Nur Ain Jaya
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Preferred name
Nur Ain Jaya
Official Name
Nur Ain, Jaya
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Jaya, N. A.
Ain Jaya, Nur
Jaya, Nur Ain
Nur, Ain Jaya
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Scopus Author ID
56354805400
Researcher ID
AAW-9244-2021

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Study on kaolin geopolymer ceramic using powder metallurgy method

2016 , Nur Ain Jaya

Geopolymer is an inorganic polymeric material synthesized from the dissolution and polycondensation of aluminosilicates in alkaline solutions at ambient temperature yielding an amorphous, three-dimensional polymeric framework. Geopolymers become an interest due to environmental friendly, low cost production, high early strength, durability and high chemical resistance. Kaolin is used as the aluminosilicate source in this study. The selection of kaolin offers a few advantages towards the common source materials used in geopolymer such as metakaolin. Dehydroxylation cause the decomposition of kaolinite crystals to a partially disordered structure to produce metakaolin. This reaction requires calcining of kaolin at temperatures between 500°C - 900 °C. Calcining kaolin limits the commercial application of metakaolin due to the added cost and consume much energy. Recent technology has been focusing on widening the application of geopolyrner by conversion to ceramics upon heating to higher temperature. In order to overcome problem arise, the effective method was to use powder metallurgy method whereby to sinter ground and compressed geopolymer powder. There are three parameters that involved to produce kaolin geopolyrner ceramics with optimum properties which are NaOH concentration, Na2Si03/NaOH ratios and sintering temperatures. The properties and characterization of kaolin ceramic and kaolin geopolyrner ceramic has been done using a flexural strength, density measurement, water absorption measurement, phase analysis and microstructural analysis. Results showed that NaOH molarity of 12 M, Na2Si03/NaOH ratio of 0.24:1 and sintering temperature of 1200 oc gives the highest flexural strength of 88.47 MPa, a density of 2.13 g/cm3 and water absorption of 1.2 %. Phase analysis show that the highest peak intensity of nepheline contributed to this high strength of kaolin geopolymer ceramic. Microstructural analysis show that sintering the geopolymer to 1200 °C resulted in the formation of pores possibly due to the decomposition of the material on sintering. As a conclusion, this study provides a better understanding on how NaOH concentration, Na2Si03/NaOH ratios and sintering temperature influence the properties (flexural strength, density measurement, volumetric shrinkage measurement and water absorption measurement) and characteristics (microstructure and phase) of kaolin geopolyrner ceramic. For future research, another aluminosilicate materials can be proposed for geopoJymer ceramic.

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Porous Metakaolin Geopolymers with Tailored Thermal Conductivity

2019-08-14 , Nur Ain Jaya , Yun-Ming L. , Mohd. Mustafa Al Bakri Abdullah , Cheng-Yong H.

In this work, a novel lightweight metakaolin geopolymers were produced by using hydrogen peroxide as foaming agent. The influence of the hydrogen peroxide incorporation content (0.25 - 1.25%) on density, compressive strength and thermal conductivity was evaluated. The experimental results show that the density and compressive strength were decrease with increasing content of hydrogen peroxide. However, the thermal insulating properties of the geopolymer foams were improved with increasing content of foaming agent. Geopolymers exhibiting thermal conductivity as low as 0.172 W/mK and a density of 0.5 g/cm3 were produced, showing the potential of these materials in applications requiring lightweight and low thermal conductivity materials.

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Cold-pressed fly ash geopolymers: effect of formulation on mechanical and morphological characteristics

2021-11-01 , Ong Shee Ween , Heah Cheng Yong , Liew Yun Ming , Mohd. Mustafa Al Bakri Abdullah , Chan L.W.L. , Ho Li Ngee , Ooi Wan-En , Nur Ain Jaya , Ng Yong-Sing

This research uses low alkali activator content and cold pressing technique for fly ash-based geopolymers formation under room temperature condition. The geopolymers were prepared using four different parameters: fly ash/alkali activator ratio, sodium hydroxide concentration, sodium silicate/sodium hydroxide ratio and pressing force. The results indicated that the compressive strength (114.2 MPa) and flexural strength (29.9 MPa) of geopolymers maximised at a fly ash/alkali activator ratio of 5.5, a 14 M sodium hydroxide concentration, a sodium silicate/sodium hydroxide ratio of 1.5 and a pressing force of 5 tons (pressing stress of 100.0 MPa and 155.7 MPa for compressive and flexural samples, respectively). The degree of reaction (40.1%) enhanced the structure compactness with minimum porosity. The improved mechanical properties confirmed that a high strength pressed geopolymer could be formed at low alkali activator content without the aid of temperature.

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Kaolin geopolymer as precursor to ceramic formation

2016 , Nur Ain Jaya , Mohd. Mustafa Al Bakri Abdullah , Che Mohd Ruzaidi Ghazali , Mohammed Hussain , Kamarudin Hussin , Romisuhani Ahmad

This paper introduced the potential application of kaolin geopolymer as ceramic precursor. This is one of the alternatives to produce high strength ceramic at a slightly lower temperature. Upon sintering the conversion of geopolymer to ceramic occur. The kaolin used were characterized using XRF and has plate-like structure upon investigating through microstructural analysis. Geopolymer mixture is produced using 12 M NaOH molarity with the Na2SiO3/NaOH ratio of 0.24. The sintering temperature used were ranging from 900 °C to 1200 °C. The flexural strength showed the highest value of 88.47 MPa when sintered at 1200 °C. The combination of geopolymerization and sintering has attributed to the strength increment as temperature increased. The density is observed to increase with increasing sintering temperature due to the appearance of the close pores in the structure. Sintering of the geopolymer resulted in the formation of liquid phase, which enables the joining of particles to produce dense microstructure.

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Cold-pressed fly ash geopolymers: effect of formulation on mechanical and morphological characteristics

2021 , Ong Shee-Ween , Heah Cheng Yong , Lynette Wei Ling Chan , Mohd. Mustafa Al Bakri Abdullah , Ho Li Ngee , Liew Yun Ming , Ooi Wan-En , Ng Yong-Sing , Nur Ain Jaya

This research uses low alkali activator content and cold pressing technique for fly ash-based geopolymers formation under room temperature condition. The geopolymers were prepared using four different parameters: fly ash/alkali activator ratio, sodium hydroxide concentration, sodium silicate/sodium hydroxide ratio and pressing force. The results indicated that the compressive strength (114.2 MPa) and flexural strength (29.9 MPa) of geopolymers maximised at a fly ash/alkali activator ratio of 5.5, a 14 M sodium hydroxide concentration, a sodium silicate/sodium hydroxide ratio of 1.5 and a pressing force of 5 tons (pressing stress of 100.0 MPa and 155.7 MPa for compressive and flexural samples, respectively). The degree of reaction (40.1%) enhanced the structure compactness with minimum porosity. The improved mechanical properties confirmed that a high strength pressed geopolymer could be formed at low alkali activator content without the aid of temperature.

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Correlation between pore structure, compressive strength and thermal conductivity of porous metakaolin geopolymer

2020 , Nur Ain Jaya , Liew Yun Ming , Heah Cheng Yong , Mohd. Mustafa Al Bakri Abdullah , Kamarudin Hussin

This paper investigates the effect of mixing parameters (that are, alkali concentration, AA ratio, and MK/ AA ratio) on the thermal conductivity of metakaolin geopolymers. The combination effect of foaming agent (H2O2) and surfactant (Tween 80) on the physical properties, compressive strength, and pore characteristic was also elucidated. Results showed that metakaolin geopolymer with maximum compressive strength of 33 MPa, bulk density of 1680 kg/m3 , porosity of 18% and thermal conductivity of 0.40 W/mK were achieved with alkali concentration of 10 M, AA ratio of 1.0 and MK/AA ratio of 0.8. Gradation analysis demonstrated that AA ratio was the strength determining factor. Whilst, thermal conductivity was dependent on the MK/AA ratio. Adding H2O2 and surfactant produced geopolymer foam with acceptable compressive strength (0.4–6 MPa). The geopolymer foam had bulk density of 471–1212 kg/m3 , porosity of 36–86% and thermal conductivity of 0.11–0.30 W/mK. Pore structure, size, and distribution were governed by H2O2 and surfactant dosages that have a great impact on the compressive strength. Narrower pore distribution and smaller pore diameter were achieved when both foaming agent and surfactant were used instead of foaming agent alone. The pore size and distribution varied to a greater extent with varying H2O2 contents. Surfactant illustrated distinct pore stabilizing effect at low H2O2 (<0.75 wt%) which diminished at high H2O2 content. In terms of thermal conductivity, even with increasing porosity at high H2O2 and surfactant content, the thermal conductivity did not show substantial reduction due to the interconnected pores as a result of pore coalescence

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Effect of sodium hydroxide molarity on physical, mechanical and thermal conductivity of metakaolin geopolymers

2018 , Nur Ain Jaya , Liew Yun Ming , Mohd. Mustafa Al Bakri Abdullah , Heah Cheng Yong , Kamarudin Hussin

In the present work, the effect of different sodium hydroxide (NaOH) molarity (6M, 8M, 10M, 12M and 14M) on the physical, mechanical and thermal conductivity of metakaolin geopolymers (MkGPs) was investigated. Geopolymers were prepared by activating the metakaolin with a mixture of NaOH with sodium silicate (Na₂SiO₃). The products obtained were characterized after 28 days of curing. The density, porosity, compressive strength and thermal conductivity (TC) were determined. In general, the NaOH molarity has a significant effect on the compressive strength of the MkGPs. The highest compressive strength was 14.6 MPa achieved with 10M of NaOH solution. The thermal conductivity of MkGPs measured in this work was low in the range between 0.71-0.97 W/mK. NaOH molarity had a significant effect on compressive strength but a marginal effect on thermal conductivity of MkGPs. The thermal conductivity was mainly affected by the bulk density and thus the total porosity. The results showed that the geopolymer can be considered to be used as the thermal insulating material.

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Effect of sodium hydroxide molarity on physical, mechanical and thermal conductivity of metakaolin geopolymers

2018 , Nur Ain Jaya , Liew Yun Ming , Mohd. Mustafa Al Bakri Abdullah , Heah Cheng Yong , Kamarudin Hussin

In the present work, the effect of different sodium hydroxide (NaOH) molarity (6M, 8M, 10M, 12M and 14M) on the physical, mechanical and thermal conductivity of metakaolin geopolymers (MkGPs) was investigated. Geopolymers were prepared by activating the metakaolin with a mixture of NaOH with sodium silicate (Na2SiO3). The products obtained were characterized after 28 days of curing. The density, porosity, compressive strength and thermal conductivity (TC) were determined. In general, the NaOH molarity has a significant effect on the compressive strength of the MkGPs. The highest compressive strength was 14.6 MPa achieved with 10M of NaOH solution. The thermal conductivity of MkGPs measured in this work was low in the range between 0.71-0.97 W/mK. NaOH molarity had a significant effect on compressive strength but a marginal effect on thermal conductivity of MkGPs. The thermal conductivity was mainly affected by the bulk density and thus the total porosity. The results showed that the geopolymer can be considered to be used as the thermal insulating material.

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Comparative mechanical and microstructural properties of high calcium fly ash one-part geopolymers activated with Na₂SiO₃-anhydrous and NaAlO₂

2021 , Ooi Wan-En , Liew Yun Ming , Heah Cheng Yong , Mohd. Mustafa Al Bakri Abdullah , Ho Li Ngee , Foo Kai Loong , Ong Shee-Ween , Ng Hui-Teng , Ng Yong-Sing , Nur Ain Jaya , Long-Yuan Li

This paper investigates the effect of varying solid alkali activators on the fresh and hardened properties and microstructural changes of one-part geopolymers (OPGs). Single and binary solid alkali activators were used to activate high calcium fly ash. The alkali activators were either solely sodium metasilicate (Na₂SiO₃) or a combination of sodium aluminate (NaAlO₂) and sodium metasilicate (Na₂SiO₃). The OPG activated with anhydrous Na₂SiO₃ achieved an excellent 28-day compressive strength of 83.6 MPa while OPG activated with NaAlO₂ and Na₂SiO₃ attained a compressive strength of 45.1 MPa. The Na₂SiO₃-activated OPG demonstrated better fluidity than the OPG activated with NaAlO₂ and Na₂SiO₃ due to the thixotropic behaviour caused by the NaAlO₂. The Na₂SiO₃-activated OPG consisted of sodium-calcium aluminium silicate hydrate ((N,C)-A-S-H) gel phase, while the OPG activated with NaAlO₂ and Na₂SiO₃ comprised of the coexistence of sodium aluminium silicate hydrate (N-A-S-H) and calcium aluminium silicate hydrate (C-A-S-H) gel phases. Regardless of the distinctive properties, the OPGs are adequate for building materials applications.

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Effect of anisotropic pores on the material properties of metakaolin geopolymer composites incorporated with corrugated fiberboard and rubber

2021 , Nur Ain Jaya , Liew Yun Ming , Heah Cheng Yong , Mohd. Mustafa Al Bakri Abdullah , Low Foo Wah , Ooi Wan-En , Ilham Mukriz Zainal Abidin , Noorhazleena Azaman

This paper compares the compressive strength and thermal conductivity of metakaolin geopolymer (MKG) incorporated with anisotropic and isotropic pores. MKG was prepared by activation with sodium hydroxide and sodium silicate. Corrugated fiberboard and rubber were included to create anisotropy of pores, and they were added in 3, 5, and 7 layers. Hydrogen peroxide and surfactant were added to generate isotropic pores. For geopolymer with corrugated fiberboard (MKG-C) and rubber (MKG-R), compressive test and thermal conductivity measurement were performed in perpendicular and parallel direction to the flat surface of fiberboard and rubber. The result showed that MKG-C and MKG-R exhibited mechanical and insulation anisotropically. The highest compressive strength was achieved in the parallel loading direction while the lowest thermal conductivity was attained in the perpendicular direction. MKG-C possessed better compressive strength of 26.9 MPa loaded in the parallel direction. The compressive strength performance of MKG-C was greater than MKG-R because of the fibrous-like structure, which further contributes to the strength. The thermal conductivity was low (0.15–0.20 W/mK) for both MKG-C and MKG-R. The anisotropy of pores led to high strength retention and improvement of thermal insulating properties. These properties were contrary to geopolymer with isotropic pores (MKG-F), which have excellent thermal insulating properties but low compressive strength to be eligible for structural applications.

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