Research Output
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PublicationChitosan/polyethylene oxide (Peo) filled carbonized wood fiber conductive composite film( 2020-01-01)Biopolymer-based conductive polymer composites (CPCs) would open up various possibilities in biomedical applications owing to ease of processing, renewable resource and environmentally friendly. However, low mechanical properties are a major issue for their applications. In this study, the investigated the conductivity of chitosan/ PEO blend films filled with carbonized wood fiber (CWF) prepared by solution casting. The effect of CWF was also investigated on tensile properties and their morphological surfaces. The tensile results from different ratios of chitosan/PEO blend films without CWF show that the tensile strength and modulus increased with the increase of chitosan content and chitosan/PEO blend film with 70/30 ratio exhibited the best combination of tensile strength and flexibility. However, a reduction of tensile strength was observed when CWF amount was increased while the modulus of the tensile shows an increment. The film also exhibited higher electrical conductivity as compared to low chitosan ratio. The addition of CWF greatly enhanced the conductivity three-fold from 10-10 to 10-6 S/cm. The electrical conductivity continued to increase with the increase of CWF up to 30 wt%. The surface morphology by Scanning Electron Microscopy (SEM) exhibits the absence of phase separation for the blends indicating good miscibility between the PEO and chitosan. Incorporation of CWF into the blend films at 5 wt% showed agglomeration. However, the increase of CWF created larger agglomerations that formed conductive pathways resulting in improved conductivity. FTIR analysis suggested that intermolecular interactions occurred between chitosan and PEO while CWF interacts more with the protons of PEO.
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PublicationThe potential of chitosan-polygonum minus leaf mediated silver-nanoparticles composite as green conductive biofilm( 2024-12)Silver-nanoparticles (AgNPs) from leaf extract have gained considerable interest from years ago until recently. However, the potential of green-synthesised AgNPs as a conductive filler in polymer biocomposites has not been widely investigated. Herein, a series of biopolymer-silver nanoparticle films were prepared by dispersing the suspension of Polygonum minus leaf mediated AgNPs into chitosan (CS) matrix via solution casting. In this work, the physicochemical properties of the composite films were evaluated, and structural property was analysed by Fourier transform infrared (FTIR) spectroscopy. The electrical conductivity and surface morphology were investigated by two-point probe and scanning electron microscopy (SEM), respectively. From the evaluation of moisture uptake, solubility and degradation tests, the rate of moisture uptake reduced as AgNPs concentration increased whereas the solubility and degradation rate increased with increasing addition of AgNPs. The FTIR analysis confirmed that there was no new covalent bond formed and suggested that AgNPs interact non-covalently with amine and hydroxyl groups of chitosan matrix. The conductivity of the CS-AgNPs films increased with one-order magnitude from 10-8 to 10-7 S/cm compared to pristine CS film. The percolation threshold was achieved at 20 wt% of AgNPs and the highest conductivity was achieved at 30 wt% AgNPs with the conductivity value of 3.20 x 10-7 S/cm. SEM micrographs revealed that the composite film with 30 wt% AgNPs exhibited smooth and homogeneous surface which agrees well with the conductivity results. This CS-Polygonum minus leaf mediated AgNPs composite film shows potential as an alternative for biodegradable biomedical implants, smart packaging and wearable electronics applications.
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PublicationEffect of two different organic solvents on mechanical properties and electrical conductivity of carbonized wood fiber filled chitosan/polyethylene oxide conductive films( 2022-05-18)Crystallization occurred upon the evaporation of solvent during solution casting usually affects the physical and chemical properties of the polymers. In this study, the effect of maleic acid (MA) and acetic acid (AA) as a solvent medium to dissolve conductive chitosan/polyethylene oxide/carbonized wood fiber (CS/PEO/CWF) film was investigated on their mechanical properties and electrical conductivity. The film with CS/PEO ratio of 70/30 and 25 wt% of CWF was prepared by dissolution in organic acid and casting into glass mold after sufficient stirring at room temperature. FTIR spectra revealed that the characteristic peaks of CS for CS/PEO/CWF-AA can be clearly understood while for CS/PEO/CWF-MA, the peaks were shifted, and some were less pronounced due to overlapping with MA residue peaks. The tensile test showed that CS/PEO/CWF-AA has better tensile strength, elongation at break and tensile modulus. We suggested that a higher crystallinity degree of CS/PEO/CWF-AA was responsible for the excellent properties. The presence of residual maleic acids after film-forming increases the brittleness of the films and lowers the tensile strength of CS/PEO/CWF-MA film. The conductivity value also favored CS/PEO/CWF-AA with the conductivity of 4.25 × 10-4 S/cm while the value for CS/PEO/CWF-MA was one order magnitude lower which is 3.46 × 10-5 S/cm. From the findings, we concluded that CS/PEO/CWF-AA formed crystalline orientation upon evaporation of AA and that promotes electron transfer resulting in higher conductivity. In conclusion, AA is a better solvent medium compared to MA for dissolution of CS/PEO/CWF to obtain conductive composite films. The difference in the structure of the organic acids has obviously affected the properties of the composite films. The conductive films have potential use as an eco-friendly material for active or intelligent packaging as well as biomedical applications.
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PublicationEffect of Uncarbonized and Carbonized Eggshell Powder on Mechanical and Thermal Properties of Recycled High Density Polyethylene/Ethylene Vinyl Acetate Blend Composites( 2020-07-09)The blend composites of recycled high density polyethylene (rHDPE)/ethylene vinyl acetate (EVA) were prepared by melt blending technique at 160 °C with rotor speed of 50 rpm within 10 minutes. Based on Fatimah et al. study[1], the optimum ratio rHDPE/EVA at 70/30 were studied and prepared for different loading of uncarbonized (fresh) and carbonized eggshell powder (5 to 25 wt%). The ESP was collected, washed, crushed, and sieved to obtained size 63 µm by method Farahana et al,.[2]. But she founded that, the mechanical properties reduced with incorporation of ESP filler. Nowadays, carbonized natural filler are the focus of some researchers and the CESP was undergoing a combustion process for 3 hours at 700 °C with air combustion via muffle furnace. The result showed tensile properties decreased with increasing filler loading for both fillers. Then, the mass swell percentage after 46 hours soaked in dichloromethane, the results showed an increment of both fillers were increased the mass swell caused by the hydrophilic nature of fillers. The intensity ratio, interlayer spacing, and crystallinity percentage value decrease with increasing filler loading for both filler give better interaction between matrix and filler. The thermal stability increase for both filler with increasing filler loading. Overall, rHDPE/EVA/CESP blend composites had excellent properties with the addition of carbonized filler.