Chitosan-zinc oxide composite for active food packaging Applications

Chitosan-zinc oxide (C-ZnO) films were prepared by a simple one pot procedure. In order to investigate the property of C-ZnO films, two composite films were prepared by varying the loading of ZnO and compared with pure chitosan film (C). The films were character-ized by various techniques such as FTIR, DSC, tensile, contact angle and water vapour permeability. FTIR analysis showed changes in hydrogen bonds band at 3351 cm-1 compared to pure chitosan film. The incorporation of ZnO in chitosan films increased the contact angle by 30.5% in C-ZnO1.0 film while water vapour transmission rate decreased by 7.8% compared to C film. From the tensile test, C-ZnO0.5 and C-ZnO1.0 films were found to be much superior by 1.5 times and 2.5 times respectively compared to bare chitosan film. Larger inhibition ring (by 47%) was exhibited by C-ZnO1.0 as compared to C-ZnO0.5 when tested against S.aureus. From the results, it is displayed that the incorporation of zinc oxide to chitosan improve their properties which also shown the potential to become a candi-date for food active packaging

Assessing the Effect of PVP of Various Molecular Weight (MW) in PES-Ag Membranes: Antimicrobial Study Using E.Coli

New polymeric silver (Ag) composites were prepared using polyethersulfone (PES) as polymer material, N-Methyl-2-pyrrolidone (NMP) as solvent and polyvinylpyrollidone (PVP) of various molecular weight (MW) as organic fillers. Silver nitrate (AgNO3) was added by various loading in order to impart an antibacterial property to the composites. The miscibility of PES/Ag/fillers composites were characterized using TGA and any changes in chemical bonding were characterized using ATR-FTIR techniques. The XPS results showed high intensity in Eb(Ag3d) range of 378.1-378.5 and 372.2-372.5 for the highest Ag loading with PVP with the highest MW. This phenomenon had altered the hydrophilicity property of composites. In this study, composites have undergone a bacteria rejection test from E.coli suspension and a domestic waste sample. Composites with highest loading of silver and highest MW of PVP (PES-Ag2P360) was observed for significantly high bacteria rejection, log reduction value (LRV~3). Therefore, PES-silver nanocomposites is a potential membrane for bacteria removal, disinfection and maybe effective for overcoming biofouling problems

Extraction of biological apatite from cow bone at different calcination temperatures: a comparative study

The purpose of this study is to extract natural hydroxyapatite (HAP) from cow bone. The hydrothermal method followed by calcination treatment at different temperatures is used in this current research. Cow bone has the potential for producing hydroxyapatite, a chief component present in bone and teeth of vertebrates. HAP is an excellent material used in bone restoration and tissue regeneration. Characterizations of the cow bone natural HAP powder were done by X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). TGA data revealed that biological apatite is thermally stable at 1100ºC. XRD data showed that the extracted HAP is, highly crystalline and hexagonal crystal structure having a crystallite size in the range of 10-83 nm. The extracted HAP material is found to be thermally stable up to 1300ºC

β-Cyclodextrin/lecithin: preparation and characterization

Lecithin is a fat which is well-known to be obtained from soybeans or egg yolks. It is also taken as a medicine and used as food additive that keep certain ingredients from separating out. Despite of its advantages, lecithin’s application in the industries is restricted due to its sensitivity to heat and light and can be easily oxidized. Hence, this study aims to investigate the effect of β-cyclodextrin (β-CD) in improving the properties of lecithin. The objectives of this study are to prepare and characterize β-CD/lecithin complex followed by study on the influence of β-CD on lecithin’s thermal stability and antioxidant property. Analytical methods employed are fourier transform infra-red (FTIR) spectroscopy for chemistry study, differential scanning calorimetry (DSC) for examination of its thermal stability, DPPH testing for its antioxidant property as well as scanning electron microscopy (SEM) for structural examination. Results from FTIR and SEM analyses confirmed the formation of β-CD/lecithin complex. Thermal stability and antioxidant property of the complexes on the other hand were found to be improved. Of the amount of β-CD studied, it was reported that the best combination of the complex was at β-CD/lecithin ratio of 2:1. The complex of the optimized ratio showed the greatest thermal stability as indicated by its highest melting point (177.8 ºC). The complex also exhibited the greatest antioxidant property as indicated by its highest percentage of DPPH scavenging activity that is 97.1%

Natural Hydroxyapatite Extracted From Bovine Bone

The aim of this study is to extract natural hydroxyapatite (HAP) from bovine bone. Hydrothermal method followed by calcination treatment at different temperatures is used in this current research. Bovine bone has potential for producing hydroxyapatite, a chief component present in bone and teeth of vertebrates. HAP is an excellent material used in bone restoration and tissue regeneration. Characterizations of the bovine bone natural HAP powder were done by scanning electron microscopy (SEM), Fourier transforms infrared (FTIR) and energy dispersive x-ray (EDX) spectroscopy. The FTIR result confirms the presence of phosphate (PO4-3), hydroxyl (OH)- and carbonate (CO3-2) groups in the powder. SEM displays the surface morphology whereas EDX provides calcium (Ca) to phosphorous (P) ratio in the HAP samples. The results of the EDX analysis indicate that the Ca/P ratio of HAP varies from 1.67 to 1.83. The extracted HAP material is found to be thermally stable up to 1100ºC

Modeling of lead (II) adsorption on sodium hydroxide treated rice husk: fixed-bed studies

Sodium hydroxide treated rice husk was explored as an adsorbent for the removal of lead (II) ions from aqueous solutions in a column studies. This paper evaluate the effect of flow rates of 3 mL/min and 9 mL/min; bed depth of 0.9 cm, 1.8 cm and 2.8 cm and influent lead concentration of 5 mg/L and 20 mg/L on the adsorption capacity of the sample in fixed-bed mode were investigated. The highest adsorption capacity of 78 % using 20 mg/L initial lead (II) ions solution was achieved at flow rate of 9 mL/min and bed depth of 2.8 cm. The experimental results obtained from the adsorption studies were correlated with the Thomas, Adams– Bohart and Yoon–Nelson models. The results of the adsorption parameters showed that, Adams–Bohart model fitted the adsorption studies well over all the other models

The Optimization of RHS-polysulfone Membrane towards Operating Condition for Humic Acid Removal

This study investigates the effects of rice husk silica (RHS) as additive in the polysulfone membrane to enhance antifouling properties in membrane separation process. The performance (of what?) was evaluated in term of pure water flux (PWF), rejection and antifouling properties. The optimized of normalized flux (Jf /Jo) at different parameter in filtration (pH, ionic strength and tranmembrane-pressure) was carried out by using the response surface methodology (RSM). The results showed that the addition of 4 wt. % RHS give the highest flux at 300.50 L/m².hour (LMH). The highest rejection was found at 3 wt. % of RHS membrane with value 98% for UV254 and 96% for TOC. The optimal value of Jf/Jo was found at 0.62 with the condition of pH: 6.10, ionic strength: 0.05 mol/L and transmembrane-pressure: 2.67 bars. Optimize of RSM analysis from ANOVA also proved that the error of model is less than 0.05% which indicates that the model is significant

Natural adsorbent made from eggshells for removal of chromium (VI) in water

Substantial utilization of heavy metals in various industrial processes nowadays had cause heavy metal pollutions in the water. Hexavalent chromium, Cr (VI), is one of the heavy metals which has been extensively used in alloy pigment production and surface treatment. The present work reports natural adsorbent synthesis made from eggshell to reduce Cr (VI) in water. The eggshell adsorbents were prepared by several steps that include boiling, drying, calcination at 900 °C, grinding, pH adjustment, precipitation, and filtration. XRD results displayed a highly crystalline hydroxyapatite (HAp) peak that was successfully synthesized. FESEM analysis showed the morphology of the powder that was agglomerate with irregular cloud-like shapes, while EDS results presented the elements in the eggshell powders that include calcium (Ca), phosphorus (P), and oxygen (O). FTIR analysis revealed the presence of hydroxyl group (OH-) that contribute to the adsorption process. The adsorption experiment demonstrates the highest Cr (VI) removal and adsorption capacity of 70% and 285.71 mg/g, respectively, was attained by 6 g adsorbent dosage within 1 hour. Kinetic studies of the adsorption process were best described by the pseudo-second-order model and Langmuir isotherm model with a high correlation coefficient of 0.98. This work's findings suggested that eggshells are potential natural adsorbent to reduce heavy metal pollutions, specifically Cr(VI) in water

The influence of Fe doped TiO2 as inorganic additive on the properties of polysulfone ultrafitration membrane

Recent development of utrafiltration (UF) technology for the mixed matrix polymeric membranes plays an important role to improve membrane properties. In this paper, the effects of inorganic additives prepared by green synthesis route towards polysulfone (PSf) membrane performance at different concentrations of Fe-TiO2 (1.0wt%, 3.0wt% and 5.0wt%) have been investigated. The blended membranes were fabricated via phase inversion using PSf as based polymer, N-metyl-2-pyrrolidone (NMP) as solvent, distilled water as a non-solvent, polyethylene glycol (PEG) as pore performing agent and Fe doped TiO2 nanomaterial as inorganic additive. The characterization and morphology of the polysulfone mixed matrix membranes were analyzed via scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle and porosity. The performances of the membrane were evaluated in terms of pure water flux (distilled water) and rejection (humic acid) by using membrane permeation testing unit. The results of microscopic images revealed that the membranes incorporated with Fe doped TiO2 have the asymmetric structure while the number and length of finger-like pores at top layer slightly increased from 3.0 wt% to 5.0 wt%, indicating the effect of hydrophilicity. Furthermore, the increasing of Fe-TiO2 percentages also increased the porosity of membrane, as well as rejection percentages and hydrophilicity of membrane

Green Zeolite Synthesis Assisted with Plants Extract

The study explores the hydrothermal synthesis of zeolite using kaolin clay from Perak in the presence of two different reduction mediums, namely turmeric extract and ginger extract, and a 2M NaOH solution, measuring their efficiency and potential for green synthesis. Before the zeolite synthesis and transformation, the kaolin clay was heated at a temperature of 650 oC for 4 hours in the furnace to produce the metakaolin phase. The synthesized zeolite involves the reaction of NaOH with potential reduction plant extracts to assist the transformation of zeolite. The characterization of the synthesized particles after being ground into a fine powder and subsequently undergoing testing and characterization via X-ray diffraction (XRD) revealed the existence of zeolite phases in both plants with slightly different zeolite compositions. Synthesis mixtures with turmeric plants show better composition of the zeolite phase as compared to ginger mixtures. Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Analysis (EDX) also revealed that the synthesized product using turmeric plant extract was able to produce zeolite LTA with a good grade. The current experimental work shows the possibility of obtaining a well crystalline zeolite from Malaysian kaolin, assisted with plant extract reduction medium