Porous Inorganic Membranes for CO2 Capture: Present and Prospects

Abstract Functionalised hexagonal mesoporous SBA-15-type molecular sieves with pore sizes in the range 51–56 A have been prepared using non-ionic block copolymers and used for immobilisation of the enzyme trypsin. Thiol, chloride, amine, and carboxylic acid functional groups were attached by siloxypropane tethers to the siliceous surface of SBA-15 via two methods, post-synthesis grafting and in situ synthesis. Phenylsiloxane groups were also incorporated using these two methods. The resulting solids were rendered porous and used to immobilise trypsin, giving variable but in general higher retention of the enzyme molecules than was observed on unfunctionalised, purely siliceous SBA-15. The resulting supported enzyme catalysts were shown to be active and stable catalysts for the hydrolysis of N -α-benzoyl-DL-arginine-4-nitroanilide (BAPNA). The solids prepared by supporting the enzyme on thiol-functionalised SBA-15 prepared by in situ synthesis were found to be the most promising. Trypsin supported on thiol-functionalised SBA-15 was shown to be recyclable.

Enzyme Immobilization Using SBA15 Mesoporous Molecular Sieves with Functionalised Surfaces

The interest in highly water-repellent surfaces has grown in recent years due to the desire for self-cleaning surfaces. A super-hydrophobic surface is one that achieves a water contact angle of 150° or greater. This article explores the different approaches used to construct super-hydrophobic surfaces and identifies the key properties of each surface that contribute to its hydrophobicity. The models used to describe surface interaction with water are considered, with attention directed to the methods of contact angle analysis. A summary describing the different routes to hydrophobicity is also given.

Preparation and Characterisation of Super‐Hydrophobic Surfaces

Efficient removal of heavy metal ions by thiol-functionalized superparamagnetic carbon nanotubes

The selective functionalization of the inner and outer surfaces of colloidal mesoporous silica (CMS) nanoparticles with different trialkoxysilanes, following a newly developed delayed co-condensation approach, results in bifunctional CMS. Complementary CMS nanoparticles were prepared with two different functional groups located either on the outer shell or in the inner core of the particle. The identification and localization of the functional groups was achieved by means of different techniques including zeta potential, nitrogen sorption measurements, and fluorescence spectroscopy. This last technique was applied to fluorescein isothiocyanate (FITC)-labeled CMS featuring aminopropyl functional groups on the periphery or the internal pore surface of the particles. Fluorescence quenching experiments were carried out with dodecanethiolate-stabilized gold nanoparticles having a diameter greater than the pore size of the CMS. It could be shown that fluorescence quenching occurs only when the FITC is positioned on the outer surface of the CMS nanoparticles, whereas no quenching was observed for FITC located in the inner core of the nanoparticle. These results clearly confirm the controlled localization of the aminopropyl groups in the nanometer space of the CMS particles. Our approach thus offers the opportunity to synthesize, in a novel multistep co-condensation strategy, various bifunctional mesoporous nanoparticles with controlled localization of different functional groups in the inner core or on the outer shell of the nanoparticle.

Multiple Core−Shell Functionalized Colloidal Mesoporous Silica Nanoparticles

Mesoporous amine-functionalized SBA-15 silica has been synthesized directly by the co-condensation of tetraethyl orthosilicate (TEOS) and aminopropyl-trimethoxysilane (APTMS) under acidic conditions with an APTMS/(APTMS + TEOS) molar ratio of 10%. The effect of synthesis conditions, including TEOS pre-hydrolysis, as well as the heating temperature and time, on the mesoscopical order and pore structure of the functionalized SBA-15 have been studied in detail by means of powder X-ray diffraction, nitrogen sorption, transmission electron microscopy, infrared spectra and solid state 29Si nuclear magnetic resonance. A functionalized SBA-15 silica with a highly ordered two-dimensional P6 mm hexagonal symmetry and a narrow pore size distribution centered at 6 nm can be obtained if TEOS is allowed to pre-hydrolyze for 2 h. For the sample with TEOS pre-hydrolysis time of 4 h, aging at 50°C or 150°C leads to a more ordered pore arrangement compared to 100°C and also a narrower pore size distribution with larger pore volume. Increasing aging time is in favor of the formation of mesoscopically ordered structure, but fails to obtain a superior pore structure.

Effect of synthesis conditions on the mesoscopical order of mesoporous silica SBA-15 functionalized by amino groups

Preparation and characterization of vinyl-functionalized mesoporous SBA-15 silica by a direct synthesis method

Direct synthesis of thiol-ligands-functionalized SBA-15: Effect of 3-mercaptopropyltrimethoxysilane concentration on pore structure

Facile synthesis of hydrophobic microporous silica membranes and their resistance to humid atmosphere

The present invention relates to Er-containing aluminum alloys with greatly improved strength properties without significant deterioration of the toughness. Specifically, the present application provides Al—Zn—Mg—Er and Al—Mg—Er series aluminum alloys and Al—Mg—Li—Zr—Er series alloys, the mechanical properties of which are improved by the addition of Er.

Jing-Xia Zou

Papers

Effect of synthesis conditions on the mesoscopical order of mesoporous silica SBA-15 functionalized by amino groups

Preparation and characterization of vinyl-functionalized mesoporous SBA-15 silica by a direct synthesis method

Direct synthesis of thiol-ligands-functionalized SBA-15: Effect of 3-mercaptopropyltrimethoxysilane concentration on pore structure

Facile synthesis of hydrophobic microporous silica membranes and their resistance to humid atmosphere

Er strengthening aluminum alloy