Periodic extensional flow reactor
US20250083372A1
Abstract
An apparatus and method for producing oriented polymer films are disclosed. The apparatus includes a curved enclosure configured to rotate and a flow obstacle. The curved enclosure has an interior volume with an opening at one end. The flow obstacle extends through the opening and interior volume, with one end rigidly coupled to a mounting plate. The flow obstacle's position is adjustable to contact the interior surface of the curved enclosure, defining a gap between them. The method involves introducing a material into the curved enclosure, adjusting the flow obstacle's position, and rotating the curved enclosure to generate an extensional flow within the material. The apparatus and method may be used for producing two-dimensional polymer films and can incorporate features such as inert gas flushing, heating systems, and various blade configurations for the flow obstacle.
Description (excerpt)
CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63/552,376, filed Feb. 12, 2024; and U.S. Provisional Patent Application No. 63/537,234, filed Sep. 8, 2023. The entire contents of each are hereby incorporated by reference. STATEMENT AS TO FEDERALLY SPONSORED RESEARCH This invention was made with Government support under W911NF-20-2-0024 awarded by the United States Army Research Laboratory. The Government has certain rights in the invention. BACKGROUND Field of the Disclosed Subject Matter The disclosed subject matter relates to systems and methods to produce oriented films. Particularly, the present disclosed subject matter is directed to periodic extensional flow reactor systems. Description of Related Art It is a common technological need to produce polymer films in which the polymer orientation is strongly anisotropic, that is, particularly oriented in one direction within the plane of the film. Common technologies to achieve oriented films include spin coating, flow coating, doctor blade coating, and extrusion coating. The polymer exists in these processes either as a melt or a fluid solution mixture. In all these technologies the polymer material experiences a single occurrence of extensional flow to orient the macromolecules before they are rendered immobile by either drying, solidification, or crystallization. Such technologies achieve orientation by subjecting the polymer to an extensional flow, this requires flow through a contraction. Once the material thickness equals the smallest contraction dimension, the material can no longer experience further extensional flow. Afterward, the polymer orientation can only be improved through additional stretching, rolling, or similar processes. These extensional flow technologies operate on time scales much shorter than the time scales required to polymerize the macromolecules. As a result, these technologies are restricted to be used only after the polymer has reached sufficient polymerization and size growth. Moreover, these technologies are not amenable to be applied repeatedly to a polymer, particularly while the polymer is growing in size from its small, low molecular weight monomers. SUMMARY OF THE DISCLOSED SUBJECT MATTER The purpose and advantages of the disclosed subject matter will be set forth in and apparent from the description that follows, as well as will be learned by practice of the disclosed subject matter. Additional advantages of the disclosed subject matter will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings. To achieve these and other advantages and in accordance with the purpose of the disclosed subject matter, as embodied and broadly described, the disclosed subject matter includes an apparatus for producing oriented polymer films comprises a curved enclosure having an exterior surface and an interior surface defining an interior volume and a flow obstacle having a first end and a second end. An opening extends through the curved enclosure and into the interior volume. The curved enclosure is configured to rotate. The second end of the flow obstacle extends through the opening and within the interior volume of the curved enclosure and the first end of the flow obstacle is rigidly coupled to a mounting plate. A position (e.g., x-, y-, z-position, and/or angle of the flow obstacle) of the flow obstacle is adjustable so that the flow obstacle contacts the interior surface of the curved enclosure. A gap is defined between the interior surface of the curved enclosure and the flow obstacle, where a material is disposed. The curved enclosure may be flushed with inert gas (e.g., nitrogen). The curved enclosure may comprise a heat transfer system including an insulator, a conductor, and a layer for heating, cooling, or a combination thereof. The material may be a two-dimensional polymer. The material may be any other type of polymer. The material may be a phase changing system, a reacting system, or a combination thereof that produces a polymer. A continuous rotation of the curved enclosure may generate a periodic extensional flow within the material. The curved enclosure may be a cylindrical enclosure. The internal flow obstacle may comprise a blade support arm connected to a blade. The blade may be a flap blade, a cylindrical blade, or any other shaped blade. The blade may be fixedly coupled to the blade support arm. The blade may be rotatably coupled to the blade support arm so that the blade rotates in response to a rotation of the curved enclosure. An extensional flow may be generated in the material. A shear flow may be generated in the material. There may be a plurality of flows generated in the material that may be laminar, turbulent, or a combination thereof. The blade may be a plurality of blades. The mounting plate can include a tip-tilt base plate, a translation stage, or a combination thereof. <
Filing details
- Inventors
- Steven Raymond Lustig
- Assignee
- United States Army Research Laboratory
- Filed
- Sep 9, 2024
- Granted
- Application pending
Bibliographic data and excerpted text sourced from Google Patents (public record) as part of IP TechMatch's current-filings monitor. This filing is not part of the 2019 historical archive. For the authoritative full text, drawings, and legal status, see the source links above or consult USPTO records directly.