Abstract: A hydrous silica gel is dehydrated by freezing, thawing, and removing water separated by thawing, thereby yielding silica particles. In addition, the silica particles thus formed is washed and fired, thereby producing a synthetic quartz glass power. A water glass is dealkalized, an oxidizing agent and an acid are added, the mixture thus formed is passed through a hydrogen type cation exchange resin, the aqueous silica solution thus formed is then gelled, and the gelled material is then washed and fired, thereby producing a synthetic quartz powder. Silica is sequentially held for a predetermined time at each temperature range of 150 to 400° C., 500 to 700° C., and 1,100 to 1,300° C., thereby producing a quartz glass.

Abstract: A method of preparing a solution for forming a doped gel monolith includes providing a first substance including a metal alkoxide. The method further includes providing a second substance including a catalyst. The method further includes providing a chemical including a dopant. The method further includes forming a solution including the dopant, said forming including mixing the first substance and the second substance together. The method further includes cooling the solution to a mixture temperature which is at or below zero degrees Celsius, wherein the solution has a significantly longer gelation time at the mixture temperature than at room temperature.

Abstract: Cup-shaped porous silica preforms suitable for manufacture of large 24-inch crucibles used in Czochralski crystal-growing furnaces are produced by a unique electrophoretic casting process using a high-purity aqueous silica slip or slurry having a predetermined particle-size distribution, an average particle size of from 6 to 10 microns and a solids content of from 80 to 85 percent by weight. The slurry contains an electrolyte, such as ammonium hydroxide, has a pH of from 7.5 to 8.5, and can be wet milled at a pH of at least 7 in such manner as to provide the micronized silica particles with excellent electrophoretic mobility, thereby providing a superb process for economical mass production of large pure silica preforms using safe voltages, such as 20 to 40 volts. The electrophoretic casting apparatus can be of the type shown in FIGS.

Abstract: The use of large dense vitreous spherical (LDVS) silica powders for making sol-gel silica bodies has been found to have important advantages. Among these are higher gel strength, higher silica loading, more rapid aging and drying of the gel, a reduction in the amount of organic additives leading to reduced process time required for organic burn-off, and easier removal of contaminant particles due to their larger size. It was also discovered that combining LDVS particles with conventional non-spherical, lower density, aggregate particle mixtures, further improves the process.

Abstract: A simple, economic wet chemical procedure is described for making sol-gel fibers. The sol-gel fibers made from this process are transparent to ultraviolet, visible and near infrared light. Light can be guided in these fibers by using an organic polymer as a fiber cladding. Alternatively, air can be used as a low refractive index medium. The sol-gel fibers have a micro pore structure which allows molecules to diffuse into the fiber core from the surrounding environment. Chemical and biochemical reagents can be doped into the fiber core. The sol-gel fiber can be used as a transducer for constructing an optical fiber sensor. The optical fiber sensor having an active sol-gel fiber core is more sensitive than conventional evanescent wave absorption based optical fiber sensors.

Abstract: A method suited for producing thin fused glass articles includes, in preferred aspects, preparing a dry gel having edges configured to reduce or eliminate warping of the gel during densification of the gel. Preferred aspects include partially densifying the gel, machining the gel into a suitable shape, and fully sintering the gel. The gel preferably is a hybrid incorporating silicon alkoxide and fumed silica particles, and it preferably is machined to have chamfered edges. The method is easier and more cost-effective than those previously known, and it allows for production of high-quality articles for use in, for example, photomask systems as pellicles.

Abstract: A method of forming a gel monolith includes preparing a first solution comprising metal alkoxide and preparing a second solution comprising a catalyst. A third solution is prepared by mixing the first solution and the second solution together. At least one of the first, second, and third solutions is cooled to achieve a mixture temperature for the third solution which is substantially below room temperature, wherein the third solution has a significantly longer gelation time at the mixture temperature as compared to a room temperature gelation time for the third solution. The method further includes allowing the third solution to gel, thereby forming the gel monolith.

Abstract: Sol-gel process for the production of optical fiber preforms or overcladdings by preparing a sol, gelling the sol, drying the wet gel to a dry porous gel and densifying the dry gel to fully dense glass, wherein during the calcination treatment from 350° C. to 900° C. to remove organic impurities in the dry gel, it is carried out at least one reduced-pressure phase at a pressure comprised between about 0.01 and 0.5 bar.

Abstract: Using sol-gel techniques, an optical gain medium has been fabricated comprising a glass ceramic host material that includes clusters of crystalline oxide material, especially tin oxide, and that is doped with active ions concentrated at the clusters. The active ions are preferentially located at the nanoclusters so that they experience the relatively low phonon energy of the oxide and are insensitive to the phonon energy of the host. A host with a high phonon energy, such as silica, can therefore be used without the usual drawback of reduced carrier lifetimes through enhanced nonradiative decay rates.

Abstract: A method processes a gel monolith comprising pores filled with liquid, an inner region, and an outer region. The method includes removing a portion of the liquid from the pores of the gel monolith while both the inner and outer regions of the gel monolith remain wet. The method further includes shrinking the volume of the gel monolith during the removal of a portion of the liquid, with the gel monolith becoming correspondingly more dense. The method further includes subsequently removing substantially all of the remaining liquid from the pores of the gel monolith. Subsequently removing substantially all of the remaining liquid includes modulating a temperature gradient between the outer region and the inner region.

Abstract: A process for making transparent porous glass monoliths from gels. The glass is produced much faster and in much larger sizes than present technology for making porous glass. The process reduces the cost of making large porous glass monoliths because: 1) the process does not require solvent exchange nor additives to the gel to increase the drying rates, 2) only moderate temperatures and pressures are used so relatively inexpensive equipment is needed, an 3) net-shape glass monoliths are possible using this process. The process depends on the use of temperature to control the partial pressure of the gel solvent in a closed vessel, resulting in controlled shrinking during drying.

Abstract: A planar lens capable of compensating for chromatic aberration and which is easy to manufacture and enables easy assembling of optical pickups and a method for fabricating the planar lens are provided. The planar lens includes a transparent substrate with a lens cavity in a surface of the transparent substrate, and a lens element formed in the lens cavity with a first refracting surface in contact with the bottom of the lens cavity and a second diffracting surface having a diffraction grating opposite to the first refracting surface.

Abstract: Pyrogenically prepared silicon dioxide with the following physicochemical properties: 1. Average particle size (D50 value) D50?150 nm (dynamic light scattering, 30 wt %) 2. Viscosity (5 rpm, 30 wt %) ??100 m·Pas 3. Thixotropy of Ti (?(5 rpm))/(?(50 rpm))?2 4. BET surface area 30-60 m2/g 5. Compacted bulk=100-160 g/L 6. Original pH?4.5 that can be used for the preparation of dispersions and glass bodies.

Abstract: The subject of the invention is a process for manufacturing compounds based on one or more silicates of alkali metals, such as Na and K and/or alkaline earth metals such as Ca, Mg, and/or on rare earths, such as Ce, optionally in the form of mixed silicates which combine alkaline-earth metals, such as Ca, with the alkali metal(s) and the rare earth(s), by conversion of silica and of halides, especially of one or more chlorides, or sulfate or nitrate, of the said alkali metals and/or of the said rare earths and/or of the said alkaline-earth metals, such as NaCl, KCl or CeCl4. The heat needed for the conversion is supplied, at least partly, by one or more submerged burners. The subject of the invention is also an apparatus for carrying out the process and for its use.

Abstract: A method of manufacturing a xerogel monolith having a pore diameter distribution includes preparing a first solution comprising metal alkoxide and preparing a second solution comprising a catalyst. A third solution is prepared by mixing the first solution and the second solution together. At least one of the first, second, and third solutions is cooled to achieve a mixture temperature for the third solution which is substantially below room temperature, wherein the third solution has a significantly longer gelation time at the mixture temperature as compared to a room temperature gelation time for the third solution. The method further includes allowing the third solution to gel, thereby forming a wet gel monolith. The method further includes forming the xerogel monolith by drying the wet gel monolith.

Abstract: The present invention discloses a method for fabricating silica glass using a sol-gel process, which includes a sol forming step for forming a sol by mixing a starting material, deionized water and an additive together; gelation step for gelatinizing the sol after filling a circular mold with the gel produced; gel drying step for separating the gel from the circular mold and drying the gel; setting step for placing the gel inside of a heat chamber and injecting helium gas into the heat chamber; and low heat treatment step for pressurizing and depressurizing an internal pressure of the heat chamber repeatedly for several times.

Abstract: A coated glass product includes a glass substrate and a porous antireflection surface coating including SiO2-based particles having a first particle fraction including a first characteristic particle size range and a second particle fraction having a second characteristic particle size range that is different from the first characteristic particle size range. In addition, a method for producing the coated glass product is provided.

Abstract: The present invention relates to a method for forming an optical blank. The method includes providing a green body that has a non-porous exterior portion and a porous interior portion. The interior portion is evacuated to create a vacuum in the interior portion. The green body is then pressed using a hot isostatic pressing technique to densify the green body into a solid glass optical blank. This method produces homogeneous optical blanks having substantially no striae. The method also produces dense, inclusion free glass. As a result, scattering is substantially reduced when EUV light is reflected from a component produced from optical blank employing the method of the present invention.

Abstract: An optical system for optical communications is composed of a transparent material having a refractive index distribution formed by changing the molar ratio of metal oxide with valence of 2 or more. The metal oxide with valence of 2 or more includes, for example, Fe2O3. Using such an optical system for optical communications, optical communication components such as an optical fiber collimator and an optical isolator are composed.

Abstract: The amount of residual carbon and hydroxyl groups in a synthetic quartz powder made by a wet process is reduced by baking the synthetic quartz powder in a low pressure atmosphere. Quartz glass crucibles made using the synthetic quartz powder have low bubble contents, and are particularly suited for growing single crystals.

Abstract: A chemical vapor deposition process for preparing a low dielectric constant organosilicate (OSG) having enhanced mechanical properties by adjusting the amount of organic groups, such as methyl groups, within the mixture is disclosed herein. In one embodiment of the present invention, the OSG film is deposited from a mixture comprising a first silicon-containing precursor that comprises from 3 to 4 Si—O bonds per Si atom, from 0 to 1 of bonds selected from the group consisting of Si—H, Si—Br, and Si—Cl bonds per Si atom and no Si—C bonds and a second silicon-containing precursor that comprises at least one Si—C bond per Si atom. In another embodiment of the present invention, the OSG film is deposited from a mixture comprising an asymmetric silicon-containing precursor. In either embodiment, the mixture may further contain a porogen precursor to provide a porous OSG film.

Abstract: The present invention relates to a glass used as a sintering aid for a resorbable moulded body containing calcium phosphate as well as to a method for manufacturing said moulded body. According to the invention, the material is &bgr;-tricalcium phosphate and the glass has a chemical composition of 68-78% by weight SiO2, 5-12% by weight MgO and 12-27% by weight Na2O. The aforesaid moulded body is manufactured by melting said glass, grinding it until a grain size D50 of 0.7-2 &mgr;m is achieved and mixing it with &bgr;-tricalcium phosphate having a grain size D50 of 1-7.5 &mgr;m, giving the mixture the desired shape and producing the moulded body by sintering said mixture at between 1,150 and 1,350° C., wherein the grain size of &bgr;-TCP must not be smaller than that of the glass.

Abstract: A glass powder fabrication method is disclosed. Fine glass powder can be fabricated without a mechanical crushing process, a phenomenon that moisture is adsorbed to a particle surface of the glass powder or hydrated compound is generated is prevented, and a transmittance of a dielectric layer used for a PDP can be increased. A glass compound is dissolved in a solvent, the dissolved glass compound is atomized to create droplets, which are then melt to be vitrified.

Abstract: A method for the production of a homogenous, shaped SiO2 body of near net shape wherein amorphous SiO2 particles comprising relatively large amorphous SiO2 particles and relatively small amorphous SiO2 particles are electrophoretically deposited from an aqueous dispersion on an electrically nonconductive membrane, the shape and geometry of which correspond to the shaped SiO2 body to be produced, wherein the membrane has an average pore size which is larger than the average particle size of the smaller amorphous SiO2 particles.

Abstract: In a method for joining a joined material having a hydroxyl group containing surface to a joining material having an organosiloxay group containing surface, the organosiloxay group containing surface is irradiated by ultraviolet radiation having wavelength of less than 220 nm thereby carrying out an oxidization treatment, and the hydroxyl group containing surface is adhered to the oxidized organosiloxay group containing surface.

Abstract: A partially modified photosensitive monolithic oxide glass apparatus formed through photolithographic imaging. The apparatus may be either a volume apparatus or a layer apparatus. Both types of apparatus may be used to diffuse light in predetermined directions or shapes. The monolithic oxide glass apparatus is capable of withstanding temperatures well beyond glass transition temperatures of plastic light shaping devices and can be formed in convex or concave surfaces through conventionally molding grinding or polishing techniques and can be coated by hot-coating techniques.

Abstract: A method of fabricating a halogen-doped glass includes providing a gel monolith having a first halogen content. The method further includes reducing an impurity concentration of the gel monolith. The method further includes consolidating the gel monolith into a glass having a second halogen content. The second halogen content is less than or equal to the first halogen content. A halogen-doped glass has a fluorine content in a range between approximately 0.5 wt. % and approximately 4 wt. %, a chlorine content less than 100 parts per million, and an OH content less than one part per million.

Abstract: Techniques for producing a glass structure having interconnected macroscopic pores, employing steps of filling polymerizable glass precursors into pores in a polymeric structure having interconnected macroscopic pores; polymerizing the precursors; and decomposing the polymers to produce a glass oxide structure having interconnected macroscopic pores. Further techniques employ steps of exposing portions of a photosensitive medium including glass precursors to an optical interference pattern; polymerizing or photodeprotecting the exposed portions and removing unpolymerized or deprotected portions; and decomposing the polymerized or deprotected portions to produce a glass structure having interconnected macroscopic pores. Techniques for filling pores of such glass structure with a material having a high refractive index, and for then removing the glass structure.

Abstract: A method for the manufacture of colored structures of a glass, particularly for applying an inscription to the glass, by locally heating volume elements of the glass by means of a laser beam, which glass contains ions of metals which, in the form of submicroscopic particles, color the glass wherein the local heating of the non-doped glass is accomplished through a solution or gel of a metallic salt which transmits the laser beam well and is directly contacted with a surface of the glass.

Abstract: A method for forming single element arc tubes is provided. The method includes the use of the lost foam process in combination with ceramic forming processes. First, a polymeric material (20) is formed to define the internal dimensions. The outer dimensions are established with an external mold (40), followed by filling the mold with a suspension (60) that hardens. The outer mold is removed and the part is debindered to melt and remove the inner foam shape, followed by sintering to form a substantially transparent ceramic arc tube (70).

Abstract: A method of machining a glass substrate by using a laser, in which a low-permittivity, low-dielectric-loss glass substrate capable of coping with mass production processes is made applicable as the substrate of a high-frequency circuit intended for microwave and millimeter-wave bands in particular. For that purpose, a glass substrate is provided in which the amount of air bubbles in glass is arbitrarily controlled to improve the workability of the substrate itself. Then, the glass substrate is machined while being irradiated with a pulsed laser for a plurality of times, thereby improving the machining shape of the glass substrate. Since glass substrates which are typically difficult to machine can be easily applied to the fabrication of high-frequency circuits, it becomes possible to supply high-performance circuits and apparatuses widely to the public.

Abstract: A process for producing an inorganic porous material, comprising the steps of preparing an aqueous medium solution containing water-glass as a silica source, a water-soluble polymer and an acid, causing phase separation and gelation in the solution at the same time to form a wet gel, and washing and drying the gel.

Abstract: A method for modification of glass-based microchannels, which uses liquid organic-based solution containing siloxane for the modification of microchannels on the glass substrate, such as quartz, boron glass, sodium glass, and the like, to form a solid film to isolate the glass surface of the microchannels from the environment. Therefore, the present invention can be applied for electrophoresis experiment, so that the operation causes no electrical-double-layer effects, and further eliminates the occurrence of electro-osmosis flow, thus the separation efficiency of electrophoresis chips is improved.

Abstract: Unique catalyst compositions and methods of using the compositions wherein the catalysts include a nucleophilic functionality and a hydrogen-bonding acceptor group and are used in the synthesis of silica, glass, silicones, and polymetallooxanes at low temperatures and at about neutral pH.

Abstract: Dental glass powders, methods for producing the powders and dental compositions including the glass powders. The powders preferably have a well-controlled particle size, narrow size distribution and a spherical morphology. The method includes forming the particles by a spray pyrolysis technique. The invention also includes dental filler and restorative compositions that include the glass powders.

Abstract: A microstructure for chemical processing and manufacture is disclosed. The microstructure includes a plurality of microchannel walls constructed of glass, ceramic, glass-ceramic or combinations of these materials, which define at least one microchannel for accommodating chemicals to be processed. At least one coating layer including a catalyst support and a catalyst is adhered to the plurality of microchannel walls. A method of manufacturing a microstructure for chemical processing and manufacture is also disclosed.

Abstract: The present invention is directed to a method of making an ultra dry high purity, Cl-free, F doped fused silica glass. Silica powder or soot preforms are used to form a glass under conditions to provide a desired level of F doping while reducing the Cl and −OH concentrations to trace levels. The method includes providing a glass precursor in the from of a silica powder or soot preform. The powder is heated in a furnace. The powder is exposed to a F-species at a predetermined temperature and time sufficient to melt the powder and form a high purity fused silica glass in the bottom of said furnace.

Abstract: Methods are provided for making and using thin films of porous silica substrates to synthesize arrays of polymers. Methods are also provided for assaying such polymers on porous silica substrates. The porous silica substrates offer an increase in array density and signal enhancement over conventional flat glass substrates. Examples of polymers that can be synthesized and assayed include biological polymers such as nucleic acids, polynucleotides, polypeptides, and polysaccharides. Arrays of nucleic acids or polynucleotides can be used for a variety of hybridization-based experiments such as nucleic acid sequence analysis, nucleic acid expression monitoring, nucleic acid mutation detection, speciation, effects of drug therapy on nucleic acid expression, among others.

Abstract: Disclosed are silica structure crack detection methods and apparatuses particularly useful in sol-gel fabrication processes. A wave signature of a crack in the silica structure is sensed to indicate that cracking has occurred. Sensing may be by active or passive techniques and may include contact and non-contact methods of monitoring. Further disclosed is a silica structure fabrication process development method wherein cracks are monitored by sensing a wave signature of a crack to isolate a process step or steps in which cracking has occurred. Process parameters are then adjusted in the isolated step to diminish or eliminate cracking.

Abstract: A process for making transparent porous glass monoliths from gels. The glass is produced much faster and in much larger sizes than present technology for making porous glass. The process reduces the cost of making large porous glass monoliths because: 1) the process does not require solvent exchange nor additives to the gel to increase the drying rates, 2) only moderate temperatures and pressures are used so relatively inexpensive equipment is needed, an 3) net-shape glass monoliths are possible using this process. The process depends on the use of temperature to control the partial pressure of the gel solvent in a closed vessel, resulting in controlled shrinking during drying.

Abstract: The present invention relates to a preform for a glass ferrule and a fabrication method thereof. It is an objective of the present invention to fabricate dual hole ferrules having various distances between two holes by using a single preform. It is another objective of the present invention to fabricate a preform for a dual hole glass ferrule by a simple process. To meet the above and other objectives, the present invention provides a preform for a glass ferrule, comprising two holes which are formed through the preform and exit out both side cross-sections of the preform, wherein the two holes are symmetrical to the center in a diameter direction of the preform and a distance between the two holes changes in a lengthwise direction of the preform.

Abstract: Methods and apparatus for manufacturing titania-containing fused silica bodies and optical elements are described. The titania-containing fused silica bodies can be subsequently processed to make extreme ultraviolet optical elements. The methods and apparatus involve providing a sol including a titania-containing silica powder, forming the sol into a shaped gel and drying and heating the gel to a glass body.

Abstract: It is described a sol-gel process that allows to obtain dry gels, and possibly the corresponding dense glassy bodies, having higher dimensions compared to similar known processes.

Abstract: The present invention is directed to a method and apparatus for forming soot used in making glass, and in particular, optical waveguides. A liquid precursor (66) is first fed into orifice (52) of a liquid orifice insert (48) within an injector (44) positioned within an atomizing burner assembly, and is thereafter discharged from the injector into a pressurization chamber (56). An atomization gas (70) is also fed into the pressurization chamber (56) to mix with the liquid precursor liquid stream (68) which breaks into droplets (76). The liquid precursor and atomization gas arm forced under pressure out of an atomization orifice (32) on the face of the burner (30) assembly. Flame gas (74), reaction gas (84) and shield gas (82) are ejected from burner orifices (40, 38, 36 and 34) to produce the flame.

Abstract: A new method is disclosed for producing thin plates by sintering a thin gel plate (e.g., silica) made using a sol-gel process, which substantially eliminates warpage of the plate during the sintering step. Sintering a sol-gel based silica plate to a dense glass typically causes significant shrinkage, and this can cause the plate to curl, especially around its edges. This phenomenon is referred to as warpage. In the method of the invention, the sintering step is performed while the gel plate is mounted on a support surface, separated by a thin layer of refractory powder. At the high sintering temperature, the powder partially fuses and sticks to both the gel plate and the support surface, which prevents non-uniform stresses in the gel plate from warping the plate.

Abstract: A method for forming EUV LITHOGRAPHY GLASS STRUCTURES WITH VOIDS is disclosed which includes forming a slurry mixture including silica soot particles, and inserting the slurry mixture into a casting mold. The method provides low weight mass reduced rigid glass structures with beneficial thermal stability. The casting mold includes therein a casting form. The casting form is adapted to provide selected geometry void spaces within the glass lithography structure. The slurry mixture is dried to form a green ware object. The casting form is removed from the green ware and the green ware object is consolidated into a lithography glass structure with voids.

Abstract: A method suited for producing thin fused glass articles includes, in preferred aspects, preparing a dry gel having edges configured to reduce or eliminate warping of the gel during densification of the gel. Preferred aspects include partially densifying the gel, machining the gel into a suitable shape, and fully sintering the gel. The gel preferably is a hybrid incorporating silicon alkoxide and fumed silica particles, and it preferably is machined to have chamfered edges. The method is easier and more cost-effective than those previously known, and it allows for production of high-quality articles for use in, for example, photomask systems as pellicles.

Abstract: The inner shape of the body part in a hollow ceramic molded article constituting a precursor of a discharge vessel is precisely controlled so as to make a large improvement in the function of a discharge vessel formed by baking the hollow ceramic molded article.

Abstract: Process for the production of an intumescent fire resistant layer by drying a waterglass solution on the surface of a glass substrate are carried out in the presence of a salt of a carbonic acid or an &agr;-hydroxy carboxylic acid such as potassium citrate. The drying is preferably carried out at a rate which reduces of pH of the solution by no more than 2 units during an initial drying period of 5 hours. The resulting interlayers provide improved fire resistance.

Abstract: The invention relates to the use of gelation moulds made from hydrophobicized glass tubes for the production of monolithic mouldings as sorbents for chromatography.