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Full-Text Articles in Engineering

Resistance To Helium Bubble Formation In Amorphous Sioc/Crystalline Fe Nanocomposite, Qing Su, Tianyao Wang, Jonathan Gigax, Lin Shao, Michael Nastasi Jan 2019

Resistance To Helium Bubble Formation In Amorphous Sioc/Crystalline Fe Nanocomposite, Qing Su, Tianyao Wang, Jonathan Gigax, Lin Shao, Michael Nastasi

Department of Mechanical and Materials Engineering: Faculty Publications

The management of radiation defects and insoluble He atoms represent key challenges for structural materials in existing fission reactors and advanced reactor systems. To examine how crystalline/amorphous interface, together with the amorphous constituents affects radiation tolerance and He management, we studied helium bubble formation in helium ion implanted amorphous silicon oxycarbide (SiOC) and crystalline Fe composites by transmission electron microscopy (TEM). The SiOC/Fe composites were grown via magnetron sputtering with controlled length scale on a surface oxidized Si (100) substrate. These composites were subjected to 50 keV He+ implantation with ion doses chosen to produce a 5 at% peak He …


Effects Of Compositional Tailoring On Drug Delivery Behaviours Of Silica Xerogel/Polymer Core-Shell Composite Nanoparticles, Wenfei Huang, Chi Pong Tsui, Chak Yin Tang, Linxia Gu Jan 2019

Effects Of Compositional Tailoring On Drug Delivery Behaviours Of Silica Xerogel/Polymer Core-Shell Composite Nanoparticles, Wenfei Huang, Chi Pong Tsui, Chak Yin Tang, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Conventional core-shell polymer nanoparticles usually exhibit a rapid release rate with their release kinetics mainly adjusted through changing composition of the polymer shells, limiting their applications for prolonged drug delivery. As a solution to these problems, silica xerogel/polymer core-shellstructured composite nanoparticles have been proposed. Different with our previous work centring on studying process variables, we here focused on investigating the effects of key compositional variables on essential properties of the composite nanoparticles. The drug release profiles (in vitro) were well interpreted by the Baker and Lonsdale model on a predicted two-stage basis. The first stage (<1 day) was well controlled from 18.6% to 45.9%; the second stage (1–14 days) was tailored in a range from 28.7 to 58.2% by changing the composition of the silica xerogel cores and polymeric shells. A substantial achievement was reducing the release rate by more than 40 times compared with that of conventional polymer nanoparticles by virtue of the silica xerogel cores. A semi-empirical model was also established in the first attempt to describe the effects of polymer concentration and drug loading capacity on the size of the composite nanoparticles. All these results indicated that the composite nanoparticles are promising candidates for prolonged drug delivery applications.


Study Of Behavior Of Plastic Modified Bitumen By Incorporating Carbon Black, Ho-Fai Wong, Hao-Jue Hong, Lai-Ming Leung, Tsz-Chun Fong, Yi-Fei Shen, Tsz-Hin Lo Jan 2019

Study Of Behavior Of Plastic Modified Bitumen By Incorporating Carbon Black, Ho-Fai Wong, Hao-Jue Hong, Lai-Ming Leung, Tsz-Chun Fong, Yi-Fei Shen, Tsz-Hin Lo

Faculty of Science & Technology (THEi)

In recent years, the performance of polymer modified bitumen has been widely studied. This study reports a research carried out to investigate the properties of polymer modified bitumen (PMB) by using polypropylene as modifier, carbon black as additives, to examine the optimum ratio of polypropylene to carbon black. With this objective, sample preparation using wet mixing method combining high shear mix was firstly performed. Subsequently, 18 samples were developed for the study, of which the polypropylene (PP) contents 10%, 12%, 14%, 16%, 18% and 20% with 2%, 3%, 4% of carbon black content. Afterwards, samples were characterized by standard tests …