Gas Research Institute

The United States of America As Represented by the United States

United States of America As Represented by the Secretary of the Air Force

The Penn State Research Foundation

Research, Incorporated

Sridhar Komarneni

Rustum N Roy

Prakash B Malla

Shoji Yamanaka

Della M Roy

William W Gould

Ann M Kazakos

Transition metal NZP type compounds are synthesized. Examples of these compounds include MnZr (PO ) , FeZr (PO ) , CoZr (PO ) , NiZr (PO ) , and CuZr (PO ) . These compounds are synthesized by the Xerogel process. These transition metal NZP type compounds can be used as colorants in applications such as ceramic glazes where high thermal stability of the colorant is important.

High stability transition metal NZP type phosphates

Disclosed is a method for treating synthetic zeolite to remove organic template material therefrom and concurrently therewith effect dealumination of the zeolite. The method comprises the steps of providing a body of synthetic zeolite containing organic template material, the zeolite having an SiO.sub.2 /Al.sub.2 O.sub.3 ratio of at least 7:1. The body is treated with a solution comprised of an alcohol selected from methanol, ethanol and propanol and an acid selected from hydrochloric, nitric and sulfuric acid at a temperature and time to remove the organic template material therefrom and to effect dealumination thereof to provide a treated zeolite product. The treated product is washed to remove residual solution and then dried to provide a synthetic zeolite product containing a reduced amount of organic template material and having an SiO.sub.2 /Al.sub.2 O.sub.3 ratio of at least 7:1.

Dealumination and selective removal of organic material from zeolites

The present invention relates to a controlled process for producing amorphous, microporous silica gels having a predetermined water sorption isotherm of moderate Type I shape having a separation factor between about 0.07 and 0.1 and micropore diameter size between about 6 and 8.7 angstroms. The present microporous silica gels are prepared by adjusting the pH of the reaction system or by doping the system with various elements during the hydrolysis and condensation of alkoxy silicates to form silica gels therefrom, and the hydrolyzed products are successively polymerized to form polymers and particles containing siloxane bonds as follows: ##STR1## Various factors, for example open vs closed system, amount of water used for hydrolysis, type of alkoxides and solvent, pH, amount of catalyst, temperature, aging and drying conditions etc., affect the nature and the rate of hydrolysis, condensation reactions and network formation, and consequently the properties of the final gel products.

Silica gels of controlled pore size as desiccant materials and processes

In order to measure the adsorption and desorption characteristics of water vapor by a porous or powdery sample, the sample is placed in an automated device which measures the difference between an equilibrium pressure and a sample pressure for various values of sample pressures, during both adsorption and desorption. A programmable computer calculates the amount of water vapor adsorption and desorption based upon the equilibrium pressure and can be used to control a printer for plotting the resulting data.

Apparatus for measuring liquid vapor adsorption and desorption

The present invention provides for a process of reducing the polarity on the internal surfaces of various zeolites having a SiO.sub.2 to Al.sub.2 O.sub.3 ratio of at least about 3 and an average pore diameter size within the range of from about 4 to about 10 angstroms. The modified zeolites in accordance with the present invention are prepared by heating the starting zeolite in an aqueous medium also containing an acid or a source of ammonium ions to at least partially dealuminize the zeolite and thereby increase the ratio of silicon to aluminum present in the tetrahedral structure. At the same time, the process provides for hydrogen ion exchange with respect to those zeolites which contain significant amounts of metallic cation in the structure thereby replacing the bulky metallic cations with less bulky hydrogen ions and thereby increasing the water adsorptive capacity of the zeolite. Achievement of the appropriate equilibrium between reduced surface polarity on the one hand and increased sorptive capacity of the zeolite on the other hand gives rise to zeolite materials having an isotherm with a separation factor within the range of from about 0.07 to about 0.1 which renders the modified zeolite an ideal desiccant for gas fired air conditioning and dehumidification equipment.

Desiccant materials for use in gas fired cooling and dehumidification

Compositionally triphasic nanocomposite gel is made by mixing two or more sols of ceramic precursor oxides. Such gel is then dried and ground to a fine powder which is pressed into compact bodies. The compact bodies are thereafter fired in a sintering oven at from 1100.degree. C. to 1400.degree. C. and, aided by the heat of reaction of the two or more nono gel powders, the (heterogeneous) mixture of such powders crystallizes into a homogeneous crystalline ceramic of .alpha.-cordierite at up to 100% of theoretical density. Thus, novel method of manufacture and novel ceramic end-product are provided.

Highly dense cordierite and method of manufacturing same

Ceramic oxide diphasic xerogels of structurally dissimilar phases (crystalline and amorphous, semicrystalline or noncrystalline) but compositionally similar phases will be converted to crystalline ceramic oxide products having enhanced densification when subjected to substantially lower sintering temperature.

Method of preparing ceramic compositions at lower sintering temperatures

Cesium can be selectively recovered from a nuclear waste solution containing cesium together with other metal ions by contact with a modified phlogopite which is a hydrated, sodium phlogopite mica. Once the cesium has entered the modified phlogopite it is fixed and can be safely stored for long periods of time.

Process for cesium decontamination and immobilization

A new cation exchanger is a modified tobermorite containing aluminum isomorphously substituted for silicon and containing sodium or potassium. The exchanger is selective for lead, rubidium, cobalt and cadmium and is selective for cesium over calcium or sodium. The tobermorites are compatable with cement and are useful for the long-term fixation and storage of radioactive nuclear wastes.

Growing community of inventors

State College, PA, United States of America

Sridhar Komarneni