The University of Osaka · 화학
켄 테라오 교수의 연구실은 고분자 물리학과 열역학을 기반으로 한 고분자 사슬의 구조-물성 상관관계를 연구합니다. 주로 고분자 사슬의 유연성, 치수 길이, 상전이 행동을 정량적으로 분석하기 위해 광산산란, 점도 측정, 소각산형광분석 등의 실험 기법을 활용합니다. 특히 고분자 구조의 이질성과 외부 조건(용매, 온도) 변화에 따른 거시적 거동 변화를 웜선형 사슬 모델을 기반으로 이론적으로 해석합니다. 이는 고분자 설계 및 신소재 개발에 필수적인 기초 연구입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
A series of polymacromonomer samples (F15) consisting only of polystyrene and having a fixed side chain length of 15 styrene residues have been prepared and studied by static light scattering in cyclohexane at different temperatures and in toluene at 15 °C. The measurement has also been made on polymacromonomer samples (F33) of the same kind but with 33 side chain residues in toluene. The second virial coefficient for the F15 polymer in cyclohexane vanishes at 34.5 °C, the ϑ temperature for line
Viscosity measurements have been made on two series of polymacromonomer samples consisting only of polystyrene (PS) and having fixed side chain lengths of 15 and 33 styrene residues (designated F15 and F33) in cyclohexane at 34.5 °C (the ϑ temperature) and in toluene at 15 °C (a good solvent). The intrinsic viscosities [η] obtained as functions of (total) weight-average molecular weight Mw (in the ranges from 5.1 × 103 to 6.5 × 106 for the F15 polymer and from 5.4 × 104 to 1.1 × 107 for the F33
In order to obtain a gelatin hydrogel crosslinked by a reagent-free method, gamma-ray and electron beam radiation was applied to porcine, bovine and fish gelatin gels and the products were characterized by measuring the gel fraction, the swelling ratio and the enzymatic degradability. On increasing the radiation dose, the gel fraction increased and both the swelling ratio and the enzymatic degradability decreased. The transition temperature from gel to sol of the hydrogel containing more than 5%
Small-angle X-ray scattering (SAXS), circular dichroism (CD), and density measurements were made on eight samples of collagen model peptides consisting of glycine (Gly), proline (Pro), and 4-(R)-hydroxyproline (Hyp), i.e., (Gly-Hyp-Hyp)n, (Gly-Pro-Hyp)n, (Gly-Hyp-Pro)n, and (Gly-Pro-Pro)n (n = 5 and 9) in pure water and in phosphate buffered saline at a wide range of temperatures between 4 and 75 °C. A complete triple-helical structure was found only for (Gly-Hyp-Hyp)9 and (Gly-Pro-Hyp)9 at 15 °
Eleven samples of poly{n-hexyl-[(S)-3-methylpentyl]silylene} (PH3MPS) ranging in weight-average molecular weight Mw from 3.1 × 103 to 8.7 × 105 in isooctane have been studied by light scattering at 25 °C, sedimentation equilibrium at 25 °C, and viscometry at five temperatures (−27,−15, 5, 25, and 45 °C) to determine their z-average radii of gyration 〈S2〉z, second virial coefficients, and intrinsic viscosities [η]. The 〈S2〉z and [η] data are analyzed quantitatively by the current theories on the
Twelve amylose tris(n-butylcarbamate) (ATBC) samples ranging in weight-average molecular weight from 1.7 × 104 to 1.7 × 106 have been prepared and studied by light and small-angle X-ray scattering, sedimentation equilibrium, viscosity, infrared absorption (IR), and optical rotation in methanol (MeOH), tetrahydrofuran (THF), and their mixtures at 25 °C (or 20−25 °C for IR). Data for the mean-square radius of gyration, the particle scattering function, and the intrinsic viscosity are analyzed on t
Small-angle X-ray scattering measurements were made for cellulose, amylose, and amylose tris(ethylcarbamate) (ATEC) in an ionic liquid [1-butyl-3-methylimidazolium chloride (BmimCl)] at 25 °C to determine z-average mean-square radius of gyration ⟨S2⟩z and the particle scattering function P(q). The obtained data were analyzed in terms of the wormlike chain model to estimate the Kuhn segment length λ–1 (the stiffness parameter, equivalent to twice of the persistence length) and the helix pitch (or
The molecular weight dependence of the radii of gyration Rg in a ϑ solvent (trans-decalin) of one regular branched comb and three regular centipede polystyrenes was studied using a gel permeation chromatography system equipped with a two-angle light scattering detector and a refractive index detector. Rg in trans-decalin for each sample of particular molecular weight was about 25% smaller than that in a good solvent (tetrahydrofuran, THF). On the other hand, they are 20−40% larger than the theor
Small-angle X-ray scattering measurements were made for nine cyclic amylose tris(n-butylcarbamate) (cATBC) samples ranging in the weight-average molar mass Mw from 1.6 × 104 to 1.1 × 105 to determine the z-average mean-square radius of gyration ⟨S2⟩z and the particle scattering function P(q) in two good solvents, tetrahydrofuran (THF) and methanol (MeOH) at 25 °C and in a Θ solvent, 2-propanol (2PrOH) at the Θ temperature (35 °C). Static and dynamic light scattering measurements were carried out
The z-average radius of gyration, the particle scattering function and the intrinsic viscosity have been determined for amylose tris(n-butylcarbamate) (ATBC) in D-, DL- and L-ethyl lactates, all at 25 °C, by light and small-angle X-ray scattering and viscometry as functions of the weight-average molecular weight ranging from 1.7 × 104 to 1.7 × 106 to investigate the chiral solvent dependence of the helical conformation of the amylose derivative. The data were analyzed in terms of the wormlike ch
Light-scattering and phase-separation experiments were performed on cyclohexane solutions of four narrow-distribution samples of four-arm star polystyrene with molecular weights of 8.5 × 104 to 1.4 × 106, and the results were compared with literature data for linear polystyrene in cyclohexane. The upper critical solution temperatures Tc for the star polymer were systematically lower than those for the linear polymer, showing a considerable effect of chain branching on phase separation. The appar
