The aims of this study are to report on the extraction and characterization of Asian swamp eel (Monopterus albus) skin gelatin. The characterization conducted were includes chemical composition, pH, gel strength, viscosity, thermal property, color and structure determination of extracted eel skin gelatin. Eel skin contains 70.28% moisture, 11.07% protein, 4.21% fat, and 5.01% ash. The chemical composition of eel skin gelatin (yield of 12.75%) was 18.8% moisture, 67.64% protein, 0.34% fat and 1.08% ash, with a pH of 4.62 and gel strength of 215.96 g (± 9.62 g). Although viscosity (2.8 cPa/min) profile of eel skin gelatin showed lower than that of bovine gelatin, the higher melting temperature (35 °C) of eel skin gelatin indicating its higher stability than bovine gelatin with FTIR spectrum similar to that of typical bovine gelatin. Eel skin gelatin has a 71.4 (± 1.14), a +3.2 (± 0.29), and a +7.52 (± 0.29) for L*, a* and b* value respectively, indicate a darker and less yellow colour. These findings show promising potential for the application of eel skin gelatin as an alternative to commercial gelatin.
Pepsin-solubilized collagen (PSC) was extracted from the body wall of crown-of-thorns starfish (COTS) (Acanthaster planci) using pepsin digestion in 0.5 M acetic acid. The electrophoretic pattern of PSC showed that it consisted of two α chains (α1 and α2 chains). In addition, the peptide mapping showed that there were some differences in peptide patterns among PSC, calf skin collagen and salmon skin collagen. This suggested that the primary structure of the PSC was different from calf skin collagen and salmon skin collagen. Furthermore, Fourier transform infrared spectroscopy (FTIR) investigation showed the existence of triple helical structure in PSC, suggesting that the triple helical structure was well preserved during the extraction of collagen from COTS. The denaturation temperature of PSC was 33.0°C, which was comparable with mammalian collagen. In addition, the amino acid composition analysis showed that the imino acid content of PSC was similar to mammalian collagen but it was higher than other marine collagen. This suggested that the imino acid content might contributed the denaturation temperature of collagen. The results in this study suggest that PSC from the underutilized COTS has potential to be exploited in various commercial applications.
Multiwall carbon nanotubes (MWCNTs) were synthesized using a tubular microwave chemical vapor deposition technique, using acetylene and hydrogen as the precursor gases and ferrocene as catalyst. The novel MWCNT samples were tested for their performance in terms of Pb(II) binding. The synthesized MWCNT samples were characterized using Fourier Transform Infrared (FT-IR), Brunauer, Emmett and Teller (BET), Field Emission Scanning Electron Microscopy (FESEM) analysis, and the adsorption of Pb(II) was studied as a function of pH, initial Pb(II) concentration, MWCNT dosage, agitation speed, and adsorption time, and process parameters were optimized. The adsorption data followed both Freundlich and Langmuir isotherms. On the basis of the Langmuir model, Qmax was calculated to be 104.2mg/g for the microwave-synthesized MWCNTs. In order to investigate the dynamic behavior of MWCNTs as an adsorbent, the kinetic data were modeled using pseudo first-order and pseudo second-order equations. Different thermodynamic parameters, viz., ∆H(0), ∆S(0) and ∆G(0) were evaluated and it was found that the adsorption was feasible, spontaneous and endothermic in nature. The statistical analysis revealed that the optimum conditions for the highest removal (99.9%) of Pb(II) are at pH5, MWCNT dosage 0.1g, agitation speed 160r/min and time of 22.5min with the initial concentration of 10mg/L. Our results proved that microwave-synthesized MWCNTs can be used as an effective Pb(II) adsorbent due to their high adsorption capacity as well as the short adsorption time needed to achieve equilibrium.
Here, a stable derivative of cellulose, called cellulose carbamate (CC), was produced from Kenaf (Hibiscus cannabinus) core pulp (KCP) and urea with the aid of a hydrothermal method. Further investigation was carried out for the amount of nitrogen yielded in CC as different urea concentrations were applied to react with cellulose. The effect of nitrogen concentration of CC on its solubility in a urea-alkaline system was also studied. Regenerated cellulose products (hydrogels and aerogels) were fabricated through the rapid dissolution of CC in a urea-alkaline system. The morphology of the regenerated cellulose products was viewed under Field emission scanning electron microscope (FESEM). The transformation of allomorphs in regenerated cellulose products was examined by X-ray diffraction (XRD). The transparency of regenerated cellulose products was determined by Ultraviolet-visible (UV-Vis) spectrophotometer. The degree of swelling (DS) of regenerated cellulose products was also evaluated. This investigation provides a simple and efficient procedure of CC determination which is useful in producing regenerated CC products.
The decolorization and degradation of Direct Blue 71 were investigated using a mono culture of Pseudomonas aeruginosa. The bacterium was able to decolorize the dye medium to 70.43 % within 48 h under microaerophilic conditions. The medium was then aerated for 24 h to promote the biodegradation of the aromatic amines generated from azo bond cleavage. Reduction in total organic carbon in dye medium was 42.58 % in the microaerophilic stage and 78.39 % in the aerobic stage. The degradation metabolites formed were studied using UV-vis techniques, high performance liquid chromatography, Fourier transform infra red spectroscopy and nuclear magnetic resonance spectroscopy analysis. Data obtained provide evidence for the formation of aromatic amines and their subsequent oxidative biodegradation by a single strain of P. aeruginosa during successive microaerophilic/aerobic stages in the same flask. The influence of incubation temperature (20-45 °C), medium pH (5-10) and initial dye concentration (25-150 mg/L) on decolorization was evaluated to greatly influence decolorization extent. The optimal decolorization conditions were determined by response surface methodology based on three-variable central composite design to obtain maximum decolorization and to determine the significance and interaction effect of the variables on decolorization. The optimal conditions of response were found to be 35.15 °C, pH 8.01 and 49.95 mg/L dye concentration giving an experimental decolorization value of 84.80 %. Very high regression coefficient between the variables and the response (R(2) = 0.9624) indicated a good evaluation of experimental data by polynomial regression model.
In this present study, a series of polymer electrolyte thin films were synthesized by incorporating different ratios of lithium triflate (LiCF3SO3) in a low molecular weight polyvinyl chloride (PVC) matrix by the solution casting technique. The incorporation of LiCF3SO3 suppressed the high degree of crystallinity in PVC enabling the system to possess an appreciable ionic conductivity. The ionic conductivity of the samples, with different LiCF3SO3 content, was determined by the aid of ac impedance spectroscopy. The highest ionic conductivity of 4.04 10–9 S cm–1 was identified for the composition of PVC: LiCF3SO3 (75:25). Further understanding of the ionic conductivity mechanism was based on temperature-dependent conductivity data which obeyed Arrhenius theory, indicating that the ionic conductivity enhancement was thermally assisted. The possible dipole-dipole interaction between the chemical constituents was confirmed with changes in cage peak, analysed using Fourier transform infrared spectroscopy.
In this work, hydrogels were prepared from carboxymethyl cellulose (CMC) and 1-vinyl-2-pyrrolidone(VP) by Electron Beam irradiation in the presence of N,N'-methylenebisacrylamide (BIS) as a crosslinkingagent. The parameters studied include stirring time and percentage of crosslinking agent. Hydrogels werecharacterized using Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy(SEM). VP and BIS were found be effective as reinforcement materials to improve the properties ofCMC. Meanwhile, the optimum conditions were 5% BIS and 3 hours of stirring time. The gel fractionincreased when irradiation dose was increased. FTIR confirmed the crosslinking reaction between CMCand VP after the irradiation process by using BIS as the crosslinking agent. TGA thermograms showedchanges in the thermal properties of CMC-VP hydrogels in the presence of different amounts of BIS.
Polyaniline (PANI) and polyaniline composites with aluminium oxide (Al2O3) were prepared using the in situ polymerization method. The composites were then blended with acrylic paint and applied to carbon steel panels. The coated steel panels were evaluated for corrosion using the immersion test technique. The results revealed that the steel panels coated with polyaniline composites and with Al2O3 containing coatings had small corrosion as compared to the bare sample and the samples coated with polyaniline and paint alone. The samples were characterized by Fourier transform infrared (FTIR) and X-ray diffraction(XRD). In addition, the morphology of the finished samples was observed using the scanning electron microscopy (SEM). This novel composite was used as a paint pigment for enhancing the barrier properties and the paint protectable against aggressive ions. Meanwhile, corrosion was evaluated through visual monitoring using a digital camera after 60 days of fully immersion test in 5% NaCl. The weight loss method was also used to evaluate corrosion.
Six new Pd(II) and Ni(II) metal complexes of N, O-bidentate (L1, L2) and ONNO-tetradentate (L3) Schiff base ligands have been synthesized. The compounds were characterized via various physicochemical and spectroscopic techniques namely elemental analysis (CHN), FT-IR, 1H and 13C NMR as well as magnetic susceptibility measurement. All complexes showed diamagnetism indicating that they are square planar complexes. Catalytic performance of Pd(L1)2 and Pd(L2)2 were investigated for Heck cross-coupling reaction under optimum operating parameters, monitored using GC-FID for 6 h of reaction time in inert conditions. High catalytic activities of up to 90% were observed in the presence of triethylamine as base and DMA as solvent at 100oC with 1 mmol% catalyst loading. The mechanism of catalyzed Heck reaction is proposed to go through a series of conversion of Pd(0)/Pd(II).
The present study was carried out to characterize red fruit (Pandanus conoideus Lam) oil (RFO) in term of FTIR spectra, fatty acid composition, and volatile compounds. FTIR spectrum of RFO was slightly
different from other common vegetable oils and animal fats, in which in the frequency range of 1750 – 1700 cm-1, RFO appear two bands. The main fatty acid composition of RFO is oleic acid accounting for 68.80% followed by linoleic acid with the concentration of 8.49%. The main volatile compounds of RFO as determined using gas chromatography coupled with mass spectrometry (GC-MS) and headspace analyser are 1,3-dimethylbenzene (27.46%), N-glycyl- L-alanine (17.36%), trichloromethane (15.22%), and ethane (11.43%).
Starch blend films made from sago and mung bean were prepared by casting with glycerol as the plasticizer and subsequently exposed to ultraviolet (UV) irradiation for 2 h. The films were characterized by thickness, moisture sorption isotherms, X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. All films produced were colorless while incorporation of glycerol resulted in more flexible and manageable films. Moisture sorption isotherms for all films showed sigmoidal shape and the control films showed slightly higher curve than treated films. While for X-ray analysis, the control and treated films for all formulations showed similar pattern, however for treated films showed more crystalline character. UV radiation showed affect on X-ray diffraction and sorption isotherms; however the UV radiation did not affect the spectra pattern of FTIR.
exhibits extensive first pass metabolism with poor oral bioavailability (27%–50%) limiting its therapeutic efficiency. The present study involved an attempt to enhance its aqueous solubility by formulating as solid dispersions (SDs) using sodium starch glycollate (SSG) as a carrier. The dispersions were formulated by dispersion method and evaluated by phase solubility, drug content, in vitro release and mathematical modelling. Solid state characterisation of samples was carried out by X-ray diffraction (XRD), differential scanning calorimetric (DSC), Fourier transform infrared spectrophotometry (FTIR), near infrared (NIR), Raman analysis and wettability studies. The phase solubility and thermodynamic parameters indicated the spontaneity and solubilisation effect of carrier. The release rate from the dispersions was higher than pure drug and found to increase with an increase in carrier content. The optimised dispersions were selected based on release studies, profiles and dissolution parameters. XRD, DSC, FTIR, NIR and Raman analysis proved the crystallinity reduction, changes in crystal quality and compatibility between drug and carriers. Wettability studies proved the increased wettability in selected dispersions. Based on the findings, possible mechanisms that would have contributed to dissolution enhancement of CLZ were suggested. Such findings could be extrapolated to enhance the aqueous solubility of other poorly water-soluble drugs.
In this study, we evaluated and characterized microbial cellulose produced from Kombucha after eighth day of fermentation by employing SEM, FTIR, X-ray diffractometry, adsorption isotherm, and by measuring the swelling properties. Results on SEM revealed microbial cellulose layer to be composed of a compact cellulose ultrafine network like structure. FTIR spectra showed the presence of a characteristic region of anomeric carbons (960 – 730 cm-1), wherein a band at 891.59 cm-1 confirmed the presence of β, 1-4 linkages. Results of FTIR spectra also showed microbial cellulose to be free from contaminants such as lignin or hemicellulose, which are often present in plant cellulose. X-ray diffraction studies exhibited the overall degree of crystallinity index for MCC to be slightly lower than that of microbial cellulose. Results on swelling properties indicated microbial cellulose to possess higher fiber liquid retention values (10-160%) compared to commercial MCC (5-70%). The adsorption isotherm curves showed similarities between microbial cellulose with that of pure crystalline substance. Overall, results obtained in this study were comparable with the commercial microcrystalline cellulose, indicating that the process developed by us can be explored industrially on a pilot scale.
UV-curable hyperbranched urethane acrylate (HBPUA) from oleic acid of palm oil has been synthesized through a medium aided by p-toluene sulfonic acid as a catalyst. This mixture was then used as the core (HBP) and reacted with palm oil oleic acid to form the hyperbranched polyol (HBP-1). HBPUA was prepared by reacting HBP-1 resin with diisocyanate and hydroxyl-containing acrylate monomer with the presence of 0.1-2 wt% dibutyltin dilaurate as a catalyst. The reaction was confirmed by several analytical data i.e. hydroxyl value (OHV), Fourier Transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy analyses. The HBPUA was easily curable when subjected to ultraviolet (UV) radiation.
Ceramic materials play key role in several biomedical applications. One of them is bone graft which is use in treating bone defect which caused by injury or osteoporosis. Calcium phosphates based ceramic are preferred as bone grafts in hard tissue engineering because of their chemical compositions are similar to the composition of human bone, superior bioresorbable and bioactivity. In this study, β-tricalcium phosphate (β-TCP) ceramic was synthesized by using sol-gel method. Phosphorous pentoxide (P2O5) and calcium nitrate tetrahydrate (Ca(NO3)2.4H2O) were used as calcium and phosphate precursors. The effects of calcination temperature on the synthesis powder were studied using the XRD, SEM-EDS and FTIR techniques. It was found that calcination temperature greatly influence the purity of the synthesized powders. The β-TCP was the dominant phase with the formation of α-TCP at calcination temperature from 600 to 800°C. Pure β-TCP was obtained at calcination of 900°C. As the temperature increased to 1000°C, the β-TCP was decomposed to for calcium phosphate oxide (CPO). The sol-gel method has some advantages over other methods, mainly its simplicity and ability to produce pure β-TCP at lower calcination temperature.
Layered double hydroxide (LDH) with Mg/Al molar ratio of 4/1 (MAN-4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was allowed to undergo ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP-4). The solid produced was characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of copper solution by MAHP-4 was carried out using batch experiment by mixing the copper solution and the sorbent MAHP-4. The effects of
various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for copper removal was found to be 4 and the optimum time of copper removal was found at 4 hours. The isotherm data was analysed using model isotherm Langmuir with the correlation coefficient of 0.999 was recorded. The maximum adsorption capacity, Qo (mg/g) of 142.8 mg/g was also recorded from the Langmuir isotherm. The remaining copper solution was determined by using EDXRF (Energy Dispersive XRay Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP-4 has potential as an effective adsorbent for removing copper from aqueous solution.
Many attempts have been focused in the past on preparing of synthetic E-tricalcium (E-TCP), which being employed as bone substitute due to its biocompatibility and resorbability. Low temperature synthesize such as sol-gel method become popular due to the high product purity and homogenous composition. Sol-gel method is less economical towards commercialization because the cost of raw materials and the yield of the product that can be achieved. This paper describes the synthesis of ETCP via mixing of CaCO3 and H3PO4 followed by calcinations process at 750qC – 1050qC. X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), fourier transformation infra-red (FTIR) were used for characterization and evaluation of the phase composition, morphology, particle size and thermal behavior of the product. E-TCP phase start to occur after calcinations at 750qC.
The aim of this work is to study the effect of hydrocolloids; guar gum (GG), xanthan gum (XG) and carboxymethyl cellulose (CMC) on the physicochemical properties, microbiological quality and sensory properties in order to investigate the potential of applying fermented cassava (tapai ubi) in ice cream. Fermented cassava ice cream (FCI) incorporated with the three types of hydrocolloid was prepared and the protein content, pH value, overrun, colour, hardness, microstructure, FTIR spectrum and sensory acceptance of all samples were determined. Fermented cassava ice cream incorporated with XG showed the highest protein content (14.88%), pH value (pH 6.07), and overrun value (4.27%) as compared to the fermented cassava ice cream incorporated with GG and CMC. Meanwhile, ice cream incorporated with GG possessed the highest L* (94.43) and hardness (3693.15 g) value as compared to XG and CMC. The microstructure study showed that the difference in uniformity at the interface obtained with different types of the hydrocolloids added demonstrated the effect of fat absorption at the air interfaces. The FTIR spectrum investigated indicated that the addition of the fermented cassava to FCI had increased the OH group in the ice cream as compared to the control. All samples were microbial safe as the total plate counts in all samples were below the standard as prescribed in Food Act 1983 with no presence of E. coli . In conclusion, fermented cassava ice cream with XG showed the good quality in terms of its pH value, overrun, total plate count and overall acceptability.
A radiotracer study was conducted to investigate the removal characteristics of cadmium (109Cd) from aqueous solution by polypyrrole/ sawdust composite. Several factors such as solution pH, sorbent dosage, initial concentration, contact time, temperature and interfering metal ions were found to have influence on the adsorption process. The kinetics of adsorption was relatively fast, reaching equilibrium within 3 hours. A lowering of the solution pH reduced the removal efficiency from 99.3 to ~ 46.7% and an ambient temperature of 25°C was found to be optimum for maximum adsorption. The presence of sodium and potassium ions inhibited 109Cd removal from its aqueous solution. The experimental data for 109Cd adsorption showed a very good agreement with the Langmuir isotherm and a pseudo-first order kinetic model. The surface condition of the adsorbent before and after cadmium loading was investigated using BET, FESEM and FTIR. Considering the low cost of the precursor's materials and the toxicity of 109Cd radioactive metal, polypyrrole synthesized on the sawdust of Dryobalanops aromatic could be used as an efficient adsorbent for the removal of 109Cd radioisotope from radionuclide-containing effluents.
Alginate microcapsules containing epoxy resin were developed through electrospraying method and embedded into epoxy matrix to produce a capsule-based self-healing composite system. These formaldehyde free alginate/epoxy microcapsules were characterized via light microscope, field emission scanning electron microscope, fourier transform infrared spectroscopy and thermogravimetric analysis. Results showed that epoxy resin was successfully encapsulated within alginate matrix to form porous (multi-core) microcapsules with pore size ranged from 5-100 μm. The microcapsules had an average size of 320 ± 20 μm with decomposition temperature at 220 °C. The loading capacity of these capsules was estimated to be 79%. Under in situ healing test, impact specimens showed healing efficiency as high as 86% and the ability to heal up to 3 times due to the multi-core capsule structure and the high impact energy test that triggered the released of epoxy especially in the second and third healings. TDCB specimens showed one-time healing only with the highest healing efficiency of 76%. The single healing event was attributed by the constant crack propagation rate of TDCB fracture test. For the first time, a cost effective, environmentally benign and sustainable capsule-based self-healing system with multiple healing capabilities and high healing performance was developed.