows one to develop structural order prior to thin film deposition, mitigating the need for intricate deposition processes and enabling the use of batch and continuous chemical processing steps. Fiber growth is framed as a traditional crystallization problem, with the balance between nucleation and growth rates determining the fiber size and ultimately the distribution of grain boundaries in the solid state. Control of nucleation can be accomplished through a sonication-based seeding procedure, while growth can be modulated through supersaturation control via the tuning of solvent quality, the use of UV irradiation or through aging. These principles carry over to the flow-induced growth of P3HT nanofibers in a continuous microfluidic processing system, leading to thin films with significantly enhanced mobility. Further gains can be made by promoting long-range polymer chain alignment, achieved by depositing nanofibers through shear-based coating methods that promote high fiber packing density and alignment. All of these developments in processing were carried out on a standard OFET platform, enabling us to generalize quantitative structure-property relationships from structural data sources such as UV-vis, AFM, and GIWAXS. It is shown that a linear correlation exists between mobility and the in-plane orientational order of nanofibers, as extracted from AFM images using advanced computer vision software developed by our group. Herein, we discuss data-driven approaches to the determination of process-structure-property relationships, as well as the transferability of structural control strategies for P3HT to other conjugated polymer systems and applications.
Collapse
Affiliation(s)
- Nils E. Persson
- School of Chemical & Biomolecular Engineering, ‡School of Chemistry & Biochemistry, and §School of Materials Science & Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ping-Hsun Chu
- School of Chemical & Biomolecular Engineering, ‡School of Chemistry & Biochemistry, and §School of Materials Science & Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Michael McBride
- School of Chemical & Biomolecular Engineering, ‡School of Chemistry & Biochemistry, and §School of Materials Science & Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Martha Grover
- School of Chemical & Biomolecular Engineering, ‡School of Chemistry & Biochemistry, and §School of Materials Science & Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Elsa Reichmanis
- School of Chemical & Biomolecular Engineering, ‡School of Chemistry & Biochemistry, and §School of Materials Science & Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| |
Collapse
|
4
|
Aggregation properties of MEH-PPV/PMMA blends in solution and thin film. JOURNAL OF POLYMER RESEARCH 2016. [DOI: 10.1007/s10965-016-1169-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
5
|
Guo RH, Hsu CH, Hua CC, Chen SA. Colloidal aggregate and gel incubated by amorphous conjugated polymer in hybrid-solvent medium. J Phys Chem B 2015; 119:3320-31. [PMID: 25607342 DOI: 10.1021/acs.jpcb.5b00575] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A practical valuable amorphous conjugated polymer, poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene (MEH-PPV), has been revealed to foster an abundance of micrometer-sized colloidal aggregates at relatively low concentration (below 1 wt %) in a hybrid-solvent medium that contains a nonsolvent, and the solution turned into gel by colloidal bridging after one-day aging at 30 °C. In contrast with typical polymer gels fostered by (anisotropic) chain cross-linking or planar packing on selective interacting sites, the MEH-PPV gel has been revealed (via dynamic light scattering, small-angle light scattering, time-sweep dynamic modulus and optical microscope) to first develop featureless aggregate clusters in solution and, as the solvent quality worsens with reduced system temperature, bridge themselves to form gel through a one-dimensional (1-D) to three-dimensional (3-D) kinetic pathway. Combined dynamic/static light scattering analyses, along with supporting scanning electron microscope image and molecular dynamics simulation, indicated a concomitant structural reorganization within the colloidal aggregates, where spontaneous chain packing was perceived to form local fiber-like materials that are elastic by nature (i.e., a q-independent decay rate). The near coincidence of the above-mentioned microscopic and macroscopic phase alterations led us to contend that similar fibrous materials have served as the exterior bridging agent to fabricate colloidal strands upon gelation. The present findings clarify previously enigmatic, much speculative, gelation phenomena of MEH-PPV, and shed light on the prospect of capitalizing on specific polymer-solvent interactions to incubate desirable colloidal aggregates and gels in room-temperature processing of practical valuable conjugated polymers.
Collapse
Affiliation(s)
- Rong H Guo
- Department of Chemical Engineering, National Chung Cheng University , Chiayi 621, Taiwan, Republic of China
| | | | | | | |
Collapse
|
6
|
Babu SS, Praveen VK, Ajayaghosh A. Functional π-gelators and their applications. Chem Rev 2014; 114:1973-2129. [PMID: 24400783 DOI: 10.1021/cr400195e] [Citation(s) in RCA: 1251] [Impact Index Per Article: 125.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Sukumaran Santhosh Babu
- Photosciences and Photonics Group, Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST) , Trivandrum 695019, India
| | | | | |
Collapse
|
7
|
Wang D, Yuan Y, Mardiyati Y, Bubeck C, Koynov K. From Single Chains to Aggregates, How Conjugated Polymers Behave in Dilute Solutions. Macromolecules 2013. [DOI: 10.1021/ma4011523] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dapeng Wang
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| | - Yuan Yuan
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| | - Yati Mardiyati
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| | - Christoph Bubeck
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| | - Kaloian Koynov
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| |
Collapse
|
8
|
Lee CK, Hua CC, Chen SA. Phase Transition and Gels in Conjugated Polymer Solutions. Macromolecules 2013. [DOI: 10.1021/ma302343e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Cheng K. Lee
- Research Center for Applied
Sciences, Academia Sinica, Taipei 115,
Taiwan, R.O.C
| | - Chi C. Hua
- Department
of Chemical Engineering, National Chung Cheng University, Chia-Yi 621, Taiwan,
R.O.C
| | - Show A. Chen
- Department of Chemical
Engineering, National Tsing Hua University, Hsin-Chu 30013, Taiwan,
R.O.C
| |
Collapse
|
9
|
Knaapila M, Monkman AP. Methods for controlling structure and photophysical properties in polyfluorene solutions and gels. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:1090-1108. [PMID: 23341026 DOI: 10.1002/adma.201204296] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Indexed: 06/01/2023]
Abstract
Knowledge of the phase behavior of polyfluorene solutions and gels has expanded tremendously in recent years. The relationship between the structure formation and photophysics is known at the quantitative level. The factors which we understand control these relationships include virtually all important materials parameters such as solvent quality, side chain branching, side chain length, molecular weight, thermal history and myriad functionalizations. This review describes advances in controlling structure and photophysical properties in polyfluorene solutions and gels. It discusses the demarcation lines between solutions, gels, and macrophase separation in conjugated polymers and reviews essential solid state properties needed for understanding of solutions. It gives an insight into polyfluorene and polyfluorene beta phase in solutions and gels and describes all the structural levels in solvent matrices, ranging from intramolecular structures to the diverse aggregate classes and network structures and agglomerates of these units. It goes on to describe the kinetics and thermodynamics of these structures. It details the manifold molecular parameters used in their control and continues with the molecular confinement and touches on permanently cross-linked networks. Particular focus is placed on the experimental results of archetypical polyfluorenes and solvent matrices and connection between structure and photonics. A connection is also made to the mean field type theories of hairy-rod like polymers. This altogether allows generalizations and provides a guideline for materials scientists, synthetic chemists and device engineers as well, for this important class of semiconductor, luminescent polymers.
Collapse
Affiliation(s)
- Matti Knaapila
- Physics Department, Institute for Energy Technology, 2027 Kjeller, Norway.
| | | |
Collapse
|
10
|
Lin J, Yu Z, Zhu W, Xing G, Lin Z, Yang S, Xie L, Niu C, Huang W. A π-conjugated polymergelator from polyfluorene-based poly(tertiary alcohol) via the hydrogen-bonded supramolecular functionalization. Polym Chem 2013. [DOI: 10.1039/c2py20618h] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
11
|
Conformational structure and aggregation behavior of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] in toluene/nonane solutions. POLYMER 2012. [DOI: 10.1016/j.polymer.2012.08.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
12
|
Wen YH, Lin PC, Hua CC, Chen SA. Dynamic Structure Factor for Large Aggregate Clusters with Internal Motions: A Self-Consistent Light-Scattering Study on Conjugated Polymer Solutions. J Phys Chem B 2011; 115:14369-80. [DOI: 10.1021/jp208399z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Yu H. Wen
- Department of Chemical Engineering, National Chung Cheng University, Chiayi 621, Taiwan, R.O.C
| | - Po C. Lin
- Department of Chemical Engineering, National Chung Cheng University, Chiayi 621, Taiwan, R.O.C
| | - Chi C. Hua
- Department of Chemical Engineering, National Chung Cheng University, Chiayi 621, Taiwan, R.O.C
| | - Show A. Chen
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, R.O.C
| |
Collapse
|
13
|
Chan NY, Hao XT, Smith TA, Dunstan DE. Aggregation of Water-Soluble Conjugated Polymers in Couette Shear Flow. J Phys Chem B 2009; 113:13138-41. [DOI: 10.1021/jp9050337] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nikko Y. Chan
- Department of Chemical and Biomolecular Engineering and School of Chemistry, University of Melbourne, Victoria 3010, Australia
| | - Xiao-Tao Hao
- Department of Chemical and Biomolecular Engineering and School of Chemistry, University of Melbourne, Victoria 3010, Australia
| | - Trevor A. Smith
- Department of Chemical and Biomolecular Engineering and School of Chemistry, University of Melbourne, Victoria 3010, Australia
| | - Dave E. Dunstan
- Department of Chemical and Biomolecular Engineering and School of Chemistry, University of Melbourne, Victoria 3010, Australia
| |
Collapse
|
14
|
Chen MC, Hung WC, Su AC, Chen SH, Chen SA. Nanoscale Ordered Structure Distribution in Thin Solid Film of Conjugated Polymers: Its Significance in Charge Transport Across the Film and in Performance of Electroluminescent Device. J Phys Chem B 2009; 113:11124-33. [DOI: 10.1021/jp901644m] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ming-Chih Chen
- Chemical Engineering Department, National Tsing Hua University, Hsinchu, 30013, Taiwan, R.O.C., and Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan, R.O.C
| | - Wei-Chun Hung
- Chemical Engineering Department, National Tsing Hua University, Hsinchu, 30013, Taiwan, R.O.C., and Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan, R.O.C
| | - An-Chung Su
- Chemical Engineering Department, National Tsing Hua University, Hsinchu, 30013, Taiwan, R.O.C., and Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan, R.O.C
| | - Su-Hua Chen
- Chemical Engineering Department, National Tsing Hua University, Hsinchu, 30013, Taiwan, R.O.C., and Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan, R.O.C
| | - Show-An Chen
- Chemical Engineering Department, National Tsing Hua University, Hsinchu, 30013, Taiwan, R.O.C., and Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan, R.O.C
| |
Collapse
|
15
|
Chen JH, Chang CS, Chang YX, Chen CY, Chen HL, Chen SA. Gelation and Its Effect on the Photophysical Behavior of Poly(9,9-dioctylfluorene-2,7-diyl) in Toluene. Macromolecules 2009. [DOI: 10.1021/ma802408u] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jean-Hong Chen
- Department of Polymer Materials, Kun Shan University, Tainan Hsien 71003, Taiwan, and Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 30013, Taiwan
| | - Chih-Shun Chang
- Department of Polymer Materials, Kun Shan University, Tainan Hsien 71003, Taiwan, and Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 30013, Taiwan
| | - Ying-Xun Chang
- Department of Polymer Materials, Kun Shan University, Tainan Hsien 71003, Taiwan, and Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 30013, Taiwan
| | - Chun-Yu Chen
- Department of Polymer Materials, Kun Shan University, Tainan Hsien 71003, Taiwan, and Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 30013, Taiwan
| | - Hsin-Lung Chen
- Department of Polymer Materials, Kun Shan University, Tainan Hsien 71003, Taiwan, and Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 30013, Taiwan
| | - Show-An Chen
- Department of Polymer Materials, Kun Shan University, Tainan Hsien 71003, Taiwan, and Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 30013, Taiwan
| |
Collapse
|
16
|
Hoth CN, Choulis SA, Schilinsky P, Brabec CJ. On the effect of poly(3-hexylthiophene) regioregularity on inkjet printed organic solar cells. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b823495g] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
17
|
Lee CK, Hua CC, Chen SA. Single-chain and aggregation properties of semiconducting polymer solutions investigated by coarse-grained langevin dynamics simulation. J Phys Chem B 2008; 112:11479-89. [PMID: 18729401 DOI: 10.1021/jp077054g] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A coarse-grained (CG) model and Langevin dynamics scheme are proposed to investigate the material properties in dilute solution of a model semiconducting conjugated polymer, poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV). While the intra- and intermolecular potentials for the CG particle (currently, a monomer unit) were determined from the molecular dynamics (MD) simulation of a united atomistic model, fluctuation-dissipation forces arising from the treatment of a solvent field were self-consistently constructed from the measured particle diffusivity in a given solvent (i.e., chloroform or toluene) through the atomistic MD simulation. It is shown that the resultant Langevin dynamics simulation, which is substantially more efficient than the counterpart MD simulation of the same CG model, is able to capture the dynamic (such as center-of-mass diffusivity) as well as the structural (such as radius of gyration) features of the investigated polymer solutions. Essential material properties that can now be directly studied include the following: Scaling exponents for estimating the exact solvent qualities were, for the first time, determined for the two solvent systems investigated; the persistence length obtained was also noted to be in excellent agreement with early experimental estimations. Preliminary observations on the supramolecular aggregation properties were in good agreement with the general observations from a wide range of recent experiments, and shed light on the essential impact of solvent quality on the supramolecular aggregation structures.
Collapse
Affiliation(s)
- Cheng K Lee
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 621, Taiwan, ROC
| | | | | |
Collapse
|
18
|
Wang PS, Lu HH, Liu CY, Chen SA. Gel Formation via Physical Cross-Linking in the Soluble Conjugated Polymer, Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], in Solution by Addition of Alkanes. Macromolecules 2008. [DOI: 10.1021/ma800076g] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Po-Shen Wang
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu, 30013 Taiwan, R.O.C
| | - Hsin-Hung Lu
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu, 30013 Taiwan, R.O.C
| | - Ching-Yang Liu
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu, 30013 Taiwan, R.O.C
| | - Show-An Chen
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu, 30013 Taiwan, R.O.C
| |
Collapse
|
19
|
Pu KY, Pan SYH, Liu B. Optimization of Interactions between a Cationic Conjugated Polymer and Chromophore-Labeled DNA for Optical Amplification of Fluorescent Sensors. J Phys Chem B 2008; 112:9295-300. [DOI: 10.1021/jp8019717] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Kan-Yi Pu
- Department of Chemical and Biomolecular Engineering, 4 Engineering Drive 4, National University of Singapore, Singapore 117567, Singapore
| | - Summer Yi-Hui Pan
- Department of Chemical and Biomolecular Engineering, 4 Engineering Drive 4, National University of Singapore, Singapore 117567, Singapore
| | - Bin Liu
- Department of Chemical and Biomolecular Engineering, 4 Engineering Drive 4, National University of Singapore, Singapore 117567, Singapore
| |
Collapse
|
20
|
Pu KY, Qi XY, Yang YL, Lu XM, Li TC, Fan QL, Wang C, Liu B, Chan H, Huang W. Supramolecule-Regulated Photophysics of Oligo(p-phenyleneethynylene)-Based Rod–Coil Block Copolymers: Effect of Molecular Architecture. Chemistry 2008; 14:1205-15. [DOI: 10.1002/chem.200700305] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
21
|
Shie SC, Hua CC, Chen SA. Brownian Dynamics Simulation of Self-Consistently Coarse-Grained Dilute Aggregated Polymer Suspensions. MACROMOL THEOR SIMUL 2007. [DOI: 10.1002/mats.200600060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
22
|
Weng CC, Chou CH, Wei KH, Huang JY. Enhanced Electroluminescence of Poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene) Films in the Presence of TiO2 Nanocrystals. JOURNAL OF POLYMER RESEARCH 2006. [DOI: 10.1007/s10965-005-9030-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
23
|
Lee YJ, Kim DY, Barbara PF. Effect of Sample Preparation and Excitation Conditions on the Single Molecule Spectroscopy of Conjugated Polymers. J Phys Chem B 2006; 110:9739-42. [PMID: 16706417 DOI: 10.1021/jp056727x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Extensive new single molecule spectroscopy (SMS) data on the conjugated polymer MEH-PPV at low temperature were obtained. In particular, the combined effects of sample preparation and excitation condition were explored in detail. The data confirm previous observations from this laboratory that (i) the distribution of emission maxima of single MEH-PPV molecules has a bimodal distribution and (ii) the single molecule emission spectrum of MEH-PPV exhibits few time-dependent fluctuations of the emission intensity, band shape, or spectral maxima. These data also help explain the discrepancy among the various published SMS data on this compound and suggest that environmental impurities, long irradiation times, nearby interfaces, and incomplete data sampling may account for some of the discrepancies among the published data.
Collapse
Affiliation(s)
- Young Jong Lee
- Center for Nano- and Molecular Science and Technology and Department of Chemistry and Biochemistry, University of Texas at Austin, 78712, USA
| | | | | |
Collapse
|
24
|
Chen SH, Su AC, Su CH, Chen SA. Phase Behavior of Poly(9,9-di-n-hexyl-2,7-fluorene). J Phys Chem B 2006; 110:4007-13. [PMID: 16509690 DOI: 10.1021/jp0555145] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Here we report the phase behavior of poly(9,9-di-n-hexyl-2,7-fluorene) (PFH), which previously received little attention as compared to its homologues poly(9,9-di-n-octyl-2,7-fluorene) (PFO) and poly(9,9-di-(2'-ethylhexyl)-2,7-fluorene) (PFEH). By means of differential scanning calorimetry, X-ray diffraction, and electron microscopy, we show that there exist four different phases in PFH. The as-cast film is mainly composed of a mesomorphic beta phase with layer spacing of ca. 1.4 nm. This beta phase is inherently metastable and, upon heating above 175 degrees C, transforms into a crystalline (alpha) form that melts into a nematic (N) liquid above 250 degrees C. Upon stepwise cooling, the nematic melt crystallizes into the alpha phase first, followed by solid-solid transformation into another crystalline (alpha') form. Unit cell structure of the alpha form is monoclinic whereas that of the alpha' form is triclinic, but departures from strict orthogonality are slight (by ca. 6 degrees). These observations not only support our previous assignment of two crystalline forms (both orthorhombic in structure) in PFO but also provide insights to the crystalline nature of the polyfluorene series.
Collapse
Affiliation(s)
- S H Chen
- Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan
| | | | | | | |
Collapse
|
25
|
Kuila BK, Nandi AK. Structural Hierarchy in Melt-Processed Poly(3-hexyl thiophene)−Montmorillonite Clay Nanocomposites: Novel Physical, Mechanical, Optical, and Conductivity Properties. J Phys Chem B 2006; 110:1621-31. [PMID: 16471725 DOI: 10.1021/jp055234p] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Poly(3-hexyl thiophene) (P3HT) organically modified montmorillonite (om-MMT) polymer nanocomposites (PNCs) are prepared in the melt-cooled state. Hierarchical structures up to third order, namely, side chain mesomorph formation followed by the interchain lamellar structure of P3HT and finally its intercalation within the clay tactoids are observed. The structures are supported by transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) experiments. The TGA curves show two-stage degradation corresponding to those of the side chain and main chain of P3HT, and both temperatures decrease with an increase in clay concentration in the PNCs. The melting points of PNCs have increased by 2-3 degrees C higher than that of P3HT. The glass-transition temperature (Tg) and beta-transition temperature (Tbeta), measured by DMA, increase with an increase in clay concentration. The storage modulus (G) of PNCs has also increased more dramatically than that of P3HT. The UV-vis spectra of the PNCs show a blue shift in the pi-pi* absorption peak of the conjugated chain, but the photoluminescence spectra showed a red shift with an increase in the clay concentration. The quantum yield of the photoluminescence process also increases in the melt-cooled PNCs, and this is in sharp contrast to that of solvent cast PNCs where photoluminescence quenching was observed. Fibrillar network structure of the solvent cast PNCs promotes energy transfer of the charge carriers, but its absence in the melt-cooled films inhibits such energy transfer, increasing the quantum yield. The room-temperature dc conductivity of the PNCs decreased by an order compared to that of P3HT in both the doped and undoped states. The I-V characteristic curve shows semiconducting behavior, and it slowly transforms into insulator with increasing clay concentration.
Collapse
Affiliation(s)
- Biplab K Kuila
- Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | | |
Collapse
|
26
|
Yang GZ, Chen P, Liu T, Wang M, Huang W. Photophysical properties and morphology of fluorene-alt-benzene based conjugated polymers. POLYM ADVAN TECHNOL 2006. [DOI: 10.1002/pat.747] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
27
|
Peng KY, Chen SA, Fann WS, Chen SH, Su AC. Well-Packed Chains and Aggregates in the Emission Mechanism of Conjugated Polymers. J Phys Chem B 2005; 109:9368-73. [PMID: 16852122 DOI: 10.1021/jp044243f] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We synthesized dialkoxy-substituted poly[phenylene vinylene]s (dROPPV-1/1, 0.2/1, and 0/1) consisting of two repeating units with different side-chain lengths (methoxy and 3,7-dimethyloctyloxy). These polymers can serve as a model system to clarify roles of aggregates (the sites with ground-state interchain interactions) and the independent chain segments in the well-packed chains (the chain segments that are compactly packed without interaction) in the emission mechanism of conjugated polymers. Due to the packing of polymer chains, films of all of these polymers are accessible to interchain excitations, after which excitons can re-form to result in delayed luminescence. Besides, some chains form aggregates so that the delayed luminescence is no more the ordinary single-chain emission but red-shifted and less structured. Not only the re-formation of these indirect excitons but also the aggregation of chains are facilitated in the polymers with short methoxy side groups, revealing that both packing and aggregation of chain segments require a short spacing between polymer chains. However, the incorporation of other side chains such as the 3,7-dimethyloctyloxy group to dROPPVs is necessary for the formation of aggregates because these long branched side chains can reduce the intrachain order imposed by the short methoxy groups, which accounts for the absence of aggregate emission in the well-studied poly[2,5-dimethoxy-1,4-phenylene vinylene]. This study reveals that the well-packed chains do not necessarily form aggregates. We also show that the photophysical properties and the film morphology of conjugated polymers can be deliberately controlled by fine-tuning of the copolymer compositions, without altering the optical properties of single polymer chains (e.g., as in dilute solutions).
Collapse
Affiliation(s)
- Kang-Yung Peng
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu, 30013 Taiwan, Republic of China
| | | | | | | | | |
Collapse
|
28
|
Chen SH, Su AC, Su CH, Chen SA. Crystalline Forms and Emission Behavior of Poly(9,9-di-n-octyl-2,7-fluorene). Macromolecules 2004. [DOI: 10.1021/ma048162t] [Citation(s) in RCA: 204] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. H. Chen
- Institute of Materials Science and Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - A. C. Su
- Institute of Materials Science and Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - C. H. Su
- Institute of Materials Science and Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - S. A. Chen
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
| |
Collapse
|