scholarly journals Rice Husk Ash/Silicone Rubber-Based Binary Blended Geopolymer Coating Composite: Fire Retardant, Moisture Absorption, Optimize Composition, and Microstructural Analysis

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 985
Author(s):  
Mohd Salahuddin Mohd Basri ◽  
Tee Hui Yek ◽  
Rosnita A. Talib ◽  
Intan Syafinaz Mohamed Amin Tawakkal ◽  
Siti Hasnah Kamarudin ◽  
...  
Keyword(s):  
Rice Husk ◽  
Silicone Rubber ◽  
Moisture Absorption ◽  
Rice Husk Ash ◽  
Microstructural Analysis ◽  
Fire Retardant ◽  
Shielding Effect ◽  
Absorption Properties ◽  
Coating Composite ◽  
Fire Retardant Properties

Geopolymer coating using rice husk ash (RHA) as the aluminosilicate source has shown excellent fire retardant properties. However, incorporation of rice husk ash into the geopolymer matrix increased water absorption properties of the polymer composite. As such, silicone rubber (SiR) was introduced to improve the moisture absorption and fire retardant properties of the composite. Additionally, the less efficient one-factor-at-a-time (OFAT) approach was conventionally used in past studies on the RHA-based geopolymer composite. In understanding the optimum value and significant effect of factors on the fire retardant and moisture absorption properties of the binary blended geopolymer coating composite, the use of statistical analysis and regression coefficient model (mathematical model) was considered essential. The objectives of this study are to identify the significant effect of factors on moisture absorption and fire retardant properties, to determine the optimum composition, and to study the microstructure of the rice husk ash/silicone rubber (RHA/SiR)-based binary blended geopolymer coating composite. The RHA/AA and SiR/Ge ratios were chosen as factors, and the response surface methodology (RSM) was employed to design experiments and conduct analyses. Fire retardant and moisture absorption tests were conducted. A scanning electron microscope (SEM) was used to observe the microstructure of geopolymer samples. The RHA/alkaline activator (AA) and SiR/Ge ratios were shown to have a significant effect on the responses (temperature at equilibrium and moisture absorption). The high ratio of RHA/AA and SiR/Ge resulted in a lower temperature at equilibrium (TAE) below 200°C and at moisture absorption below 16%. The optimum formulation for the geopolymer coating composite can be achieved when the RHA/AA ratio, SiR/Ge ratio, and sodium hydroxide concentration are set at 0.85, 0.70, and 14 M, respectively. SEM micrographs of samples with good fire retardant properties showed that the char residue of the geopolymer composite coating, which is a layer of excess silicone rubber, is porous and continuous, thus providing a shielding effect for the layer of geopolymer underneath. The sample with good moisture absorption showed the formation of a thin outer layer of silicone rubber without any cracks. The unreacted SiR formed a thin layer beneath the geopolymer composite matrix providing a good moisture barrier.

scholarly journals Rice Husk Ash-Based Geopolymer Binder: Compressive Strength, Optimize Composition, FTIR Spectroscopy, Microstructural, and Potential as Fire-Retardant Material

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4373
Author(s):  
Mohd Salahuddin Mohd Basri ◽  
Faizal Mustapha ◽  
Norkhairunnisa Mazlan ◽  
Mohd Ridzwan Ishak
Keyword(s):  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Construction Material ◽  
Fire Retardant ◽  
Major Effect ◽  
Material Behavior ◽  
Promising Alternative ◽  
Fire Retardant Properties ◽  
Geopolymer Binder

Compressive strength is an important property in construction material, particularly for thermal insulation purposes. Although the insulation materials possess high fire-retardant characteristics, their mechanical properties are relatively poor. Moreover, research on the correlation between fire-retardant and compressive strength of rice husk ash (RHA)-based geopolymer binder (GB) is rather limited. In addition, previous studies on RHA-based GB used the less efficient one-factor-at-a-time (OFAT) approach. In understanding the optimum value and significant effect of factors on the compressive strength, it was deemed necessary to employ statistical analysis and a regression coefficient model (mathematical model). The objective of the study is to determine the effect of different material behavior, namely brittle and ductile, on the compressive strength properties and the optimum material formulation that can satisfy both compressive strength and fire-retardant properties. The factors chosen for this study were the rice husk ash/activated alkaline solution (RHA/AA) ratio and the sodium hydroxide (NaOH) concentration. Compressive strength and fire-retardant tests were conducted as part of the experiments, which were designed and analyzed using the response surface methodology (RSM). The microstructure of geopolymer samples was investigated using a scanning electron microscope (SEM). Results showed that RHA/AA ratio was highly significant (p < 0.000) followed by NaOH concentration (p < 0.024). When the RHA/AA ratio was at 0.7 to 0.8 and the NaOH concentration was between 12 and 14 M, high compressive strength above 28 MPa was recorded. Optimum compressive strength of approximately 47 MPa was achieved when the RHA/AA ratio and NaOH concentration were 0.85 and 14 M, respectively. Brittle samples with low Si/Al ratio of 88.95 were high in compressive strength, which is 33.55 MPa, and showed a high degree of geopolymerization. Inversely, ductile samples showed low compressive strength and degree of geopolymerization. Water content within the geopolymer binder had a major effect on its fire-retardant properties. Semi-ductile GB showed the best fire-retardant properties, followed by semi-brittle and brittle GB. Using RHA as an aluminosilicate source has proven to be a promising alternative.

scholarly journals Rice-Husk-Ash-Based Geopolymer Coating: Fire-Retardant, Optimize Composition, Microstructural, Thermal and Element Characteristics Analysis

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3747
Author(s):  
Mohd Salahuddin Mohd Basri ◽  
Faizal Mustapha ◽  
Norkhairunnisa Mazlan ◽  
Mohd Ridzwan Ishak
Keyword(s):  
Thermal Properties ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Fire Retardant ◽  
Coating Materials ◽  
Promising Alternative ◽  
Low Thermal Expansion ◽  
Characteristics Analysis ◽  
Fire Retardant Properties ◽  
Furnace Slag

Geopolymer using aluminosilicate sources, such as fly ash, metakaolin and blast furnace slag, possessed excellent fire-retardant properties. However, research on the fire-retardant properties and thermal properties of geopolymer coating using rice husk ash (RHA) is rather limited. Additionally, the approach adopted in past studies on geopolymer coating was the less efficient one-factor-at-a-time (OFAT). A better approach is to employ statistical analysis and a regression coefficient model (mathematical model) in understanding the optimum value and significant effect of factors on fire-retardant and thermal properties of the geopolymer coating. This study aims to elucidate the significance of rice husk ash/activated alkaline solution (RHA/AA) ratio and NaOH concentration on the fire-retardant and thermal properties of RHA-based geopolymer coating, determine the optimum composition and examine the microstructure and element characteristics of the RHA-based geopolymer coating. The factors chosen for this study were the RHA/AA ratio and the NaOH concentration. Rice husk was burnt at a temperature of approximately 600 °C for 24 h to produce RHA. The response surface methodology (RSM) was used to design the experiments and conduct the analyses. Fire-retardant tests and thermal and element characteristics analysis (TGA, XRD, DSC and CTE) were conducted. The microstructure of the geopolymer samples was investigated by using a scanning electron microscope (SEM). The results showed that the RHA/AA ratio had the strongest effect on the temperature at equilibrium (TAE) and time taken to reach 300 °C (TT300). For the optimization process using RSM, the optimum value for TAE and TT300 could be attained when the RHA/AA ratio and NaOH concentration were 0.30 and 6 M, respectively. SEM micrographs of good fire-resistance properties showed a glassy appearance, and the surface coating changed into a dense geopolymer gel covered with thin needles when fired. It showed high insulating capacity and low thermal expansion; it had minimal mismatch with the substrate, and the coating had no evidence of crack formation and had a low dehydration rate. Using RHA as an aluminosilicate source has proven to be a promising alternative. Using it as coating materials can potentially improve fire safety in the construction of residential and commercial buildings.

scholarly journals Study and Use of Rice Husk Ash as a Source of Aluminosilicate in Refractory Coating

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3440
Author(s):  
Mohd Na’im Abdullah ◽  
Mazli Mustapha ◽  
Nabihah Sallih ◽  
Azlan Ahmad ◽  
Faizal Mustapha ◽  
...  
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Agricultural Waste ◽  
Fire Retardant ◽  
Sem Analysis ◽  
Refractory Coating ◽  
Alkyd Paint ◽  
Passive Fire Protection ◽  
In Fire ◽  
Geopolymer Binder

The utilisation of rice husk ash (RHA) as an aluminosilicate source in fire-resistant coating could reduce environmental pollution and can turn agricultural waste into industrial wealth. The overall objective of this research is to develop a rice-husk-ash-based geopolymer binder (GB) fire-retardant additive (FR) for alkyd paint. Response surface methodology (RSM) was used to design the experiments work, on the ratio of RHA-based GB to alkyd paint. The microstructure behaviour and material characterisation of the coating samples were studied through SEM analysis. The optimal RHA-based GB FR additive was formulated at 50% wt. FR and 82.628% wt. paint. This formulation showed the result of 270 s to reach 200 °C and 276 °C temperature at equilibrium for thermal properties. Furthermore, it was observed that the increased contents of RHA showed an increment in terms of the total and open porosities and rough surfaces, in which the number of pores on the coating surface plays an important role in the formation of the intumescent char layer. By developing the optimum RHA-based GB to paint formulation, the coating may potentially improve building fire safety through passive fire protection.

Effects of Rice Husk Nano-Silica and Methylcyclohexylphosphinate on the Thermal and Fire-Retardant Properties of Epoxy Resin

2014 ◽  
Vol 4 (4) ◽  
pp. 306-310 ◽  
Author(s):  
Xueqing Liu ◽  
Jiyan Liu ◽  
Liyong Zou ◽  
Xiaomeng Wang ◽  
Wenjun Wei ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Rice Husk ◽  
Fire Retardant ◽  
Nano Silica ◽  
Fire Retardant Properties

scholarly journals Fire Retardant Performance of Rice Husk Ash-Based Geopolymer Coated Mild Steel - A Factorial Design and Microstructure Analysis

2016 ◽  
Vol 841 ◽  
pp. 48-54 ◽  
Author(s):  
Mohd Salahuddin Mohd Basri ◽  
Faizal Mustapha ◽  
Norkhairunnisa Mazlan ◽  
Mohamad Ridzwan Ishak
Keyword(s):  
Mild Steel ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Fire Retardant ◽  
Silica Content ◽  
Curing Temperature ◽  
Silica Source ◽  
Five Factors ◽  
Alkaline Activator ◽  
C 50

Higher content of silica in geopolymer coating resulted in better thermal properties. Since rice husk ash (RHA) has the highest silica content compared to other aluminosilicate sources available, it offers the best potential to be an alternative silica source in producing geopolymer coating binder. In this study, five factors including ratio of alkaline activator (AA) (A), ratio of RHA/AA (B), curing temperature (C), curing time (D) and concentration of NaOH (E) were analyzed using statistical analysis to identify the significant factors that mostly influence fire retardant performance of RHA-based geopolymer coating. The fire retardant tests were conducted and results recorded included (i) time taken to reach 300°C and (ii) temperature at equilibrium. Sample S7 (coating composition of A=5.5, B=0.3, C=50°C, D=7days, E=8M) which produced the best fire retardant performance was selected for further detailed investigation using thermogravimetry analysis (TGA) and scanning electron microscopy (SEM). It was found that the back temperature of mild steel plate of sample S7 reached 300°C after 17 minutes and achieved an equilibrium state at 398°C. SEM micrographs showed the presence of needle-like structures formed after fire test might be the reason for the best fire performance of sample S7.

Mechanoactivation Of Rice Husk Ash In Laboratory Conditions

2019 ◽  
pp. 20-26
Keyword(s):  
Mechanical Activation ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Silicon Oxide ◽  
Rice Husk Ash ◽  
Pozzolanic Activity ◽  
Maximum Solubility ◽  
Laboratory Conditions ◽  
Before And After ◽  
Mineral Additive

In many rice producing countries of the world, including in Vietnam, various research aimed at using rice husk ash (RHA) as a finely dispersed active mineral additive in cements, concrete and mortars are being conducted. The effect of the duration of the mechanoactivation of the RHA, produced under laboratory conditions in Vietnam, on its pozzolanic activity were investigated in this study. The composition of ash was investigated by laser granulometry and the values of indicators characterizing the dispersion of its particles before and after mechanical activation were established. The content of soluble amorphous silicon oxide in rice husk ash samples was determined by photocolorimetric analysis. The pizzolanic activity of the RHA, fly ash and the silica fume was also compared according to the method of absorption of the solution of the active mineral additive. It is established that the duration of the mechanical activation of rice husk ash by grinding in a vibratory mill is optimal for increasing its pozzolanic activity, since it simultaneously results in the production of the most dispersed ash particles with the highest specific surface area and maximum solubility of the amorphous silica contained in it. Longer grinding does not lead to further reduction in the size of ash particles, which can be explained by their aggregation, and also reduces the solubility of amorphous silica in an aqueous alkaline medium.

Desalination Technology of Water by using Rice Husk Ash

2014 ◽  
Vol 27 (2) ◽  
pp. 148-160
Author(s):  
Hassan K. Hassan ◽  
Najla J. Al-Amiri ◽  
Mohammed M. Yassen
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Desalination Technology

Adsorption of Cr(VI) by material synthesized from red mud and rice husk ash

2018 ◽  
Vol 60 (4) ◽  
pp. 3-7
Author(s):  
Thi To Yen Nguyen ◽  
Phung Anh Nguyen ◽  
Thi Thuy Van Nguyen ◽  
Tri Nguyen ◽  
Ky Phuong Ha Huynh ◽  
...  
Keyword(s):  
Rice Husk ◽  
Red Mud ◽  
Rice Husk Ash

Effect of alkaline treatment on physico-mechanical properties of black rice husk ash filled polypropylene biocomposites

2015 ◽  
Vol 57 (4) ◽  
pp. 370-376 ◽  
Author(s):  
Ahmad Adlie Shamsuri ◽  
Ahmad Khuzairi Sudari ◽  
Edi Syams Zainudin ◽  
Mazlina Ghazali
Keyword(s):  
Mechanical Properties ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Alkaline Treatment ◽  
Black Rice
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