Abstract: Methods and devices are provided for the continuous production of a network of nanotubes or other nanoscale fibers. The method includes making a suspension of nanoscale fibers dispersed in a liquid medium, optionally with surfactant and/or sonication, and filtering the suspension by moving a filter membrane through the suspension, such that the nanoscale fibers are deposited directly on the filter membrane as the fluid medium flows through the filter membrane, thereby forming a continuous membrane of the nanoscale fibers. The deposition of the nanoscale fibers can occur when and where the filter membrane moves into contact with a static, porous filter element or a dynamic, porous filter element. The filtering can be conducted within a magnetic field effective to align the nanoscale fibers, and/or with the aid of vacuum to pull water through the filter membrane, applied pressure to press water though the filter membrane, or a combination thereof.
Type:
Grant
Filed:
July 20, 2005
Date of Patent:
December 2, 2008
Assignee:
Florida State University Research Foundation
Inventors:
Zhiyong Liang, Ben Wang, Chun Zhang, Jonnattan T. Ugarte, Chih-Yen Lin, James Thagard
Abstract: Polypropylene resin compositions are provided that are useful in the production of biaxially oriented polypropylene films (BOPPs). The resins of the present invention are blends of high crystalline (low solubles) polypropylene homopolymer and an ethylene/propylene random copolymer (RCP). These blends can be used to replace standard high solubles BOPP grade polypropylene homopolymers. In addition, the use of high crystalline polypropylene homopolymers in the blends imparts improved stiffness to the finished films while maintaining good processability of the blends.
Abstract: A high density polyethylene (HDPE) film is provided having high-biaxial orieniation. The film includes HDPE having a density of at least about 0.940, and a melt index of from about 0.5 to about 10. The film is stretched in the machine (longitudinal) direction to a degree of from about 5:1 to about 8:1, preferably from about 6:1 to about 7:1. The film is also stretched in the transverse (lateral) direction to a degree of from about 6:1 to about 15:1, preferably from about 9:1 to about 13:1. Preferably, the film has an orientation imbalance, with a higher degree of transverse orientation than machine orientation. Skin layers such as heat seal layers can be provided. Preferably, the film contains one or more layers of a casting promoter material employed to promote casting of a high gauge HDPE sheet subsequently high biaxially oriented to provide the film. The film can also be cavitated, or otherwise modified (e.g., corona-treated, coated, metallized, etc.) to provide films suitable for special applications.