6752 results about "Polyvinylidene difluoride" patented technology

Devices, systems and methods are provided for stimulation of tissues and structures within a body of a patient. In particular, implantable leads are provided which are comprised of a flexible circuit. Typically, the flexible circuit includes an array of conductors bonded to a thin dielectric film. Example dielectric films include polyimide, polyvinylidene fluoride (PVDF) or other biocompatible materials to name a few. Such leads are particularly suitable for stimulation of the spinal anatomy, more particularly suitable for stimulation of specific nerve anatomies, such as the dorsal root (optionally including the dorsal root ganglion).

A porous polymeric membrane formed from a blend of a polymeric membrane forming material, such as polyvinylidene fluoride or polysulfone and a polymeric reactivity modifying agent adapted to modify the surface active properties of the porous polymeric membrane. The reactivity modifying agent is preferably a linear polymeric anhydride, such as poly(alkyl vinyl ether / maleic anhydride). The surface activity modifications include modification of the hydrophilicity / hydrophobicity balance of the membrane, or hydrolysis followed by reaction with a polyamine to form a crosslinked polyamide layer. Such modified membranes have use as reverse osmosis membranes.

Cast semi-permeable membranes made from synthetic polymer used in reverse osmosis, ultrafiltration and microfiltration are treated with a non-leaching antimicrobial agent to prevent its bio-fouling and bacterial breakthrough. The semi-permeable membranes include a polymeric material and a non-leaching antimicrobial agent that is incorporated into and homogeneously distributed throughout the polymeric material. The polymeric material, in the case of one membrane, may be cellulose acetate. In the case of thin film composite polyamide membranes, the antimicrobial agent is incorporated in a microporous polysulfone layer that is sandwiched between a reinforcing fabric and an ultrathin polyamide material. The invention also includes a treatment of flat and hollow fiber semipermeable membranes made with polysulfones and polyvinylidene fluoride.

The invention discloses a method for preparing a polyvinylidene fluoride porous membrane and relates to a method which makes use of a thermally induced phase separation method to prepare the polyvinylidene fluoride porous membrane. The method comprises the following steps: polyvinylidene fluoride with the weight percentage of 30wt-60wt and diphenyl carbonate with weight percentage of 70wt to 40wt or a composite thinner containing diphenyl carbonate with weight percentage of 70wt to 40wt are added into a high temperature resistant container, heated, rested and defoamed to prepare a polymer homogeneous film-casting solution; the film-casting solution is directly coated on a flat membrane formed by supporting network or spinned into hollow fiber by a spinneret, and then the flat membrane or the hollow fiber is immersed into cooling liquid to be treated with curing and the membrane is formed; the formed membrane is put into an extractant to extract the solvent, therefore, the polyvinylidene fluoride porous membrane is obtained. The method is characterized in that: the method adopts the diphenyl carbonate or the thinner taking the diphenyl carbonate as a main component to prepare the polyvinylidene fluoride porous membrane, the section structure of which is in communicating spongy structure, and the membrane has large water flux, high strength and good toughness.