The CaCO3 hollow spheres made of fine CaCO3 particles were prepared by a novel method. The principle of this method was as follows: the CaCO3 fine particles were made attached to the surface of kerosene droplets in CaC12 aqueous solution. Then, those particles were bound with CaCO3 gradually precipitated by the reaction between CO+ and C082- in the aqueous phase. The spherical shells were obtained by replacing kerosene with ethyl alcohol and then drying at 343 K. The structure of the hollow spheres have been observed through the scanning electron microscope. The powder size distribution and the specific surface area of them were measured. These results show that each sphere is 100-250 pm in size and has the spherical shell which consists of the single layer of the component particles bound with microcrystalline CaCO3. The effects of CaC12 concentration and pH on the preparation are discussed. The eff iciency of formation was dependent on the concentration of CaC12 in aqueous phase where emulsion was formed. On the basis of electrokinetic data for the solid particles and the droplets, the interaction between them was discussed. t A Novel Preparation Method of Hollow Spheres. I.

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Several kinds of hydroxoaluminum species and their content in polyaluminum hydroxide solution having different OH/A1 ratio and concentration were investigated by Ferron method and HPLC method. Three kinds of Al-polymer having different degrees of polymerization, PAH-H, PHA-M and PAH-L, existed in the polyaluminum hydroxide solution. The molecular weights for some Al-polymer species were also estimated by ultrafiltration. Chemical composition for predominant species of Al-polymer was investigated by utilizing intercalation with synthetic mica. The number and molar ratios of Al-polymeric species depend on OH/Al ratio in solution; the content of Al-polymer increases with increasing OH/A1 ratio of solution, while that of Al-monomer decreases. When the Al-concentrated solution was diluted, PAH-H having the highest degree of polymerization decreased in content with increasing aging time and finally vanished, indicating that the number and distribution of Al-species is strongly influenced by Al-concentration. Apparent molecular weights of PAH-H, PAH-M and PAH-L obtained by ultrafiltration were 34000, 12000 and 1900 respectively, and those values corresponded to 18: 6: 1 in volume ratios. This clearly shows that PAH-H, PAHM and PAH-L species have a different dimension, i. e., different degree of polymerization. For predominant species of PAH-L in diluted solution the chemical composition is estimated to be [Al₁₃O_1.97, (OH)_31.37]^3.69+ from the results of intercalation under controlled conditions. These results show that the degree of hydrolysis and positive charge of PAH-L is smaller than those of [Al₁₃O₄, (OH)₂₄]⁷⁺ reported earlier.

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The removal of chromium(VI) or manganese(VII) oxometalate ion from aqueous solution by the magnesium-aluminium oxide solid solution, Mgo.58A10.281-1 prepared by the thermal decomposition of a synthetic hydrotalcite was investigated at 25 °C. The oxide adsorbed highly Cr042- and Mn04- to reconstruct the hydrotalcite-type structure with the basal spac ing of 8.7 A. As seen in Fig.2, the Freundlich's adsorption isotherm can be well applied in bot h cases. The Freundlich parameters, k and n values, were calculated to be 55.2 mgc' and 5.0 for Cr042-, and 7.7 m gg-' and 2.5 for Mnac. Thus the amount of divalent anion adso rbed was larger than that of monovalent anion in the wide region of equilibrium concentration. In addition, the crystallinity of the solid product was found to be poor with the increase in the amount of the guest anions adsorbed as shown in Figs.3 and 4. Then, the hydrotalcite-like compounds incorporating these oxom etalates ions were heated at 300-900 °C for 1 h and the dissolution behaviors of Cr or Mn ion from the heated products in aqueous solutions were tested. These metal ions were fixed in the matrix of the resulting MgO (Periclase) phase at 500-750 °C and in the chemically stable MgAl2O4( Spinel) phase as the solid solutions at 800-900°C. By these heat-treatment, neither metal ions were leached into the solutions of pH 4-10 and pH 2-12 from the products heated above 500 °C and 800 °C, respectively.

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Amorphous silica with high specific surface area was prepared from serpentinite by acid treatment. Surface properties of the porous materials were studied by volumetric adsorption isotherms using N2 and NH3 gas molecules. The specific surface area of the high silica (99.3wt%) was evaluated to be 170 rn2fg having the pore volume and the pore size of O.1 miig and 20 A, respectively. In contrast, the MgO content in the material strongly affects the specific surface area. The sample of 6 wt% MgO gave the highest specific surface area (340 m2/g), of which pore volume and pore size were 0.21 mllg and 10 A, respectively. With the heat treatment of the material, the surface area was decreased to 230 rn'ig at 800 °C, and to 70m2fg at 1000°C, respectively. The surface acidity of the porous materials was detected b y chemical adsorption of NH3 molecules.

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Concentrations of dissolved oxygen (DO) in natural spring waters and river waters in the Kusatsu-shirane volcano area, Gunma, were measured in situ with a portable DO meter. In advance of the field study, a series of laboratory experiments were carried out to examine the applicability of the DO meter to the field use. It was found that the DO meter was usable beyond the temperature range of 0-40 °C in which the reading of the meter was guaranteed, if appropriate correction was made the meter can be used to measure DO concentrations of hot spring waters with temperatures of 40-90 °C. Importance of in situ measurements at water outlets was also pointed out, when measuring spring waters. As for the natural spring waters examined, the degrees of DO saturation varied from spring water to spring water, ranging from 0 to 100%, which indicated the variety of history of the waters. For some spring waters, correlation was observed between their DO concentrations and residence times underground. That is, the longer the residence time was, the lower the DO concentration was, and this showed the underground strata were reductive. The river waters examined generally showed high degrees of DO saturation (over 79%) as is usually the case with river waters.

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After nitrazepam and diazepam were measured by gas chromatograph mass spectrometer (GC/MS), their quantitative analyses were carried out with the ion intensities of many fragment ions by multivariate analysis. Dotriacontane (n-C821-166) was used as an internal standard. Their fragment ions of nitrazepam, diazepam and dotriacontane used for the quantitative calculation were subtracted with quantification IV. Cluster analysis, cluster analysis from deviation and principal component analysis were performed with the ion intensities of the subtracted fragment ions, and it was made certain which one of unknown samples among all was the closest to a given known sample. Furthermore, the concentrations of unknown samples were exactly determined with the principal component scores and eigen values obtained from principal component analysis. The calculated concentrations of nitrazepam and diazepam agreed well with the theoretical concentrations, and the quantitative analysis which has high preciseness was made possible.

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Oxidation of cyclic ethers with sodium bromite (NaBrO2) in the presence of a catalytic amount of chlorotrimethylsilane (Me3SiC1) afforded coresponding lactones. The oxidizing system was shown to be useful for the preparation of rbutyrolactone from tetrahydrofuran (THF). Further, cyclic vinyl ethers were also oxidized readily and gave bromo substituted lactones in good yields. The oxidations of 6 and 7 membered cyclic eyhers to the lactones proceeded, but with less satisfactory results. In such cases, the use of hydrochloric acid as a co-catalyst led to an increase in the yields. On the other hand, tributylchlorostann ane (Bu3SnC1) and copper(II) sulfate, which presented a facile technuque for the activation of NaBrO2 as an oxidizing agent, were not effective in those reactions. As to the co-catalyst, the organic acids such as acetic, p-toluenesulfonic, and m-chlorobenzoic acid did not enhance the formation of lactones from THF. The oxidation reaction employing a catalytic amount of Me3SiC1a nd hydr ochloric acid with NaBrO2 was demonstrated to be usable as a convenient procedure for the one-pot transfor mation of cyclic ethers to lactones underjmild conditions.

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Oxidation of primary alcohols by use of an aqueous sodium bromite (NaBr02) solution containing copper powder or tributyltin chloride (n-Bu3SnC1) was found to give aldehydes according to equation (1). It was observed that a hydroxyl group positioned near to a phenyl group led to a good yield of an aldehyde, but that a hydroxyl group near to an electron donating group led to production of an ester by reaction of the aldehyde with the unchanged alcohol according to equation (2). A primary alcohol having an electroA donating group near to the hydroxyl group was preferable for a selective formation of the aldehyde.

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It was confirmed that the cyclization product of a-(phenoxy)phenylacetic acid (1 a) with polyphosphoric acid is 3-phenyl-2(3 H)-benzofuranone (3 a) instead of 2-phenyl-3(2 H)benzofuranone (2 a ). Some mechanistic studies including crossover experiments by use of 1 a and a-(p-methylphenoxy)-p-tolylacetic acid (1 d) demonstrated that the rearrangement occurs intramolecularly. The rearrangement of benzyl phenyl ethers with polyphosphoric acid was also investigated.

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The pyrolysis of the two isomers in 4-t-butyl-1-methylcyclohexyl phenyl sulfoxide ( 1), one of which is that the phenylsulfinyl group on substrate ( 1 ) is sited in an axial position (E-form) and other is in an equatorial position (Z-form), was investigated by comparing the reaction rates in dioxane. As the pyrolytic products, the mixtures of two kinds of 4-t-butyl1-methylcyclohexene (endo-olefin) and 4-t-butyl-1-methylenecyclohexane (exo-olefin) were obtained from the substrates. The formation ratio of olefin isomers, (exolenclo), of Z-form was about 1/4 compared with that of E-form, while, the reaction rate of Z-for m was about three times larger than that of E-form. The activation parametets were that Ea is ca.120 kJmo1-1 both isomers E and Z, while 4S considerably differed in both isomers as ca. -2 in E-form and ca.15 JK-' in Z-from, respectively. From these results, it was suggested that the fas reaction rate of Z-form than that of E-form was considered to be due to a repulsing act n of a r-hydrogen in an axial position to the sulfur atom in the phenylsulfinyl group of cyclohexyl ring in the substrate ( 1 ), and further, a predominant formation of the endo-olefin in the pyrolysis of Z-form than that of E-form could also be explained by the above described action of the 1-position hydrogen.

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A kinetic study on the hydroxymethylation of 6-substituted 2, 4-diamino-1, 3, 5-triazine (XGH), where X was H, CHs, NH2, and OCH(CH3)2, with formaldehyde was carried out in aqueous NaHCO3-Na2CO3 buffers. A Linear relationship was found in the Hammett's plot with substituent constant upfor the rate constant of C082-catalyzed hydroxymethylation, where the reaction constant p was positive (1.6). The same value of reaction constant (p=1.6) was obtained in the Hammett's plot with ap for the hydroxymethylation with NaOH as a catalyst; here, X was H, CH3, NH2, OCH3, OCH(CH3)2, and N (CH3)2. The chemical shift 5 of the amino proton of XGH had linear, rerationship with ap with a positive slope (0.9). On the basis of these results, a plausible mechanism for hydroxymethylation cataly zed by CO32- and OH- was proposed. t Studies on Formaldehyde Resin. XXXV.

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We have prepared hydrogels consisting of N-isopropylacrylamide (NIPAAm) and acrylamide (AAm) copolymer whose molar ratios were 100/0, 95/5, 90/10, 85/15, and 180/20. Equilibrium water content of each copolymer during stepwise heating (every 5 °C) after each swelling had reached to its equilibrium in water at 10 °C showed a curve with an inflection point attributed to its transition temperature, Ttr. However, each water content curve at temperature change (from 10 °C to each constant temperature for measurement, that is, 30, 35, 40, 45, or 60 °C) decreased with temperature as the above did and then resumed the almost original water content above the Ttr. The Ttr shifted to a higher temperature range with an increase in AAm composition. These experimental results suggest that the densely packed surface structure of the gel is immediately formed when the hydrogel is immersed in water at higher temperature than the Ttr. Based on this phenomenon, we could control the release of Methylene Blue (MB) molecules absorbed in the hydrogel by changing the temperature around the Ttr. Since diffusion coefficients (D) estimated from the permeation of MB through hydrogel membranes below Ttr have showed a different temperature (T) dependence from those above Ttr, we can determine their Ttr from the intersections of Arrhenius plots of log D vs 1171. Diffusion of MB with hydrophobic and cationic nature into the hydrogel membranes showed the same temperature dependence and Ttr as those of neutral glucose used as a reference perk meant, through the diffusion coefficients of glucose through the membranes were lower than those of MB. Further we p ursued an adsorption of MB on the hydrogels and investigated an interaction of MB with hydrogel structures thermodynamically. MB had a strong hydrophobic interaction with hydrogel structures in the range below Ttr but not above Ttr because of the strong hydrophobic interaction between the gel structures themselves.

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Natural gas hydrate is stable only under low temperature and/or high pressure. Some additives such as acetone, tetrahydrofuran, furan and 1, 3-dioxolane make the hydrate stable. This result is obtained from the equilibrium data of methane hydrate formation (Fig.3).. This effect depends on the molecular structure and the size of these additives (Fi g.8). On the other hand, hydrate structure seems to be changed by coexistence of the additives, because the hydrate formation equilibrium depends on the concentration of the additives (Fig.9). Not only type I but type II hydrate or some other types of hydrate would be formed around methane molecules.

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Nineteen strains of algae and one Altermia sania were tested for their ability to collect metal ions. A method was described to collect the several metal ions in water with the microalgae (boiling water-treated powder algae). A 50 ml solution containing Cd2+, Co2+, cu2+2 Ni2+, mn2+ and Zn2+ was mixed with 100 mg of the microalgae under stirring fo r 30min. The solution was then centrifuged or filtered through and the concentrations of meta l ions in the filtrate were determined with an atomic absorption spectrometer. The red tide phytoplankton (Chattonella antiqua) tested were found to be more collective to Cd2+, Cu2+, Ni2+ and Co"- than the green algae or the other micro algae. The collect order of the metals by Chattonella antiqua (boiling water-treated powder algae) was CdRCu>Zn>Mn>Ni>Co>Ga.

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trans-4-Substituted 5-[(methylsulfonyloxy)methy1]-3-methoxycarbony1-2-isoxazoline 2oxide (3 a-d) were prepared through mesylation of the corresponding 5-hydroxymethyl derivatives (2 a-d), which were prepared from trans-4-substituted 3, 5-his(methoxycarbony1)-2isoxazoline 2-oxides (1 a-d). Compounds (3 a-d) were then allowed to react with titanium tetrabromide to afford ring expansion products, cis-4-substituted 5-hydroxy-3-methoxycarbonyl5, 6-dihydro-4 H-1, 2-oxazines (4 a-d).

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A dipivaroylmethane (Hdpm) chelate of titanium(N), [T, i(dpm)2(i-C3H70)2] was synthesized by the reaction of tetraisopropoxytitanium(N) with Hdpm in a nonaqueous solvent under a highly pure argon atmosphere and characterized by means of ICP, elemental analyses, FT-IR, 13C-NMR, and TG-DTA. The product was proved to be sufficiently pure so as to be used as a good source of MOCVD for the preparation of ferroelectric thin films.

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Quantitative analysis were carried out to determine the contents of icosapentaenoic acid (EPA) in lipid of seaweeds collected from the shore in Miyagi prefecture. It was found that Fudaraku (Pachymeniopsis lanceolata) included much more EPA than other algae examine d. Main fatty acid components of the lipid in the seaweed were EPA, palmitic acid and arachidonic acid, and their contents were 38.7, 33.9 and 13.2%(w/w), respectively. The EPA content in Fudaraku was 378 mg per 100 g of dried alga, which was mostly included in the polar part in acetone soluble lipid. The amount of EPA was considerably greater than that of Asakusanori (Porphyra tenera) which was reported to contain a high content of EPA. This seaweed is, therefore, suggested to be a useful resource of EPA and a suitable species for breeding to obtain an EPA-rich strain.

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