Conference Papershttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/202024-03-29T07:01:59Z2024-03-29T07:01:59ZSynthesis of sodium silicate from rice husk ash as an activator to produce epoxy-geopolymer cementL. HandayaniS. ApriliaAbdullahC. RahmawatiMohd Mustafa Al Bakri, AbdullahIkmal Hakem, AzizEmy Aizat, Azimihttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/748702022-03-30T07:49:05Z2021-03-01T00:00:00ZSynthesis of sodium silicate from rice husk ash as an activator to produce epoxy-geopolymer cement
L. Handayani; S. Aprilia; Abdullah; C. Rahmawati; Mohd Mustafa Al Bakri, Abdullah; Ikmal Hakem, Aziz; Emy Aizat, Azimi
Rice husk ash (RHA), a byproduct of the rice industry, is the primary source of amorphous silica for producing sodium silicate solutions to replace standard commercial sodium silicate in geopolymer mixture design. The effect of various concentrations of NaOH used as an activator to produce epoxy-geopolymer cement was studied. Three initial concentrations of NaOH were used (8, 10, and 12M) to examine the optimum dissolution and formation of silica oligomers that can function as the activator during the geopolymerization. The result indicated the increase of NaOH concentration raises the silica yield strength. The silica yield found was 65.84%, 70.53% and 72.06% on NaOH use of 8, 10, 12 M, respectively. IR-spectra results showed silica functional groups and the sodium silicate were successfully synthesized. The IR spectra indicated the appearance of hydroxyl bonds, which strengthen the geopolymer matrix. SEM results showed the C-S-H and N-A-S-H bonds in the geopolymer. With 10M NaOH, the compressive strength of the geopolymer cement paste was optimal at 27.53 MPa. Thus, Rice husk ash (RHA) is feasible to be used as an activator in high calcium fly ash-based epoxy geopolymer cement
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2021-03-01T00:00:00ZSynthesis and characterization of fly ash based geopolymer ceramics: effect of NaOH concentrationRomisuhani, AhmadWan Mastura, Wan IbrahimMohd Mustafa Al Bakri, AbdullahSandu, Andrei VictorNurul Aida, Mohd MortarNoratikah, HashimWarid Wazien, Ahmad Zailanihttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747062022-03-17T03:23:12Z2020-02-01T00:00:00ZSynthesis and characterization of fly ash based geopolymer ceramics: effect of NaOH concentration
Romisuhani, Ahmad; Wan Mastura, Wan Ibrahim; Mohd Mustafa Al Bakri, Abdullah; Sandu, Andrei Victor; Nurul Aida, Mohd Mortar; Noratikah, Hashim; Warid Wazien, Ahmad Zailani
Ceramic materials have demonstrated impressive performance under severe conditions in a wide number of areas including health, energy and environment, transportation and electronic applications. In order to meet the growing demand of specific properties of ceramics, the use of geopolymer method were introduced as an alternate way by providing new material to fabricate geopolymer as ceramic precursor and moving towards green technology. Geopolymer ceramic was produced using fly ash as source materials. Different molarities of sodium hydroxide solution in the range of 8 M to 14 M were used in the preparation of fly ash geopolymer ceramic. The ratio of fly ash/alkaline solution and alkaline activator were kept constant at 2.0 and 2.5 respectively. Physical and mechanical properties such as density, flexural strength and shrinkage were determined. The optimum flexural strength of 61.6 MPa is obtained at the sodium hydroxide concentration of 12 M with the density of 2.21 g/cm³. The formation of almost fully crystalline phase with appearance of albite contribute to the flexural strength of fly ash geopolymer ceramic. Microstructure image result shows that a presence of pores due to sintering effect and smoother matrix which gives denser structure as supported by the excellent density.
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2020-02-01T00:00:00ZCompressive strength and thermal conductivity of metakaolin geopolymers with anisotropic insulationsNur Ain, JayaYun-Ming, LiewMohd Mustafa Al Bakri, AbdullahKamarudin, HussinCheng Yong, HeahRidho, BayuajiMuhammad Faheem, Mohd Tahirhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747052022-03-17T03:21:17Z2020-02-01T00:00:00ZCompressive strength and thermal conductivity of metakaolin geopolymers with anisotropic insulations
Nur Ain, Jaya; Yun-Ming, Liew; Mohd Mustafa Al Bakri, Abdullah; Kamarudin, Hussin; Cheng Yong, Heah; Ridho, Bayuaji; Muhammad Faheem, Mohd Tahir
This research investigated the properties of thermally insulating geopolymer prepared using waste filler (fibreboard and rubber) to act as anisotropic pore/insulation. The geopolymer matrix was synthesised using metakaolin and an alkaline solution consists of sodium hydroxide solution and sodium silicate mixture. Geopolymers with varying content (0, 3, 5 and 7 layers) of coin-shaped fibreboard and expanded polystyrene are produced to examine the anisotropic insulation effect on the material characteristics. The compressive strength and thermal conductivity were determined experimentally. From the results, it is proved that the use of anisotropic insulations can improve the thermal conductivity and minimizing the reduction of compressive strength. Geopolymer incorporated with fibreboard had better performance in terms of strength while geopolymer incorporated with rubber had better thermal conductivity.
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2020-02-01T00:00:00ZIn Vitro bioactivity study of thermoplastic Starch/Bentonite/Hydroxyapatite composites for biomedical applicationsNurul Husna, ZakariaNoorhafiza, MuhammadMohd Mustafa Al Bakri, AbdullahS. N. F., M. Noorhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747042022-03-17T03:19:45Z2020-02-01T00:00:00ZIn Vitro bioactivity study of thermoplastic Starch/Bentonite/Hydroxyapatite composites for biomedical applications
Nurul Husna, Zakaria; Noorhafiza, Muhammad; Mohd Mustafa Al Bakri, Abdullah; S. N. F., M. Noor
Potato starch composites film incorporating hybrid bentonite and hydroxyapatite (HA) were investigated as novel biomaterial for potential biomedical applications. The selected potato starch/bentonite composites were prepared using different ratios of HA (1, 5 and 10 wt%) through solution casting technique. The in vitro bioactivity of potato starch composites film and neat potato starch film to be used as a control were evaluated through immersion in simulated body fluid (SBF) at 37°C for 14 days. The composites films were also subjected to characterization such as morphology, pH evaluation and biodegradability analyses following immersion in SBF. The obtained results showed that the incorporation of HA into starch/bentonite composites improves the bioactivity of the starch hybrid composites by formation of apatite layer on the surface. Increasing HA content in the composite is directly proportional to the quantity of the apatite formed on the scaffolds indicating active surface interactions between the composites and SBF. Furthermore, increasing HA content contributes also to lowering biodegradability of the composite decreases.
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2020-02-01T00:00:00Z