Use of natural raw materials to synthesise undoped and doped akermanite bioceramics
| dc.contributor.author | Ng, Yi Cheng | |
| dc.date.accessioned | 2021-02-19T03:20:45Z | |
| dc.date.available | 2021-02-19T03:20:45Z | |
| dc.date.issued | 2019-07 | |
| dc.description.abstract | Akermanite is a Ca-, Mg-, Si- containing bioceramic that has the capability to be used as bone graft substitute due to its good biocompatibility and bioactivity and also controllable degradation rate. However, low mechanical strength, especially fracture toughness has limit its contribution in biomedical applications. This present project aims to study the different in properties of akermanite bioceramics synthesised with bionatural resources and sintered at different sintering temperature as well as the properties between undoped and doped akermanite bioceramics. The raw materials include ostrich eggshell and chicken eggshell as calcium source, rice husk ash provides silica and magnesium oxide chemical powder. The raw materials were calcined to transform into oxide. Mechanical milling and mixing was proceeded with high energy planetary milling followed by sintering at different temperature (1150°C, 1200°C and 1250°C) to synthesise akermanite bioceramic. For doped akermanite, concentration of strontium was varied at 1 mol% and 3 mol%. The phase identification, surface morphologies, functional group identification, mechanical properties and bioactivity evaluation of samples were studied. XRD analysis showed the presence of secondary phase diopside in 1150°C, but only single phase akermanite when temperature increased to 1200°C and 1250°C. For doped akermanite, incorporation of Sr into the calcium site of akermanite was indicated by the peak shifted to the left. FESEM result showed the reduction of porosities but increasing grain size when sintering temperature increased. It also revealed smaller grain size was produced in doped akermanite due to the ability of Sr to minimize grain growth. DTS test and Vickers microhardness showed that mechanical properties increased when temperature increased and apparently, akermanite synthesized with ostrich eggshell has greater properties compared to akermanite synthesized with chicken eggshell. This might be due to smaller grain size were found in akermanite synthesized with ostrich eggshell. Fracture toughness of pure akermanite synthesized with ostrich eggshell increases from 1.149 MPa.m1/2 to 1.393 MPa.m1/2 as temperature increases from 1150°C to 1250°C. Addition of Sr dopant has further improve the fracture toughness to 1.424 MPa.m1/2 (1 mol% SrO) and 1.539 MPa.m1/2 (3 mol% SrO). Pure and doped akermanite support the formation of apatite layer after 21 days of soaking in SBF solution. Overall, favourable akermanite properties can be possibly obtained for biomedical application by controlling the sintering temperature, raw material used and the concentration of dopant. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/11377 | |
| dc.language.iso | en | en_US |
| dc.title | Use of natural raw materials to synthesise undoped and doped akermanite bioceramics | en_US |
| dc.type | Other | en_US |
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