Nanocrystal HZSM-5 zeolite aggregates with different SiO2/Al2O3 molar ratios were prepared under low temperature and were used to catalyze the conversion of methanol to propylene and butene. The coke location, coke content, and coke species deposited on HZSM-5 aggregates were investigated. The near-graphite carbon on the external surface of HZSM-5 zeolite (SiO2/Al2O3 molar ratio = 400) was dist...

SiO2/high-κ dielectric stack is a candidate for replacing the conventional SiO2-based dielectric stacks for future Flash memory cells. Electron traps in the high-κ layer can limit the memory retention via the trap-assisted tunneling, and there is a pressing need for their characterization. A new two-pulse C–V measurement technique is developed in this letter, which, for the first time, allows u...

Protein aggregation is a problem in biotechnology. High temperature is one of the most important reasons to enhance enzyme inactivation and aggregation in industrial systems. This work focuses on the effect of TiO2 and SiO2 nanoparticles on refolding and reactivation of lysozyme. In the presence of TiO2 and SiO2 nanoparticles, after enzyme heat treatment at 98C for 30 min, not only aggregates w...

The doping effects of Al2O3 on SiO2 ( -cristobalite) have been studied by first principles calculations, with emphasis on the structural, electronic and optical properties. Compared to pure SiO2 crystal, the electronic density of states (DOS) of the Al2O3 doped SiO2 show significant changes. The electron energy states corresponding to the newly emerged sharp DOS peaks are found to exhibit local...

This paper reports the fabrication of a novel microsensor structure using inductively coupled plasma source (ICP) dry etching process. The novel sensor is based on a SiO2/Si/SU-8 trilayered microcoil/microspring structure. The diameter of the microcoil was approximately 600 m. The ICP process and SU-8 exposing time are discussed. The SiO2 layer can be conveniently modified according to typical ...

Binary SiO2/TiO2 and SiO2/Fe2O3 nanoparticle (diameter < 100 nm) aerosols of varying mole ratios of Ti or Fe to Si were generated in a premixed Bunsen-type aerosol flame reactor. The distribution of species within the particles was investigated using transmission electron microscopy, electron energy loss spectrometry, x-ray diffraction, and Fourier transform infrared spectroscopy. Phase segrega...

Complex engineered nanomaterials (CENs) are a rapidly developing class of structurally and compositionally complex materials that are expected to dominate the next generation of functional nanomaterials. The development of methods enabling rapid assessment of the toxicity risk associated with this type of nanomaterial is therefore critically important. We evaluated the toxicity of three differe...

Zirconium oxide (ZrO2) is one of the leading candidates to replace silicon oxide (SiO2) as the gate dielectric for future generation metal-oxide-semiconductor (MOS) based nanoelectronic devices. Experimental studies have shown that a 1–3 monolayer SiO2 film between the high permittivity metal oxide and the substrate silicon is needed to minimize electrical degradation. This study uses density f...

Application of silica nanoparticles (SiO2-NPs) may result in human exposure. Here we investigate unexplored modes of action by which SiO2-NPs with average size of 225 nm act on human hepatoma cells (Huh7). We focused on the endoplasmic (ER) stress response and on mitogen-activated protein kinase (MAPK) signaling pathways. Both pathways were induced. ER stress and the associated three unfolded p...

The effect of radio frequency ~rf! bias frequency on SiO2 feature etching using inductively coupled fluorocarbon plasmas is investigated. It is found that the rf bias frequency can have an important effect on SiO2 feature etch rate, microtrenching phenomena, and SiO2-to-photoresist etch selectivity. In addition, the effect of rf bias pulsing on inductively coupled fluorocarbon plasma SiO2 etchi...