摘要:
In using partially alkali metal exchanged forms of FAU zeolite as selective adsorbents for use in insulated glass windows, particularly for use in a matrix in insulated glass windows, it has been discovered that significant reduction in the nitrogen loading on the zeolite results when the alkali metal content is maintained at a low level. For example, such FAU zeolites, particularly zeolite X which has been ion-exchanged with potassium ions to a level of between about 5 and about 75 equivalent mole percent indicate a nitrogen adsorption loading of between about 400 and 600 percent lower than unexchanged zeolite X and about 200 percent less than fully potassium exchanged zeolite X. The adsorbent is particularly useful in a sealant matrix for insulated glass windows and may be used in combination with zeolite A to reduce out-gassing problems.
摘要:
Difluoromethane (R32) is of current interest as a partial replacement for chlorodifluoromethane (R22) refrigerant heretofore widely used in vapor compression refrigeration systems. R32 has, however, proved to be more reactive than is desirable with the zeolite A adsorbent-desiccant compositions used in such systems to prevent corrosion and freeze-up problems. The sodium cation form of a zeolite having the crystal structure of zeolite B is found to be an effective adsorbent for that purpose and to be significantly less reactive with the R32.
摘要:
A process of forming an array of powder samples arranged in predefined locations where all samples have a flat surface in a common plane has been developed. A main support having at least N perforations from a first surface of the main support through a second surface of the main support in predefined locations. The main support is equipped with a flat support temporarily attached to its first surface. All samples are loaded simultaneously. A flat surface of each sample, where the flat surfaces are a common plane, is formed by forcing the samples within the perforations against the flat support. The samples are retained in position within the perforations against the flat support using at least one cover. The flat surfaces of the samples are in predefined locations and are all in a common plane.
摘要:
A process of forming an array of powder samples arranged in predefined locations where all samples have a flat surface in a common plane has been developed. A main support having at least N perforations from a first surface of the main support through a second surface of the main support in predefined locations. The main support is equipped with a flat support temporarily attached to its first surface. All samples are loaded simultaneously. A flat surface of each sample, where the flat surfaces are a common plane, is formed by forcing the samples within the perforations against the flat support. The samples are retained in position within the perforations against the flat support using at least one cover. The flat surfaces of the samples are in predefined locations and are all in a common plane.
摘要:
Low silica forms of faujasite-type zeolites are prepared from more siliceous forms of the same zeolite species by contacting the starting zeolite with a highly caustic concentrated sodium aluminate solution at elevated temperatures. In view of the fact that the process does not favor the formation of undesirable impurity phases such as zeolite A and thus does not require the presence of zeolite A nucleation inhibitors, the process is particularly advantageous in the production of forms of zeolite X having Si/Al.sub.2 molar ratios below 2.5.