Liquid deposition, highly networks

Liquid Deposition of Highly Aligned Networks of SWNTs... 

Liquid deposition of SWNT networks presents another major step toward the inclusion of SWNTs into manufacturable device structures. This is due to the fact that liquid deposition, combined with a laminar flow drying technique allows the formation of highly aligned SWNTs electrical networks (15, 16). In a maimer similar to molecular combing of DNA, high purity air is applied to the air/liquid interface in a manner which aligns the SWNTs in aqueous suspension and then deposits them on a desired substrate. 

There are two procedures used to prepare dealuminated zeolites. One procedure involves a rapid hydrothermal dealumination at a relatively high temperature of 500°C (10,11). The resulting material contains a network of larger zeolitic mesopores within the crystal and connecting directly to the zeolitic pore system. Another procedure uses silicon hexafluoride at a relatively low temperature, <100°C (12). The result is a slow dealumination with the formation of much less mesopore structure. The two procedures result in zeolites that differ in the distribution of active framework aluminum sites as well as in the presence or absence of mesoporosity. The liquid phase dealumination results in a zeolite with the active aluminum sites preferentially removed from the outside of the zeolite particle or crystal. Further, during the dealumination process, additional silicon is deposited on the zeolite surface (13). The exact opposite happens during hydrothermal dealumination. While the framework is more or less uniformly dealuminated, the aluminum atoms removed from the framework do not remain within the pore system, but are observed to migrate to the outside of the zeolite particle (14). Consequently, unless the alumina is removed, the outside of the zeolite particle is alumina rich. 

Essentially, concrete is a hard sponge with a network of small conduits or capillaries allowing directional passage of water firom interior to exterior regions to cool hot contact surfaces. However, as moisture moves within the concrete, small amounts of soluble salts are in solution which deposit within the pores of the concrete as the water quickly evaporates during the fire event. As the salt deposit fills-in the voided areas, the concrete pores become blocked and do not allow further transfer of water to cool high-temperature contact surfaces. Therefore, the water accumulates behind this barrier and is phase changed from a liquid into a gas. 

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