Abstract:
A thin film filter portion (20) comprises a plurality of members (22) and (24) interconnected by bridges (26), forming walls of a plurality of port slits (28). The width (W) of slits (28) corresponds to diameter of the largest spherical particles that can pass through the slits (28) while the length (L) of slits (28) is the shortest path through the slits (28). The dimension of the slit width (W) can be precisely controlled and as small as about 50 angstroms. The filter portions (20) can withstand high temperatures and harsh solvents.
Abstract:
Disclosed is a porous polypropylene hollow fiber membrane of large pore diameter which have (a) rectangular pores formed by microfibrils that are oriented in the lengthwise direction of the fibers and joint portions that are composed of stacked lamellae, the pores being contiguous with each other from the inner wall surface to the outer wall surface of the hollow fiber membrane to form a stacked, multicellular structure, (b) an average pore diameter ranging from greater than 1 µm up to 10 µm as measured with a mercury porosimeter, (c) a porosity of 70 to 95%, and (d) an air permeability of not less than 4 x 10⁵ l/m²·hr·0.5 atm. This hollow fiber membrane can be produced by melt-spinning polypropylene, annealing the resulting unstretched hollow fiber under specific conditions, and then cold-stretching and hot-stretching the annealed hollow fiber under specific conditions.
Abstract translation:公开了大孔直径的具有(a)以微纤维FORMED矩形孔并在纤维和接合部的长度方向取向的多孔聚丙烯中空纤维膜也由层叠片晶的,孔是连续的彼此从 内壁面到中空纤维膜的外壁面,以形成一层叠的,多细胞结构,(b)关于平均细孔径为大于1微米到10微米,与压汞仪测定,(C )的70%至95%,和(d)以不小于4×10 <5> L / M <2> .hr.0.5大气压透气性的孔隙率。 这一中空纤维膜可通过熔融纺丝聚丙烯,在特定条件下退火所得的未拉伸中空纤维,并在特定条件下,然后冷拉伸和热拉伸退火的中空纤维来制造。
Abstract:
Provided is a method for producing a separator which has uniform and dense pores on the negative electrode surface side. A method for producing a porous polyimide film according to the present invention comprises: a first un-burned composite film forming step wherein a first un-burned composite film is formed on a substrate using a first varnish that contains (A1) a polyamide acid or a polyimide and (B1) fine particles at a volume ratio (A1):(B1) of from 19:81 to 45:65; a second un-burned composite film forming step wherein a second un-burned composite film is formed on the first unburned composite film using a second varnish that contains (A2) a polyamide acid or a polyimide and (B2) fine particles at a volume ratio (A2):(B2) of from 20:80 to 50:50 and has a lower fine particle content ratio than the first varnish; a burning step wherein an un-burned composite film composed of the first un-burned composite film and the second un-burned composite film is burned, thereby obtaining a polyimide-fine particle composite film; and a fine particle removal step wherein the fine particles are removed from the polyimide-fine particle composite film.
Abstract:
A method comprises forming etching islands on a substrate and exposing the substrate with etching islands to a solution that reacts with the etching islands to form a filter passage of interconnected pores in the substrate. The filter passage has an inlet into the substrate and an outlet from the substrate.
Abstract:
Provided is a method for producing a separator which has uniform and dense pores on the negative electrode surface side. A method for producing a porous polyimide film according to the present invention comprises: a first un-burned composite film forming step wherein a first un-burned composite film is formed on a substrate using a first varnish that contains (A1) a polyamide acid or a polyimide and (B1) fine particles at a volume ratio (A1):(B1) of from 19:81 to 45:65; a second un-burned composite film forming step wherein a second un-burned composite film is formed on the first unburned composite film using a second varnish that contains (A2) a polyamide acid or a polyimide and (B2) fine particles at a volume ratio (A2):(B2) of from 20:80 to 50:50 and has a lower fine particle content ratio than the first varnish; a burning step wherein an un-burned composite film composed of the first un-burned composite film and the second un-burned composite film is burned, thereby obtaining a polyimide-fine particle composite film; and a fine particle removal step wherein the fine particles are removed from the polyimide-fine particle composite film.
Abstract:
Methods and systems disclosed in the present application include membrane-like filters and methods and systems that employ these membrane-like filters to isolate circulating tumor cells and other abnormal cells from biological fluids, such as blood. The disclosed methods and systems use membrane-like filters that include a pattern or array of small, tapered apertures fabricated within a relatively thin but mechanically robust polymeric material that resists accumulation of biological-solution components and clogging during filtration of biological solutions.
Abstract:
A process for manufacturing a micromechanical structure (25) envisages: forming a buried cavity (10) within a body (1, 12) of semiconductor material, separated from a top surface (12a) of the body by a first surface layer (12); and forming an access duct (18a) for fluid communication between the buried cavity (10) and an external environment. The method envisages: forming an etching mask (14) on the top surface (12a) at a first access area (17a); forming a second surface layer (15) on the top surface (12a) and on the etching mask (14); carrying out an etch such as to remove, in a position corresponding to the first access area, a portion of the second surface layer (15), and an underlying portion of the first surface layer (12) not covered by the etching mask (14) until the buried cavity is reached, thus forming both the first access duct (18a) and a filter element (20), set between the first access duct and the same buried cavity.
Abstract:
The purpose of the present invention is to provide a porous hollow fiber membrane that can efficiently separate and remove the substances to be removed such as small-particle virus contained in a solution and, at the same time, useful recovering substances such as protein can be efficiently permeated and the decrease of its transmission rate with elapse of time is small. The porous hollow fiber membrane of the present invention is characterized in that the filtration downstream surface thereof has dot-shaped or slit-shaped pores, the filtration upstream surface thereof is a network structure or a fine particle aggregate structure, the central region of the membrane is composed of a substantially homogeneous structure, the membrane wall is composed of a structure having substantially no macrovoids, the permeability for pure water is 10 to 300 L/(h· m 2 ·bar) and the permeability for a 0.1% by weight solution of bovine γ-globulin is 30 to 100% of the permeability for pure water. Also, the hollow fiber membrane is characterized in that the permeability for a 0.1% by weight solution of bovine γ-globulin in a 20 mmol/L phosphate buffer is 30 to 100% of the permeability for a 0.1% by weight solution of bovine γ-globulin in a 20 mmol/L phosphate-buffered physiological saline solution.