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Novel DNA–lipid complexes carrying pyrene and anthracene were prepared by substituting sodium counter cations with cationic amphiphilic lipids, namely lipid(PY) and lipid(Anth), in which the actual mole ratios of phosphate to lipid were 1:1.11 and 1:1.03, respectively. DNA–lipid(PY) and DNA–lipid(Anth) complexes were soluble in common organic solvents including CHCl3, CH2Cl2, methanol and ethanol, while insoluble in THF, toluene, and aqueous solutions. CD spectroscopy revealed that DNA–lipid(PY) and DNA–lipid(Anth) complexes took a predominantly double helical structure in methanol and that the helical structure was fairly stable against heating. The solution of DNA–lipid(PY) complex emitted fluorescence in 27.8% quantum yield, which were higher than that of the corresponding lipid(PY) (16.8%), while the fluorescence quantum yields of the solution of DNA–lipid(Anth) (45.4%) was lower than that of the lipid(Anth) (53.0%). The onset temperatures of weight loss of DNA–lipid(PY) and DNA–lipid(Anth) were both 220 °C according to TGA in air.

Optical resolution with membranes derived from marine polymersNovel polyion-lipid complexes were prepared from quaterinized chitosan (QCh), which was a derivative of marine (natural) polymer, and three types of anionic amphiphile, such as sodium 1-dodecanesulfate (C12SNa), sodium 1-tetradecanesulfate (C14SNa), and sodium 1-hexadecanesulfate (C16SNa). Those complexes gave durable self-standing membranes. The QCh-lipid complex membranes prepared in the present study showed chiral separation ability; in other words, they selectively transported L-Lys from racemic mixture of Lys adopting a concentration gradient as a driving force for membrane transport. Permselectivity of QCh-C12S membrane toward L-Lys was determined to be 3.31 under the concentration difference of 1.0 × 10−3 mol dm−3. From transport experiments and adsorption studies, it was revealed that the permselectivity was dominantly determined by diffusivity selectivity. It is expected that the present study would open a door to novel materials.

A novel DNA―lipid complex carrying carbazole (Cz) moieties was prepared by substituting the sodium counter cation with cationic lipid, namely lipid(2Cz), in which the actual mole ratio of phosphate to lipid was 1:1.05. The DNA―lipid(2Cz) complex was soluble in common organic solvents including CHCl 3 , CH 2 Cl 2 , methanol, and ethanol, while insoluble in THF, toluene, and water. CD spectroscopy revealed that the DNA― lipid complex took a predominantly double helical structure in methanol and that the helical structure was fairly stable against heating. A solution of the DNA―lipid(2Cz) complex emitted fluorescence in 40.0% quantum yield, which was lower than that of the corresponding lipid(2Cz) (76%). The cyclic voltammograms of the complex indicated that the oxidation potential of DNA― lipid(2Cz) was 0.65 V. The onset temperature of weight loss of the DNA―lipid complex is 230 °C according to TGA in air.

Novel DNA-lipid complexes carrying azobenzene moieties were prepared by substituting sodium counter cations with cationic amphiphilic lipids, namely lipid(AZO) and lipid(diAZO), in which the actual molar ratios of phosphate to lipid were 1:1.05 and 1:1.02, respectively. DNA-lipid(AZO) and DNA-lipid(diAZO) complexes were soluble in common organic solvents including CHCl3, CH2Cl2, methanol, and ethanol, while insoluble in THF, toluene, and water. CD spectroscopy revealed that DNA-lipid(AZO) and DNA-lipid(diAZO) complexes took a predominantly double helical structure in methanol and CHCl3 and that the helical structure was fairly stable against heating. The trans-azobenzene of the DNA-lipid complexes in the side chain isomerized into cis upon UV irradiation, while the helical conformation of DNA backbone hardly changed. The cis-azobenzene moiety reisomerized into trans upon visible-light irradiation, but they did not recover completely the original geometry of azobenzene moieties in the side chain. Both DNA-lipid(AZO) and DNA-lipid(diAZO) exhibited lyotropic LC properties. The onset temperatures of weight loss of DNA-lipid(AZO) and DNA-lipid(diAZO) were both 226 °C according to TGA in air.

Novel DNA–lipid complexes carrying carbazole and triphenylamine moieties were prepared by substituting the sodium counter cation with cationic amphiphilic lipids, namely lipid(Cz) and lipid(TPA), in which the actual mole ratios of phosphate to lipid were 1:1.10 and 1:0.83, respectively. The DNA–lipid(Cz) and DNA–lipid(TPA) complexes were soluble in common organic solvents including CHCl 3 , CH 2 Cl 2 , methanol and ethanol, while insoluble in THF, toluene, and aqueous solutions. CD spectroscopy revealed that the DNA–lipid complexes took a predominantly double helical structure in CHCl 3 and methanol and that the helical structure was fairly stable against heating. Solutions of DNA–lipid(Cz) and DNA–lipid(TPA) complexes emitted fluorescence in 5.7 and 76.4% quantum yields, which were higher than those of the corresponding lipid(Cz) and lipid(TPA) (4.4 and 55.3%). The cyclic voltammograms of the complexes indicated that the oxidation potentials of DNA–lipid(Cz) and DNA–lipid(TPA) were 0.95 and 0.85 V, respectively. The onset temperatures of weight loss of the DNA–lipid complexes were both 220 °C according to TGA in air.

Novel polyion complex membranes were prepared from DNA-Na and poly(4-vinylbenzyl)trimethylammonium chloride (PVBTMAC). The newly prepared DNA-PVBTMA polyion complex membranes showed a chiral separation ability toward racemic lysine (Lys) mixtures. The membranes transported D-Lys in preference to the corresponding L-isomer of Lys. The permselectivity toward the D-isomer reached 1.26. From transport experiments and adsorption studies, it was revealed that the permselectivity was mainly determined by diffusivity selectivity.

Novel polyion complex membrane was prepared from DNA-Na and polydiallyldimethylammonium chloride (PDADMAC). The newly prepared DNA-PDADMA polyion complex membrane showed a chiral separation ability, which was measured by using various racemic amino acids as model racemic mixtures. The membrane transported the L-isomer of Trp or Phe in preference to the corresponding D-isomer and permselectivities toward the L-isomer were determined to be 1.26 for L-Trp and 1.25 for L-Phe, respectively. From adsorption experiments, it was revealed that the permselectivity was mainly governed by adsorption selectivity.

The effect of solvents or chelating agents on polycondensation reactions was investigated. Solution polycondensation of nylon 66 salt was enhanced in ketone solvents such as methyl acetophenone or diisobutyl ketone, a polyamide of high molecular weight being formed. Room-temperature polycondensation of N-(hydroxyethyl)-β-alanine ester or 4-thio-e-aminocaproate was influenced by solvents and chelating agents with functional groups, and the rate or the equilibrium of the reaction were apparently changed. Interfacial polycondensation of m-phenylenediamine and isophthaloyl chloride yielded aromatic polyamide having a high molecular weight in ketone solvents such as cyclohexanone or methyl acetophenone. It was found that isophthaloyl chloride reacted slowly with cyclohexanone to yield quantitatively isophthalic acid. These effects of solvents or chelating reagents on polycondensation reactions might be attributed to the reactivity change of functional group during polycondensation reactions.

種々のスピロピラン化合物をインターカレートしたDNA-脂質複合体の薄膜に紫外-可視光照射した場合のホトクロミック効果を検討した. スピロピラン化合物の種類によってDNA膜のホトクロミック現象は大きく異なり, ナフタレン環を有するスピロオキサジンは非常に速いホトクロミック現象を示した. またホトクロミック現象には脂質の構造が及ぼす影響も大きいことを見いだした. おそらくスピロピランの構造変化に対する脂質の立体的効果によるものと思われる.

Hydrocarbon elastomers bearing polar functional groups at their chain ends or at both chain ends can greatly reduce the hysteresis of a tire compound and thus improve rolling resistance and fuel economy. These functional elastomers can be easily prepared via living anionic polymerization techniques. However, to prepare an elastomer with more than two functional groups in the same polymer chain, especially along the polymer backbone, a more elaborate and costly process is normally required. To facilitate the in-chain functionalization of tire elastomers, we have developed a series of new styrenic and Eφ-methyl styrenic monomers containing various amine functional groups starting from relatively inexpensive divinylbenzene or diisopropenylbenzene. These functional monomers allow one to prepare novel functionalized tire elastomers containing any number of amine functional groups at any location within the polymer chain via anionic co-polymerization with any conjugated diene or styrene monomer. More importantly, polymerization can be carried out over a wide temperature range, even at the elevated temperatures normally used for commercial production of tire elastomers. The preparation of these new functional monomers and their co-polymerization with diene monomers will be presented. The physical properties of these novel functionalized polymers will be compared to their conventionally prepared counterparts in carbon black and silica filled compounds.

Purified deoxyribonucleic acid (DNA) derived from salmon and scallop sperm has demonstrated excellent passive and active optical properties. Characterization of the optical and electromagnetic properties of DNA suggests suitability for photonic applications. One of interesting features of DNA we discovered was an intercalation of aromatic compounds into stacked layers within the double helix of DNA molecules. We found that various optical dyes inserted into the double helix of DNA molecules rendered active optical waveguide materials with excellent nonlinear optical properties. Our research included the investigation of DNA for use as an optical waveguide material as well as intercalation of fluorescent dyes, photochromic dyes, nonlinear optic chromophores, two photon dyes and rare earth compounds into DNA for use as a nonlinear optical material.

Our research in nonlinear optic (NLO) polymer-based electro-optic (EO) modulators has centered on optimizing device performance through the using of polymer cladding layers with higher relative conductivities than the NLO core material. We have demonstrated as much as a 10 times increase in the effective EO coefficient of electrode poled, guest/host NLO polymers, compared to using passive polymer claddings. We have achieved the lowest poling voltage to date for maximum EO coefficient, 300 V, for a two-layer waveguide structure consisting of a 2 μm thick NLO polymer layer and 2 μm thick conductive cladding layer. Optimized polymer cladding materials posessing the desired optical and electromagnetic properties we find need to be balanced with materials processability. In addition to the conventional polymer materials under investigation, a novel material, deoxyribonucleic acid (DNA), derived from salmon sperm, has shown promise in providing both the desired optical and electromagnetic properties, as well as...

鮭あるいはホタテ貝などの海洋生物から由来するデオキシリボ核酸 (DNA) に各種の光学的機能を有する色素をインターカレートすることによってDNAを, 光学機能を有する薄膜材料に転換する研究を行った. 有機非線形光学色素をDNA-脂質複合体中にインターカレートさせた膜の蛍光強度は色素単独の場合に比べて100～150倍も大きく増大することを見いだした. DNA-脂質複合体の中にインターカレートされる有機色素は専ら核酸塩基層の中でA-T層に入り, C-G層には入りにくいことを, 合成DNAを用いて明らかにした. DMASDB色素をインターカレートしたDNA-脂質膜のレーザー発振機能を評価して膜の断面方向から強いレーザー発振が起こり, 新しいフィルムレーザーとなることを見いだした. さらに, スピロピラン色素をインターカレートしたDNA-脂質複合体は紫外-可視光の繰返し試験で300回以上の再現性があることを確認して, 新しい光記憶膜となることを見いだした. DNAとポリ (アニリン) などの導電性高分子とは任意の比率で混合して均一な薄膜を形成して, 新しい導電性材料となることを見いだした.

サケの白子から由来する高純度DNAをフィルム化するに当たり, DNAと脂質複合体の合成を行う時に用いる各種の脂質の種類によって, 得られたDNAフィルムの力学的性質が大きく変化することを見いだした. 得られたフィルムの力学的特性はC-12に脂質がもっとも良好であった. また, これらのDNA-脂質複合体フィルムの吸湿性も脂質の種類によって大きく変化することを明らかにした.

*Reprinted from Functional Monomers and Polymers, 2nd ed.; Takemoto, K., Ottenbrite, R.M., Kamachi, M., Eds.; Marcel Dekker, Inc.: New York; 1997, 387–431.

Series of polyelectrolyte−surfactant complexes, DNA−cationic surfactant complexes (cetyltrimethylammonium, cetylpyridinium, and cetylbenzyldimethylammonium), and their self-assembled bulk film materials were prepared on a large scale. Circular dichroism (CD) analysis indicated that the right-handed double helix structure of DNA was retained in these bulk film materials. TGA analysis suggested that 4 molecules of water were required to retain the B-type conformation of the DNA helix in the self-assembled bulk film materials. In addition, it revealed that DNA and the DNA−surfactant complex film materials were thermostable up to as high as 180 °C. Thermodynamical analysis indicated that these film materials were thermo-extensive over a temperature range from 100 to 148 °C. The DNA conformation in the supramolecular complex films can be reversibly tuned by changing the environmental humidity. Film formation was found to occur by self-assembly and self-organization with evaporation of solvent molecules. Variou...

Styrene (St) was polymerized in mixed solvents of ethanol/n-hexane as good-poor solvents for matrix polymers such as poly(methylvinylether) (PMVE) in solution. Conformational change of the matrix polymer from extended to random coil structures provided different dimensional fields for in-situ polymerization of St, resulting in control of particle size and distribution of poly(St) (PSt). Neutron scattering of St solution suggested the formation of St monomer clusters in matrix polymer solution.

A novel proton-conducting polymer, sulfopropylated poly(benzimidazole) (PBI-PS), was synthesized by the ring-opening reaction of 1,3-propanesultone onto the reactive N–H groups of PBI. The equilibrium water uptake of PBI-PS films increased with increases in the relative humidity and sulfoalkylation level, and the maximum value of water uptake reached 11.3 H 2 O per sulfonic acid group (H 2 O/SO 3 H) at 90% R.H. and room temperature. The hydrous PBI-PS films showed a high proton conductivity of the order of 10 −3 S cm −1 in the temperature range from 20°C to 140°C, which is superior to that of conventional proton-conducting polymers.

Incorporation of functional (e.g. thermally responsive) polyelectrolytes (PE) into inherently conducting polymers, such as polypyrrole (PPy), has been investigated. The materials produced were studied using cyclic voltammetry. Conductivity and equilibrium water content were determined as were the dehydration/rehydration profiles. Lower critical solution temperature (LCST) measurements and UV-visible spectroscopy were also carried out. It was found that the 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) content in polyelectrolytes affects the nature of the PPy–PE produced. As the AMPS content increases, the electrochemical and electrical properties improved. Higher AMPS content also resulted in decreasing water content and a lower rate of dehydration and rehydration.

We synthesized thermally stable proton-conducting polymers composed of poly(benzimidazole) (PBI) and strong acids. PBI films were doped with strong acids such as phosphoric, sulfuric, and hydrochloric acid by immersing them into a mixed solution of strong acid and methanol. We found that the PBI films and strong acids formed polymer complexes because they showed the acid–base or the hydrogen bonding interactions between imidazole groups of PBI and acid molecules. The PBI/H 3 PO 4 complexes were thermally stable up to 500°C, and the proton conductivity of anhydrous complexes reached 10 −5 S cm −1 at 160°C.

New proton conducting polymers based on poly(silamine) (PSA) were synthesized by complexing the polymer and H 3 PO 4 , and the proton conduction of these materials was investigated. The PSA/H 3 PO 4 complex was thermally stable up to 200°C, as indicated by TG/DTA analysis. The conductivity of 10 −5 S cm −1 was observed at 160°C for anhydrous PSA/H 3 PO 4 complexes with a concentration of 0.8 H 3 PO 4 per repeat unit. The carrier ion was proven to be proton on the basis of the H/D isotope effect on conductivity for PSA/H 3 PO 4 and PSA/D 3 PO 4 complexes.

To investigate the influence of molecular architecture of poly(acrylic acid) (PAAc)-graft-poly(N,N-dimethylacrylamide) (PDMAAm) (PAAc-g-PDMAAm) on its solution properties in aqueous media, graft copolymers were synthesized by free radical copolymerization of AAc with PDMAAm macromonomer. PAAc-g-PDMAAms were water-soluble at lower temperatures, while they showed a liquid−liquid phase separation from water above the characteristic transition temperatures. The phase transition behavior was affected by the copolymer compositions and pH of the solution. Below the transition temperature, hydrogen-bonding formation between AAc and DMAAm units was observed in the PAAc-g-PDMAAm aqueous solution by FT-IR−ATR measurement. Graft copolymers were thus formed spherical associates with a diameter of ca. 150 nm estimated from the dynamic light scattering measurement. At higher temperatures, the dehydrated regions and the weak dehydration of the PDMAAm chains induced cooperatively the hydrophobic aggregation, resulting in ...

Poly(6-(acryloyloxymethyl)uracil) (PAU) having uracil moieties as side chains was synthesized by ordinary radical polymerization to investigate its molecular discrimination for soluble nucleic acid bases in terms of phase transition changes of the polymer aqueous solution. PAU itself in distilled water formed a precipitate due to the polymer complexes at lower temperatures and changed drastically to become water-soluble above a characteristic transition temperature, showing an upper critical solution temperature (UCST). The phase transition behavior was shifted to lower temperatures with increasing concentrations of adenosine (Ado), which is the complementary nucleic acid base to uracil moiety. Ado might interact specifically with uracil moieties of the polymers, preventing the formation of the polymer complex at lower temperatures. Such changes were not observed in PAU aqueous solution containing guanosine (Guo). Additions of Ado and Guo exerted different effects to phase transition changes of the polymer. Moreover, addition of poly(adenylic acid) (Poly(A)) lowered remarkably the transition behavior of PAU solution as compared with Ado addition. It was conceivable that PAU and Poly(A) formed stable polymer complexes, assuming soluble states in even cold water. PAU changed its phase-transition temperature in response to species of the additive materials, demonstrating the specific molecular discrimination in aqueous milieu.

Super-fine particles of sub-micron sizes of poly(styrene- co -methyl methacrylate) were synthesized by dispersion copolymerization in an ethanol–hexane mixture in the presence of a matrix polymer of poly(methyl vinyl ether). The effects of the matrix polymer, monomer feed ratio, ethanol-to-hexane ratio, and polymerization temperature were investigated for particle size and size distribution by SEM, molecular weights, and polydispersity index by GPC. Solubility of the matrix polymer in the medium to provide excluded free volumes in the polymer solution is plausibly the main attribute of controlling the morphology of the matrix polymer that directly affects the particle size and distribution in addition to its steric barrier effect. Particles with a spherical shape of 1–5 μm were formed. The average molecular weights became larger in smaller particles. The copolymers in bulk and solution (without PMVE) were aggregated into a big lump. Increasing the styrene feed decreased the particle sizes with a narrow size distribution. Increasing the ethanol-to-hexane ratio decreased the copolymer particle sizes. The polymerization temperature range for the copolymerization was 50–64°C. The reaction did not occur when polymerizing at 40°C and the agglomerated particles were produced at a 73°C reaction temperature. This article describes the effects of each parameter on the particle size and distribution. Solution and bulk copolymerizations were also carried out to compare the particle size and composition of the copolymer.

Novel Langmuir–Blodgett (LB) films were fabricated from mixed monolayers containing stearic acid and various poly(3-alkylthiophene)s, which contained almost 100% head-to-tail couplings. The LB films exhibited well-defined layered structures and self-organized properties of the regioregular polymers. The molecular organization, the layered structures and the electrical properties depended on the regioregularity and the length of the alkyl side chains of the regioregular polymers. The regioregular polymers have considerably improved the electrical conductivity and the third-order optical non-linearity.

We synthesized an optically active regioregular poly(3-substituted thiophene), head-to-tail poly(3-[2-((S)-2-methylbutoxy)ethyl]thiophene) (HT-P(S)MBET), according to a modified Rieke method. The HT-P(S)MBET was an optically active polymer with the HT linkage of larger than 93%, as estimated by NMR. The mixed monolayers of the polymer and stearic acid (SA) were found to be stable at the air–water interface and could be deposited onto solid substrates as Y-type films by the vertical dipping method. These Langmuir–Blodgett (LB) films exhibited well-defined layer structures and unique optical properties. The electrical conductivities of the LB films with and without doping of SbCl5 were about 10−1 and 10−5 S/cm, respectively.

In order to obtain a thermo-responsive polymer which exhibits hydration change in response to foreign optically active compounds as external stimuli, binary copolymers composed of N-(S)-sec-butylacrylamide ((S)-sec-BAAm) and N-isopropylacrylamide (IPAAm) were synthesized by ordinary radical copolymerization. Turbidity of the polymer aqueous solutions containing various concentrations of tryptophan (Trp) isomer was measured to determine lower critical solution temperature (LCST) values. Poly((S)-sec-BAAm-co-IPAAm) having 50 mol% of (S)-sec-BAAm content was a water-soluble polymer which exhibited LCST at 23.1°C. The LCST of the copolymer aqueous solution in the presence of l -Trp was shifted remarkably to 34.5°C, while that in the presence of d -Trp was 28.7°C. On the other hand, a racemic (R,S)-sec-BAAm-containing copolymer showed the same phase transition temperatures in the presence of d - and l -Trp. There was no influence of Trp concentration on LCST for poly(N-isopropylacrylamide) aqueous solution. It was clear that the optically active (S)-sec-BAAm in the copolymer stereospecifically interacted with l -Trp, showing a relatively higher LCST value. The LCSTs of the copolymer increased in response to increasing concentration of l -Trp. It was found that the introduction of the optically active moieties into the copolymer chains resulted in the phase-transition behavior changes of the copolymers in response to the aromatic amino acids in aqueous solution. The results, therefore, revealed that the thermo-responsive copolymer with optically active moieties demonstrated chiral recognition to the enantiomers.

A [2]catenane consisting of a π-electron-accepting tetracationic cyclophane of cyclobis(4,4′-azopyridinium-p-phenylene) and a π-electron-donating macrocyclic polyether of bis-p-phenylene-34-crown-10 was synthesized via a template-directed synthesis in 68% yield. The [2]catenane exhibited charge transfer bands with λmax=526 nm and 566 nm in CH3CN. A precursor of the cyclophane, bis[4-(4-pyridylazo)pyridinium], spontaneously formed a charge transfer complex with the macrocyclic polyether. The investigation of the charge transfer complex using UV-visible and 1H NMR spectroscopy revealed that the complex had a pseudo-rotaxane structure with a stability constant (Ka) of 120 dm3 mol-1 at 25°C in CH3CN. The highly efficient catenation of 68% yield was attributable to cooperative self-assembling processes derived from the strongly π-electron deficient 4,4′-azopyridinium and 4-(4-pyridylazo)pyridinium units. These results suggested that there was a new formation mechanism of the catenated structure through preorganization of the charge transfer complex.

Poly(oxy-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene) (PEEK) and poly(4-phenoxybenzoyl-1,4-phenylene, Poly-X 2000) (PPBP), were sulfonated with sulfuric acid by incorporating sulfonic acid moieties in order to convert these polymers to proton-conducting polymers. The sulfonated polymers containing 65 mol% sulfonic acid showed a high proton-conductivity of 10−2–10−4 S cm−1 at room temperature. Sulfonated PPBP showed a much higher and more stable proton conductivity than sulfonated PEEK, which is in agreement with the strong water absorption of the former compound.

Copolymers (IABb) composed of N-isopropylacrylamide (I), N-(3-dimethylaminopropyl)-acrylamide (A), 3-acrylamidophenylboronic acid (B), and a hydrophobic comonomer, n-butyl methacrylate (b), were synthesized as cell culture substrata since we previously learned that bovine aortic endothelial cells (BAECs) cultured on the phenylboronic acid-containing copolymer (IAB) differentiated into capillary structures after 26 days culture. The synthesized IABb copo ymers contained higher boron and amine moieties than the IAB copolymer. The results of the dynamic contact angle measurement revealed that IABb copolymer-coated surfaces showed a relatively hydrophobic nature, changing to hydrophilic in response to the aqueous environment. BAECs cultured on the copolymer substrata developed into capillary networks after 7 days. This is probably due to the enrichment of boron and amine segments in the vicinity of the hydrophilic copolymer surface, enhancing more pronounced interaction of boronates with cell membrane glycocalyx. The introduction of n-butyl methacrylate into the polymers might enhance the diffusion of the hydrophobic segments to the bulk polymers and the concentration of relatively hydrophilic segments at the outermost polymer surfaces by contact with water. A copolymer (IAP) without boronic acid groups was also prepared using N-phenylacrylamide (P) as a comonomer instead of 3-acrylamidophenylboronic acid in the IAB copolymer to investigate the effect of boronic acid moieties on the capillary formation of the cultured cells. Although the endothelial cells seeded on the copolymer without boronic acid groups adhered during the early culture period, these cells showed neither proliferation nor differentiation and detached from the surface after 13 days. These results strongly support the opinion that the phenylboronic acid groups in the copolymers are responsible for the specific induction of tissue formation of BAECs through the interaction with glycoconjugates on the cell membranes.

The effect of NaCl concentration on the redox potential of α-ferrocenylundecyl-ω-hydroxy-polyoxyethylene (FPEG) micelles has been studied in aqueous solutions. With increasing NaCl concentration, the anodic half-wave potentials E 1 2 of cyclic voltammograms of the aqueous solutions shift to higher potential, and the peak currents of the cyclic voltammograms decrease. The results are discussed in terms of thermodynamics of the micelle formation. An equation which interprets the correlation between the E 1 2 , the salt concentration, diffusion coefficient of the micelle DM, and the aggregation number m, has been derived. The changes in DM and m with NaCl concentration do not explain the change in the value of E 1 2 . The decrease in the equilibrium constant for the micelle-disruption Kd with increasing NaCl concentration affects the redox-potential of the FPEG micellar solutions.

Optical resolutions through self-assembled membranes were carried out by using poly(pyrrole) (PPy) doped with chiral anionic polymers such as poly(L-glutamic acid) or dextran sulfonic acid. Preferential permeations of either L- or D-Tryptophane occurred through the PPy membranes.

Organic photochrome azopyridiniums were systematically prepared by quaternizing azopyridines with either dimethyl sulfate or 1,3-propanesultone. Photochemical, electrochemical, and photoelectrochemical studies on the azopyridiniums as methyl sulfate, hexafluorophosphate, and zwitterionic compounds were carried out in aprotic solvents and in aqueous solutions. The azopyridiniums, which have 3-located quaternized nitrogens to the azo group, exhibited photochemical activity of trans cis isomerization. Quaternization of the pyridine moiety decreased the photochemical conversion between the trans and cis forms. The photochromic properties were influenced by an electronic effect of quaternized nitrogens and an electrostatic interaction of counter anions. In electrochemical studies, new redox-active azopyridiniums were found by using cyclic voltammetry and an electrochemical technique coupled with UV-vis spectroscopy. By the quaternization of azopyridines, the formal reduction potentials were shifted to a positi...

The dissolved states of redox-active non-ionic surfactant (FPEG) in the swollen state of N-isopropyl acrylamide (NIPA) hydrogel have been studied by using a gel-modified electrode. The pronounced decrease in the peak current and the negative shift in the formal potential of CV at the gel-modified electrode, as compared with the normal GC electrode, was observed in the micelle-solution; this indicates that the diffusive FPEG molecules which form the micelle hardly penetrate into the NIPA gel. This result suggests that there exists an interaction between FPEG molecules and the NIPA gel in the vicinity of the surface of the NIPA gel in the micelle-solution. However, this also indicates that a small amount of FPEG molecules which can form micelles exist in the NIPA gel.

A new tetracationic cyclophane, cyclobis(4,4′-azopyridinium-p-phenylene) (2.4PF6), was synthesized via template-directed synthesis and characterized by MS and NMR spectroscopy. For the preparation of π-electron-deficient 2.4PF6, the use of π-electron-rich templates such as 1,4-bis[2-(2-hydroxyethoxy)ethoxy]-benzene (4) and 1,5-bis[2-(2-hydroxyethoxy)ethoxy]naphthalene (5) enhanced the cyclophane formation in 17 and 19% yields, respectively. 1H NMR spectra of the reaction mixture revealed that the cyclophane precursor 1.2PF6 formed supramolecular assembling complexes with hydroquinone derivatives 4 and 5 before the ring formation. The intermolecular charge transfer interaction and the stability constants (Ka) of complexes generated between the electron-acceptor 2.4PF6 and electron-donors 1,4-dimethoxybenzene 3, 4, and 5 were evaluated using UV-vis. spectroscopy and spectroscopic titration. The absorption bands attributable to CT interactions were centred at 580 nm for 3, 635 nm for 4, and 646 nm for 5, with stability constants of 17 ± 2, 2100 ± 200, and 2400 ± 300, respectively.

Conductive Langmuir-Blodgett (LB) films were fabricated from mixed monolayers containing structurally homogeneous poly (3-hexylthiophene) and stearic acid in different molar ratios. The structure of these mixed LB films was probed by visible absorption and X-ray diffraction measurements. These regioregular polymers containing almost 100% head-to-tail couplings showed the self-organized properties and affected the molecular structure in the LB films. Conductivities of the LB films doped with strong oxidizing agents were dramatically improved due to their well-defined polymer structure and were in the range of 102-101 S cm−1.

The in-situ polymerization of acrylamide in solutions of poly(styrene) (PSt) was carried out by anionic polymerization to form Nylon 3 in PSt as micro-composites in which Nylon 3 was dispersed as fine particles. Copolymers of styrene (St) and 4-vinylpyridine (4-VPy) were used as matrix polymers in order to improve a compatibility between the in-situ formed Nylon 3 and matrix polymer through hydrogen-bonding. These micro-composites showed great improvement of mechanical properties owing to reinforcement by ultra-fine particles of Nylon 3. Especially, the micro-composite derived from poly(St-co-4-VPy) showed excellent improvements of mechanical properties owing to the hydrogen bonding interactions between Nylon 3 and 4-VPy.

High-performance composites of vinylpyridine-styrene copolymers and polyamic acid (PAA) were prepared by the so-called ‘in situ polymerization method’. Poly(4-vinylpyridine-co-styrene) (P4VPy-St) and poly(2-vinyl pyridine-co-styrene) (P2VPy-St) were used as flexible matrix polymers. A molecular composite could be obtained from a polymer pair having an attractive interaction such as a coulombic interaction. Their morphologies were observed by scanning electron microscopy (SEM); mechanical properties of these composites were studied by tensile tests. The PAA content dependence of tensile strength for the composite films obtained by the in situ polymerization method was investigated. The tensile strength of the resulting composite was about 1.5 times higher than that of PAA film. The coulombic interaction between the pyridine moiety in the matrix copolymer and resulting PAA enhanced both the miscibility and mechanical properties of the composites. Furthermore, a polyimide (PI) structure was formed by stepwise heat-treatment and greatly enhanced the tensile strength of the composite films.

Glucose-Sensitive Lower Critical Solution Temperature Changes of Copolymers Composed of N -Isopropylacrylamide and Phenylboronic Acid Moieties

Conductive ultra thin films were fabricated from mixed monolayers containing stearic acid and structurally homogeneous poly (3-hexyl-thiophene), which had almost 100% head-to-tail couplings with a Mw of 8100 ( M w M n =1.5) as estimated by 1H NMR, 13C NMR, and gel permeation chromatography. The mixed monolayers were found to be stable at the air-water interface and could be readily deposited onto solid substrates as Y-type films by the vertical lifting method. These Langmuir-Blodgett (LB) films exhibited well-defined layered structures as determined by UV-Vis absorption and X-ray diffraction measurements. The conductivity of the mixed LB films doped with NOPF6 was in the range of 50–100 S cm−1 and was 50- to 100-fold higher than that of the mixed LB films using poly(3-hexylthiophene) synthesized by the usual chemical oxidation with FeCl3.

Electrochemical studies of a nonionic surfactant, α-(ferrocenylundecyl)-ω-hydroxy-oligo(ethylene oxide) (FPEG), have been conducted in 0.16 M NaCl aqueous solution at a glassy carbon electrode. The correlation between electrochemical responses and dissolved states has been examined in detail. Cyclic voltammograms (v = 10 mV/s) of the FPEG solutions change with the concentration; below the critical micelle concentration (cmc), the voltammetric shape is of a typical surface-confined species, while above the cmc the diffusion-controlled waves are superimposed at the cathodic side of the surface waves, and far above the cmc the voltammetric shape is of a typical diffusion-controlled species. FPEG in the aqueous solutions adsorbs onto the glassy carbon electrode surface to form a monolayer because of its surface activity. The adsorption isotherm has been represented by the Frumkin isotherm, which includes the repulsive interaction between the adsorbed FPEG molecules. Above the cmc, FPEG forms micelles. Chronoa...