Reversible Change between Excimer and Monomer Forms of Perylene Induced by Water Absorption and Dehydration of Poly--isopropylacrylamide Gel.

Several fluorescence patterns derived from the excimer states of perylene have been reported, but most of these have been obtained from rigid forms such as crystals or for perylene embedded in hard polymers. We observed perylene excimer emission on absorption of water by a poly--isopropylacrylamide gel containing perylene molecules, which were not fixed to the gel framework by chemical bonding. We propose that this emission arises because the hydrophobic perylene molecules cannot dissolve in water and form aggregates.

Magnetic-Field-Induced Liquid Phase Transformation of an Ionic Liquid ,,-Trimethyl--propylammonium Bis(trifluoromethanesulfonyl)imide.

An ionic liquid, ,,-trimethyl--propylammonium bis(trifluoromethanesulfonyl)imide (TMPA TFSI), was transformed from a liquid phase to another fluidic phase by application of the threshold magnetic field at constant temperature (). The magnetic-field-induced (MFI) phase transformation was detected by the electric potential generated between two Pt electrodes set to the bottom and upper parts in a TMPA TFSI liquid during sweep of the magnetic field (). The magnetic susceptibility and Verdet constant of TMPA TFSI also were slightly changed over 3 T.

Improving the Micropore Capacity of Activated Carbon by Preparation under a High Magnetic Field of 10 T.

The influence of an applied magnetic field on the formation of carbon materials from coal tar pitch is investigated. Under an applied magnetic field, crystallites in a mesophase resembling liquid crystals are magnetically oriented during the carbonization process. Compared with that under a nonmagnetic field, carbonized coal tar pitch under a strong magnetic field of 10 T, generated by a superconducting magnet, has a highly oriented structure of carbon crystallites.

Dynamic Polymorph Formation during Evaporative Crystallization from Solution: The Key Role of Liquid-Like Clusters as "Crucible" at Ambient Temperature.

Understanding the polymorph phenomenon for organic crystals is essential for the development of organic solid materials. Here, the fluorescence study of the evaporative crystallization of 1,3-dipyrrol-2-yl-1,3-propanedione boron difluoride complex (1), which has three polymorphs showing different emission profiles, is reported. The droplet of 1 in 1,2-dichloroethane showed blue emission just after dropping.

Micropore Formation of [Zn(Oxac) (Taz)]·(HO) via CO Adsorption.

As-synthesized [Zn(Oxac) (Taz)]·(HO), referred to as ZOTW, was prepared from aqueous methanol solutions of Zn(CO)(OH) and two kinds of ligands of 1,2,4-triazole (Taz) and oxalic acid (Oxac) at 453 K for 12 h. The crystal structure was determined by the Rietveld method. As-synthesized ZOTW was pretreated at 383 K and 1 mPa for t h, ZOTW(th).

Effects of Al(3+) Ions on Formation of Silica Framework and Surface Active Sites for SO4(2-) Ions.

Al(3+) ions were introduced into silica framework at 318 K in order to make active Al sites for SO4(2-) by the addition of aqueous sodium silicate solution to aqueous sulfuric acid solution of Al2(SO4)3. The (27)Al and (29)Si NMR spectra of aluminosilicates were measured at 278 K with reaction time. (29)Si NMR spectra were analyzed by the multivariate curve resolution.

Negative thermal expansion of water in hydrophobic nanospaces.

The density and intermolecular structure of water in carbon micropores (w = 1.36 nm) are investigated by small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD) measurements between 20 K and 298 K. The SAXS results suggest that the density of the water in the micropores increased with increasing temperature over a wide temperature range (20-277 K).

Effect of a quaternary ammonium salt on propylene carbonate structure in slit-shape carbon nanopores.

The effect of addition of tetraethylammonium tetrafluoroborate (Et(4)NBF(4)) on the structure of propylene carbonate (PC) confined in slit-shaped carbon nanopores of activated carbon fiber (pore width = 1.0 nm) was studied by synchrotron X-ray diffraction and reverse Monte Carlo simulation. PC molecules are randomly packed in the slit carbon nanopores of 1 nm in the absence of Et(4)NBF(4).

Magnetic field effects on electric behavior of [Fe(CN)] at bare and membrane-coated electrodes.

The cyclic voltammetric behavior of [Fe(CN)] was investigated under homogeneous magnetic fields perpendicular to the electrode surface in order to determine the effects of magnetic fields on the distribution of an Fe/Fe redox couple. The cathodic current was enhanced much more than the anodic current by a homogeneous magnetic field, suggesting that the concentration gradient of paramagnetic [Fe(CN)] and diamagnetic [Fe(CN)] formed at an electrode surface may also contribute to the asymmetric current. The apparent diffusion coefficient of the redox couple increased by over 30% in both cathodic and anodic processes upon applying a magnetic field.

Magnetic field control of electron tunneling pathways in the monolayer of (ferrocenylmethyl)dodecyldimethylammonium bromide on a gold electrode.

The electron-tunneling reaction in the monolayer of (ferrocenylmethyl)dodecyldimethylammonium bromide (FDDA) and the mixed monolayer of FDDA and 11-mercaptoundecanoic acid (MUA) on gold electrodes was affected by homogeneous, steady magnetic fields perpendicular to the monolayer membrane. Both the current and peak-to-peak separation potential of the ferrocenyl/ferricenium redox couple in cyclic voltammograms increased with increasing magnetic field intensity. The electron tunneling reaction of FDDA depended not on the barrier thickness of the monolayer but on the electron tunneling pathways.

Transient oxygen clathrate-like hydrate and water networks induced by magnetic fields.

Recently, careful experiments of oxygen-dissolved pure water treated by high magnetic fields showed indirectly the existence of magnetic field-affecting water (MFA water), which brought about a decrease in the contact angle of water on metals, an increase in the electrolytic potential of water, inhibition of metal corrosion, and changes in the crystal structure of calcium carbonate due to magnetic treatment. Here we report the infrared and Raman spectroscopic evidence indicating quasi-stable structures in the MFA water; oxygen clathrate-like hydrate and developed water networks, which were induced by magnetic interactions while a vacuum-distilled water, followed by oxygen exposure, crossed a steady magnetic field. The mechanism of MFA water formation and survival under thermal fluctuation is a challenging problem for the science community.

Does magnetic treatment of water change its properties?

Some properties and functions of water treated under magnetic field were examined. No change in properties of pure water distilled from ultrapure water in vacuum was observed by magnetic treatment. However, when the same magnetic treatment was carried out after the distilled water was exposed to O2, water properties such as vibration modes and electrolytic potential were changed.