title: Biodegradable shape memory nanocomposites with thermal and magnetic field responsiveness.
abstract: Thermal and magnetic field responsive biodegradable shape memory polymer nanocomposite was prepared with Fe3O4 nanoparticles and poly(L-lactides) (PLLA). The magnetic Fe3O4 nanoparticles with an average size of 9 nm were initially synthesized by co-precipitation method and then followed by surface modification using oleic acid. The TEM and SEM results show that the surface modified Fe3O4 nanoparticles can evenly disperse in chloroform and PLLA polymer matrix. The tensile test results show that the addition of Fe3O4 nanoparticles to a PLLA matrix greatly improved the elastic modulus, tensile strength, elongation at break, and the shape memory properties as well. Moreover, the shape recovery process of the nanocomposites driven by an alternating magnetic field was also observed. However, the shape recovery ratio and the recovery speed in an alternating magnetic field are lower than that occurred in 70 °C water. The lower shape recovery ratio and the recovery speed in an alternating magnetic field is attributed to the low frequency and strength of the magnetic field, which lead to small heat generated by Fe3O4 nanoparticles.
authors.affiliation: Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001, PR China.
authors.forename: Xvming
authors.initials: X
authors.lastname: Zhang
authors.forename: Xili
authors.initials: X
authors.lastname: Lu
authors.forename: Zhaomin
authors.initials: Z
authors.lastname: Wang
authors.forename: Jianyong
authors.initials: J
authors.lastname: Wang
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Sun
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry; D052203:Ferrosoferric Oxide / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry* / Q000528:radiation effects; D010316:Particle Size; D011091:Polyesters; D011108:Polymers / Q000737:chemistry; D013696:Temperature; D013718:Tensile Strength / Q000502:physiology* / Q000528:radiation effects*; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D058185:Magnetite Nanoparticles; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D052203:Ferrosoferric Oxide