http://hdl.handle.net/10204/920 2013-05-21T21:33:52Z http://hdl.handle.net/10204/6673 Title: Fabrication and properties of polylactic acid fabric based sandwich panels with arylated soy protein isolate as the binder Authors: Kumar, R; Moyo, D Abstract: PLA fabrics were coated with arylated soy protein isolate (ASPI) dispersions at different levels of 2,2-diphenyl-2-hydroxy ethanoic acid (DPHEAc) (1 to 10 wt.% wrt SPI). In order to optimize the level of DPHEAc in ASPI, the fabricated ASPI coated PLA fabric were subjected to mechanical, thermal, thermomechanical and water uptake studies. Interfacial interactions between ASPI and PLA were assessed by fracture morphology. Finally, ASPI coated PLA fabrics at the 5 wt.% of DPHEAc were successfully used to prepare sandwich panels with the ASPI coated PLA fabric skins for a Nomex based honeycomb core. The ultimate bending and peeling load of the sandwich panels with one layer of ASPI coated PLA fabric were determined. A few remnants of the honeycomb core attached to the PLA fabrics after peeling load tests visually suggested the presence of strong adhesive bond between honeycomb core and PLA fabric skins. Description: Copyright: 2012 American Scientific Publishers. This is an ABSTRACT ONLY. The definitive version is published in Journal of Biobased Materials and Bioenergy, vol. 6(5), pp 521-530 2012-10-01T00:00:00Z http://hdl.handle.net/10204/6469 Title: Synthesis, properties, and applications of hydroxyapatite Authors: Chetty, A; Wepener, I; Marei, MK; Kamary, YE; Moussa, RM Abstract: Hydroxyapatite (HA) has been extensively investigated and used in bone clinical application for more than four decades. The increasing interest in HA is due to its similar chemical composition to that of the inorganic component of natural bone. HA displays favourable properties such as bioactivity, biocompatibility, slow-degradation, osteoconduction, osteointegration, and osteoinduction. HA is commercially available either from a natural source or as synthetic HA. Various methods have been reported to prepare synthetic HA powders which include solid state chemistry and wet chemical methods. For bone applications, pure HA, biphasics with ß-tricalciumphosphate (ß-TCP) and HA composites have been widely investigated. HA is processed into dense bodies by sintering and sintering temperature, stoichiometry, phase purity, particle grain size, And porosity are important processing parameters. Furthermore porosity in particular pore size; macro and microporosity; pore interconnectivity; morphology; pore size distribution, and surface properties influence bone remodelling. At high sintering temperatures, HA is transformed primarily into ß-TCP which is amorphous and resorbable. Despite the success of HA derived implants one of the major drawbacks of this material is its poor tensile strength and fracture toughness compared to natural bone. This makes HA unsuitable for several load-bearing applications. HA has been reinforced with a number of fillers including polymers such as collagen, metals and inorganic materials such as carbon nanotubes, and HA has also been applied as coatings on metallic implants. To improve the biomimetic response of HA implants, nano-HA powder has been synthesised, and HA nanocomposites containing electrospun nanofibers, and nanoparticles have been produced. Nano-HA displays a large surface area to volume ratio and a structure similar to natural HA, which shows improved fracture toughness, improved sinterability, and enhanced densification. Biological entities such as bone morphogenic proteins (BMP s), stem cells, and other growth factors have also been incorporated into HA nanocomposites. HA implants have been applied in the form of dense and porous block implants, disks, granules, coating, pastes, and cements. Some of the frequent uses of HA include the repair of bone, bone augmentation, acting as space fillers in bone and teeth, and coating of implants. In this book chapter, we will focus on the synthesis and properties of HA powders and HA implants with specific application in bone engineering. We will also share our experience over the past 20 years in dental and craniofacial reconstruction. Description: Copyright: Nova Science Publishers, Hauppage, USA 2012-08-01T00:00:00Z http://hdl.handle.net/10204/6287 Title: Polymer microcantilevers for water quality monitoring Authors: Ojijo, V; Kumar, S; De Villiers, M; Chen, J; Cele, H; Land, K Abstract: The microcantilever project aims to develop novel polymer based microcantilevers able to detect E.coli in water samples for use as a rapid diagnostic for on-site water quality monitoring. Description: 4th CSIR Biennial Conference: Real problems relevant solutions, CSIR, Pretoria, 9-10 October 2012 2012-10-01T00:00:00Z http://hdl.handle.net/10204/6223 Title: CSIR facilities geared to support the Biocomposites Centre of Competence Authors: Anandjiwala, R Abstract: Over the past few years, the CSIR has made a significant investment into fibres and biocomposite research and infrastructure at its Port Elizabeth campus. The Department of Science and Technology (DST) has invested approximately R10.8 million in new equipment to complement this research. With the hub of the country’s newly created Biocomposites Centre of Competence situated in Port Elizabeth, the CSIR is ideally positioned to provide optimum support. Description: 4th CSIR Biennial Conference: Real problems relevant solutions, CSIR, Pretoria, 9-10 October 2012 2012-10-01T00:00:00Z