研究者業績
基本情報
研究キーワード
2研究分野
1経歴
5-
2021年3月 - 現在
-
2017年4月 - 2021年2月
-
2007年4月 - 2017年3月
-
2002年10月 - 2007年3月
-
1997年4月 - 2002年9月
受賞
1-
2003年
論文
111-
Colloid and Polymer Science 282 250-255 2004年1月1日Colloidal single crystals of cationic polymer spheres (198-250 nm in diameter) in deionized aqueous dispersions were formed for the first time. The spheres used were poly(styrene-co-methacryloyl-oxyphenyldimethylsulfonium) cations. These cations are unstable in deionized suspensions with mixed beds of cation-exchange and anion-exchange resins. This was clarified by reflection spectroscopy, pH, conductance and ζ-potential measurements for 250 days after suspension preparation. Colloidal crystals formed over a period of 24 h for the deionized suspensions at sphere concentrations higher than 0.09 in volume fraction. The nearest-neighbor intersphere distances coincide satisfactorily with the calculated values using the diameter and the concentration of the spheres. Alloy crystals formed from binary mixtures of the cationic polymer spheres and the anionic silica spheres when the ratio of the volume fraction of cationic spheres against the sum of the both cationic and anionic spheres was smaller than 0.3. © Springer-Verlag 2003.
-
高分子論文集 60(11) 629-635 2003年11月 査読有り主鎖にポリウレタン鎖, 枝鎖にアルキル鎖 (炭素数4から18) とポリエチレングリコール (PEG) 鎖 [エチレンオキシド (EO) ユニット数9と23] を有する櫛形高分子界面活性剤 (PUS) を重付加により合成した. 得られたPUSは水溶性で曇り点を示したが, アルキル鎖炭素数18のPUS水溶液は100℃以下で曇り点を示さなかった. PUSの界面化学的特性を表面張力とピレン蛍光強度測定により評価した. PUSの空気/水界面での界面活性を吸着効力 (Γm), 吸着効率 (pC20) と臨界ミセル濃度 (CMC) から検討した. アルキル鎖炭素数が12まで増加するとPUSの界面活性は増加し, 一般的な一本鎖型界面活性剤の特徴と一致した. しかしながら, アルキル鎖炭素数18のPUSでは界面活性は低下し, 界面活性がアルキル鎖炭素数に対して最大値を示した. PUSの吸着効力はアルキル鎖炭素数12で最大となり, これは吸着効率やミセル形成よりもアルキル鎖炭素数が12のPUSでの界面活性が最大値を示すおもな要因であると推測された.
-
Chemistry letters 32(6) 518-519 2003年6月5日Novel, comb-like polymeric surfactants with polyurethane (PUSs) as the backbone, and dodecyl and polyethylene glycol (PEG) groups as the side chains were synthesized. The surface-active properties of the resulting PUSs in terms of surface tension reduction of water were found to be higher than those of polyacrylates (PASs) with the corresponding side chains.
-
KOBUNSHI RONBUNSHU 60(2) 84-91 2003年 査読有りThis paper describes syntheses of novel comb-shaped polymeric surfactants (PUSs) with polyurethane chain as the backbone and dodecyl and polyethylene glycol (PEG) groups as the side chains. The estimation of surface-active and micelle-forming properties of the PUSS in aqueous media was completed. Aqueous solutions of the PUSS with low contents of dodecyl chain exhibited cloud points at 60 to 80 degreesC, but those of the PUSS with high contents did not show such points below 100 degreesC. Surface activity of the PUSS was the highest at 17 mol% dodecyl chain to total side chains, within the results obtained in this study, and this activity become lower at higher contents of dodecyl chain. Micelle formation of the PUSS occurred above their critical micelle concentrations, which decreased with increasing the content of dodecyl chain. Reduction of surface activity at higher content of dodecyl chain in PUSS can be ascribed to the fact that the micelle formation of PUSS preceded their adsorption at air/water interface.
-
CHEMISTRY LETTERS (12) 1180-1181 2002年12月 査読有りPolymer particles bearing sulfonium groups are found to be self-assembled on a gold substrate by simply immersion into latex. Millimeter-sized large domain of 2-D highly ordered particle arrays were also obtained in a self-assembled particle monolayer. Polymer particles were selectively assembled on a patterned gold substrate at the particle size level by a combination with photolithographic technique.
-
COLLOID AND POLYMER SCIENCE 280(10) 942-948 2002年10月 査読有りMonodispersed cationic polymer particles with sulfonium groups and active ester groups at their surfaces were prepared by emulsifier-free emulsion copolymerization of styrene (ST) with a water-soluble active ester monomer, methacryloyloxyphenyl-dimethylsulfonium methylsulfate (MAPDS). The cationic polymer particle monolayers were fabricated on unmodified and animated glass plates by electrostatic interactions and chemical reactions, respectively. The polymer particles were immobilized onto unmodified glass plates at relatively regular intervals in the absence of electrolytes, and the morphology of particle monolayers on the glass plates was changed with solid content of latex, electrolyte and cationic surfactant concentration. The polymer particles were immobilized onto aminated glass plate as aggregates by controlling the pH of latex and electrolyte concentration. Remaining active ester groups of the particle monolayers were confirmed to react easily with primary amino compounds.
-
Chemistry Letters 1188-1189 2002年8月 査読有り
-
MACROMOLECULAR SYMPOSIA 151 529-534 2000年2月 査読有りReactive polymer microspheres with active ester groups on their surfaces were synthesized via emulsifier-fi ee emulsion copolymerization of styrene (ST) with methacryloxyphenyldimethylsulfonium methylsulfate (MAPDS). Glass or steel substrates aminated with coupling agents were immersed into P(ST-co-MAPDS) latex to chemically immobilize polymeric microspheres. Coverage of the aminated inorganic substrates with the microspheres increased with increasing the solid content of latex. Proper addition of an electrolyte decreased electrostatic repulsion between microspheres to form stable particle monolayer.
-
色材協會誌 72(12) 748-759 1999年12月20日部分的に末端がビニル基で封鎖されたポリウレタンに酸モノマーを含むビニルモノマーの混合物をグラフトすることによって, 両親媒性アクリルーポリウレタングラフト共重合体を合成した。分散剤を使用して有機溶媒中にあらかじめ分散されたカーボンブラックと有機顔料は, この両親媒性重合体を用いた転相乳化プロセスによってカプセル化できた。有機顔料を疎水性樹脂からなる固体の顔料分散体を使用しても同様な方法でカプセル化が可能であった。乳化条件と顔料/バインダー比の影響について研究した。ポリウレタンセグメント中に三級アミノ基を有する両親媒性アクリルーポリウレタングラフト共重合体を使用することによって, 分散剤を使用せずに顔料を直接樹脂でカプセル化できる可能性を示した。
主要なMISC
15-
Colloids and Surfaces B: Biointerfaces 145 152-159 2016年9月1日© 2016 Elsevier B.V. Luminescent particles have been attracting significant attention because they can be used in biochemical applications, such as detecting and imaging biomolecules. In this study, luminescent polystyrene latex particles were prepared through miniemulsion polymerization of styrene with dissolved europium complexes in the presence of bovine serum albumin (BSA) and poly(ethylene glycol) monomethoxy methacrylate as surfactants. The solubility of the europium complex in styrene has a strong effect on the yield of the particle. Europium tris(2-thenoyl trifluoroacetonate) di(tri-n-octyl phosphine oxide), which has a high solubility in styrene, was sufficiently incorporated into the polystyrene particles compared to europium tris(2-thenoyl trifluoroacetonate), which has a low solubility in styrene. The luminescence property of the europium complex could remain intact even after its incorporation through the miniemulsion polymerization. In the aqueous dispersion, the resulting particles could emit strong luminescence, which is a characteristic of the europium complex. The antibody fragments were covalently attached to BSA-covered particles after a reaction with a bifunctional linker, N-(6-maleimidocaproyloxy)succinimide. The time-resolved fluoroimmunoassay technique showed that 3.3 pg/mL of human α-fetoproteins (AFP) can be detected by using the resulting luminescent particles. An immunochromatographic assay using the resulting particles was also performed as a convenient method to qualitatively detect biomolecules. The detection limit of AFP measured by the immunochromatographic assay was determined to be 2000 pg/mL. These results revealed that the luminescent particles obtained in this study can be utilized for the highly sensitive detection of biomolecules and in vitro biochemical diagnosis.
-
Colloids and Surfaces A: Physicochemical and Engineering Aspects 482 68-78 2015年10月5日© 2015 Elsevier B.V. Polystyrene latex particles with controlled size were prepared by polymerization of oil-in-water (O/W) emulsion styrene droplets obtained through the phase inversion temperature (PIT) emulsification using amphiphilic comb-like block polymers, polystyrene-b-poly[oligo(ethylene glycol) methyl ether methacrylate] (PStn-b-POEGMAm-Cl). PStn-b-POEGMAm-Cl block polymers were synthesized by sequential atom transfer radical polymerization (ATRP) of St and OEGMA. The interfacial properties of PStn-b-POEGMAm-Cl in aqueous media were investigated by means of surface tension measurement, fluorescence probe technique, and transmittance measurement. The length of hydrophobic PSt block chain was found to affect the critical micelle concentration, the micelle aggregation number, and the cloud point. O/W emulsions were obtained through the PIT process using PStn-b-POEGMAm-Cl as a surfactant by lowering the temperature of emulsions below the PIT in an ice bath. PSt particles with precisely controlled size in a range between 30 and 120nm were successfully prepared by a free radical polymerization of St droplets initiated by the water- or oil-soluble initiators. FE-SEM observation revealed that the morphology of polystyrene particles was found to depend on the relative PSt chain length of PStn-b-POEGMAm-Cl.
-
COLLOIDS AND SURFACES B-BIOINTERFACES 29(1) 53-65 2003年5月The adsorption of anti-a-feto protein (anti-AFP) onto polystyrene-core-poly(N-isopropylacrylamide)-shell particles was investigated as a function of temperature, pH, and salinity. The influence of various physicochemical parameters onto the colloidal and surface properties of such stimuli-responsive particles was first studied. Then, the adsorption of anti-AFP antibody was investigated in order to point out the driving forces involved in the adsorption process. The effects of salinity, pH, and temperature demonstrated that adsorption was mainly governed by electrostatic interactions. In addition, the adsorption isotherms were analyzed on the basis of a Langmuir model leading to the determination of affinity constants. Finally, based on this adsorption study, various covalent coupling methodologies of the antibody were compared by using two different copolymers as a reactive spacer arm. The amount of chemically grafted antibody was obtained after performing the desorption step (by lowering the temperature, changing the pH, or raising ionic strength). The grafted quantity of antibody was found to be related to the adsorbed amount as a function of pH and ionic strength. (C) 2002 Elsevier Science B.V. All rights reserved.
Works(作品等)
2共同研究・競争的資金等の研究課題
6-
日本学術振興会 科学研究費助成事業 2021年4月 - 2024年3月
-
日本学術振興会 科学研究費助成事業 2018年4月 - 2021年3月
-
日本学術振興会 科学研究費助成事業 2001年 - 2002年
-
日本学術振興会 科学研究費助成事業 1998年 - 1999年