Related Experiment Video
Updated: Nov 10, 2025
10:27
The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight
Published on: October 11, 2016
9.7K
Rice Husk Ash/Silicone Rubber-Based Binary Blended Geopolymer Coating Composite: Fire Retardant, Moisture Absorption,
Mohd Salahuddin Mohd Basri1,2,3, Tee Hui Yek1, Rosnita A Talib1
1Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, UPM, Serdang 43400, Selangor, Malaysia.
Polymers
|April 3, 2021
Summary
This study optimized geopolymer coatings using rice husk ash and silicone rubber for improved fire retardancy and reduced water absorption. Statistical analysis identified optimal ratios for enhanced material performance and microstructure.
Area of Science:
- Materials Science: Development of advanced composite materials.
- Chemical Engineering: Formulation and optimization of geopolymer coatings.
- Nanotechnology: Microstructural analysis of composite materials.
Background:
- Rice husk ash (RHA) geopolymer coatings offer excellent fire retardancy but suffer from high water absorption.
- Silicone rubber (SiR) incorporation aims to mitigate moisture uptake and enhance fire resistance in RHA-geopolymer composites.
- Traditional one-factor-at-a-time (OFAT) methods are inefficient for optimizing complex composite formulations.
Purpose of the Study:
- To determine the significant effects of RHA/alkaline activator (AA) and SiR/Ge ratios on fire retardant and moisture absorption properties.
- To identify the optimal composition for RHA/SiR-based binary blended geopolymer coating composites.
- To investigate the microstructure of the developed geopolymer coating composites.
Main Methods:
- Response Surface Methodology (RSM) was employed to design experiments and analyze the effects of formulation variables.
- Fire retardant and moisture absorption tests were conducted to evaluate material performance.
- Scanning Electron Microscopy (SEM) was used for microstructural characterization of the geopolymer samples.
Main Results:
- Both RHA/AA and SiR/Ge ratios significantly influenced the temperature at equilibrium (fire retardancy) and moisture absorption.
- Higher RHA/AA and SiR/Ge ratios led to lower equilibrium temperatures (<200°C) and reduced moisture absorption (<16%).
- Optimal formulation achieved with RHA/AA ratio of 0.85, SiR/Ge ratio of 0.70, and 14 M sodium hydroxide concentration.
Conclusions:
- The optimized geopolymer coating composite exhibits enhanced fire retardant properties due to a porous, continuous silicone rubber char layer.
- Good moisture resistance is attributed to a thin, crack-free silicone rubber outer layer and an underlying unreacted SiR barrier.
- RSM effectively identified optimal parameters for developing high-performance RHA/SiR geopolymer coatings with balanced properties.
Related Concept Videos
01:21Pozzolans
288
Pozzolans are siliceous or aluminous materials blended with Portland cement. They interact with the calcium hydroxide produced during the hydration of Portland cement and contribute to improved strength and durability of concrete. The pozzolanic activity, a measure of a pozzolan's effectiveness, is typically assessed using the strength activity index, as defined in ASTM C 618-93, which calculates the ratio of the compressive strength of cement mixtures with and without pozzolan.
Fly ash is...
Fly ash is...
288
01:19Retarders
168
Retarders are chemical admixtures designed to extend the setting time, which is especially useful when there is a delay in sequential concrete pours to prevent cold joints and to achieve a cohesive structure. Retarders, when used in appropriate amounts, can also enhance the architectural appearance of exposed aggregate finishes.
The function of retarders is to delay the setting of concrete, and this effect can be measured using a penetration test. The retardation process involves adding...
The function of retarders is to delay the setting of concrete, and this effect can be measured using a penetration test. The retardation process involves adding...
168
01:22Waterproofing and Anti-Bacterial Admixtures in Concrete
139
Concrete's susceptibility to water absorption is due to the capillary action within the pores of its hydrated cement paste. This action draws water in, creating the need for waterproofing admixtures to prevent such penetration. The efficacy of these admixtures is contingent upon the water pressure, with variations arising from different conditions such as rain, capillary rise, or hydrostatic pressure in structures intended to hold water.
Waterproofing admixtures render concrete hydrophobic,...
Waterproofing admixtures render concrete hydrophobic,...
139
01:29Additives and Fillers in Concrete
192
Additives and fillers are integral to enhancing the properties of concrete. Pozzolans and blast-furnace slag are additives or admixtures due to their reactions with calcium hydroxide released during cement hydration. Fillers, which are finely ground and similar in fineness to Portland cement, improve concrete attributes such as workability density, and reduce capillary bleeding or cracking. Some fillers possess hydraulic properties or participate in benign reactions within the cement paste.
The...
The...
192
01:30Superplasticizers
162
Superplasticizers are advanced admixtures that enhance the workability of concrete by lowering the water content without compromising the strength of the material. These substances are highly effective water reducers, improving concrete flow, making it easier to work with, and enabling concrete to reach inaccessible areas or densely reinforced sections without mechanical vibration. The key components in superplasticizers are either sulfonated melamine or naphthalene formaldehyde condensates,...
162
01:23Abrasion Resistance of Concrete
319
Abrasion resistance is an essential characteristic of concrete that determines its durability and longevity under various wear conditions. Concrete surfaces are vulnerable to different types of abrasion. For instance, surfaces may wear down due to the constant movement of vehicles or be eroded by solids carried in water, as seen in concrete canal linings. Specific tests are conducted to measure the abrasion resistance of concrete.
One such test is the revolving disc test, where three plates...
One such test is the revolving disc test, where three plates...
319