Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Yoshiaki Takahashi Last modified date:2019.06.11

Associate Professor / Hybrid Material Science / Department of Advanced Device Materials / Institute for Materials Chemistry and Engineering

1. Li Yi Tan, Yoshitaka Tsuchido, Kohtaro Osakada, Zhengguo Cai, Yoshiaki Takahashi, Daisuke Takeuchi, Synthesis and Aggregation Behavior of Poly(arylene alkenylene)s and Poly(arylene alkylene)s Having Dialkoxyphenylene and Aromatic Diimide Groups, Macromolecules, 10.1021/acs.macromol.8b02468, 52, 4, 1642-1652, 2019.02, Polycondensation reactions of 2,5-dialkoxy-1,4-diiodobenzene with N,N′-ω-dialkenylpyromellitic diimide and N,N′- ω-dialkenyl naphthalenetetracarboxylic diimide in the presence of a Pd(OAc)
-NaOAc catalyst produce six polymers containing the two aromatic groups connected alternatingly by alkenylene spacers.
H NMR spectrum of a polymer prepared from 2,5-bis(dodecyloxy)-1,4-diiodobenzene and N,N′-(10-undecenyl)pyromellitic diimide (poly(1a-IA)) indicates that the polymerization involves 2,1- and 1,2-insertion of a vinyl group into the Pd-Ar bond in 70:30 selectivity. Matrix-assisted laser deportion/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) spectra of poly(1a-IA) and a polymer from 2,5-bis(dodecyloxy)-1,4-diiodobenzene with N,N′-dialkenyl naphthalenetetracarboxylic diimide (poly(1a-IIA)) contained a series of polymer fragments with M
up to 4500. Measurement of electrospray ionization MS (ESI-MS) of the polymers revealed formation of cyclic molecules for 1:1 and 2:2 oligomers. Hydrogenations of poly(1a-IA) by using [Ir(cod)(py)(PCy

(cod = 1,5-cycloctadiene; PCy
= tricyclohexylphosphine) catalyst and of poly(1a-IIA) by a mixture of p-toluenesulfonyl hydrazide (TSH) and tripropylamine (TPA) produce the poly(arylene alkylene)s with saturated spacers in 93% degree of hydrogenation. The absorption spectrum of poly(1a-IA) in CHCl
shows an absorption edge at 410 nm, which is at a longer wavelength than that of a mixture of the monomers (370 nm). Light-scattering measurement of the solution (1.00 mmol L
) indicates the presence of aggregates with a hydrodynamic radius of 48 nm. The polymers exhibit weak elasticity at room temperature, as determined by dynamic viscoelasticity analysis (DMA), and it becomes negligible on heating to 75-80 °C (polymer with pyromellitic diimide groups) and 110-122 °C (polymer with naphthalenetetracarboxylic diimide groups). The above properties of the polymers are attributed to attractive interaction between the electron-rich alkoxyphenylene and the electron-deficient aromatic diimide groups both in solution and in the solid state..
2. Takuro Iwamoto, Yuya Doi, Keita Kinoshita, Atsushi Takano, Yoshiaki Takahashi, Eunhye Kim, Tae Hwan Kim, Shin Ichi Takata, Michihiro Nagao, Yushu Matsushita, Conformations of Ring Polystyrenes in Semidilute Solutions and in Linear Polymer Matrices Studied by SANS, Macromolecules, 10.1021/acs.macromol.8b00934, 51, 17, 6836-6847, 2018.09, Conformations of highly purified ring polystyrene, R-70, with the molar mass of 70 kg/mol, in a good solvent and in linear polymer homologue matrices were examined by small-angle neutron scattering (SANS) measurements. The radii of gyration Rg of R-70 were estimated by the Guinier's approximation from the SANS profiles obtained, and the polymer volume fraction φ dependence of Rg
2 was discussed. In deuterated toluene as a good solvent, R-70 exhibits the Rg
2 ∼ φ-0.29±0.01 dependence at high φ above the overlap volume fraction, φ0∗ (i.e., 1 < φ/ φ0∗ < 20). This exponent -0.29 shows stronger φ dependence than that for semidilute solutions of linear polymers, -0.25, predicted from the scaling theory, suggesting that the ring expands more sensitively than linear chains when φ decreases in semidilute regime. In contrast, the φ dependence of Rg
2 of R-70 is evidently weaker than that of the recent simulation for ring polymer solutions (Rg
2 ∼ φ-0.59) by Reigh et al. This difference is thought to originate from the difference in the ring chain length; i.e., the simulation treated much longer rings than the ring adopted in this study. Therefore, it is expected that the exponent -0.29 for the ring polymer solutions obtained in this study is not a limiting value but is a transit one toward higher φ/ φ0∗ region. The size of R-70 is also increased when the ring was diluted with linear polystyrenes. However, the degree of expansion of the rings in linear polymer matrices is considerably lower than that in toluene solutions. Moreover, the molar masses of the linear chains added hardly effect the expansion behavior of the rings. In fact, the dimension of rings gets closer to that of the Gaussian rings as a larger amount of linear chains is added..
3. Takuro Iwamoto, Yuya Doi, Keita Kinoshita, Yutaka Ohta, Atsushi Takano, Yoshiaki Takahashi, Michihiro Nagao, Yushu Matsushita, Conformations of Ring Polystyrenes in Bulk Studied by SANS, Macromolecules, 10.1021/acs.macromol.7b02358, 51, 4, 1539-1548, 2018.02, We prepared five pairs of hydrogenous and deuterated ring polystyrene samples over a wide range of molecular weights (10 kg/mol ≤ Mw ≤ 400 kg/mol) and investigated their chain conformations in bulk by small-angle neutron scattering (SANS) measurements. From the SANS profiles obtained, we estimated the radii of gyration Rg of the ring polymers by the Guinier approximation. Rg can be related to the degree of polymerization N as Rg ∼ N0.47. This scaling exponent ν = 0.47 ± 0.01 is evidently smaller than that for the Gaussian chains (ν = 0.50) but higher than previous experimental reports (ν = 0.42-0.43). Then our data were compared with various simulation and experimental data by introducing the entanglement degree of polymerization Ne for linear polymers as a normalized parameter. Rg of three smaller rings, i.e., R-10, R-30, and R-70, where the numbers denote molecular weights in kg/mol unit, are in good agreement with simulation results, while two larger rings, R-100 and R-400, exhibit higher Rg values than the simulations. Considering that the latter two higher molecular weight samples include maximum 3% of linear contamination, their effects on chain dimension were calculated. As a result, it has been confirmed that 3% of linear contaminations can overestimate Rg of rings as much as 6% for R-100 and 12% for R-400. Thus, Rg for pure large rings should be considerably lower than the present experimental values. We conclude Flory's exponent v in Rg ∼ Nv for rings may not be constant but rather show molecular weight dependence due to their topological constraint..
4. Hu Hao, Yoshiaki Takahashi, Dynamic viscoelastic properties of dilute pullulan ionic liquids solutions, Nihon Reoroji Gakkaishi, 10.1678/rheology.45.133, 45, 3, 133-138, 2017.06, Dynamic viscoelastic properties of standard pullulan samples with different molecular weights and narrow molecular weight distributions in ionic liquids are measured in non-entangled region over a wide range of chain overlapping (1 ≤ C [η ] ≤ 12.6) and compared with Rouse-Zimm (RZ) theory with and without introducing correction term called long time (LT) term, proposed by Osaki et al. (J. Polym. Sci., Part B, Polym. Phys. Ed., 39, 211-217, (2001)). When chains are overlapped (say 2.5 ≤ C [η ]), loss modulus data (G" ) can be well expressed by the RZ theory with experimentally determined longest relaxation time τRZ while storage modulus (G' ) was larger than the calculation. However, addition of LT term made reasonable correction for calculation of G' similar to the results for standard polystyrenes. To apply the RZ fitting for Mw estimation of unknown sample (fitting G" by RZ theory), estimation error for τRZ and resulting Mw are examined. At high C [η ], relative error of estimated Mw was about 15%, as long as t RZ can be determined with small error and coincidence of τ RZ and the longest Rouse relaxation time calculated from estimated Mw is confirmed. At lower C [η ], this method tend to underestimate Mw and the error become larger..
5. Yuya Doi, Atsushi Matsumoto, Tadashi Inoue, Takuro Iwamoto, Atsushi Takano, Yushu Matsushita, Yoshiaki Takahashi, Hiroshi Watanabe, Re-examination of terminal relaxation behavior of high-molecular-weight ring polystyrene melts, Rheologica Acta, 10.1007/s00397-017-1014-3, 56, 6, 567-581, 2017.06, For high-molecular-weight (M) ring polymers with low contamination of linear chains, recent viscoelastic tests revealed broad terminal relaxation associated with no clear entanglement plateau. This relaxation behavior is qualitatively similar to that deduced from molecular models (double-folded lattice-animal model and the fractal loopy globule model) for entangled ring polymers, but quantitatively important differences are also noted: For example, the full terminal relaxation of those polymers is slower than the model prediction. This study re-examined the viscoelastic data of entangled high-M ring polystyrene (PS) samples (coded as R-240; M = 244×103) specifically for two points: the purity of the ring samples after the viscoelastic tests and the molecular origin of the stress. For the first point, the R-240 samples contaminated with linear chains at low but different levels were prepared by tuning either the purification efficiency or the retention time of the sample at high temperature (T) before/during the viscoelastic test. The fraction wL of the linear contaminant, determined after the viscoelastic measurement, was ranging from 0.7 to 4.9%, and the extrapolation of the modulus data to wL = 0 gave the data for the ideally pure ring melt. This pure ring melt exhibited broad terminal relaxation that started faster but completed slower compared to the model prediction, indicating that the ring relaxation is not well described by the current model(s) even in the absence of linear contaminant. For the second point, dynamic birefringence measurements were conducted for the R-240 samples with wL = 4.6 and 1.0%. These samples obeyed the stress-optical rule, and their stress-optical coefficient was indistinguishable from that for linear PS samples, revealing that the stress of the ring PS chains reflects the orientational anisotropy of the chains (as is the case also for linear chains). The relaxation behavior of pure ring PS melt is discussed on the basis of these findings, with the focus being placed on the ring-ring threading not considered in the models..
6. Adisak Takhulee, Yoshiaki Takahashi, Visit Vao-soongnern, Molecular simulation and experimental studies of the miscibility of PLA/PLAx-PEGy-PLAx blends, Journal of Polymer Research, 10.1007/s10965-017-1344-y, 24, 11, 2017.10, To design a more efficient plasticizer for PLA based on PEG derivative, the miscibility enhancement of PLA/PLAx-PEGy-PLAx blends were investigated by both atomistic and mesoscale simulations. Flory-Huggins interaction parameters (χij) of PLAx-PEGy-PLAx blends, with PLA block fractions = 0.1–0.5, were calculated using molecular dynamic (MD) simulation to determine the miscibility of PLA/PLAx-PEGy-PLAx blends and compared with PLA/PEG blends (Takhulee et al. J Polym Res 24:8, 2017). Based on the calculated χij and radial distribution functions, PLA/PLAx-PEGy-PLAx showed better miscibility compared to PLA/PEG. The values of χij for PLA/PLAx-PEGy-PLAx blends are always lower than those for PLA/PEG blends at the same PEG composition. For PLA/PLAx-PEGy-PLAx blends, χij increased as a function of PLA block fractions. Mesoscale properties of PLA/ PLAx-PEGy-PLAx blends were then determined using dissipative particle dynamic (DPD) simulation. Smaller PEG domain in PLA/PLAx-PEGy-PLAx blends was observed, compared to that in PLA/PEG blend. Miscibility behavior of PLA/PLAx-PEGy-PLAx blends was investigated by experiments at selected conditions based on the simulation results. By differential scanning calorimetry measurements, acceleration of the crystallization of PLA matrix by blending PLAx-PEGy-PLAx was observed. Although PLA/PEG 70/30 (wt/wt) blend was phase separated when slowly cooled from the melt, due to the crystallization of PEG component, this phenomenon was not observed in PLA/PLAx-PEGy-PLAx blends. The melting temperature (Tm) depression of PLA/PLAx-PEGy-PLAx blends was also more pronounced. From dynamic mechanical analysis, the storage (G′) and loss moduli (G′′) curves in terminal region were determined. The slope of G′ curves for PLA/PEG 75/25 and 70/30 (wt/wt) was less than 2 while this deviation was found only at 70/30 (wt/wt) for PLA/PLAx-PEGy-PLAx. These results indicate that PLAx-PEGy-PLAx is better miscible with PLA..
7. Satoru Matsushima, Atsushi Takano, Yoshiaki Takahashi, Yushu Matsushita, Dynamic viscoelasticity of a series of poly(4-n-alkylstyrene)s and their alkyl chain length dependence, Polymer, 10.1016/j.polymer.2017.10.065, 133, 137-142, 2017.12, Dynamic viscoelastic measurements were performed for a series of poly(4-n-alkylstyrene)s with six different n-alkyl side chains, that is, methyl, ethyl, propyl, butyl, hexyl and octyl groups. Based on the time-temperature superposition principle, storage modulus G′, loss modulus G″ and loss tangent tan δ were shifted with horizontal shift factor aT and vertical shift factor bT, giving well superposed master curves for all the polymers. With increase of the number of carbon atoms, plateau modulus GN 0, which corresponds to G′ value at minimum tan δ, decreases, while entanglement molecular weight Me(=ρRT/GN 0) increases, where ρ is the polymer density, R is the gas constant and T is the absolute temperature. Degree of polymerization at onset of entanglement, Ne, which defined as Me/M0, where M0 denotes the molecular weight of each monomer, also increases with increase of n-alkyl side chain length. Packing length estimated from the empirical equation by Fetters also increases with increase of n-alkyl lengths. These results are presumably due to large polymer chain thickness caused directly by substituents on phenyl rings of styrene units..
8. Satoru Matsushima, Atsushi Takano, Yoshiaki Takahashi, Yushu Matsushita, Precise Synthesis of a Series of Poly(4-n-Alkylstyrene)s and Their Glass Transition Temperatures, JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, 10.1002/polb.24326, 55, 9, 757-763, 2017.05.
9. Xu Zhe, Yoshiaki Takahashi, Molecular Weight Estimation of Cellulose in Ionic liquid Solution by Fitting Dynamic Viscoelastic Data to Rouse Model, NIHON REOROJI GAKKAISHI, 45, 2, 119-124, 2017.04.
10. Xu Zhe, Yoshiaki Takahashi, Study on the Dissolution Process of Different Kinds of Cellulose into Ionic Liquids, NIHON REOROJI GAKKAISHI, 45, 1, 71-78, 2017.02.
11. Takhulee, Adisak, Yoshiaki Takahashi, Vao-soongnern, Visit, Molecular simulation and experimental studies of the miscibility of polylactic acid/polyethylene glycol blends, JOURNAL OF POLYMER RESEARCH, 10.1007/s10965-016-1174-3, 24, 1, 2016.12.
12. Yuya Doi, Yutaro Iwasa, Kazuki Watanabe, Masahide Nakamura, Atsushi Takano, Yoshiaki Takahashi, Yushu Matsushita, Synthesis and Characterization of Comb-Shaped Ring Polystyrenes, 49, 3109-3115, 2016.04.
13. Yuya Doi, Atsushi Takano, Yoshiaki Takahashi, Yushu Matsushita, Melt Rheology of Tadpole-Shaped Polystyrenes, 48, 23, 8667-8674, 2015.11.
14. Yuya Doi, Kazuki Matsubara, Yutaka Ohta, Tomohiro Nakano, Daisuke Kawaguchi, Atsushi Takano, Yoshiaki Takahashi, Yushu Matsushita, Melt Rheology of Ring Polystyrenes with Ultrahigh Purity, 48, 3140-3147, 2015.04.
15. Hao Hu, Akihiko Takada, Yoshiaki Takahashi, Intrinsic Viscosity of Pullulan in Ionic Liquid Solutions Studied by Rheometry, Nihon Reoroji Gakkaishi (Journal of the Society of Rheology, Japan), 42, 3, 191-196, 2014.01.
16. Hao Hu, Akihiko Takada, Yoshiaki Takahashi, A study of density for pullulan/ionic liquids solutions, 1, 1, 14-19, 2014.03.
17. Zhe Xu, Yoshiaki Takahashi, Akihiko Takada, Elastic Modulus of the Gel made from Interpenetrating Polymer Networks in Phase Separated States, 1, 1, 1-5, 2014.03.
18. Akihiko Takada, Koji Saeki, Shoichi Murata, YUKIHIRO MOTOYAMA, Atsushi Takano, Hiroko Yamamoto, Yoshiaki Takahashi, Thermo-reversible Solid-like and Liquid-like Behaviors of Carboxyl-terminated Telechelic Poly(ethylene-butylene) Neutralized by Octadecylamine, Nihon Reoroji Gakkaishi (Journal of the Society of Rheology, Japan, 42, 1, 33-38, 2014.01.
19. Long Fang, Yoshiaki Takahashi, Atsushi Takano, Yushu Matsushita, Molecular Weight Dependence of Viscoelastic Properties for Symmetric Poly(styrene-b-2-vinylpyridine)s in the Nanophase Separated Molten States, Macromolecules, 46, 7, 7097-7105, 2013.08.
20. Long Fang, Yoshiaki Takahashi, Atsushi Takano, Yushu Matsushita, A Separation Method of Responses from Large Scale Motions and Chain Relaxations for Viscoelastic Properties of Symmetric Poly(styrene-b-2-vinylpyridine)s in the Ordered State, Nihon Reoroji Gakkaishi (Journal of the Society of Rheology, Japan), 41, 2, 93-99.
21. Yoshiaki Takahashi, Long Fang, Atsushi Takano, Naoya Torikai, Yushu Matsushita, Viscoelastic Properties of Low Molecular Weight Symmetric Poly(styrene-b-2-vinylpyridine)s in the Ordered and Disordered States under Steady Shear Flow, Nihon Reoroji Gakkaishi (Journal of the Society of Rheology, Japan), 41, 2, 83-91.
22. Yumi Matsumiya, Hiroshi Watanabe, Atsushi Takano, Yoshiaki Takahashi, Uniaxial Extensional Behavior of (SIS)p-Type Multiblock Copolymer Systems: Structural Origin of High Extensibility, 46, 7, 2681-2695, 2013.03.
23. Yuya Doi, Yutaka Ohta, Masahide Nakamura, Atsushi Takano, Yoshiaki Takahashi, Yushu Matsushita, Precise Synthesis and Characterization of Tadpole-Shaped Polystyrenes with High Purity, 46, 3, 1075-1081, 2013.01.
24. Atsushi Takano, Takeshi Horaiya, Fumitake Odamaki, Yoshihiko Akazawa, Yutaka Ohta, Daisuke Kawaguchi, Yoshiaki Takahashi, Yushu Matsushita, Preparation and characterization of polyisoprenes and polybutadienes having 1,2- and 3,4-linkages preferentially, 53, 3354-3359, 2012.06.
25. A. Dawn, T. Shiraki, H. Ichikawa, A. Takada, Y. Takahashi, Y. Tsuchiya, N. T. L. Le, S. Shinkai, Stereochemistry-Dependent, Mechanoresponsive Supramolecular Host Assemblies for Fullerenes: A Guest-Induced Enhancement of Thixotropy, J. Am. Chem. Soc., 134, 2161-2171, 2012.02.
26. A. Takano, Y. Ohta, K. Matsubara, T. Nakano, A. Hieno, M. Itakura, K. Takahashi, S. Kinugasa, D. Kawaguchi, Y. Takahashi, Y. Matsushita, , Radii of Gyration of Ring-Shaped Polystyrenes with High Purity in Dilute Solutions, MACROMOLECULES, 45, 369-373, 2012.01.
27. Hiroko Yamamoto, Kohji Tashiro, Norio Nemoto, Yukihiro Motoyama, and Yoshiaki Takahashi, Systematic Study of Aggregation Structure and Thermal Behavior of a Series of Unique H-Shape Alkane Molecules, J. Phys. Chem. B, 115, 9537–9546, 2011.06.
28. A. S. El-Khouly, Y. Takahashi, A. A. Safaan, E. Kenawy, Y. A. Hafiz, Study of Heavy Metal Ion Absorbance by Amidoxime Group Introduced to Cellulose-graft-Polyacrylonitrile, J. Appl. Polym. Sci., 120, 2, 866-873, 2011.01.
29. A. S. El-Khouly, E. Kenawy, A. A. Safaan, Y. Takahashi, Y. A. Hafiz, K. Sonomoto, and T. Zendo, Synthesis and Antimicrobial Activity of Some Modified Cellulose-graft-Polyacrylonitrile Derivatives, Carbohydrate Polymers, 83, 346-353, 2011.01.
30. A.S. El-Khouly, Y. Takahashi1, A. Takada, A. A. Safaan, E. Kenawy, Y. A. Hafiz, Characterization and Mechanical Properties of Cellulose-graft-Polyacrylonitrile Prepared by using KMnO4/different acids as Redox System, Nihon Reoroji Gakkaishi (J. Soc. Rheol. Jpn.), 38, 3, 133-140, 2010.06.
31. A. S. El-Khouly, Y. Takahashi, A. Takada, A. A. Safaan, E. Kenawy, Y. A. Hafiz, Characterization and Thermal Stability of Cellulose-graft-Polyacryloniytrile Prepared by Using KMnO4/Citric Acid Redox System, J. Appl. Polym Sci, 116, 1788-1795, 2010.01.
32. S. Murata, A. Takada, H. Yamamoto, Y. Takahashi, Viscoelastic Properties of Worm-like Micelle of Aluminum Tristearylate/Decahydronaphthalene, Nihon Reoroji Gakkaishi (J. Soc. Rheol. Japan), 36, 191-194, 2008.09.
33. A Takada, K. Imaichi, T. Kagawa, and Y. Takahashi, Abnormal Viscosity Increment Observed for an Ionic Liquid by Dissolving Lithium Chloride, J. Phys. Chem. B, 112, 9660-9662, 2008.07.
34. Y. Takahashi, S. Hasegawa, Shear Effects on the Loop Bridge Ratio of Middle Block Chains in Sphere-Forming ABA Triblock Copolymers Examined by Simple Elongation Measurements, J. Solid Mech. and Matls. Eng., 2, 473-477, 2008.02.
35. Y. Takahashi, K. Imaichi, M. Noda, A. Takano, and Y. Matsushita, Hysteresis Behavior in Shear Rate Dependence of First Normal Stress Difference of Diblock Copolymers in Ordered State near Order-Disorder Transition, Polym. J, 2007.06.
36. Yoshiaki Takahashi, Yoshihiko Akazawa, Atsushi Takano, Yushu Matsushita, Elasticity of Sphere-forming Polystyrene-b-polyisoprene-b-poly(2-vinylpiridyne)/ Polystyrene-b-polyisoprene/ Polyisoprene-b-poly(2-vinylpiridyne) blends: The role of Dangling Chains, Polymer Journal, vol36, pp603-605, 2006.06.
37. Yoshiaki Takahashi, Shuhei Yahata, Atsushi Takano, Yushu Matsushita, Annealing Effects on the Elastic Properties of Sphere-Forming ABA and ABC Triblock Copolymers, Nihon Reoroji Gakkaishi, vol34, pp177-180, 2006.06.
38. A. Takano, I. Kamaya, Y. Takahashi, and Y. Matushita, Effect of Loop/Bridge Conformation Ratio on Elastic Properties of the Sphere-Forming ABA Triblock Copolymers. Preparation of Samples and Determination of Loop/Bridge Ratio, Macromolecules, 38, 9718-9723, 2005.12.
39. Y. Takahashi, Y. Song, N. Nemoto, A. Takano, Y. Akazawa, and Y. Matsushita, Effect of Loop/Bridge Conformation Ratio on Elastic Properties of the Sphere-Forming A-B-A Triblock Copolymers under Uniaxial Elongation, macromolecules, 10.1021/ma050720w, 38, 23, 9724-9729, 38, 9723-9729, 2005.12.
40. Y. Takahashi, M. Noda, S. Kitade, K. Matsuoka, Y. Matsushita, and I. Noda, Flow-Induced Structure and Viscoelastic Properties of Poly(styrene-block-2-vinylpyridine)s Solutions near the Order-Disorder Transition, Polym. J.
41. Y. Takahashi, M. Naruse, Y. Akazawa, A. Takano, and Y. Matsushita, Comparison between Flow-Induced Alignment Behaviors of Poly(styrene-block-2-vinylpyridine)s and Poly(styrene-block-isoprene)s Solutions near the ODT, Polym. J, 10.1295/polymj.37.900, 37, 12, 900-905, 37, 900-905, 2005.12.
42. Yoshiaki Takahashi Tuyoshi Kato, 5) Coalescence behavior of dispersed domains in binary immiscible fluid mixtures having bimodal size distributions under steady shear flow, Korea-Australia Rheology Journal, 17, 3, 125-130, 2005.09.