Papers by Author: Yan Feng Dai

Abstract: Atomic defects play an important role in the brittle deformation of nanowires at low temperatures. With molecular dynamics simulations, we study the influence of vacancy defects on the deformation and breaking behaviors of [10 oriented single-crystal gold nanowires at 50 and 150 K. The size of the nanowire is 10a × 10a × 30a (a stands for lattice constant, 0.408 nm for gold). It is shown that good crystalline structure appears in the whole deformation process, and it is in a brittle way at low temperature. The nanowire breaking behavior is sensitive to atomic vacancies when the atomic vacancy ratio is 1% in single-layer crystalline plane. Within the limitation of vacancy-induced breaking of the nanowire, the mechanical strengths increase under atomic vacancies. However, it decreases with the defect ratio increasing.

Abstract: Cross-linked poly(N-isopropylacrylamide) tethered Hydroxyapatite hybrid materials (HA- PNIPAM) were prepared by the ATRP reaction. The hybrid materials were characterized by FT-IR、TGA、SEM and UV spectra. The TGA results demonstrated that there was 122 g PNIPAM grafted on the surface of per 100g of HA. The UV results showed that the HA-PNIPAM have thermal responsive property around 33°C.