Method of making solid crystalline narrow band radiation filter
AssigneeUniversity of Pittsburgh—Of the Commonwealth System of Higher Education
InventorsSanford A. Asher, Sesh Jagannathan
Life of this patent
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Abstract
A method of making a solid filter material which filters a predetermined wavelength band from a broader spectrum of radiation includes creating a colloidal structure composed of particles dispersed within a medium, and introducing a solvent thereto. Thereafter, the solvent is evaporated and the remaining structure solidifies into a solid crystalline array. Another embodiment of the method includes electrophoretically attracting the particles in a medium to form an ordered array. The particles can also be fused together by polymerization using one of several methods which are provided. Additionally, one aspect of the invention involves coating the particles with an electrostatically-charged material to facilitate inter-particle interactions.
Claims18
A method of making a solid filtering material for filtering a predetermined wavelength band from a broad spectrum of radiation, comprising the steps of
- creating a colloidal structure by providing particles with a polymeric outer shell dispersed in a crystalline array within a first liquid medium,
- introducing a second substance comprising a solvent into said colloidal structure to solubilize and swell the outer shells of said particles, and
- evaporating at least a substantial portion of said second substance and said first liquid medium from said structure to condense said particles into a solid three-dimensional, ordered array having a lattice spacing structure, which is substantially equal to said predetermined wavelength band, and to fuse surfaces of said particles to one another.
A method of making a solid filtering material for filtering a predetermined wavelength band from a broad spectrum of radiation comprising
- creating a colloidal structure by providing ionized particles of the same polarity dispersed in a crystalline array established by the relative repulsion of said ionized particles within a medium,
- adding a polymerization inducing substance to said medium, and
- polymerizing said medium around said particles to form a solid, ordered array having a lattice spacing structure, said spacing structure being substantially equal to said predetermined wavelength band.
A method of making a solid filtering material for filtering a predetermined wavelength band from a broad spectrum comprising the steps of
- (a) coating surfaces of silica particles with a sulfonate-containing material on outer surfaces of said particles,
- (b) adding said particles to a medium and allowing them to self-assemble into a three-dimensional array to create a colloidal structure, and
- (c) evaporating at least a substantial portion of said medium out of said colloidal structure to solidify said structure to create a lattice structure having spacing substantially equal to said predetermined wavelength band.
A method of creating a solid filtering material for filtering a predetermined wavelength. band from a broad spectrum of radiation, comprising the steps of
- creating a colloidal structure composed of electrostatically-charged particles suspended within an electrically neutral medium comprising a monomer,
- placing a bipolar electric field across said structure to facilitate travel of said particles toward one pole of said field and packing of said particles in an ordered array, and
- polymerizing said monomer around said particles and allowing said structure to solidify into a lattice structure having spacing substantially equal to said predetermined wavelength band.
Dependencies are inferred from the claim text.