Abstract:
Gradient-index glass is produced in a sol-gel process by utilizing water or a mixture of water and alcohol. This technique is particularly suitable for production of glass bodies with a ternary system of metal alkoxides, including silicon alkoxide, an index modifying metal alkoxide, such as alkoxides of titanium and zirconium, and an additional metal alkoxide, such as an alkoxide of aluminum, boron, or germanium.
Abstract:
This invention relates to the immobilization of toxic, e.g., radioactive materials, internally in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive anions, and in some cases cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are internally incorporated into a glass matrix, having hydrous organofunctionalsiloxy groups, e.g., hydrous aminoalkylsiloxy or carboxyorganosiloxy, bonded to silicon atoms of said glass and/or hydrous polyvalent metals bonded to silicon atoms of said glass through divalent oxygen linkages or otherwise immobilized therein, by a process which involves the ion exchange of said toxic, radioactive anions with hydroxyl groups attached to said organofunctionalsiloxy groups or with hydroxyl groups attached to the hydrous polyvalent metal. Thereafter, the resulting glass now characterized by a distribution of internally bonded or immobilized, toxic, radioactive anions can be packaged in suitable containers, and disposed of as by burial, and/or they can be sintered to collapse the pores thereof to disposal or for producing useful radiation sources. The porous glass or a porous silica gel having said silicon-bonded organofunctionalsiloxy groups and/or said hydrous polyvalent metal oxy groups, the pores of said glass or silica gel remaining open and uncollapsed, can be used advantageously as a backfill for an underground radioactive waste burial site and as overpack in the waste disposal container. Also included is a novel method for bonding the polyvalent metal to the porous silica glass or gel by substituting the protons of the silicon-bonded hydroxyl groups thereof with an alkali metal or ammonium cation followed by displacement of said cation with the non-radioactive polyvalent metal cation.
Abstract:
In producing silica glass, which may contain additional metal(s) such as Ti or Zr, from a solution of a silicon alkoxide, mixed with alkoxide(s) of the additional metal(s) where necessary, in water and a hydrophilic organic solvent by shaping the solution into a desired form such as a coating film on a substrate, self-supporting film, fiber or lump when the solution exhibits a suitably high viscosity and sufficiently heating the shaped solution, a water-soluble organic polymeric substance is added to the solution as a viscosity adjusting agent to soon increase the viscosity of the solution to the desirable level. Therefore, shaping of the solution can be performed without awaiting the progress of hydrolysis of the alkoxide in the solution, and the glass can be obtained with improved uniformity of its properties. A cellulose ether is preferred as the viscosity adjusting agent, and hydroxypropyl cellulose is particularly preferable.
Abstract:
This invention relates to the immobilization of toxic, e.g., radioactive materials, internally in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive anions, and in some cases cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are internally incorporated into a glass matrix, having hydrous organofunctionalsiloxy groups, e.g., hydrous aminoalkylsiloxy or carboxyorganosiloxy, bonded to silicon atoms of said glass and/or hydrous polyvalent metals bonded to silicon atoms of said glass through divalent oxygen linkages or otherwise immobilized therein, by a process which involves the ion exchange of said toxic, radioactive anions with hydroxyl groups attached to said organofunctionalsiloxy groups or with hydroxyl groups attached to the hydrous polyvalent metal. Thereafter, the resulting glass now characterized by a distribution of internally bonded or immobilized, toxic, radioactive anions can be packaged in suitable containers, and disposed of as by burial, and/or they can be sintered to collapse the pores thereof prior to disposal or for producing useful radiation sources. The porous glass or a porous silica gel having said silicon-bonded organofunctionalsiloxy groups and/or said hydrous polyvalent metal oxy groups, the pores of said glass or silica gel remaining open and uncollapsed, can be used advantageously as a backfill for an underground radioactive waste burial site and as overpack in the waste disposal container. Also included is a novel method for bonding the polyvalent metal to the porous silica glass or gel by substituting the protons of the silicon-bonded hydroxyl groups thereof with an alkali metal or ammonium cation followed by displacement of said cation with the non-radioactive polyvalent metal cation.
Abstract:
A method of producing a glass body composed of two or more oxides by the flame hydrolysis technique, for example incorporating an additive or dopant oxide in a fused silica glass body. The method comprises forming a gas stream containing vapors of a compound that will hydrolyze to a glass forming oxide, e.g. silicon tetrachloride (SiCl4), entraining an oxide, or material convertible thereto, in the form of solid particles not over about one micron in size, and simultaneously passing the vapors and particles into a flame of combustible gas to form and codeposit an oxide mixture.
Abstract:
A copper-doped glass formed by placing a target glass in a container, surrounding the target glass with a powder mixture comprised of SiO2 powder and Cu2S powder, wherein the SiO2 powder and the Cu2S powder are mixed according to the formula (SiO2)(1-x)(Cu2S)x, where 0.01
Abstract:
Disclosed are a wollastonite crystallized glass for an artificial tooth and a method for coloring same, the method enabling a production of a uniform shade without degrading the physical properties of a crystallized glass by means of simply adding a small amount of coloring additive powder when preparing the crystallized glass.
Abstract:
Near-infrared shielding includes a glass material. The shielding provides transmittance at wavelengths between 390 to 700 nm, but near infrared absorbing species are distributed throughout the glass material and the shielding blocks light in the near infrared range. Further, the glass material has a near zero or negative coefficient of thermal expansion, allowing the glass material to heat up when the shielding is blocking a near infrared laser, without expanding much.
Abstract:
A cover glass lamination structure includes: a glass substrate having opposed first and second surfaces; an ultraviolet (UV) textured layer disposed on the first surface; and a coating layer disposed on the UV textured layer, wherein an inner edge of the coating layer extends beyond an inner edge of the UV textured layer and is attached to the first surface.