Yuko Kado

Immobilization of a fluorinated polymer Langmuir–Blodgett monolayer on a solid substrate for surface nanocoating

N-(1H,1H-Pentadecafluorooctyl)methacrylamide copolymers containing carboxyl groups as reactive moieties were prepared to explore a novel method for surface nanocoating materials. All the copolymers form stable monolayers on a water surface. Those monolayers can be transferred onto solid substrates, thereby creating Y-type Langmuir–Blodgett (LB) films. Contact angle and critical surface tension measurements were used to characterize the surfaces of the copolymer LB films. The copolymer monolayer can be immobilized onto solid substrates that are modified with an aminosilane coupling agent through heat treatment. We monitored the immobilization process using water contact angle and X-ray photoelectron spectroscopy (XPS) measurements. The immobilized monolayer on SiO2 surface yields a smooth surface at the nanoscale, which was observed using atomic force microscopy.

Surface modification using polymer Langmuir-Blodgett films

We describe a simple and effective approach to introduce a functional group into polymer film on a solid surface using reactive polymer LB films. N-dodecylacrylamide copolymers containing terminal amino groups in the side chains as the reactive moiety form a stable monolayer, and the monolayer was transferred onto a solid support to modify the solid surface using the Langmuir-Blodgett method. The transferred coatings were characterized with fluorescence, IR spectroscopies, and X-ray diffraction. The reactivity of the terminal amino group incorporated in the LB films was investigated in detail using fluorescein isothiocyanate (FITC) as a fluorescent probe. The chemical reaction between amino groups in the LB films and FITC in the bulk solution was completed within approximately 30 minutes and the chemical bond formation was confirmed by infrared spectroscopy. Furthermore, the fluorescent image of the multilayers reacted with FITC were observed with fluorescent microscopy. This method is effective for tailoring functional organic ultrathin films on solid substrates.

NANOSURFACE MODIFICATION USING REACTIVE LANGMUIR–BLODGETT FILMS

We describe a simple and effective approach to the introduction of a functional group into polymer nanofilms on the solid surface using reactive Langmuir–Blodgett films. N-Dodecylacrylamide copolymers containing a terminal amino group in the side chains as a reactive moiety form a stable monolayer on a water surface, and the monolayer was transferred onto a solid support with a transfer ratio of unity. The LB films were characterized by various spectroscopic methods. The reactivity of the terminal amino group incorporated in the LB films was investigated in detail using fluorescein isothiocyanate (FITC) as a fluorescent probe. The chemical reaction between the amino group in the LB films and FITC in the bulk solution was completed within approximately 30 min and the chemical bond formation was confirmed by FT-IR spectroscopy. Furthermore, the ability as a pH sensor was observed with fluorescent microscopy.

Nano-surface Modification Using Reactive Polymer Langmuir-Blodgett Films.

反応性高分子ラングミュア・ブロジェット (LB) 膜を作製し, より効果的かつ簡便に高分子薄膜に機能団を導入する方法を報告する. 反応性基として側鎖端末にアミノ基を有するN一ドデシルアクリルアミド共重合体は水面上で安定な単分子膜を形成し, LB法により固体基板上に積層された. このLB膜の構造は表面圧-面積等温線, X線回折 (XRD), フーリエ変換赤外分光法 (FT-IR) によって調査された. LB膜中のアミノ基の反応性は蛍光プローブとしてフルオレセインイソチオシアネート (HTC) を用いて詳細に検討した. 蛍光スペクトル測定から, LB膜中のアミノ基とFITCのイソチオシアニル基の反応は30分で完了し, LB膜内でも高い反応性を保持していることが実証された. また, これらの化学結合の形成はFT-IRにて確認した. HTCで修飾されたLB膜の発光強度を利用してpHセンサー能を調査したところ, pH5～9の間でよい応答性を示した. 同様の発光挙動は蛍光顕微鏡でも観察され, 視覚的にもそのセンサー能を確認することができた.