Papers by Keyword: Ethylene-Vinyl Alcohol Copolymer (EVOH)

Abstract: The nanofibers of EVOH which was dissolved in DMAC/IPA solution system were successfully prepared by eletrospinning. Through designed the electrospinning parameter of EVOH and observed the fiber morphology by the Field Emission Scanning Electronic Microscope(FESEM), we analyzed the influence of different spinning parameters to the fibers. And finally the optimum spinning process of EVOH nanofibers was obtained, which has the spinning concentration of 18wt%, spinning voltage of 29kV and receiving distance of 18cm. The average diameters of the well spun fibers using the solution system were concentrated between 65nm-105nm.

Abstract: A composite layer of fibroblast growth factor-2 (FGF-2) and low-crystalline apatite was formed on an ethylene-vinyl alcohol copolymer specimen using two types of aqueous calcium phosphate solutions supplemented with 10 !g·mL-1 FGF-2; one is a CP solution that is prepared by dissolving chemical reagents into ultrapure water and the other is an RKB solution that can be prepared by mixing clinically approved infusion fluids. In both solutions, a sufficient amount of FGF-2 for new skin tissue formation (1 !g·cm-2) was immobilized on the specimen surface.

Abstract: A laminin–DNA–apatite composite layer was successfully formed on the surface of an ethylene–vinyl alcohol copolymer. The immobilized DNA was transferred to the cells adhering onto the laminin–DNA–apatite composite layer more efficiently than those adhering onto a lamininfree DNA–apatite composite layer. It is considered that laminin immobilized in the surface layer enhances cell adhesion and spreading, and DNA locally released from the layer is effectively transferred into the adhering cells, taking advantage of the large contact area. The present gene transferring system, which shows high efficiency and safety, would be useful in gene therapy and tissue engineering.

Abstract: An ethylene-vinyl alcohol copolymer (EVOH) film with a laminin–apatite composite layer on its surface showed improved adhesion and compatibility to living epithelial tissue compared to untreated EVOH film. This result can be attributed to the good biocompatibility of apatite and the cell-adhesion activity of the laminin on the EVOH surface. This composite material, consisting of laminin, apatite, and EVOH, is considered a promising material for skin terminals to prevent epidermal downgrowth.

Abstract: This study investigates the influence of viscoelastic properties of a series of ethylene-vinyl acetate copolymer on impact noise and vibration damping of wood/polymer/wood sandwich composites. It was found that the impact noise and vibration damping of composites are very sensitive to the state of molecular motion of polymer. The noise and vibration damping of composites was better when the polymer was in the glass transition state (vinyl acetate 55~75%) at the test-temperature, and it was worse when the polymer was in rubbery state (vinyl acetate 47~20%) or in glassy state (vinyl acetate100~87%). The impact noise decreased by about 6-12dB when the glass transition state of polymer was sandwiched between wood panels.

Abstract: Ethylene-vinyl alcohol copolymer (EVOH), poly(ethylene terephthalate) (PET) and polyethylene (PE) were modified with calcium silicate on their surfaces by a sol-gel method, before or after glow discharge treatment in O2 gas, soaked in a simulated body fluid (SBF) and implanted into knee bone of a rabbit. EVOH and PET formed nano-sized bonelike apatite uniformly on their surfaces in SBF, without being subjected to the glow discharge, and bonded to the living bone of the rabbit, whereas PE formed the apatite only sparsely even when being subjected to the glow discharge. Three dimensional fabrics with open spaces in various sizes of the former fibers modified with the calcium silicate might be useful as bone substitutes.

Abstract: Mechanism of formation of a laminin-apatite composite layer on the surface of an ethylene-vinyl alcohol copolymer (EVOH) using a liquid phase coating process was investigated by transmission electron microscopy (TEM). In this coating process, an EVOH substrate is alternately dipped in calcium and phosphate solutions, and then immersed in a laminin-containing calcium phosphate (LCP) solution. From the results obtained by the present study, formation of the laminin-apatite composite layer on EVOH is likely to proceed via the following events. By the alternate dipping process, particulate amorphous calcium phosphate, which is a precursor of apatite, was deposited onto the EVOH surface. When the specimen was subsequently immersed in the LCP solution, the amorphous calcium phosphate on the specimen transformed itself into needle-like apatite crystal, and then grew into a layer. During this process, laminin molecules contained in the LCP solution were incorporated into a matrix of the apatite crystals to produce a laminin-apatite composite layer on the EVOH surface.