Abstract: Porous polymeric materials are hardened by a process of plasma-annealing, involving treatment of at least one surface with a gas plasma formed by glow discharge through a gas containing a saturated alkane or an acetylene. Plasma-annealed porous polymers with reduced adsorption toward proteins were obtained by exposure to a glow discharge through a gas mixture containing an alkane such as methane in combination with oxygen, air, or a hydrophilic unsaturated organic monomer. For example, porous polysulfone sheet and hollow fiber were plasma-annealed by treatment with a gas plasma containing methane and air or acrylic acid with simultaneous deposition of a hydrophilic polymerizate thereon.

Abstract: The lumen surface of tubing is modified by exposure to a gas plasma in a vacuum apparatus. A method and apparatus are disclosed whereby plasma treatment of the lumen surface, such as by deposition of a plasma polymerizate, may be achieved inside a continuous length of tubing. A gas such as a monomer vapor is caused to enter the lumen of the tubing through openings sequentially arranged at a periodic interval along the length of the tubing, and is excited to a plasma state concurrently as the tubing passes through a tubular reaction conduit having an inner diameter in occlusive contact with the tubing's outer diameter. Essentially crack-free plasma polymerizate coatings with thicknesses greater than 1000 angstroms are selectively deposited on the lumen wall of the continuous tubing. Plasma-modified tubing is prepared having usefulness in medical devices such as catheters, vascular grafts and enteral feeding tubes.

Abstract: A minimally invasive sensing device, and method for its use, is disclosed which utilizes a light-conducting fiber having a localized textured site thereon, wherein a reagent is deposited. Interaction of the reagent with an analyte specific to the reagent produces a response, such as development of a colored product, which is detectable by means of a change in characteristics of a light beam transmittable through the fiber. By means of the textured site and its increased surface area, the sensitivity of the device is greatly enhanced, such that less than 5 microliters of a fluid is needed for an analysis. The sensor is particularly useful in blood glucose determinations, requiring smaller blood samples than flat strip devices.

Abstract: Improved porous materials useful in blotting analyses of proteinaceous and genomic matter are prepared by treating porous substrates with a gas plasma containing at least one monomer. Thus, a porous sheet-like substrate is modified by means of a deposit of a plasma polymerizate on at least one of its surfaces, whereby this modified surface exhibits reduced nonspecific binding of chemical probes in a blotting analysis. By means of a controlled deposition of the plasma polymer at a plasma composite parameter W/FM of less than 1.0.times.10.sup.9 Joules/kilogram, improved porous materials are obtained having increased signal-to-background ratios and enhanced sensitivities in genomic analyses.

Abstract: Disclosed is a method for concentrating by 20 to 10,000 fold a semivolatile or essentially nonvolatile organic compound, such as a herbicide or pesticide, from a contaminated aqueous solution into a carrier fluid for simultaneous or subsequent analysis. A perstraction membrane is contacted on one surface with a large volume of an aqueous feedstream containing a low concentration of an organic compound, and an opposite surface of the same membrane is contacted with a small volume of a carrier fluid. The perstraction membrane is characterized by a nonporous layer therein which precludes convective flow and mixing between the aqueous and carrier fluid phases. The organic compound is absorbed into the nonporous skin layer from the aqueous fluid and is transferred from the nonporous skin layer into the carrier fluid by an affinity driving force, the affinity of the carrier fluid for the organic compound being greater than the affinity of water for the same compound.

Abstract: An apparatus for the treatment of articles with a polymerizate-producing gas plasma is disclosed wherein a set of movable film liners is used to shield the walls of a gas-plasma-containing reaction tunnel from excessive build-up of polymerizate deposits. In an operation involving continuous gas plasma coating of a film, fiber, fabric, tubing or string of workpieces, at least 75 to 90 percent of potential wall deposits are removable by the set of film liners.

Abstract: Plasma polymerization of a fully alkylated disiloxane is greatly enhanced by the addition of oxygen to the plasma feed gases. Deposition rate of polysiloxane polymerizate upon substrates is increased, and the deposits are nontacky. Composite permselective membranes made by deposition of plasma-polymerized polysiloxanes in the presence of oxygen are useful for applications such as gas separations. Composite hollow fiber membranes of polysiloxane polymerizate on porous polypropylene exhibit oxygen/nitrogen permselectivities greater than 2.3 combined with increased oxygen permeability.