Decio Coutinho

Preparation and characterization of zeolite X membranes via pulsed-laser deposition

Zeolite X films have been prepared utilizing pulsed-laser deposition onto TiN-coated silicon wafers and porous stainless steel disks. Laser ablation of zeolite X onto TiN-coated silicon wafers followed by a hydrothermal treatment resulted in partially oriented, crystalline NaX membranes. Hydrothermal treatment of laser-deposited films on stainless steel mesh produced a coated wire mesh with a ∼3-μm-thick zeolite X film. Hydrothermal treatment of the laser-deposited films on 0.5 μm diameter pore stainless steel frits resulted in a densely packed non-continuous film.

Further studies of DAM-1 mesoporous silica preparations

Abstract A number of preparations for the synthesis of novel hexagonal mesoporous materials referred to as Dallas amorphous material-1 (DAM-1) have been developed using Vitamin E tocopheryl polyethylene glycol 1000 succinate (TPGS), a water-soluble form of the lipid soluble natural Vitamin E, as the structure directing agent. Depending upon the temperature and gel composition, highly ordered and hydrothermally stable 2-D hexagonal mesoporous DAM-1 with various morphologies could be achieved, including spheres, gyroids, discoids, hexagonal plates, and rods.

Molecular imprinting of mesoporous SBA-15 with chiral ruthenium complexes

Abstract A novel strategy for imprinting mesoporous SBA-15 using chiral ruthenium complexes is reported. This imprinting strategy combines the triblock copolymer (PEO) 20 (PPO) 70 (PEO) 20 template and the chiral dichlorotris(1,10-phenanthroline)ruthenium(II) complex. A chiral PEO helix is formed by interaction of the chiral ruthenium complex with the block copolymer during the templated synthesis of the mesoporous SBA-15 molecular sieves. Upon removal of the chiral ruthenium complex, a stereospecific cavity is created. Preliminary results indicate that stereoselective absorption of either Δ or Λ -Ru(phen) 3 2+ isomers from a racemic mixture can be achieved depending on the chirality of the PEO chain.

Synthesis and Characterization of Organosilane Functionalized DAM-1 Mesoporous Silica

Organic functionalized mesoporous DAM-1 containing amine, cyclopentadienyl, phenyl, and thiol groups was synthesized under acidic conditions by the direct co-condensation of TEOS or TMOS with respective organosilanes using vitamin E TPGS as the structure directing agent. Well-ordered functionalized mesoporous DAM-1 containing both amine and thiol were successfully prepared yielding ∼1 mmol g−1 of sulfur and 0.73 mmol g−1 of nitrogen when started with ∼0.088 molar ratio of APTMS/TMOS and MPTMS/TMOS. The incorporation of both amine and thiol was confirmed by forming a fluorescent isoindole from o-phthalaldehyde. The presence of cyclopentadiene in the mesopore was demonstrated by synthesizing a supported half sandwich compound CpMn(CO)3-DAM-1 from Mn2(CO)10 via photolysis. The samples were characterized by fluorescence and vibrational spectroscopy as well as x-ray diffraction and surface area measurements.

Synthesis and characterization of DAM-1 type materials

Vitamin E-TPGS (α-tocopheryl polyethylene glycol 1000 succinate) was found to be an effective template for the preparation of a novel hexagonal mesoporous silica referred to as DAM-1 (Dallas Amorphous Material-1). Depending upon the temperature and gel composition various morphologies can be achieved, including spheres, gyroids, discoids, hexagonal plates and rods. Characterization of these composites as well as a preliminary evaluation of DAM-1 as a drug delivery system under physiological conditions is also presented.

Microwave synthesis of NTHU-4

This paper presents the successful microwave synthesis of luminescent gallium phosphate NTHU-4 after heating for 4 hours at 160 °C. This material represents a promising option for single source white light emission for different optoelectronics applications. Different synthesis conditions are currently under study to provide further advances on color and brightness optimizations.

Preparation of Line Patterned Mesoporous DAM-1 Thin Films via Pulsed Laser Deposition

Patterned mesoporous DAM-1 thin films were prepared on flexible transparent film utilizing the pulsed laser deposition and a line patterning technique. The patterned lines are transferred to the transparent film using a laser printer or copy machine. Laser ablation of DAM-1 onto the patterned substrate followed by a hydrothermal treatment resulted in a densely packed mesoporous film. Upon removal of the patterned lines (i.e. the underlying toner) by ultrasonic treatment in toluene, patterned DAM-1 films were produced.