Abstract:
Porous polymers are made by adding biologically active agent and growth substrates (e.g., yeast and sugar, preferably in the presence of water or other suitable fluid) to a polymer forming material, which may be a liquid. The yeast acts on the sugar, forming carbon dioxide gas bubbles. The material is then polymerized so that the gas bubbles create permanent pores within the polymeric material. The polymer can be an epoxy for example. The pores will contain residue of the yeast. Also, porous metals can be made by combining a metal powder with yeast, sugar, and water. The porous metal paste is then sintered. Porous ceramics and semiconductors can be made by combining the yeast and sugar with a ceramic forming liquid such as polysilazane. Polysilazane converts to silica when heated, which helps to bind the ceramic or semiconductor powder particles at a reduced temperature. Biological agents other than yeast (e.g. bacteria, enzymes), and growth substrates other than sugar can also be used.
Abstract:
An improved porous article and a method for forming such porous article are provided. A mixture of ceramic or metal particles and pliable organic hollow spheres is prepared in a liquid, typically as a suspension. The article is formed by pressing, slip casting, extruding or injection molding the mixture. The article is dried to remove the liquid, and then is fired so that the particles are bonded such as by sintering, and the organic spheres are eliminated, resulting in a strong porous article having uniformly spaced interconnected voids.
Abstract:
An improved porous article and a method for forming such porous article are provided. A mixture of ceramic or articles and pliable organic hollow spheres is prepared in a liquid typically as a suspension. The article is formed by pressing, slip casting, extruding or injection molding the mixture. The article is dried to remove the liquid, and then is fired so that the particles are bonded such as by sintering, and the organic spheres are eliminated, resulting in a strong porous article having uniformly spaced interconnected voids.
Abstract:
The present invention relates to a solid high temperature phosphorus diffusion source that is an R.sub.2 O.sub.3 /P.sub.2 O.sub.5 compound in which the ratio of R.sub.2 O.sub.3 to P.sub.2 O.sub.5 is 1 to 3 and R is La, Y, Ce, Nd, Eu, Pt, Sm, Ho, Tb, Er, Yb, Tm or Dy. The invention also relates to a method of making the diffusion source, a method of using the diffusion source to evolve P.sub.2 O.sub.5 to dope a silicon wafer, and to the doped silicon wafer.
Abstract:
The present invention relates to a solid high temperature phosphorus diffusion source that is an R.sub.2 O.sub.3 /P.sub.2 O.sub.5 compound in which the ratio of R.sub.2 O.sub.3 to P.sub.2 O.sub.5 is 1 to 3 and R is La, Y, Ce, Nd, Eu, Pr, Sm, Ho, Tb, Er, Yb, Tm or Dy. The invention also relates to a method of making the diffusion source, a method of using the diffusion source to evolve P.sub.2 O.sub.5 to dope a silicon wafer, and to the doped silicon wafer.
Abstract:
The present invention relates to a solid low temperature phosphorus diffusion source that is an R.sub.2 O.sub.3 /P.sub.2 O.sub.5 compound in which the ratio of R.sub.2 O.sub.3 to P.sub.2 O.sub.5 is 1 to 5 and R is Nd, Eu, Pr, Sm, Ho, Tb, Er, Yb, Tm or Dy. The invention also relates to a method of making the diffusion source, a method of using the diffusion source to evolve P.sub.2 O.sub.5 to dope a silicon wafer, and the doped silicon wafer.
Abstract:
Porous polymers are made by adding biologically active agent and growth substrates (e.g., yeast and sugar, preferably in the presence of water or other suitable fluid) to a polymer forming material, which may be a liquid. The yeast acts on the sugar, forming carbon dioxide gas bubbles. The material is then polymerized so that the gas bubbles create permanent pores within the polymeric material. The polymer can be an epoxy for example. The pores will contain residue of the yeast. Also, porous metals can be made by combining a metal powder with yeast, sugar, and water. The porous metal paste is then sintered. Porous ceramics and semiconductors can be made by combining the yeast and sugar with a ceramic forming liquid such as polysilazane. Polysilazane converts to silica when heated, which helps to bind the ceramic or semiconductor powder particles at a reduced temperature. Biological agents other than yeast (e.g. bacteria, enzymes), and growth substrates other than sugar can also be used.
Abstract:
An improved porous ceramic article and a method for forming such porous ceramic article. A mixture of ceramic particles and pliable organic hollow spheres is prepared in a liquid, typically as a suspension. The article is formed by pressing, slip casting, extruding or injection molding the mixture. The article is dried to remove the liquid, and then is fired so that the ceramic particles are bonded such as by sintering, and the organic spheres are burned off, resulting in a strong porous ceramic article having uniformly spaced interconnected voids.
Abstract:
An improved porous ceramic article and a method for forming such porous ceramic article. A mixture of ceramic particles and pliable organic hollow spheres is prepared in a liquid, typically as a suspension. The article is formed by pressing, slip casting, extruding or injection molding the mixture. The article is dried to remove the liquid, and then is fired so that the ceramic particles are bonded such as by sintering, and the organic spheres are burned off, resulting in a strong porous ceramic article having uniformly spaced interconnected voids.
Abstract:
The present invention relates to a solid low temperature phosphorus diffusion source that is an R.sub.2 O.sub.3 /P.sub.2 O.sub.5 compound in which the ratio of R.sub.2 O.sub.3 to P.sub.2 O.sub.5 is 1 to 5 and R is Nd, Eu, Pr, Sm, Ho, Tb, Er, Yb, Tm or Dy. The invention also relates to a method of making the diffusion source, a method of using the diffusion source to evolve P.sub.2 O.sub.5 to dope a silicon wafer, and the doped silicon wafer.