Kaur G.,Virginia Polytechnic Institute and State UniversityBlacksburg |
Pickrell G.,Virginia Polytechnic Institute and State University |
Kumar V.,Virginia Polytechnic Institute and State UniversityBlacksburg |
Homa D.,Virginia Polytechnic Institute and State University
Journal of Biomedical Materials Research - Part B Applied Biomaterials | Year: 2015
Biomaterial development is currently the most active research area in the field of biomedical engineering. The bioglasses possess immense potential for being the ideal biomaterials due to their high adaptiveness to the biological environment as well as tunable properties. Bioglasses like 45S5 has shown great clinical success over the past 10 years. The bioglasses like 45S5 were prepared using melt-quenching techniques but recently porous bioactive glasses have been derived through sol-gel process. The synthesis route exhibits marked effect on the specific surface area, as well as degradability of the material. This article is an attempt to provide state of the art of the sol-gel and melt quenched bioactive bioglasses for tissue regeneration. Fabrication routes for bioglasses suitable for bone tissue engineering are highlighted and the effect of these fabrication techniques on the porosity, pore-volume, mechanical properties, cytocompatibilty and especially apatite layer formation on the surface of bioglasses is analyzed in detail. Drug delivery capability of bioglasses is addressed shortly along with the bioactivity of mesoporous glasses. © 2015 Wiley Periodicals, Inc.
Yao Y.,Virginia Polytechnic Institute and State UniversityBlacksburg |
Chen Z.,Virginia Polytechnic Institute and State UniversityBlacksburg |
Lu G.-Q.,Virginia Polytechnic Institute and State UniversityBlacksburg |
Boroyevich D.,Virginia Polytechnic Institute and State UniversityBlacksburg |
Ngo K.D.T.,Virginia Polytechnic Institute and State UniversityBlacksburg
Journal of Applied Polymer Science | Year: 2014
Silicones are widely used for electrical insulation owing to their high dielectric strength and thermal stability. However, recent studies revealed insufficient stability of silicone for high-temperature applications. To study the effect of Al2O3 fiber on silicone stability, we measured the dielectric strength of unfilled silicone and Al2O3/silicone composites as a function of aging time at 250°C in air and analyzed data by Weibull probability distribution to determine characteristic dielectric strength (E0) and shape parameter (β). Prior to aging, unfilled silicone and composites had similar behavior, with E0 at about 20 kV/mm and β>15. During aging, unfilled silicone developed both micro- and macrocracks, with β dropped below five in 240 h and E0 decreased significantly. Composites developed microcracks, with β dropped below 5 in longer time and E0 remained almost constant. Addition of Al2O3 slowed down crack growth in silicone matrix, resulting in longer lasting high-temperature dielectric materials. © 2014 Wiley Periodicals, Inc.