Abstract:
The present invention relates to a miniature rheometer, a parallel rheometer, and improved force sensor elements which may advantageously be used in combination with the miniature rheometer and the parallel rheometer. The miniature rheometer is adapted to determine rheological characteristics of materials which are provided in the form of small quantity samples. The miniature rheometer comprises an actuating element, a sensing element and a feedback circuit to provide rebalance of the shear force applied by the sample to the sensing element, which insures an exceptional stiffness in determining the shear strain so as to allow measurements of high accuracy. The parallel rheometer of the present invention allows simultaneous measurements of a plurality of samples so as to allow of a plurality of samples within a short time period. The force sensor element according to the present invention allows simultaneous measurement of a shear force and a normal force applied to the sensor element. Moreover, a rheometer is provided which comprises a force sensor based on stress-optic material.
Abstract:
A library of material samples is screened for properties such as permeability. A library of material samples is provided. A stimulus such as an exposure to a permeate fluid is provided to each member of the library. A response of each of the material samples due to the stimulus is measured and the response, the stimulus or both are recorded and related to provide data. Thereafter, the data is analyzed to reach conclusions regarding the properties of the material samples.
Abstract:
An apparatus for parallel processing of reaction mixtures, including a reactor block including reaction chambers for containing reaction mixtures under pressure, the reactor block further including a first sidewall, a second sidewall, and a first plurality of fluid flow paths providing fluid communication with the first sidewall and respective reaction chambers and the second sidewall and respective reaction chambers;; a stirring system including a base plate defining a second plurality of flow paths, wherein respective flow paths of said second plurality of flow paths are in fluid communication with respective reaction chambers and respective fluid flow paths of said first plurality of flow paths, and the base plate also supports a plurality of stirring blade assemblies for mixing the reaction mixtures; interchangeable manifolds supported by the first sidewall and the second sidewall, the interchangeable manifolds defining a plurality of manifold inlet/outlet ports, wherein respective inlet/outlet ports of said plurality of inlet/outlet ports are in communication with respective fluid flow paths of said first plurality of fluid flow paths and permit fluid to be introduced into or vented from the respective reaction chambers; and a sampling manifold assembly coupled in fluid communication with the respective reaction chambers, wherein a portion of the reaction mixture retained in the respective reaction chambers can be withdrawn from the respective reaction chamber through respective fluid flow paths of said first plurality of fluid flow paths and respective flow paths of said second plurality of flow paths, or both, without depressurizing or lowering the pressure in the respective reaction chamber.
Abstract:
Control agents that have a nitrogen-nitrogen bond covalently bonded to a thiocarbonyl moiety are provided for living-type free radical polymerization of a wide variety of monomers. These control agents provide superior properties for control of the polymerization and/or the properties of the polymers obtained and/or the monomers that may be polymerized. In some embodiments, a bulky group is pendant off the activated thiocarbonyl portion of the control agents. Multifunctional control agents provide the opportunity for a variety of structurally unique polymers, including block copolymers, stars and hyper-branched polymers.
Abstract:
An apparatus for characterizing a library containing an array of samples. The apparatus includes an x-ray beam directed at the library, a chamber housing the library and a beamline for directing the x-ray beam onto the library in the chamber. The chamber may include a translation stage that holds the library and that is programmable to change the position of the library relative to the x-ray beam and a controller that controls the movement of the translation stage to expose an element to the x-ray beam in order to rapidly characterize the element in the library. During the characterization, the x-ray beam diffracts upon impinging the element and a detector detects the diffracted x-ray beam in order to generate characterization data for the element.
Abstract:
A method of free radical polymerization and for cleaving a thio group from the resulting polymer is provided. The method comprises forming a mixture of one or more monomers, at least one free radical source and a control agent, wherein the control agent comprises a thio moiety. The mixture is polymerized, and the resulting polymer is mixed with a free radical source, and optionally an addition fragmentation agent under cleavage conditions. The thio moiety on the polymer is replaced with a group of interest.
Abstract:
Metal-ligand complexes that are useful as precursors to catalysts for the polymerization of olefins are provided. Certain of the catalysts are particularly effective at polymerizing ethylene and styrene into copolymers having novel properties, including a low molecular weight and close comparison between vinyl and methyl end groups.
Abstract:
An apparatus for parallel processing of multiple reaction mixtures comprises a plurality of reactor vessels for holding reaction mixtures at pressures of at least about 15 psig. Cannula passages communicate with respective vessels, and a cannula is adapted to be inserted into each cannula passage. A sealing mechanism, comprising a valve and a seal, in each cannula passage maintains a respective vessel sealed when the cannula is inserted into and withdrawn from the cannula passage. A robot system is operable to insert the cannula to a location where a distal end and port of the cannula are past the open valve and seal, and to withdraw the cannula. Methods for transferring fluid reaction material to and from a series of pressurized vessels, establishing fluid communication between a cannula and a vessel of a combinatorial chemistry reactor and establishing fluid communication between a cannula and a series of pressurized vessels of a combinatorial chemistry reactor are also disclosed.
Abstract:
An apparatus and method for synthesis and screening of materials are disclosed. According to one aspect of the present invention, a parallel batch reactor for effecting chemical reactions includes a pressure chamber, an inlet port, two or more reaction vessels within the pressure chamber, and a reaction vessel cover. The inlet port is in fluid communication with the pressure chamber, and pressurizes the pressure chamber from an external pressure source. Each of the two or more reaction vessels are in isolatable fluid communication with the pressure chamber such that during a first pressurizing stage of operation, each of the two or more reaction vessels can be simultaneously pressurized through common fluid communication with the pressure chamber. In addition, during at least a second reaction stage of operation, each of the two or more pressurized reaction vessels can be isolated from each other by positioning the reaction vessel cover appropriately.
Abstract:
Devices and methods for controlling and monitoring the progress and properties of multiple reactions are disclosed. The method and apparatus are especially useful for synthesizing, screening, and characterizing combinatorial libraries, but also offer significant advantages over conventional experimental reactors as well. The apparatus generally includes multiple vessels for containing reaction mixtures, and systems for controlling the stirring rate and temperature of individual reaction mixtures or groups of reaction mixtures. In addition, the apparatus may include provisions for independently controlling pressure in each vessel, and a system for injecting liquids into the vessels at a pressure different than ambient pressure. In situ monitoring of individual reaction mixtures provides feedback for process controllers, and also provides data for determining reaction rates, product yields, and various properties of the reaction products, including viscosity and molecular weight. Computer-based methods are disclosed for process monitoring and control, and for data display and analysis.