Study on the Morphology Stability of TiO2 Nanotube Arrays towards Temperature as a Potential Toxic Gas Sensor

AbstractTiO2 nanotube arrays were prepared by electrochemical anodization of titanium foil in mixed electrolyte solution of NH4F, water, and glycerol. The anodized TiO2 nanotube arrays were calcined at various temperatures and characterized using scanning electron microscope to study the morphology transformation. The results show that at low calcination temperature (300̊C) highly ordered TiO2 nanotube arrays are observed and remained up to 500̊C. At 700̊C, TiO2 nanotube arrays are completely destroyed and transformed to irregular shaped particle

A Study Of Cadmium Sulfide Nanoparticles With Starch As A Capping Agent

Capping agents such as starch can be used to protect semiconductor nanoparticles from aggregation and obtain uniform structures. Cadmium sulfide (CdS) nanoparticles with starch as a capping agent were prepared with an aqueous precipitation technique at different pH levels to study the optimum condition for producing a narrow distribution of nanoparticles. The morphology of the prepared nanoparticles was measured by scanning electron microscopy (SEM). Grain sizes of the samples determined by X-ray Diffraction (XRD) with Scherer’s equation were relatively dependet on the pH applied in the synthesized process. Infrared spectroscopy (FT-IR) indicated that the starch and the nanoparticles were bonded by R-N=C=S bonds, but bondinbg depended on the pH used. The band gap of the CdS nanoparticles measured by UV-Vis spectroscopy was 2.39 eV, which was lower than CdS in bulk phase because of distorted structures in obtained CdS nanoparticles

Review on natural clay ceramic membrane: Fabrication and application in water and wastewater treatment

Membrane technology is important in industrial wastewater and water treatment. Recently, the polymeric membrane technology is widely chosen in these applications. However, they are low-temperature ranges, low corrosion resistance, and low lifespan. Thus, researchers are actively trying to develop a better membrane technology such as natural clay ceramic membrane due to their excellent in chemical, mechanical and thermal resistance, high-pressure application and long lifespan. This detailed review compiles through the literature of current scientific research over the last ten years. Its highlights the key findings of factors in the fabrication of natural clay ceramic membrane that contributed to its properties. This review article presented an outline of the advantages, disadvantages, and how to overcome the disadvantages, structure, and preparation of ceramic membrane, including method, raw materials, drying and sintering temperature. The review confirmed that the sintering temperature, the composition of raw materials and pore-forming agent are significantly enhanced the mechanical strength and porosity of the natural clay ceramic membrane. However, further development and modification of the natural clay ceramic membrane technology and their applications to treat different environmental pollutants is still necessary

Gellan gum hydrogels filled edible oil microemulsion for biomedical materials: phase diagram, mechanical behavior, and in vivo studies

The demand for wound care products, especially advanced and active wound care products is huge. In this study, gellan gum (GG) and virgin coconut oil (VCO) were utilized to develop microemulsion-based hydrogel for wound dressing materials. A ternary phase diagram was con-structed to obtain an optimized ratio of VCO, water, and surfactant to produce VCO microemulsion. The VCO microemulsion was incorporated into gellan gum (GG) hydrogel (GVCO) and their chemical interaction, mechanical performance, physical properties, and thermal behavior were examined. The stress-at-break (σ) and Young’s modulus (YM) of GVCO hydrogel films were increased along with thermal behavior with the inclusion of VCO microemulsion. The swelling degree of GVCO hydrogel decreased as the VCO microemulsion increased and the water vapor transmission rate of GVCO hydrogels was comparable to commercial dressing in the range of 332–391 g m−2 d−1. The qualitative antibacterial activities do not show any inhibition against Gram-negative (Escherichia coli and Klebsiella pneumoniae) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. In vivo studies on Sprague–Dawley rats show the wound contraction of GVCO hydrogel is best (95 ± 2%) after the 14th day compared to a commercial dressing of Smith and Nephew Opsite post-op waterproof dressing, and this result is supported by the ultrasound images of wound skin and histological evaluation of the wound. The findings suggest that GVCO hydrogel has the potential to be developed as a biomedical material

Antibacterial Study of Gellan Gum (GG) Film Incorporated Norfloxacin

A series of norfloxacin-loaded films were fabricated by combining with gellan gum (GG) using evaporative casting technique. The films were evaluated in terms of morphological, water vapour transmission rates (WVTR), water uptake, release study and antibacterial study. The prepared films contained smooth appearance of cross-section distributed by good film of materials. The results indicated that the film swelling were increased at higher concentration of norfloxacin loaded, however decreased the WVTR properties. All films showed almost 100 % of drug release within 5 - 20 minutes. It was found that, the antibacterial activity was directly proportional to the release rate which is at higher concentration of norfloxacin resulted in stronger antibacterial properties

Fabrication and Characterization of Antibacterial Titanium Dioxide Nanorods Incorporating Gellan Gum Films

The aim of this work was to develop bionanocomposite films based biopolymer GG and TiO2-NRs for active food packaging. The TiO2-NRs were incorporated as antimicrobials agent into GG via solvent casting method. The films appearance was have 94 % of transparency. SEM micrographs indicate that the TiO2-NRs were successfully incorporated and attached to the surface of developed GG films. FTIR results revealed the interaction between TiO2-NRs and hydroxyl group of GG polymer. XRD results showed the crystalline peaks of TiO2-NRs and amorphous peaks of GG+TiO2-NRs films. The thermal stability of GG films were increasing by incorporation of TiO2-NRs materials. The GG+TiO2-NRs films showed good antibacterial activity against Gram-positive (Staphylococcus aureus (S. aureus) and Streptococcus (strep.)) and Gram-negative (Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa)) and potentially used as antibacterial packaging films

Photocatalytic activity of hydrothermally synthesized Al2O3graphene nanocomposite

In this study, Al2O3-graphene nanoplatelets (GNP) nanocomposite was evaluated on its properties and performance towards methyl orange (MO) dye. Al2O3-GNP nanocomposite was prepared by conventional hydrothermal at 200°C for 24 h. The result showed the crystallite size of Al2O3 is decreased and internal strain increased with the increased GNP content. The particle size of nanocomposite becomes larger with the increment GNP amount in the nanocomposite. Nanocomposite with lower graphene contents (20 wt%) and higher Al2O3 contents performed (80 wt%) the optimum for the MO absorption with efficiency of 75% in visible light