Showing papers on "Polymer nanocomposite published in 1993"

High refractive index films of polymer nanocomposites

Abstract: Solutions of PbS particles and gelatin were used for the preparation of nanocomposites by a spin-coating process. This allows for the preparation of nanocomposite films with controlled thickness, e.g., between 40 nm and 2 μm for a film containing 45 wt.% PbS. Surface roughness and film thickness were investigated by surface profilometry and scanning electron microscopy (SEM). The refractive index at 632.8 nm can be expressed by a linear function of the volume fraction of PbS in the range of 0 to 55 vol. % PbS. In this range, the refractive index increases from 1.5 to 2.5 with increasing PbS ratio and belongs, therefore, to the highest refractive indices known for polymeric composite materials.

Foamed polymer for use as dielectric material

Abstract: The present invention relates to an insulating foamed polymer having a pore size less than about 1000 Å made from a copolymer comprising a matrix polymer and a thermally decomposable polymer by heating the copolymer above the decomposition temperature of the decomposable polymer.

Polymer nanocomposites with “ultralow” refractive index

Abstract: Nanocomposites of gelatine and gold were prepared by reduction of AuCl4H in a gelatine solution, followed by a spin coating process and a brief washing. The thickness of the films thus obtained was typically 200–400 nm. The surface of the nanocomposites was investigated by scanning electron microscopy (SEM) and surface profilometry. The size of the gold particles is in the range of ca. 2–10 nm, as elucidated by transmission electron microscopy (TEM). Refractive indices were measured by ellipsometry at wavelengths of 632.8 and 1300 nm. The refractive index depends linearly on the volume fraction of gold, at least at 1300 nm. The lowest refractive indices measured are 1.008±0.060 at 1300 nm and 0.963±0.062 at 632.8 nm (limits are 95% confidence interval). These values are, to our best knowledge, the lowest reported for a polymer or polymer composite.

Medical implement, polymer composition and optical material

Abstract: A polymer composition comprising a thermoplastic norbornene polymer which preferably has a number average molecular weight of 10,00 - 200,000 as determined by gel permeation chromatography in toluene solvent and calculated as styrene and a content of norbornene polymer components having a number average molecular weight of 2,000 or less of 1% by weight or less, and a compounding ingredient, such as a rubber-like polymer, wherein the compounding ingredient is preferably dispersed in the form of microdomains in the norbornene polymer; and medical implements and optical naturals formed essentially of the composition.

Polymer dispersed liquid crystal with polymer glass transition above 50° C. and low isotropic transition shift

Abstract: A liquid crystal display device according to the present invention includes a pair of electrode substrates and a polymer dispersed liquid crystal complex film interposed between the pair of substrates. The polymer dispersed liquid crystal complex film includes a liquid crystal composition and a polymer resin composition. It is ensured that a value ΔT is 25° C. or less, and a glass transition temperature T g of the polymer resin composition is 60° C. or more, the value ΔT being defined as a difference between a phase transition temperature T CI of the liquid crystal composition between a liquid crystal phase and an isotropic liquid phase thereof and a phase transition temperature T matrix of the polymer dispersed liquid crystal complex film.

Biomaterials with hydrophilic surfaces

Abstract: A protein-compatible polymer blend made from a water-soluble polymer and a matrix polymer. The glass transition temperature of either the water-soluble polymer or the matrix polymer is greater than the application temperature, i.e., the temperature at which the protein-compatible polymer blend is being used.

Polymer particles and method for preparing by polymerization of encapsulated monomers

Abstract: A method for preparing polymer particles having diameters within the range from less than 0.1 micron to about 200 microns is described. The method involves encapsulating at least one water insoluble monomer within a water soluble polymer containing at least one thiol functional group. This is accomplished by combining an organic phase containing the monomers and a free radical source with an aqueous phase containing the polymer to form a two phase mixture, and subjecting the two phase mixture to agitation or ultrasonic irradiation. This invention allows for the preparation of polymer particles with sizes not available by conventional suspension or emulsion polymerization methods. It also provides for polymer particles within the specifed size range having compositions not readily obtained by other polymerization methods. The polymer particles made by this method have an exterior portion of water soluble polymer bound to an interior polymer. The exterior polymer, when it is a condensation polymer such as for example a protein, may be removed by acid hydrolysis.

Manufacture of hollow fiber dual membrane

Abstract: PURPOSE:To form a thin nonporous layer free from pinhole, crack, or break by a method wherein a crystalline thermoplastic polymer A and a polymer B having the capability of being thermally bonded to the polymer A are disposed in two layers and subjected to melt conjugate spinning using a multiple cylindrical spinning nozzle, which layers are then stretched to make only the layer comprising the polymer A porous. CONSTITUTION:A crystalline thermoplastic polymer A and a polymer B having the capability of being thermally bonded to the polymer A are disposed in two layers so as to be subjected to melt conjugate spinning using a multiple cylindrical spinning nozzle, which is then stretched to make only the layer comprising the polymer A porous. And the polymer B is comprised of the same monomer, as a principal constituent element, as the polymer A and the polymer B has a lower degree of attainable crystallization than the polymer A. Further the polymer A and the polymer B are 4-methylpentene-1 based polymers. And the polymer A is disposed on the inner side. A hollow fiber dual membrane thus obtained serves as a degassing membrane for liquid. As a result, a thin nonporous layer free from pinhole, crack, or break can be formed.

Polymer composite, method and polymer composition

Abstract: A polymer composite contains colorant molecules dispersed therein. The colorant molecules can be dispersed in the polymer or bound to the polymer molecules. When the polymer is a polyamide, the polyamide is in a noncrystalline state due to the inhibition of crystallization imparted by the size and shape of the colorant molecules because the colorant is separated on a molecular level. A high colorant availability is obtained. A method of producing the polymer composite includes the steps of forming a metastable polymer resin layer, applying a film of colorant to the layer, stabilizing the layer, dissolving the stable layer in a solvent, aspirating the solution to remove impurities and aggregates and then removing the solvent. A polymer composition can be produced by mixing the polymer composite with a polymer.

Method of making a polymer film having a conductivity gradient along its thickness and polymer film so made

Abstract: A polymer film having a conductivity gradient across its thickness is maderom a mixed solution of an insulating polymer, A and a polymer, B that can be made conducting by doping or protonation by a method including the steps of: (A) mixing the solution of the insulating polymer, A and the polymer, B that can be made conducting by doping or protonation, (B) casting the mixed solution together as a solid composite film, and (C) exposing the film to a treating agent that can dope or protonate polymer B and make polymer B conductive and create a conductivity gradient across the thickness of the polymer films.

Pharmaceutical containers and medical devices with hydrophilic protein-compatible surfaces

Abstract: A protein-compatible polymer blend made from a water-soluble polymer and a matrix polymer. The glass transition temperature of either the water-soluble polymer or the matrix polymer is greater than the application temperature, i.e., the temperature at which the protein-compatible polymer blend is being used.