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Inorganic/organic hybrid membranes for use in fuel cells were synthesized from 3-glycidoxypropyltrimethoxysilane (GPTMS), N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole (NESPHI), and 1,3-propanesultone (PS) through a simple one-pot process. Fourier transform infrared spectroscopy and 13C nuclear magnetic resonance (NMR) measurements confirmed the sultone ring-opening reaction and formation of chemical bonds among the starting materials. The 29Si NMR measurements revealed that a siloxane network had formed within the hybrid membranes via the sol–gel process. The thermogravimetric analysis indicated that the synthesized membranes were thermally stable up to 170 °C. The conductivity of the membranes at low levels of relative humidity (RH) was improved by the addition of NESPHI. The best cell performance at intermediate temperatures and low RHs was achieved by the membrane electrode assembly using the NESPHI/GPTMS/PS = 1:3:4 hybrid membrane with a catalyst ink consisting of Nafion and the hybrid solution at a 1:1 ratio. At 120 °C and 53 % RH, the power density of the NESPHI/GPTMS/PS = 1:3:4 membrane was 6.6 mW/cm2.

A manganese zinc ferrite nanoparticle/polymer hybrid nanocomposite was synthesized in situ from metal acetylacetonates at 80 °C. A mixture of manganese(II) acetylacetonate (MA), zinc(II) acetylacetonate (ZA), and iron(III) 3-allylacetylacetonate (IAA) was hydrolyzed and polymerized, yielding a spinel oxide nanoparticle/organic hybrid. The crystallite size of the spinel particles was dependent upon the hydrolysis conditions of MA–ZA–IAA. Crystalline manganese zinc ferrite nanoparticles less than 5 nm in size were uniformly dispersed in the organic matrix. The magnetization of the hybrid increased as the amount of water for hydrolysis increased. The magnetization versus field curve for the manganese zinc ferrite nanoparticle/organic hybrid showed neither remanence nor coercivity above 11 K. The magnetization versus H/T curves from 50 to 200 K were superimposed on the same curve described by the Langevin equation. The remanent magnetization and coercive field of the hybrid were 2.1 emu/g and 20 Oe, respectively, at 4.2 K. The absorption edge of the hybrid film was blue-shifted as compared to that of bulk ferrite.

Transparent TiO2 nanoparticle/polymer hybrids were synthesized from titanium isopropoxy methacrylate via hydrolysis and polymerization in 2-methoxymethanol. Crystalline TiO2 nanoparticles were uniformly dispersed in the polymer matrix. A highly transparent free-standing TiO2 nanoparticle/polymer hybrid film was synthesized. The refractive index (RI) of the hybrid films on Si substrates could be controlled by varying the concentration of TiO2 nanoparticles: the RI increased with increase in Ti content. A further increase in the RI was achieved upon irradiation with ultraviolet light. A TiO2 nanoparticle/PMMA hybrid without the silica component exhibited an RI of 1.717 and an Abbe number of 21.6.

A transparent BaTiO3 particle/poly(2-hydroxyethyl methacrylate) (PHEMA) hybrid was synthesized from a Ba–Ti double alkoxide modified with an organic ligand, and the refractive index and ferroelectric properties of the hybrid were studied. The transparent hybrid was flexible and could be shaped not only in the form of thin films on substrates but also in the form of flexible self-standing films. BaTiO3 particles around 5 nm in diameter were dispersed uniformly in the polymer matrix. The refractive indexes of the hybrid films increased with decreasing wavelength and were dependent on the volume fractions of the BaTiO3 and polymer phases. The hybrid film synthesized at a molar ratio of BaTiO3:2-vinlyloxyethanol:H2O:PHEMA = 1:8:30:5 gave the best result, with a refractive index of 1.55 at 589 nm and an Abbe number of 37.5. A transparent hybrid film on platinized silicone substrates exhibited a polarization–electric field hysteresis loop.

An Er-doped ZnO nanoparticle/organic hybrid was synthesized in situ from zinc acrylate (ZA) and erbium acetate (EA) using methylhydrazine. Nano-sized Er-doped ZnO particles were formed in an organic matrix by hydrolysis and polymerization of ZA–EA at 80 °C. The crystallinity of the Er-doped ZnO particles in the hybrid was dependent upon the hydrolysis temperature and water amount. Analysis by transmission electron microscopy and energy dispersive X-ray analyzer revealed that crystalline ZnO nanoparticles doped with Er were dispersed in the organic matrix. The hybrid film sandwiched between fused silica plates was highly transparent. The Er-doped ZnO particle/organic hybrid showed a photoluminescence peak at 0.81 eV (1.54 μm) attributed to the transition of Er3+ ions.

The reaction route and morphology of lanthanum-β-aluminate (LBA) crystals formed in Ce-TZP matrix were studied by examining the crystal phase changes and the microstructures in relation to the heat-treatment time, heat-treatment temperatures and the particle size of raw Al2O3 powders. In the Ce-TZP matrix, the LBA crystal was formed by the reaction between La2O3 and Al2O3 through the LaAlO3 phase as the intermediate. La2Zr2O7 forms at 800 °C and remains in the temperature range 800–1500 °C, and LaAlO3 forms between 1200 and 1400 °C. The LaAlO3 reacts with Al2O3 to form LBA above 1500 °C. The diffusion of La3+ through the La2Zr2O7 phase was faster than that of Al3+. The morphology of LBA crystals was dependent on the particle size of the starting raw Al2O3 particle. When submicrometre size Al2O3 (0.4μm) particles were used as the starting particles, anisotropic, plate-like LBA crystals, about 10μm long, were formed during heat treatments. On the other hand, Al2O3 of larger grain sizes (3.6, 10.3μm) yield conglomerates of LBA crystals. The size of the conglomerates is similar to that of the raw Al2O3 particle. The dependence of the morphology of LBA on the particle size of Al2O3 can be attributable to the sintering process of the Ce-TZP matrix, leading to the control of the mechanical properties of Ce-TZP ceramics with LBA crystals.

Nickel ferrite-dispersed carbon could be synthesized by pressure pyrolysis of divinylbenzene (DVB)-vinylferrocene (VF)-nickelocene (Cp2Ni) polymer in the presence of water under 125 MPa and at temperatures below 700°C. By heat treatment at 550°C with water, nickel ferrite particles could be dispersed finely in the carbon matrix, although a small amount of nickel-iron carbide also began to form above 600°C. The morphologies of the carbon particles formed were observed to be polyhedral, coalescing spherulitic and spherulitic. When 30 wt% H2O, spherulitic carbons a few micrometres in diameter were prepared, in which nickel ferrite particles from 10–30 nm were dispersed in the carbon matrix. The saturation magnetization of carbon composites formed from DVB-3.0 mol% Cp2Ni-6.0 mol% VF and 20 wt% H2O at 550°C was about 30 e.m.u.g−1 and increased with pyrolysis temperature. The coercive force of the carbon composite was 120 Oe and was affected by the amount of added water using pressure pyrolysis. Thermomagnetic measurement shows that the Curie temperature of nickel ferrite-dispersed carbon was about 580 °C.

The crystallization process of epitaxial LiNbO3 films on sapphire (0 0 0 1) substrates was investigated by Raman microprobe spectroscopy. LiNbO3 gel films were prepared by the sol-gel method using metal alkoxide precursors on sapphire (0 0 0 1) substrates and heat treated at various temperatures below 500 °C to produce epitaxial LiNbO3 films. Analyses by electron spectroscopy for chemical analysis and SEM revealed LiNbO3 films were stoichiometric and homogeneous. Raman spectra of the film prepared at 250 °C indicated that the NbO6 octahedral coordination structure in LiNbO3 began to form as the initial state of crystallization. As the heat-treatment temperature was raised, the Raman bands became sharper and increased in spectral intensity and were seen to be the characteristic Raman bands of crystalline LiNbO3. Refractive indices of the obtained films indicated appropriate values. As a method to crystallize the more highly preferred orientation to (0 0 6) LiNbO3 film at relatively low temperature, the formation of an underlayer film from diluted solution prior to multiple dip-coating, was found to be very promising.

SiC-AIN solid-solution ceramics were prepared by pressureless sintering using Al2O3 and Y2O3 as the sintering additives. The resulting ceramics were subjected to annealing treatments over a range of temperatures from 1400 °C to 1800 °C in the spinodal region. The fracture toughness of the annealed ceramics was examined, by the indentation method, in relation to the annealing temperature and annealing time. X-ray diffraction profiles revealed that phase separation occurred during annealing. In ceramics containing 50 mol % SiC annealed at 1800 °C, the morphology of the phase separation is the characteristic modulated stratiform structure. Energy-dispersive X-ray spectroscopy (EDS) showed that the structure consisted of alternations of silicon-rich and aluminium-rich composition. The fracture toughness of the annealed ceramics increased compared to the as-sintered solid-solution ceramics. The phase separation is expected to contribute to the toughening of ceramics with nanometre-scale texture.

Polycrystalline alumina-zirconia fibres were successfully synthesized by pyrolysis of preceramic fibres formed from mixed aluminium-zirconium chelate compounds. Ethyl 3-oxobutanoatodiisopropoxyaluminium (EOPA) was reacted with zirconium tetrabutoxide (TBZ) in the presence of glacial acetic acid yielding a polymeric product. The infrared absorptions from 500–625 cm−1 due to Al-O and Zr-O bonds changed from sharp to coalesced bands by treatment with acetic acid. The signal at 40 p.p.m. in the 27Al spectra of EOPA-TBZ increased in intensity on treating with acetic acid. The viscosity of the polymeric product increased as the amount of acetic acid increased. The viscosity of the precursor decreased on increasing the measurement temperature from 60 °C to 75 °C. The precursor polymer pyrolysed at 800 °C in air showed a broad X-ray diffraction of γ-alumina, and crystallized in a mixture of γ-alumina and tetragonal zirconia at 1000 °C. The median diameter of tetragonal zirconia in the α-alumina matrix was 33 nm, when EOPA-TBZ (Al/Zr=9/1) was heat treated at 1300 °C for 1 h. The precursor fibres were pyrolysed at 1300 °C to yield fine-grained fibres of α-alumina including tetragonal zirconia, which was confirmed by Raman microprobe spectroscopy.

Polycrystalline alumina fibre was successfully synthesized by pyrolysis of a preceramic fibre formed from aluminium compounds with alkoxy and chelate ligands. A mixture of ethyl 3-oxobutanoatodiisopropoxyaluminium (EOPA) and tri-sec-butoxyaluminium (SBA) was reacted with glacial acetic acid yielding a polymeric product. The IR absorptions at 630 and 700 cm−1 due to the Al-O bond changed from sharp to broad bands by treatment with acetic acid. The 27Al resonance at 35 p.p.m. increased in intensity when EOPA-SBA (7/3) was treated with 30 mol% acetic acid. An increase in the EOPA to SBA ratio 5/5 to 9/1 also raised the intensity of the signal at 35 p.p.m. The viscosity of the polymeric product increased in intensity as the amount of acetic acid increased. The viscosity of precursor increased with increasing the ratio of EOPA to SBA, and decreased with increasing measurement temperature from 45 to 75°C. The precursor polymer pyrolysed at 500°C in air was amorphous to X-rays, and crystallized in γ-alumina at 840°C. The precursor fibres were pyrolysed to yield finegrained fibres of α-alumina at 1200°C for 1 h.

Cubic BN was synthesized under high temperature and pressure conditions from BN powder formed by reaction of triammoniadecaborane (TAD) with ammonia. The BN powder formed from TAD and ammonia had a low degree of ordering. The crystal lattice of the BN powder increased in regularity with increasing synthesis temperature and time for the reaction of TAD with ammonia. The conversion yield of cubic BN at 1300 °C and 6.5 GPa in the presence of AIN increased with decreasing of reaction temperature of TAD and ammonia from 1000–700 °C. Cubic BN decreased in yield with increasing reaction time of TAD and ammonia at 800 °C. BN powder pre-heat treated at 1550 °C had a crystallite size,Lc, of 22 nm, and was converted to cubic BN in a 43% yield at 1300 °C and 6.5 GPa for 10 min. The activation energy for cubic BN synthesis from BN powder-20 mol% AIN was 97 kJ mol−1, when the starting BN was synthesized at 800 °C. The conversion yield of cubic BN from the disordered BN-20 mol% AIN was 100% after heat treatment at 1300 °C and 6.5 GPa for 20 min.

Polycrystalline alumina fibre was successfully synthesized by pyrolysis of preceramic fibre formed from aluminium chelate compound. Ethyl 3-oxobutanoatodiisopropoxyaluminium (EOPA) was reacted with glacial acetic acid yielding a polymeric product. The absorption bands ascribed to Al-O from 630–705 cm−1 changed from a sharp to a broad band on treatment with acetic acid. The13CNMR spectrum of EOPA changed from sharp singlets to multiplets after the reaction with acetic acid. The viscosity of the polymeric product increased in intensity with increasing amount of acetic acid. The viscosity of the polymeric product formed from EOPA-30 mol % acetic acid was 450 Pa s at 30 °C, and decreased to 5.4 Pa s with increasing measurement temperature from 30–70 °C. The27Al resonance at 35 p.p.m. increased in intensity with increasing viscosity of the polymeric precursor. The molecular weight of the precursor was distributed from 400–800. The polymeric precursor pyrolysed at 500 °C in air was amorphous to X-rays, and crystallized in γ-alumina at 840 °C. The precursor fibres were pyrolysed, to yield fine-grained fibres of α-alumina, at 1300 °C for 1 h.

Platinum-dispersed carbon was synthesized by pressure pyrolysis of divinylbenzenebis (2-allylphenyl)platinum (APPt) and phenylacetylene-APPt at 550 °C and 125 MPa. The crystallinity of platinum dispersed in the carbon matrix synthesized from phenylacetylene(PA)-APPt was higher than that from divinylbenzene(DVB)-APPt. Platinum particles less than 60 nm were dispersed in the carbon matrix synthesized from DVB-APPt at 550 °C and 125 MPa. The carbon matrix formed from PA-APPt contained platinum particles of about 120 nm. The specific area of platinum-dispersed carbon synthesized at 550 °C and 125 MPa increased on subsequent heat treatments in argon, and reached 90 m2 g−1 after heat treatment at 800 °C for 1 h. The activity of platinum-dispersed carbon for the hydrogenation of cyclohexene increased with increasing specific area. Platinum-dispersed carbon formed from DVBAPPt was more active for hydrogenation reaction than that from PA-APPt. The highly active platinum-dispersed carbon could be synthesized from DVB-APPt at 520 °C. The surface area reached 154 m2 g−1 after heat treatment at 800 °C.

Boron-dispersed carbon was synthesized by pressure pyrolysis of divinylbenzene-tris(allyl)-borane and styrene-tris(allyl)borane at 125 MPa below 650° C. Amorphous boron dispersed in a carbon matrix was oxidized easily to yield boric acid by heat treatment under air at 300° C. The BKα image of the product showed that boron was dispersed uniformly in a carbon matrix. Boron-dispersed carbon had the morphology of coalescing spherulite and polyhedra depending upon the concentration of boron in the parent copolymer. The grain size of carbon polyhedra decreased from 2.0μm to 0.2μm with an increase in the boron concentration from 1.3 to 5.7 wt%. The presence of 0.5 wt% boron in a carbon matrix enhanced the graphitization at 4.0 GPa and 1200° C, decreasing the lattice spacing with an increase in the crystallite size. The crystallite sizes were comparable to each other after heat treatment at 1100° C and 4.0 GPa when the specimen contained boron from 0.5 to 2.5 wt%. The lattice constant (c0) and crystallite size (Lc) of boron-dispersed carbon containing 2.5 wt% boron were 677.0 pm and 30 nm, respectively, after heat treatment at 1200° C and 4.0 GPa.

Boron nitride (BN) of low crystallinity was synthesized from triammoniadecaborane (TAD) and hydrazine at 125 MPa below 650° C. TAD itself was pyrolysed at 600° C and 125 MPa to form a mixture of amorphous boron and boron nitride containing BH and NH bonds. The infrared spectrum of the pyrolysed product of TAD itself at 600° C and 125 MPa showed the BNB absorption at 800cm−1 due to the formation of B3N3 structures. The X-ray diffraction (XRD) of the reaction product from TAD and hydrazine at 600° C had broad diffractions centred at 2η=25.5° and 43.0° (CuKα). The BH absorption at 2500cm−1 decreased in intensity on increasing the N/B ratio from 0.3 to 0.85, and disappeared finally at a ratio of N/B=1.3. The reaction product at 125 MPa had a porous structure. The electron diffraction of the specimen changed from faint rings to spots on circular rings after heat treatment at 800° C for 10 h. The heat-treated specimen, however, did not give sharp reflections corresponding to hexagonal BN in the XRD profile. BN of low crystallinity was transferred to cubic BN at 1200° C and 6.5 GPa in a 90% yield, which was higher than that of well-crystallized BN in the presence of AIN.

Cementite-dispersed carbons were synthesized by pressure pyrolysis of divinylbenzene-vinylferrocene and styrene-vinylferrocene copolymer at temperatures below 600° C and the pressure of 125 MPa. The pyrolysis process of both copolymers was analysed by infrared spectra and magnetization of the pyrolysed substances. The absorption band of iron-carbon bond of divinylbenzene-vinylferrocene copolymer decreased on increasing its pyrolysis temperature from 300 to 450° C and finally disappeared at 500° C. The carbonization of divinylbenzene-vinylferrocene proceeded more rapidly than styrene-vinylferrocene at temperatures between 450 and 500° C. Styrene-vinylferrocene was heat-treated at 250° C for 2 h under 100 MPa affording a paramagnetic product, whereas the paramagnetic character of divinylbenzene-vinylferrocene was revealed after heat-treatment at 380° C. The saturation magnetization of cementite-dispersed carbon synthesized from both kinds of copolymers was comparable when the pressure pyrolysis was carried out at temperatures between 520 to 600° C at 125 MPa. The saturation magnetization of cementite-dispersed carbon formed at 550° C under 125 MPa was correlated linearly with the iron content in carbon. Threedimensional cross-linked divinylbenzene-vinylferrocene copolymer gave the highly dispersed cementite particles less than 50 nm with the coercive force of 950 Oe. On the other hand, the larger particle size of cementite up to 120 nm and the lower coercive force about 400 Oe were obtained in carbon matrix prepared by the pressure pyrolysis of styrene-vinylferrocene copolymer.

Carbons dispersed with Fe-Co alloy were synthesized by the pressure pyrolysis of vinylferro cene-phenylethynylcobaltocene-divinylbenzene copolymer at temperatures below 700° C and at 125 M Pa. As-prepared carbon synthesized at 550° C contained finely dispersed metallic particles of less than 10nm diameter with low crystallinity, which crystallized to form Fe-Co alloy particles with a higher crystallinity by subsequent heat treatment at 800° C. Larger particles of the alloy of more than 50nm diameter were dispersed in the carbon matrix synthesized at 700° C. Thermomagnetization measurement of the as-prepared carbon synthesized from divinylbenzene-2.1 mol% vinylferrocene-4.8mol% phenylethynylcobaltocene copolymer at 550° C and 125 M Pa confirmed that iron formed an alloy with cobalt in the carbon matrix. Fine, superparamagnetic metallic particles in the as-prepared carbon aggregated and crystallized by the heat treatment during the thermomagnetic measurement to increase the magnetization of the alloy-dispersed carbon. The saturation magnetization and the coercive force of alloy-dispersed carbon increased from 128 to 187e.m.u.g−1 and from a few to 50 Oe, respectively, on increasing the pyrolysis temperature of the starting copolymer from 550 to 700° C. The saturation magnetization of alloy-dispersed carbon from divinylbenzene containing iron and cobalt with a ratio of 5∶2 was higher than that from divinylbenzene including those with a ratio of 2∶5. The carbon with finely dispersed Fe-Co alloy showed a high saturation magnetization of 213 e.m.u.g−1 and a coercive force of 230 Oe, and the magnetization persisted above 800° C.

Magnetite-dispersed carbon was synthesized by pressure pyrolysis of the divinylbenzene-vinylferrocene system in the presence of water at 125 MPa below 700°C. Supercritical water influenced the phase separation of oligomers formed during the pyrolysis to give carbons with various morphologies, such as spherulitic, coalescing spherulitic and polyhedral carbon, depending upon the concentration of water. Carbon spherulites from 5 to 10 μm diameter dispersed with magnetite particles (

Cobalt-dispersed carbons were synthesized by pressure pyrolysis of cobaltocene-divinylbenzene and phenylallylcobaltocene-divi nylbenzene at 125 MPa below 700° C. The carbons resulting from cobaltocene-divinylbenzene contained uniformly dispersed fine particles, < 20 nm diameter, of metallic cobalt of lower crystallinity, which were composed of ferromagnetic and superparamagnetic particles. Metallic cobalt particles of cubic and hexagonal structures with higher crystallinity were formed during pyrolysis of phenylallylcobaltocene-divinyibenzene. Cobaltucence-divinylbenzene and phanylallylcobaltocene-divinylbenzene changed their magnetic properties from diamagnetism to paramagnetism at 250 and 200° C, respectively. The infrared absorption band of the cyclopentadienyl ring at 995 cm−1 disappeared at 350° C in cobaltocene divinylbenzene and at 300° C in phenylallylcobaltocene-divinylbenzene. Superparamagnetic particles from cobaltocene-divinylbenzene aggregated and crystallized to produce larger particles of diameter 30 to 100 nm, which increased the magnetization during thermomagnetic measurement. The saturation magnetization of cobalt-dispersed carbons from phenylallylcobaltocene-divinylbenzene was higher by about 10% than that from cobaltocene-divinylbenzene. The coercive forces of cobalt-dispersed carbon from phenylallylcobaltocene-divinylbenzen and cqbaltocene-divinylbenzene were 350 and 250 Oe (2.79 × 104 and 1.99 × 104 Am−1), respectively.

Versatile carbons with finely dispersed iron were synthesized by pressure pyrolysis of a copolymer prepared from divinylbenzene and vinylferrocene at temperatures below 680‡ C and pressures of 125 MPa. The pyrolysis conditions of the copolymer were found to influence the final morphology of carbons to give fibrils, spheres and polyhedra. The resulting carbons contained uniformly fine particles of cementite (Fe3C) which were less than 30 nm in size, whereas the magnetite was dispersed in the carbon matrix by pressure pyrolysis in the presence of water. Highly dispersed cementite in carbon was found to decompose into metallic iron by further heat treatment above 850‡ C. Porous spherulitic carbons were also synthesized by heat treatment of magnetite containing carbon spherulites.

α-Iron-dispersed carbon was synthesized, through pressure pyrolysis of divinylbenzene-vinylferrocene above 750°C, and by reduction of magnetite-dispersed carbon. Divinylbenzenevinylferrocene copolymer was pyrolysed at 125 MPa above 750°C to yield carbons dispersed with α-iron accompanied by cementite. Magnetite in the carbon matrix was reduced to α-iron after heat treatments at 500°C in a flow of hydrogen. Carbons synthesized by the pressure pyrolysis of divinylbenzene-vinylferrocene at 800°C and 125 MPa contained iron-compound particles up to 200 nm, whereas the median diameter of α-iron particles in the carbon matrix after reduction treatments was 20 nm. α-Iron-dispersed carbon had a Curie temperature of 770°C. The saturation magnetization of iron-dispersed carbon increased with increasing the pyrolysis temperature of divinylbenzene-vinylferrocene copolymer, and reached a constant value of 183 e.m.u.g−1 at 800°C. The saturation magnetization of α-iron-dispersed carbon after the reduction treatment revealed practically the theoretical value of α-iron. Carbons finely dispersed with only α-iron particles were synthesized successfully by reduction of magnetitedispersed carbons.