Facile synthesis of polymers bearing cyclic carbonate structure through radical solution and precipitation polymerizations accompanied by concurrent carbon dioxide fixation

The radical polymerization of glycidyl methacrylate (GMA) was conducted under a carbon dioxide atmosphere (1 atm) in the presence of catalysts for the reaction of carbon dioxide and the oxirane group to afford the five‐membered cyclic carbonate group. The degrees of the carbon dioxide fixation depended on catalysts, concentration, and solvents. In solution reaction, the slower polymerizations resulted in faster carbon dioxide fixation, due to the faster carbon dioxide fixation to GMA than to oxirane moieties in polymers. When the polymerization was conducted in 1,4‐dioxane, which is a good solvent for polyGMA but a poor solvent for the analogous polymer bearing cyclic carbonate moieties, the resulting polymers were precipitated out as the progress of the polymerization and the carbon dioxide fixation. As a result, polymers could be isolated by simple filtration and rinsing with methanol. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3170–3176, 2009     

Dynamic properties of the polyethylene glycol molecules on the oscillating solid–liquid interface

The dynamic properties of polyethylene glycol (PEG) molecules on the solid–liquid interface oscillating at MHz were investigated using the quartz crystal microbalance (QCM). The number-average molecular weights (M_n) of the PEG molecules were systematically varied over 4 orders of magnitude. This study makes it clear that the series-resonant frequency shift, ΔF, of the QCM against the square root of the density–viscosity product of the PEG solution is linear and has the intercept. Moreover, systematical analysis reveals that the ΔF slope rapidly decreases with M_n and that the ΔF intercept becomes constant above 4.0 × 10³ g mol⁻¹. As a result, those reveal that the resonant length of the PEG molecule moving with the oscillating plate of 9 MHz is 54.2 Å. We also find that the behaviors of ΔF due to M_n are mainly caused by the length of the PEG molecule.     

Photoinduced Upregulation of Calcitonin Gene-Related Peptide in A549 Cells through HNO Release from a Hydrophilic Photocontrollable HNO Donor

Nitroxyl (HNO), a one-electron-reduced form of nitric oxide, has various biological activities, including a cardioprotective effect. Here, we first synthesized another, more hydrophilic photocontrollable HNO donor (3), which can release HNO in a spatially and temporally controlled manner, and then examined the properties of our series of compounds as practical HNO donors in a cellular system under photocontrol. We selected compound 2 as the preferred donor, and used it to show that calcitonin gene-related peptide (CGRP) can be upregulated in A549 cells via photocontrolled HNO release. This result demonstrates the suitability of this photocontrollable HNO donor for biological investigations.     

Enantioseparation of α‐hydroxy acids by chiral ligand exchange CE with a dual central metal ion system

Using two kinds of central metal ions in a background electrolyte, ligand exchange CE was investigated for the simultaneous enantioseparation of dl ‐malic, dl ‐tartaric, and dl ‐isocitric acids. Ligand exchange CE with 100 mM d ‐quinic acid as a chiral selector ligand and 10 mM Cu(II) ion as a central metal ion could enantioseparate dl ‐tartaric acid but not dl ‐malic acid or dl ‐isocitric acid. A dual central metal ion system containing 0.5 mM Al(III) ion in addition to 10 mM Cu(II) ion in the background electrolyte enabled the simultaneous enantioseparation of the three α‐hydroxy acids. These results suggest that the use of a dual central metal ion system can be useful for enantioseparation by ligand exchange CE.     

Improvement of focusing characteristics of a spiral plasmonic lens

We designed and fabricated a spiral plasmonic lens (PL) with multi-circular grooves to increase light intensity in a farfield region via the constructive interference of the light scattered by the multi-circular grooves. To compare the beam focusing characteristics of a spiral PL with multi-circular grooves with those of a conventional spiral PL, we simulated the electric field distribution of the PLs operating at a 405 nm wavelength. We confirmed that the light intensity increased about twofold at 0.75 μm above the PL surface owing to the effect of the multi-circular grooves. Furthermore, the circular grooves negligibly affect the full width at half-maximum of the focal spot, keeping the subwavelength size (～200 nm) of incident light.     

Melting point depression of ionic liquids confined in nanospaces

A new physical method was proposed to control the liquid properties of room temperature ionic liquids (RT-ILs) in combination with nanoporous materials; the melting point of ILs confined in nanopores remarkably decreases in proportion to the inverse of the pore size.     

Nanoscale patterning of two metals on silicon surfaces using an ABC triblock copolymer template

Patterning technologically important semiconductor interfaces with nanoscale metal films is important for applications such as metallic interconnects and sensing applications. Self-assembling block copolymer templates are utilized to pattern an aqueous metal reduction reaction, galvanic displacement, on silicon surfaces. Utilization of a triblock copolymer monolayer film, polystyrene-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) (PS-b-P2VP-b-PEO), with two blocks capable of selective transport of different metal complexes to the surface (PEO and P2VP), allows for chemical discrimination and nanoscale patterning. Different regions of the self-assembled structure discriminate between metal complexes at the silicon surface, at which time they undergo the spontaneous reaction at the interface. Gold deposition from gold(III) compounds such as HAuCl4(aq) in the presence of hydrofluoric acid mirrors the parent block copolymer core structure, whereas silver deposition from Ag(I) salts such as AgNO3(aq) does the opposite, localizing exclusively under the corona. By carrying out gold deposition first and silver second, sub-100-nm gold features surrounded by silver films can be produced. The chemical selectivity was extended to other metals, including copper, palladium, and platinum. The interfaces were characterized by a variety of methods, including scanning electron microscopy, scanning Auger microscopy, X-ray photoelectron spectroscopy, and atomic force microscopy.     

Determination of Kamlet-Taft solvent parameters pi* of high pressure and supercritical water by the UV-Vis absorption spectral shift of 4-nitroanisole

Kamlet-Taft solvent parameters, pi*, of high pressure and supercritical water were determined from 16-420 degrees C based on solvatochromic measurements of 4-nitroanisole. For the measurements, an optical cell that could be used at high temperatures and pressures was developed with the specification of minimal dead space. The low dead space cell allowed us to measure the absorption spectra of 4-nitroanisole at high temperature conditions before appreciable decomposition occurred. The behavior of pi* in terms of water density (pi* = 1.77rho- 0.71) was found to be linear, except in the near critical region, in which deviations were observed that could be attributed to local density augmentation. Excess density, which was defined as the difference between local density and bulk density, showed a maximum near the critical density of water. The frequencies of UV-Vis spectra of 4-(dimethylamino)benzonitrile and N,N-dimethyl-4-nitroaniline were correlated with pi* based on a linear solvation energy relationship (LSER) theory. Local density augmentation around 4-nitroanisole and that around 4-(dimethylamino)benzonitrile were similar but the augmentation observed around N,N-dimethyl-4-nitroaniline was larger.     

Intertwining operator realization of non-relativistic holography

We give a group-theoretic interpretation of non-relativistic holography as equivalence between representations of the Schrödinger algebra describing bulk fields and boundary fields. Our main result is the explicit construction of the boundary-to-bulk operators in the framework of representation theory (without specifying any action). Further we show that these operators and the bulk-to-boundary operators are intertwining operators. In analogy to the relativistic case, we show that each bulk field has two boundary fields with conjugated conformal weights. These fields are related by another intertwining operator given by a two-point function on the boundary. Analogously to the relativistic result of Klebanov–Witten we give the conditions when both boundary fields are physical. Finally, we recover in our formalism earlier non-relativistic results for scalar fields by Son and others.