Immobilization Of Colloidal Particles Research Articles

High density gold nanoparticles immobilized on surface via plasma deposited APTES film for decomposing organic compounds in microchannels

Immobilization of colloidal particles (e.g. gold nanoparticles (AuNps)) on the inner surface of micro-/nano- channels has received a great interest for catalysis. A novel catalytic ozonation setup using a gold-immobilized microchannel reactor was developed in this work. To anchor AuNps, (3-aminopropyl) triethoxysilane (APTES) with functional amine groups was deposited using plasma enhanced chemical vapor deposition (PECVD) process. The results clearly evidenced that PECVD processing exhibited relatively high efficiency for grafting amine groups and further immobilizing AuNPs. The catalytic activity of gold immobilized microchannel was evaluated by pyruvic acid ozonation. The decomposition rate calculated from High Performance Liquid Chromatography (HPLC) indicated a much better catalytic performance of gold in microchannel than that in batch. The results confirmed immobilizing gold nanoparticles on plasma deposited APTES for preparing catalytic microreactors is promising for the wastewater treatment in the future.

Immobilization of colloidal particles into sub-100 nm porous structures by electrophoretic methods in aqueous media

Conventional direct current (DC) and pulse-DC assisted electrophoretic depositions of colloidal particles, with average sizes of 10 and 50nm, into sub-100nm scaled pore arrays made from anodized aluminum substrate has been investigated. At the applied voltages lower than the decomposition voltage of water (∼1V), the number concentration of particle deposited on the surface by conventional DC was higher than that of pulse DC. The number of deposited particles increased with increasing pH. Deposition efficiency inside the pores can be enhanced by applying pulse DC. In the case of high (∼10V) applied voltage, no particles were observed inside pores even though pulse DC has been applied. The adhesion strength (removal behavior) of deposition was evaluated by applying a particle detachment simple system based on ultrasonic energy. The particles deposited inside the pores were not detached compared with those of the surface of the substrate.

ChemInform Abstract: Immobilization of Colloidal Platinum Particles onto Polyacrylamide Gel Having Amino Groups and Their Catalyses in Hydrogenations of Olefins

Colloidal platinum dispersions, prepared by photo-reduction of tetrachloroplatinate(II) ion in the presence of a copolymer of N-vinyl-2-pyrrolidone and acrylamide, are treated with polyacrylamide gel having amino groups, resulting in stable immobilization of colloidal particles onto the gel. The immobilized catalysts exhibit high activities in hydrogenations of olefins at 30 °C under 1 atm.