Synthesis and characterization of mesoporous gamma-alumina by glucose as soft-template for molybdenum-99 adsorption: high and low molar ratio of water to aluminium isopropoxide effect

The mesoporous gamma-alumina is a good material for metal adsorption. Its textural properties are excellent, mainly for molybdenum-99 radioisotopes adsorption as part of 99Mo/99mTc generator in nuclear medicine. In this work, we have prepared mesoporous gamma-alumina by sol-gel treatment in the presence of glucose as a soft template. The molar ratio of reactant (water: aluminium isopropoxide(AIP)) was applied in the high and low ratios (150:1 and 25:1). The resulted mesoporous gamma-alumina was investigated using characterization analysis of X-ray diffraction, Nitrogen adsorption-desorption, and FTIR. The results indicate that the mesoporous gamma-alumina in the high molar ratio of water to AIP had a higher surface area and better crystallinity than the low molar ratio of reactants. Furthermore, in the Mo adsorption test, the mesoporous gamma-alumina with the high molar ratio posed a higher Mo adsorption capacity up to 55.69 mg Mo g−1 adsorbent. In the future, the molar ratio of reactants should be tuned in the range of around 150:1 to obtain the optimal Mo adsorption capacities of the resulted mesoporous gamma-alumina using the glucose template.

Synthesis, spectroscopic [IR, (1H, 13C, 27Al) NMR] and mass spectrometric studies of aluminium(III) complexes containing O- and N-chelating Schiff bases

Reactions of aluminium isopropoxide with 2-(o-hydroxyphenyl)-benzoxazole (pbox

Research on the Sol-Gel Method of Preparing Ternary Nano SiO2-Al2O3-TiO2 Materials

Tetraethyl orthosilicate (TEOS), butyl titanate [Ti (OBu)4] and aluminium isopropoxide were used as molecular precursor of ternary nanoSiO2-Al2O3-TiO2 materials. The influences of temperature and the dosage of compounds on the characteristic of ternary nanomaterials were investigated. Transmission electron microscopy (TEM), x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were employed to investigate the characteristics of the nanomaterials synthesized by the sol-gel method. In addition, the adsorption of nanomaterials for different kinds of surfactants was also studied. Results revealed that the influences of temperature, compounds dosages and water on the size of ternary nanomaterials had a significant impact. With the increase of ammonia dosage, the concentration of the OH- ion became higer, and system showed a faster reaction rate. The higer temperature of the system was, the larger size of the ternary nanomaterials was. Moreover, the higer tempreature woule also lead to divide into layer and precipitate. Optimal parameters can be chosen to prepare monodispersed ternary nanoSiO2-Al2O3-TiO2 materials. Results also showed that the surface characteristic of ternary nanoSiO2-Al2O3-TiO2 particles differed from nanosilica, which manifested in forms of the adsorption dosage of surfactants.

Characterization and Analysis on the Thermal Transformation of Boehmite Synthesized by Yoldas Method

The boehmite (AlOOH) sol derived from aluminium isopropoxide was synthesized by Yoldas method. The physicochemical process and phase transition of AlOOH were investigated by TG-DSC, N2 adsorption-desorption, XRD and TEM. The results showed that upon heating, AlOOH lost the physicsorbed water first, and then lost the chemisorbed water at 242 °C, and the dehydroxylation occurred at 361 °C. The BET surface area, total pore volume and pore diameter increased, since the waters were lost. The orthorhombic AlOOH transformed to the cubic γ-Al2O3 at 361 °C, the cubic η-Al2O3 appeared after 484 °C, the monoclinic θ-Al2O3 and rhombohedral α-Al2O3 appeared after 1026 °C, and it totally turned into α-Al2O3 at 1237 °C.

Sintering of High-Strength Dense Al2O3 Using Rod-Like Submicron Al2O3 as Sintering Aid

Rod-like submicron Al2O3 powder was prepared by the controllable hydrolyzation of aluminium isopropoxide in streams atmosphere. XRD data show the rod-like Al2O3 has a γ- Al2O3 structure. TEM images display the length of the submicron Al2O3 is in the range of 100-300 nm and the slenderness ratio is above 10. The rod-like Al2O3 powder was added into the submicron Al2O3 (D50 = 0.5 μm, purity > 99.99%) to increase the bending strength of the sintered body and to decrease the sintering temperature. SEM images display that the Al2O3 sintered at 1450 °C with rod-like Al2O3 added has a higher density than the virgin Al2O3 and the Al2O3 grains have the trans-crystalline fracture. The bending strength of the sintered Al2O3 with 5 wt% rod-like Al2O3 added is 205 MPa, which increases 241%. A sharp shrinkage in 1300-1400 °C appeared in the sintering shrinkage curves characterized by DIL show the rod-like Al2O3 also acts as the sintering aid.

Development of Permeable Reactive Barrier for Phosphorus Removal

Permeable reactive barriers were developed for phosphorus removal. The barrier consists in an organic-inorganic hybrid material, which allows water and others species to flow through it, while selectively removes the contaminants. Polyethylene oxide (POE) and aluminium oxide (Al2O3) were used as the organic and the inorganic parts, respectively. The hybrid material was obtained by sol-gel reaction, using aluminium isopropoxide as inorganic percursor in order to attain Al2O3. The hybrid material produced was characterized by FT-IR spectroscopy and thermogravimetry. The previous tests for phosphorus removal have shown the effectiveness capacity of the developed material to remove it.

Synthesis and Characterization of Well-Defined SolubleAlq3- andZnq2-Functionalized Polymers via RAFT Copolymerization

The reversible addition-fragmentation chain transfer (RAFT) copolymerizations of 2-((8-hydroxyquinolin-5-yl)methoxy)ethyl methacrylate (HQHEMA) with styrene (St) or methyl methacrylate (MMA) were successfully carried out in the presence of 2-cyanoprop-2-yl dithionaphthalenoate (CPDN). The polymerization behaviors showed the typical living natures by the first-order polymerization kinetics, the linear dependence of molecular weights of the polymers on the monomer conversions with the relatively narrow molecular weight distributions(Mw/Mn), and the successful chain extension experiments. The soluble polymers having tris(8-hydroxyquinoline)aluminum (Alq3) and bis(8-hydroxyquinoline) znic(II) (Znq2) side chains were obtained via complexation of the polymers with aluminium isopropoxide or zinc acetate in the presence of monomeric 8-hydroxyquinoline, which had strong fluorescent emission at 520 nm. The obtained polymers were characterized by GPC, NMR, UV-vis, and fluorescent spectra.