Roadmapping an emerging energy technology: An ex-ante examination of dimethyl ether development in China

Technology roadmapping has been used to strategise the development of energy technologies. However, there have been limited roadmapping applications that analyse the emergence of a new energy technology that then forms a new industry and propels broad-based low-carbon economic growth. This paper, therefore, attempts to develop a roadmapping framework by integrating the lifecycle analysis tool, in order to strategise the emergence of dimethyl ether, an alternative energy based on advanced engineering technologies such as carbon capture and storage. This paper compares two scenarios of dimethyl ether vs. diesel and finds that the superiority of dimethyl ether will not arise until 2030, when the complementary engineering technologies become available. This proposed framework can also be generalised to other clean energy industries, and we anticipate our paper will spark inspiration for roadmapping and strategising the 'right' technologies for the growth of Chinese energy industries. Copyright © 2012 Inderscience Enterprises Ltd.

Phototransistors utilizing individual WS2 nanotubes

We report on the photoresponse characteristics of tungsten disulfide (WS2) nanotubes. Field effect transistors (FETs) were fabricated by using individual WS2 multiwall nanotubes. Photo-sensitivity to visible light is clearly observed, with enhancement of the channel conductivity, carrier mobility and carrier concentration upon illumination in the visible regime. Polarization-sensitive measurements reveal a strong anisotropy of the photocurrent on the polarization angle of the incident light with respect to the WS2 nanotube axis. This nano-scale transistor capable of detecting visible light would have a wide range of applications in medical and consumer electronics. © 2008 IEEE. Crown Copyright.

Using mesoscopic models to design strong and tough biomimetic polymer networks

Using computational modeling, we investigate the mechanical properties of polymeric materials composed of coiled chains, or "globules", which encompass a folded secondary structure and are cross-linked by labile bonds to form a macroscopic network. In the presence of an applied force, the globules can unfold into linear chains and thereby dissipate energy as the network is deformed; the latter attribute can contribute to the toughness of the material. Our goal is to determine how to tailor the labile intra- and intermolecular bonds within the network to produce material exhibiting both toughness and strength. Herein, we use the lattice spring model (LSM) to simulate the globules and the cross-linked network. We also utilize our modified Hierarchical Bell model (MHBM) to simulate the rupture and reforming of N parallel bonds. By applying a tensile deformation, we demonstrate that the mechanical properties of the system are sensitive to the values of N in and N out, the respective values of N for the intra- and intermolecular bonds. We find that the strength of the material is mainly controlled by the value of N out, with the higher value of N out providing a stronger material. We also find that, if N in is smaller than N out, the globules can unfold under the tensile load before the sample fractures and, in this manner, can increase the ductility of the sample. Our results provide effective strategies for exploiting relatively weak, labile interactions (e.g., hydrogen bonding or the thiol/disulfide exchange reaction) in both the intra- and intermolecular bonds to tailor the macroscopic performance of the materials. © 2011 American Chemical Society.