C.M. Ruzaidi

Kaolin-based geopolymers with various NaOH concentrations

Kaolin geopolymers were produced by the alkali-activation of kaolin with an activator solution (a mixture of NaOH and sodium silicate solutions). The NaOH solution was prepared at a concentration of 6–14 mol/L and was mixed with the sodium silicate solution at a Na2SiO3/NaOH mass ratio of 0.24 to prepare an activator solution. The kaolin-to-activator solution mass ratio used was 0.80. This paper aimed to analyze the effect of NaOH concentration on the compressive strength of kaolin geopolymers at 80°C for 1, 2, and 3 d. Kaolin geopolymers were stable in water, and strength results showed that the kaolin binder had adequate compressive strength with 12 mol/L of NaOH concentration. When the NaOH concentration increased, the SiO2/Na2O decreased. The increased Na2O content enhanced the dissolution of kaolin as shown in X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses. However, excess in this content was not beneficial for the strength development of kaolin geopolymers. In addition, there was the formation of more geopolymeric gel in 12 mol/L samples. The XRD pattern of the samples showed a higher amorphous content and a more geopolymer bonding existed as proved by FTIR analysis.

Mechanical Properties of Polymer Composites with Sugarcane Bagasse Filler

Natural fibers reinforced polymer composites have gained more interest because of their biodegradable, light weight, less expensive sources, easy processing, high specific modulus and also environmentally friendly appeal. This paper presents an overview of a study aimed at showing on how the bio-composites which is bagasse fibers combined with resins as an alternative of bagasse-fiber-based composites panel. Transforming bagasse fibers into panel products provides a prospective solution. Bagasse-fiber-based composites offer potential as the core material replacing high density and expensive wood-based fiberboard. Biodegradable composites reinforced with bagasse fibres after being modified or treated by alkali treatment were prepared and also the mechanical properties were investigated. The bio-composites panel samples were processed by hot press machine. All panels were made with aspect ratios between bagasse fibers and polystyrene thermoplastics resins and also the sieve size of bagasse fibers which has short fibers and combination of short fiber and granules fibers. The polystyrene was added as a modified from natural fibers to determine the effect it had on physical and mechanical properties of the panel. Resin content level and panel density were very important in controlling the strength properties of the panels. Surface hardness value, compressive strength, bending strength and bending modulus values all increases in resin content level and panel density. Bagasse-based-panel products can be commercialize successfully if have good development of a cost manufacturing process on an establishment of a market base for the products.

Feasibility Study on Composition and Mechanical Properties of Marine Clay based Geopolymer Brick.

Geopolymer is an inorganic polymer performed in synthesis process of an aluminosilicate material which activated by alkaline activator solution. Marine clay, considered to be a waste substance which have an important aluminosilicate sources in developing geopolymer synthesis since it contains sufficient amounts of alumina and silica. In this experimental study, local marine clay composition was been identified to determine the amount of alumina and silica. The raw sample compositions were identified by using X-ray fluorescence (XRF). Incorporated with it composition, compressive strength of brick were been tested in aged of 1, 2 and 3 day and compared with local production of cement brick (CB). This research is aimed at determining the properties of Kuala Perlis marine clay in order to verify its suitability as a pozzolana materials as well as the sufficient amount of Al and Si to enhance the properties of geopolymer brick.

Epoxy Layered Silicates with Fly Ash-Based Geopolymer: Flexural Properties

The effect of fly ash-based geopolymer in epoxy-layered silicates nanocomposites was studied through flexural properties and morphological characterization. In this study, a series of nanocomposites with fly ash-based geopolymer containing 1-7% wt were prepared. It was found that the addition of fly ash with lower content in the beginning showed lower flexural strength than nanocomposites without fly ash. However, flexural properties suddenly increased at 3% wt of fly ash geopolymer content in comparison to origin. This indicates the blending of fly ash geopolymer in nanocomposites systems have the ability for further studied.

Effect of Fly Ash/Alkaline Activator Ratio and Sodium Silicate/NaOH Ratio on Fly Ash Geopolymer Coating Strength

Fly ash geopolymer coating material potential used to protect surface used in exposure conditions. Ratio of fly ash/alkaline activator and Na2SiO3/NaOH play important parameter on determining the best flexural strength of geopolymer coating material. Fly ash and alkali activator (Al2O3/Na2SiO3) were mixed with the solids-to-liquid ratios in range of 1.0-3.0 and different ratios of Na2SiO3/NaOH (1.0-3.0) to prepare geopolymer coating material at constant NaOH concentration of 10 M. Effect of fly ash/alkaline activator ratio and Na2SiO3/NaOH on geopolymer coating was determined with respect to the highest flexural strength of the 1200oC sintering temperature of geopolymer coating substrates. The results concluded that the highest strength for fly ash geopolymer coating material is achieved 42 MPa when the solid/liquid ratio is 2.0 and the Na2SiO3/NaOH ratio is 2.5.

Strength of Concrete with Ceramic Waste and Quarry Dust as Aggregates

This research focuses on a study of the strength of concrete with ceramic waste as coarse aggregate and quarry dust as fine aggregate. The sources of ceramic waste and quarry dust are obtained from the industrial in Malaysia. Presently, in ceramics industries the production goes as waste, which is not under going the recycle process yet. In this study an attempt has been made to find the suitability of the ceramic industrial wastes and quarry dust as a possible replacement for conventional crushed stone coarse and fine aggregate. Experiment were carried out to determine the strength of concrete with ceramic waste coarse aggregate and quarry dust fine aggregate to compare them with the conventional concrete made (with crushed stone coarse aggregate). From the results show that compressive strength of concrete with quarry dust as aggregates is the highest with 30.82 MPa with density 2251.85 kg/m3. This show, ceramic waste and quarry dust can be alternative aggregate for comparable properties.

Microstructure Studies on Different Types of Geopolymer Materials

Geopolymer is a new binding material produced to substitute the ordinary Portland cement (OPC) function as a binder in concrete. As we know, different types of geopolymer will have different properties. In this research, the different types of geopolymer raw materials had been studied in term of microstructure. Different type of materials which is fly ash (class F) and kaolin had been mixed with alkaline solution consist of sodium silicate and sodium hydroxide with suitable geopolymer raw material to alkaline activator and sodium silicate to sodium hydroxide ratios. The geopolymer samples with different types of raw material were then cured at a temperature 70°C for 24 hr and maintained at room temperature until the testing was conducted. After the geopolymers were aged for seven days, the testing was conducted.

Structure Characterization of Low Cost Fabricated Soft Material Built Microchannel

To perform the entire laboratory activities on a centimeter limit scale electronic chip, the most important aspect is to fabricate a device which persist sensitive and selective for the delivery of fluids flow and have the ability to execute a fast mixing of distinctive chemicals and bio samples. To resolve this issues the current paper is one of the good struggle, therefore the objective was arranged in according to the scope of research such as; to design and fabricate a polydimethylsiloxane (PDMS) material made, micro channel and its structure characterization for the investigation of internal subterranean area. By using an AutoCAD software the channel was first designed, however for the fabrication process the design was transferred to mask. Starting from SU-8 resist the pattern was transferred, and then by using the polydimethylsiloxane (PDMS) the mold was fabricated by adopting a low cost photolithography technique. Finally by employing Hawk 3 D surface nanoprofiler the structure was characterized. In our forthcoming research the device will be tested for real biological samples using a simple hand-operated inoculation technique.

Effect of Solid/Liquid Ratio on Mechanical Properties of Kaolin Coated Teak Wood via Geopolymer Technology

Kaolin, an aluminosilicate source materials was mixed with alkaline activator solution to create a geopolmer paste which was coated on teak wood subsrates. In this work, the effect of solid/liquid ratio (0.4, 0.6, 0.8 and 1.0) was analysed while other parameters were maintained constant. Coating teak wood substrates via geopolymer technology was focused to see the enhancement made to the mechanical properties of teak wood. Various test such as adhesive strength test, water absorption and morphology study was conducted after seventh day of sample preparation. Kaolin coated sample with 1.0 solid/liquid ratio showed the highest adhesive strength of 10.5 MPa and the lowest water absorption of 6.3%. Morphology studies also supported the trend of promising compatibility between kaolin coating and teak wood substrate at 1.0 solid/liquid ratio which further evident the accuracy of collected data.

Epoxy Layered-Silicates Filled with Fly Ash Based Geopolymer: Compressive Properties

The effect of fly ash based geopolymer in epoxy layered silicates nanocomposites was studied using a compressive test. A series of nanocomposites with fly ash based geopolymer 1-7phr content was prepared. Qualitative evaluation of the three-dimensional shape of a fly ash based geopolymer surface and the origin was characterized using scanning electron microscopy. It was found that the addition of fly ash at the beginning with lower content are showing lower compressive strength than nanocomposites without fly ash filled. However, compressive properties suddenly increased at 3phr of fly ash geopolymer content compared to nanocomposites without fly ash. This indicated the blending of fly ash geopolymer in nanocomposites system have the ability for further studies.