Physico-mechanical and morphological properties of rice husk-coconut husk fiber reinforced epoxy composites

In the recent years, many researches focus on “waste to wealth” concept, where agro-waste is converted into various valuable products especially on natural fiber polymeric composites. Selected fibers for this research were rice husk (RH) and coconut husk (CH). This research focused on the property enhancement of RH-CH fiber reinforced epoxy composites and comparison RH reinforced epoxy composites, CH reinforced epoxy composites, and RH-CH reinforced epoxy composites. RH-CH reinforced epoxy composites were well-fabricated by mixing epoxy resin and different ratios of two types natural fibers via compression molding and stir casting methods. All the fabricated RH-CH reinforced epoxy composites were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Vickers Hardness Test (VHT), and tensile test (TT). FTIR results showed that 10wt% RH-CH reinforced epoxy composites created the strongest covalent bonding between cellulose inside RH-CH fiber and epoxide group compared to RH reinforced epoxy composites and CH reinforced epoxy composites. The combination of RH and CH fiber with the introduction of epoxy resin reduced the hydroxyl groups compared to either RH or CH fiber composites, respectively. This proved that mixture of RH and CH with epoxy matrix improved the properties of pure RH and CH and thus, better composites were fabricated. SEM images of 10wt% RH-CH reinforced epoxy composites showed better dispersion of RH-CH fiber within polymer matrix compared to RH reinforced epoxy composites and CH reinforced epoxy composites under the magnification of 2000. Both RH reinforced epoxy composites and CH reinforced epoxy composites showed porosity within the matrix. VHT showed that 10wt% RH-CH reinforced epoxy composites showed the smallest indentation value compared to RH reinforced epoxy composites and CH reinforced epoxy composites due to the highest interfacial adhesion between matrix and filler, which was proven by the SEM images. Tensile test of 10wt% RH-CH reinforced epoxy composites showed the highest tensile modulus with value of 2.6MPa. RH-CH reinforced epoxy composites showed higher tensile strength and modulus compared to RH and CH reinforced epoxy composites. Overall, it could be concluded that 10wt% RH-CH reinforced epoxy composites performed the best in terms of physical, mechanical, and morphological perspective than RH reinforced epoxy composites and CH reinforced epoxy composites. This proved that RH and CH could be well-introduced as reinforcing filler in epoxy matrix to fabricate better composites for structural application

Polyvinyl Alcohol/Silica/Clay Composites: Effect Of Clay On Surface Morphology And Thermo-Mechanical Properties

A simplified route towards the synthesis of polyvinyl alcohol/silica/clay (PVA-SiO2-clay) composites was presented. PVA-SiO2-clay composites were prepared via solution intercalation method. All the composites were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), adsorption isotherm (BET), X-ray fluorescence (XRF), tensile test and Thermogravimetric Analysis (TGA). FTIR spectrum indicated that PVA-SiO2-clay composites especially clay (1.28E) loaded composites had much less transmittance percentage compared to pure PVA and others clay composites. The SEM revealed that the interfacial bonding between PVA-SiO2 and clay (1.28E) was much better than others clay loaded composites which was reflected in adsorption isotherm. The BET result also showed high specific surface area with low diameter of pore size of the composites. The thermal stability of PVA-SiO2-clay (1.28E) composites was the highest and it had higher activation energy due to the strong bonding between the trimethyl stearyl ammonium with both PVA-SiO2. The XRF result showed that clay (1.28E) loaded composites contained significant high percentage of Si which confirmed the presence of Si-O-Si stretching vibration while the high percentage of K proved the clay mineral content in the composite. Clay (1.28E) enhanced the tensile strength and modulus of PVA-SiO2-clay composites among all the composites

Physical, mechanical, morphological and thermal analysis of styrene-co-glycidyl methacrylate / fumed silica / clay nanocomposites

Styrene-co-glycidyl methacrylate-fumed silica-clay (ST-co-GMA-fsi-clay) nanocomposites have been prepared via free radical polymerization in the presence of benzoyl peroxide. The nanocomposites are characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), adsorption isotherm, tensile test, thermogravimetric analysis (TGA) and moisture absorption. FT-IR shows the Si-O-C peak that represented ST-co-GMA-fsi bonding while Si-O-Si peak shows the bonding of fsi-clay. The surface morphology shows the well dispersion of clay (1.30E) into ST-co-GMA-fsi nanocomposite. 2wt% of ST-co-GMA-fsi-clay (1.30E) nanocomposite has higher specific surface area and average pore volume with less pore size. Incorporation of 2wt% of clay (1.30E) improves the tensile strength and modulus of the nanocomposites as well as higher thermal stability and activation energy. 2wt% of ST-co-GMA-fsi-clay (1.30E) nanocomposite shows the lowest moisture absorption value. © 2017 Penerbit UTM Press. All rights reserved

Physical, Mechanical, and Thermal Analysis of Polylactic Acid/Fumed Silica/Clay (1.28E) Nanocomposites

Polylactic acid/fumed silica/clay (PLA/FS/clay) (1.28E) nanocomposites have been successfully prepared by solution-intercalation film-casting technique. The resultant nanocomposites were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), tensile test, thermogravimetric analysis (TGA), and moisture absorption test. The FT-IR spectrum indicated that PLA/FS/clay with 2 wt% hadmuch broader peak compared to 5 wt%, 10 wt%, and 15wt% nanocomposites. Incorporation of clay (1.28E) with 2wt% showed the best compatibility with PLA/FS matrix. PLA/FS/clay (1.28E) nanocomposite with 2wt% of clay loading had higher tensile strength and modulus compared to other nanocomposites. The thermal stability and activation energy of 2wt% of PLA/FS/clay (1.28E) nanocomposite are the highest among all the nanocomposites. The moisture absorbed into PLA/FS/clay (1.28E) nanocomposite was significantly reduced with clay loading of 2 wt%

Fabrication and characterisation of novel algin incorporated bioactive-glass 58S calcium-silicate-based root canal sealer

The usage of bioceramic-based root canal sealers has escalated over the years due to their excellent properties. The present study aimed to fabricate a novel algin incorporated bioactive glass 58S calcium-silicate (Bio-G) sealer and characterise its surface microstructure and chemical compositions in comparison to commercially available bioceramic sealers (BioRoot RCS and iRoot SP). Materials and methods: The powder form of experimental Bio-G sealer consisted of synthesised BG 58S particle, calcium silicate, zirconia dioxide, calcium carbonate and alginic acid powder as binder. The liquid composed of 5% calcium chloride solution. Five standardised disc specimens were prepared for each sealer group according to the manufacturer’s instructions. Subsequently, sealer disc-specimens were placed in an incubator at 37 �C, 95% relative humidity for 72 h to allow setting prior to testing under scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transformed infrared spectroscopy (FTIR) and Xray diffraction (XRD). Results: Experimental Bio-G sealer revealed irregular micro-sized particles ranging from 0.5 mm to 105 mmaggregated in clusters comparable to those of BioRoot RCS and iRoot SP. EDS microanalysis showed that Bio-G had high content of oxygen, silicon, and calcium, with the presence of aluminium and chloride similar to BioRoot RCS. Meanwhile, the FTIR and XRD findings suggested that all sealers predominantly contained calcium silicate hydrate, calcium carbonate, and zirconium dioxide, while calcium aluminium silicate oxide was detected in Bio-G. Conclusion: The present novel Bio-G sealer demonstrated desirable particle size distribution and acceptable degree of purity. Future studies are warranted to explore its properties and clinical application

Performance analysis of fabricated bio-filtration system for small-scaled greywater treatment: TSS and turbidity removals

River pollution, which is mainly due to excessive drainage of untreated domestic greywater, has becoming a serious concern in both poor and developing areas like Sarawak in the current years. Realizing the vital role of Sarawak rivers, the need to improve the level of pollution, demand for clean freshwater resources, as well as to save cost on household water supply, the greywater generated daily from every household needs to be pretreated for reuse, otherwise, discharged. This further demands for cost-effective pretreatment technology for domestic and residential use. This research, therefore, analyzes the efficiency of a low-cost biofiltration system which utilizes agricultural wastes, namely rice husk and coconut coir, as biofilter media to improve the quality of greywater effluent samples in terms of total suspended solids (TSS) and turbidity removals. This paper presents the extended results obtained from the previous research work using the same fabricated pre-treatment system, which consists of six main units i.e. wastewater storage tank, water feed tank, pre-sedimentation tank, bio-filter, postsedimentation tank and treated water storage tank. The system is operated for six hours to complete several cycles of treatment. At every one-hour interval, both TSS and turbidity levels of the wastewater samples are recorded and the removal performances are evaluated and analyzed. Positive outcomes are attained from this research study such that the rice husk system is able to reduce the TSS and turbidity levels by 49.06% i.e. from 53.00 mg/L to 27.00 mg/L with an average rate of 4.33 mg/L.hr, as well as 57.79% i.e. from 41.70 FNU to about 17.60 FNU, at a rate of 4.02 FNU/hr respectively. Besides, the coconut coir bio-filtration system achieves TSS removal efficiency of 49.70% i.e. from 65.60 mg/L to 33.00 mg/L at mean rate of 5.43 mg/L.hr, and 63.10% turbidity removal i.e. from 48.40 FNU to 17.86 FNU, at 5.09 FNU/hr respectivel

EFFECTIVENESS OF FOOD WASTE BIO-COMPOSTED FERTILIZERS ON PLANTATIONS

This research studied the production of organic fertilizer from food wastes through composting in view of its easy availability in Malaysia. In methodology, food wastes such as banana peels, Chinese kale and eggshells in different proportions will be stacked up layer by layer in a compost bin prepared with the inclusion of bulking agents such as dry leaves and soil to produce matured compost to supply useful microorganisms to the decomposition process. Results from the application of the biofertilizers produced on the growth of water spinach and green onion plants had revealed the potential of banana peels in supporting the growth of the plants, while for the ones produced from the combinations of eggshells and Chinese kale, nitrogen loss could be observed, thereby suppressing their growth and resulting in a much slower growth rate. Meanwhile, from the statistical analysis conducted, the findings obtained were proven to be significant, indicating the positive influence of fertilizers type on the growth of plants. Hence, it could be concluded that this research would certainly provide an insight to the potential management of organic waste in our country by converting organic wastes from food into biofertilizer

Physico-mechanical, thermal and morphologicalproperties of furfurylalcohol/2-ethylhexyl methacrylate/halloysite nanoclay woodpolymer nanocomposites (WPNCs)

In this study, the physical, morphological, mechanical and thermal properties of furfuryl alcohol/2-ethylhexyl methacrylate/halloysite nanoclay wood polymer nanocomposites (FA-co-EHMA-HNC WPNCs) were investigated. FA-coEHMA-HNC WPNCs were prepared via an impregnation method and the properties of the nanocomposites were characterized through the weight percent gain, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), three-point flexural test, dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) analysis and moisture absorption test. The weight percent gain in the 50:50 FA-co-EHMA-HNC WPNC was the highest compared with the raw wood (RW) and other WPNCs. The FT-IR results confirmed that polymerization took place in the nanocomposites, especially 50:50 FA-co-EHMA-HNC WPNC, which had a reduced amount of hydroxyl groups. The SEM results revealed that the 50:50 FAco-EHMA-HNC WPNC had the smoothest and most uniform surface among all of the nanocomposites. The 50:50 FA-co-EHMA-HNC WPNC showed the highest flexural strength and modulus of elasticity. The results revealed that the storage modulus and loss modulus of the FA-co-EHMA-HNC WPNCs were higher and the tan δ of FA-co-EHMA-HNC WNPCs was lower compared with the RW. The FAco-EHMA-HNC WPNCs exhibited the higher thermal stability in the TGA and DSC analysis. The 50:50 FA-co-EHMA-HNC WPNC exhibited remarkably lower moisture absorption compared with the RW. Overall, this study proved that the ratio 50:50 FA-co-EHMA ratio was the most suitable for introduction in the in the RW

Dislodgment Resistance, Adhesive Pattern, and Dentinal Tubule Penetration of a Novel Experimental Algin Biopolymer-Incorporated Bioceramic-Based Root Canal Sealer

The currently available bioceramic-based sealers still demonstrate low bond strength with a poor seal in root canal despite desirable biological properties. Hence, the present study aimed to determine the dislodgment resistance, adhesive pattern, and dentinal tubule penetration of a novel experimental algin-incorporated bioactive glass 58S calcium silicate-based (Bio-G) sealer and compared it with commercialised bioceramic-based sealers. A total of 112 lower premolars were instrumented to size 30. Four groups (n = 16) were assigned for the dislodgment resistance test: control, gutta-percha + Bio-G, gutta-percha + BioRoot RCS, and gutta-percha + iRoot SP, with exclusion of the control group in adhesive pattern and dentinal tubule penetration tests. Obturation was done, and teeth were placed in an incubator to allow sealer setting. For the dentinal tubule penetration test, sealers were mixed with 0.1% of rhodamine B dye. Subsequently, teeth were cut into a 1 mm-thick cross section at 5 mm and 10 mm levels from the root apex, respectively. Push-out bond strength, adhesive pattern, and dentinal tubule penetration tests were performed. Bio-G showed the highest mean push-out bond strength (p < 0.05), while iRoot SP showed the greatest sealer penetration (p < 0.05). Bio-G demonstrated more favourable adhesive patterns. No significant association was noted between dislodgment resistance and dentinal tubule penetration (p > 0.05)

A review of advanced optimization strategies for fermentative biohydrogen production processes

The inability of statistical optimization to represent the dynamic interaction of the biohydrogen process, which is highly non-linear and complicated, has been identified. However, incorporating a data-driven black-box model could overcome the limitations of conventional methods to provide correct responses rapidly and cost-effective modeling. Despite significant reports on the optimization of hydrogen production from fermentation, fewer studies have been made for the case using artificial intelligence algorithms. As a result, critical and extensive analyses of previous works are conducted to develop a general methodological framework for advanced response optimization