title: Nano-composite of poly(L-lactide) and halloysite nanotubes surface-grafted with L-lactide oligomer under microwave irradiation.
abstract: In order to improve the bonding between halloysite nanotubes (HNTs) and poly(L-lactide) (PLLA), and hence to increase the mechanical properties of HNTs/PLLA nano-composite, HNTs were surface-grafted with PLLA under microwave irradiation and then blended with PLLA matrix. The optimal conditions for grafting polymerization are: irradiation time of 30 min, microwave power of 30 W and reaction temperature of 130 degrees C. The structure and properties of the surface-grafted HNTs (g-HNTs) were characterized by Fourier transformation infrared (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and dynamic light scattering (DLS). Nano-composites of g-HNTs/PLLA and non-grafted HNTs/PLLA were subsequently evaluated in terms of crystallinity, dispersion, interfacial interaction, mechanical performance and cytocompatibility by polarized optical microscopy (POM), field scanning electron microscope (FESM), tensile testing and cell culture experiment. Results show that the grafted PLLA chains on the surfaces of HNTs, as inter-tying molecules, played an important role in improving the adhesive strength between the nanotubes and the polymer matrix. The enhanced interaction among g-HNTs and PLLA matrix resulted in a better tensile strength and modulus compared to the pristine PLLA and HNTs/PLLA. Cell culture results indicated that g-HNTs promoted both adhesion and proliferation of M3T3 fibroblasts on the g-HNTs/PLLA composite film.
authors.affiliation: Biomaterial Research Laboratory, Department of Material Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632, P R. China. tluobh@jnu.edu.cn
authors.forename: Bing-Hong
authors.initials: BH
authors.lastname: Luo
authors.forename: Chung-En
authors.initials: CE
authors.lastname: Hsu
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Li
authors.forename: Liang-Feng
authors.initials: LF
authors.lastname: Zhao
authors.forename: Ming-Xian
authors.initials: MX
authors.lastname: Liu
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Wang
authors.forename: Chang-Ren
authors.initials: CR
authors.lastname: Zhou
mesh_terms: D000538:Aluminum Silicates / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D000077215:Clay; D004146:Dioxanes / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology / Q000648:ultrastructure; D051379:Mice; D008872:Microwaves; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011091:Polyesters / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength / Q000187:drug effects; D013818:Thermogravimetry; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D004146:Dioxanes; D011091:Polyesters; C033616:poly(lactide); C091880:dilactide; D000077215:Clay