Abstract:
A method of forming a microporous fluoropolymer membrane comprising the steps of: irradiating a sheet of fluoropolymer at a dosage level below the rupture energy of the carbon-to-fluorine (C-F) bonds of the fluoropolymer, but sufficient to rupture carbon-to-carbon (C-C) bonds; and exposing the sheet of fluoropolymer to an etching for a period of time sufficient to etch away disrupted atoms and molecules, wherein continuous microphages are formed through the sheet.
Abstract:
Das Verfahren zur Herstellung eines Filterelements enthält die folgenden Schritte: Sl) Aufbringen einer Membranschicht (1) auf ein Trägersubstrat (2), S2) Ätzen einer Membrankammer (3) auf der der Membranschicht (1) gegenüberliegenden Seite des Trägersubstrats (2) , so dass noch eine Restschicht (5) des Trägersubstrats (2) verbleibt, S3) Erzeugen von Poren (6) in der Membranschicht (1) zur Schaffung einer perforierten Membran, S4) Entfernen der Restschicht (5) durch Ätzen zum Freilegen der Membranschicht (1), S5) wobei die Membranschicht (1) während Schritt S1 oder in einem späteren Schritt einer zusätzlichen Behandlung zur Erhöhung der mechanischen Festigkeit ausgesetzt wird, um ihr eine Kristallstruktur mit einer gegenüber dem Grundmaterial der Membranschicht (1) erhöhten mechanischen Festigkeit und/oder eine verdichtete Struktur zu geben und vorzugsweise eine innere mechanische Vorspannung in ihr zu erzeugen.
Abstract:
Capillary-pore (track-etched) membranes were known to have residual negative charges formed during manufacture. We demonstrated that residual negative charges were concentrated on the interior face of the uniform passageways through the membrane stock, and then demonstrated that they were from carboxyl groups (ca 40 nanomoles per cm2 of membrane surface). We then demonstrated that these endogenous carboxyl groups could be used for modification of the surface of these highly uniform passageways, by covalent linkage with one or more compounds, thus providing a configured separation membrane.
Abstract translation:已知毛细孔(轨道蚀刻)膜在制造过程中形成残留的负电荷。 我们证明残余负电荷集中在通过膜原料的均匀通道的内表面上,然后证明它们来自羧基(约40纳摩尔/ cm 2膜表面)。 然后我们证明这些内源性羧基可以用于通过与一种或多种化合物的共价连接来改性这些高度均匀的通道的表面,从而提供配置的分离膜。
Abstract:
The invention relates to a method for creating pores in a sheet polymer material, especially to a method for creating nanoscale pores, typically of less than 200 nm in a polymer material such as sheet polycarbonate or an equivalent. The inventive method comprises ionic bombardment (4), optionally, a UV treatment and chemical etching (6). The invention is characterized in that a pre-etching process (2) is carried out prior to the ionic bombardment (4) and reduces the thickness (e) of the sheet of polymer material (1).
Abstract:
A membrane consisting of dielectric material such as an organic polymer, separates two chambers of an electrolytic cell from each other. The membrane is produced using an etching solution which is provided in one of the chambers. Said etching solution contains active etching ions which etch the organic polymer. The other chamber contains a solution which does not have an etching action. An electrical field is generated through the membrane with an electrode that is dipped into the respective electrolytes and a voltage source connecting the two electrodes. The etching process makes its way along the ion tracks on one side, through the membrane and first produces one funnel-shaped pore per ion track. Immediately prior to the breakthrough, the ions which do not have an etching action begin to penetrate the still existent thin layer with fine pores - the active layer - and to displace the ions with an etching action at the exit point. An intensified electric current, driven by the adjacent field, is established. The etching process on the floor of the pore shifts sideways according to the concentration of etching ions still present. The process can be stopped by deactivating the field and washing the membrane and the sole size, i.e. the active layer size, adjusted. A membrane produced in this way can be operated as an electrochemical valve and can be used with one or more pores as a sensor or with many pores to control concentration.
Abstract:
Microstructured membrane comprising a sheet having first and second faces with an array of pores extending into the sheet from the first face, and in some instances extending through the entirety of the sheet. Substantially each pore within the array is individually surrounded by a flat land area and the major portion of the walls of each pore are substantially parallel to the longitudinal axis of the pore. The pores have an average characteristic dimension of between about 0.1 and about 5000 microns and a pore size distribution of less than about 10 percent, the longitudinal axes of pores within the array being substantially parallel with each other. Also, articles incorporating such membranes and methods for making such membranes.