| 高分子 Vol.68 No.9 |
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特集 やわらかい微粒子
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| 展望 COVER STORY: Highlight Reviews |
| 高分子鎖の会合に基づくゲル微粒子の作製 Preparation of Gel-Particles Based on Association of Polymer Chains |
遊佐 真一 Shin-ichi YUSA |
| ＜要旨＞ ゲル微粒子は、ゲルと微粒子両方の性質をもつ大変ユニークな材料で、作製法の一つに高分子会合体内部の架橋が挙げられる。ゲル微粒子の架橋点は、通常のバルクゲルと同じ物理架橋と化学架橋がある。これまでにさまざまな架橋法でゲル微粒子が合成されている。本稿では「やわらかい微粒子」の作製法について、おもに架橋法にフォーカスして紹介する。 Keywords: Gel-Particles / Self-Association / Physical Cross-Linking / Chemical Cross-Linking / Random Copolymer / Block Copolymer / Hydrogel / Control Release |
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| ゲル微粒子ペーストのレオロジー Rheology of Microgel Pastes |
浦山 健治・南 沙央理 Kenji URAYAMA, Saori MINAMI |
| ＜要旨＞ 変形、相互貫入、体積変化を生じるゲル微粒子を高濃縮した懸濁液（ペースト）は、小さな外力には弾性応答し、降伏値以上の外力には粘性流動する塑性体の性質を示す。ペーストの弾性率、降伏値と流動挙動の支配因子、および温度応答性ゲル微粒子のペーストが示すコロイドゲル形成をともなう興味深いレオロジー挙動を紹介する。 Keywords: Microgel / Suspension / Rheology / Viscoelasticity / PNIPAM / Yield Fluid / Paste |
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| 柔らかい粒子の界面動電現象の理論 Theory of Electrokinetic Phenomena of Soft Particles |
大島 広行 Hiroyuki OHSHIMA |
| ＜要旨＞ 表面をソフトマターで覆われた粒子（柔らかい粒子）の界面動電現象は表面構造をもたない剛体粒子と異なる。剛体粒子では重要な意味をもつゼータ電位が柔らかい粒子では意味を失い、ドナン電位が本質的な役をする。以下、柔らかい粒子の界面動電現象理論の解説と最近の発展について述べる。 Keywords: Soft Particle / Electrokinetic Phenomena / Electrophoretic Mobility |
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| トピックス COVER STORY: Topics and Products |
| 両親媒性ランダム共重合体の自己組織化 Self-Assembly of Amphiphilic Random Copolymers |
寺島 崇矢 Takaya TERASHIMA |
| ＜要旨＞ We have recently developed controlled self-assembly systems of amphiphilic random copolymers bearing hydrophilic poly(ethylene glycol) (PEG) and hydrophobic alkyl or functional pendants to produce various nanostructure polymer materials in aqueous/organic media and solid/film state: size-controlled, core-crystalline, reverse, and multicompartment micelles, vesicles, hydrogels, and sub-10 nm microphase separation materials. Typically, random copolymers carrying PEG and dodecyl pendants induced chain folding via the self-assembly of the hydrophobic pendants in water to form uniform and thermoresponsive micelles. The size, aggregation number, and cloud point temperature were controlled by the composition and chain length of the polymers. Uniquely, the random copolymers further afforded self-sorting in water: self-recognition of identical copolymers via dynamic chain exchange in the presence of different copolymers. Owing to such unique self-sorting properties, ABA-triblock copolymers consisting of the amphiphilic random copolymer A segments gave self-healing and selectively adhesive hydrogels. Keywords: Amphiphilic Random Copolymer / Self-Assembly / Self-Sorting / Micelle / Vesicle / Hydrogel |
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| 生体内分子を利用して機能化する分子インプリントポリマーナノゲル Molecularly Imprinted Nanogels Functionalized by Interacting with Endogeneous Biomacromolecules In Situ |
北山 雄己哉・竹内 俊文 Yukiya KITAYAMA, Toshifumi TAKEUCHI |
| ＜要旨＞ Stealthiness is a criteria of nanocarriers for drug delivery systems (DDS). In this issue, we report molecularly imprinted polymer nanogels (MIP-NGs) acquiring stealth capability in situ via protein corona regulation as a novel nanocarrier for DDS. Molecular imprinting is a powerful approach to implement molecular recognition properties into polymer-based materials. Thus, MIP-NGs capable of dysopsonic protein recognition were prepared by molecular imprinting in a precipitation polymerization system. The fluorescent resonance energy transfer between fluorescein-labeled MIP-NGs and rhodamine-labeled albumin was observed in vivo, indicating that the protein corona was regulated in situ using intrinsic dysopsonic proteins. Thus MIP-NGs show prolonged blood circulation compared to the reference nanogels prepared without a molecular imprinting process. Due to the passive targeting property toward the tumor tissue of the MIP-NGs, we are currently developing MIP-NGs containing gold nanoparticles as a novel stealth radiation sensitizer. Keywords: Molecularly Imprinted Polymers / Nanogels / Stealth / Protein Corona / Drug Delivery / Molecular Recognition / Radiation Therapy |
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| 光から観たゲル微粒子 Gel Particles Seen by Light |
呉羽 拓真・柴山 充弘 Takuma KUREHA, Mitsuhiro SHIBAYAMA |
| ＜要旨＞ In this issue, we describe investigations of the dynamics for soft microgel suspensions by dynamic light scattering (DLS). In the diluted concentration region, the microgels were regarded as conventional colloidal particles. With increasing their concentration up to the intermediate concentration region, the dynamics was decomposed to the concentration fluctuations of the microgel inside as fast mode and the dynamics of large clusters formed by neighboring microgels as slow mode. At high concentration region, the slow mode became a long-time relaxation and the nonergodicity appeared, resulting in the formation of glass. The concentration fluctuations of the gel remained in the microgel paste. This result shows that DLS is a powerful tool to investigate the dynamics ranging from a dilute colloidal suspension to a microgel paste. Keywords: Dynamics Light Scattering / Microgels / Ergodicity / Speckle / Glass |
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| グローイングポリマー Polymer Science and I: A Personal Account |
| 「両利き」を目指して Be Ambidextrous |
山本 俊介 Shunsuke YAMAMOTO |
| ＜要旨＞ This is an essay by a researcher who just arrived at the UK as a visiting scholar reviewing his research career from undergraduate onwards. “Boundary”, “interface”, and a prefix “ambi- / amphi-” are important keywords throughout the story. |
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| 高分子科学最近の進歩 Front-Line Polymer Science |
| メカノクロミックポリマー Mechanochromic Polymers |
相良 剛光 Yoshimitsu SAGARA |
| ＜要旨＞ Polymers that change absorption and emission properties in response to mechanical stimuli are useful materials because such “mechanochromic polymers” can visualize mechanical stress applied to materials. Several mechanisms to induce changes in photophysical properties have been established so far. In this contribution, firstly, dye-doped polymers are briefly introduced as well as explanation on their working mechanism. Aggregation behavior of dyes in host-polymers plays a pivotal role to induce emission color changes upon tensile deformation. Secondly, polymers in which so-called “mechanophores” are covalently introduced are described. When mechanical stimuli are applied, weak bonds in mechanophores cleave to result in significant changes in absorption and emission properties. Finally, new mechanophore types that never require covalent bond scission for activation are also described. Keywords: Mechanochromic Polymers / Dye-Doped Polymers / Mechanophores / Supramolecular Mechanophores / Stimuli Responsive Materials / Luminescence |
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