Abstract:
A method of preparing nanothin polymer films having uniform and selectively sized pores utilizing pore forming templates. Lipids and pore forming templates are dissolved into a first solution. The solvent is removed thereby creating a lipid bilayer with pore forming templates dispersed throughout. The bilayer is hydrated and monomers and crosslinkers are added to create a second solution. A nanothin film with pore forming templates is created through polymerization of said second solution. The pore forming templates are dissolved into a third solution by addition of a chemical in which the pore forming template is soluble, but the lipid bilayer is insoluble. This third solution is separated from the mixture leaving a nanothin polymer film with pores of a uniform thickness and surface area. In summary, the guided assembly method presented here suggests a new general strategy for the fabrication of nanothin materials with controlled permeability, which provides improvements over the currently existing technology.
Abstract:
L' invention a trait à un procédé de préparation d'un copolymère dibloc comprenant un bloc hydrophile (B) et un bloc hydrophobe (A), ou d'un copolymère tribloc comprenant un bloc hydrophile (B), un bloc hydrophobe (A) et un second bloc hydrophobe (A' ), ledit procédé comprenant les étapes suivantes : a) une étape d'addition 1,2 sur un groupe terminal éthylénique, ou deux groupes terminaux éthyléniques, d'un polymère hydrophile, d'une alcoxyamine répondant à la formule (I) suivante : dans laquelle : * R 1 et R 3 , identiques ou différents, représentent un groupe alkyle, linéaire ou ramifié, ayant un nombre d'atomes de carbone allant de 1 à 3; * R 2 représente un atome d'hydrogène, un métal alcalin, tel que Li, Na, K, un ion ammonium tel que NH 4 +, NBu 4 +, NHBu 3 +, un groupe alkyle, linéaire ou ramifié, ayant un nombre d'atomes de carbone allant de 1 à 8, un groupe phényle; b) une étape de mise en contact avec le milieu issu de l'étape a) d'un ou plusieurs monomères précurseurs d'un bloc hydrophobe pendant un temps suffisant pour obtenir le copolymère dibloc bloc hydrophile (B) - b -bloc hydrophobe (A) dans le cas où l'étape d'addition a) s'est produite sur un seul groupe terminal éthylénique du polymère hydrophile; ou pour obtenir le copolymère tribloc bloc hydrophile (A) -b-bloc hydrophile (B) -b-second bloc hydrophobe (A' ) dans le cas où l'étape d'addition a) s'est produite sur deux groupes terminaux éthyléniques du polymère hydrophile. Utilisation des copolymères obtenus en tant qu'agents structurants de matériaux mésoporeux, tels que la silice présentant des tailles de pores supérieures à 15 nm.
Abstract:
The present invention includes a microfluidic filter and concentrator that can separate a filtrate from a fluid containing components, e.g. a suspension of particles, to be removed from the fluid at least to some extent. The filter may employ principals of tangential flow filtration, also known as cross-flow filtration. In one aspect, a microfluidic filter described herein includes at least a first, main channel and one or more secondary, filtering channels that connect to the main channel. Filtration occurs when a fluid portion of a sample that is flowed through the main channel enters one or more of the filtering channels and at least some of the components in the sample do not enter or do not flow through the secondary, filtering channels. The secondary channels may be dimensioned to inhibit flow of components through them, and/or a porous material such as a layer may be positioned to inhibit flow of components through the secondary channels.
Abstract:
In certain aspects, the invention features methods for forming crystalline membranes (20) (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals (32). The rate of growth of the seed crystals in the plane of the substrate (30) is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains (35) of uniform crystallographic orientation that extend through the depth of the layer.
Abstract:
Sample preparation device and method for desalting and concentrating samples prior to further analysis such as by MALDI TOF and/or electro-spray ionization (ESI) mass spectrometry. The device in accordance with an embodiment of the present invention contains a three dimensional structure preferably comprising a plurality of sorptive particles e, it apped in a porous polymer matrix so as to form a device capable of carrying out solid phase extraction. The device is manufactured by introducing casting solution containing polymer and optionally particles into a housing, and subsequently exposing the device to a quench bath for a time sufficient to allow for solvent exchange and precipitation to form the composite structure in the housing. The present invention is also directed towards a method of sample preparation using the device of the present invention.
Abstract:
Sample preparation device and method for desalting and concentrating samples prior to further analysis such as by MALDI TOF and/or electro-spray ionization (ESI) mass spectrometry. The device in accordance with an embodiment of the present invention contains a three dimensional structure preferably comprising a plurality of sorptive particles e, it apped in a porous polymer matrix so as to form a device capable of carrying out solid phase extraction. The device is manufactured by introducing casting solution containing polymer and optionally particles into a housing, and subsequently exposing the device to a quench bath for a time sufficient to allow for solvent exchange and precipitation to form the composite structure in the housing. The present invention is also directed towards a method of sample preparation using the device of the present invention.
Abstract:
Die Erfindung betrifft ein Verfahren zur Herstellung von Hohlfasern, insbesondere zur Herstellung von Meso- und Nanoröhren, bei denen die Röhren oder Hohlfasern mit einem Innendurchmesser im Nano- bis Mikrometerbereich vorzugsweise in einer Richtung orientiert sind, sowie deren Verwendung. Gegenstand dieser Erfindung sind weiterhin die durch das Verfahren hergestellten Hohlfasern bzw. Röhren und diese enthaltende poröse Verbundmaterialien.
Abstract:
Membrane microfilters are formed in situ in a defined region of a blank (c) by embossing one surface of the defined region (e) of the blank (c) to provide an array of indentations (h), and ablating the material of the blank in the defined region until the indentations become through pores (p). Ablation may be carried out by various means such as chemical etching or laser ablation.
Abstract:
This invention relates to the area of microelectromechanical systems in which electronic circuits and mechanical devices are integrated on the same silicon chip. The method taught herein allows the fabrication of thin film structures (2) in excess of 150 microns in height using thin film deposition processes. Wafers may be employed as reusable molds for efficient production of such structures. Various material properties may be varied within the structures to produce electrical, mechanical or electromechanical devices.