Electrospun polyethersulfone/Ag-Clinoptilolite to remove chemical oxygen demand from real wastewater

Ag-Clinoptilolite/Polyethersulfone (PES/Clin/AgNPs) nanofiber was synthesized through the electrospinning method. The effect of solvent, the amount of Ag-Clinoptilolite, and PES were investigated. Parameters such as electric field, spinning distance, and concentration of the dope solution were studied in order to demonstrate their effects on the electrospinning ability and morphology of the nanofiber. The structure of PES/Clin/AgNPs nanofiber was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) analyses. In the optimum conditions, the nanofibers could be prepared at the size of 250–800 nm. Then, their ability to remove chemical oxygen demand (COD) from real wastewater was studied. The result revealed about 85% removal of COD at pH = 10 and in 10 min for PES/Clin/AgNPs (25%). A successful fabrication method using low-cost natural zeolite and the green polymer was introduced. The reusability of the column was assessed.

Copolymerization of palm oil with sulfur using inverse vulcanization to boost the palm oil industry

Nowadays, most of the world’s palm oil is being produced in Malaysia and Indonesia; however, the demand for this vegetable oil as an edible oil is declining in many countries since consuming palm oil in excess can result in serious health problems. Consequently, finding new applications such as the production of bio-based polymers to make use of this cheap and abundant vegetable oil seems necessary. Herein, we report the copolymerization of palm oil with sulfur with different feed ratios via inverse vulcanization. The copolymers are then characterized using Fourier-transform infrared spectroscopy, differential scanning calorimetry and X-ray diffraction analysis. The results confirmed the formation of the polymers and their stability against depolymerization. Altogether, the obtained sulfur-palm oil copolymers showed great properties such as thermal stability up to 230°C under a nitrogen atmosphere and rubbery properties at room temperature. Although the Thermogravimetric analysis (TGA) thermograms had previously confirmed the high conversion of elemental sulfur into the polymeric structure by comparing the initial sulfur content and the final polysulfide content in the polymer, some unreacted elemental sulfur was also observed in the final product. Sulfur-palm oil (S-Palm oil) is a new green polymer that helps to find a new use for palm oil as a big industry as well as sulfur which is underutilized and left in stockpile as a byproduct in gas and petroleum refineries.

Development and potential applications of gelatine, honey, and cellulose electrospun nanofibres as a green polymer

Nanofibres have emerged as a brilliant technology to be applied in various areas due to their excellent properties that include having a great flexibility, prominent specific surface area and structural strength. Electrospinning is one of the most effective and favourable methods to fabricate nanofibres mainly because electrospun nanofibres have been demonstrated to possess small pore sizes, large specific surface area, and can be produced with different functions to fill the need of various applications in industries. Due to their remarkable properties, electrospun nanofibres have been proven to be suitable for applications in food packaging, medical, pharmaceutical and even in tissue engineering. Currently, there have been numerous research utilising both electrospun synthetic and natural polymers. Natural or green polymers are considered more favourable due to their biodegradable properties and potential biocompatibility. Therefore, there has been a shift to include more research regarding these green polymers. Green polymers can source from both plant polysaccharides and animal protein. Considering the different characteristics of synthetic polymers, the processing and fabrication methods may differ and must be adjusted accordingly. To well summarise the development of these green polymer nanofibres, we review fabrication methods of gelatine, honey and cellulose-based nanofibre and their potential applications in industries. There are indeed numerous promising areas for the usage of these green polymers which are based on their splendid individual properties especially when combined to form nanofibres via electrospinning. We hope this will promote continuous research and development for the applications in various industries including but not limited to tissue engineering, biomedical, food and pharmaceutical industries.

Effect of Alkali Treatment on the Properties of Acacia Caesia Bark Fibres

As possible substitutes for non-biodegradable synthetic fibre, ligno-cellulosic fibres have attracted much interest for their eco-friendliness; a large number of them are already used for the production of green polymer composites. The search for further green candidates brings into focus other fibres not previously considered, yet part of other production systems, therefore available as by-products or refuse. The purpose of this study is to explore the potential of alkali treatment with 5% sodium hydroxide (NaOH) to enhance the properties of bark-extracted Acacia Caesia Bark (ACB) fibres. The microscopic structure of the treated fibres was elucidated using scanning electron microscopy (SEM). Moreover, the fibres were characterised in terms of chemical composition and density and subjected to single-fibre tensile tests (SFTT). Following their physico-chemical characterisation, fibre samples underwent thermal characterisation by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and their crystallinity was assessed using X-ray diffraction (XRD). This level of alkali treatment only marginally modified the structure of the fibres and offered some improvement in their tensile strength. This suggested that they compare well with other bark fibres and that their thermal profile showed some increase of degradation onset temperature with respect to untreated ACB fibres. Their crystallinity would allow their application in the form of fibres with an average length of approximately 150 mm, even in thermoplastic biocomposites.

Green Polymer-Based Nanocomposites Containing Ceria and Their Use in the Process of Stem Cell Proliferation

A technique of fabrication of bacterial cellulose-based films with CeO2 nanofiller has been developed. The structural and morphological characteristics of the materials have been studied, their thermal and mechanical properties in dry and swollen states having been determined. The preparation methodology gives way to obtaining composites with the uniform distribution of nanoparticles. The catalytic effect of ceria regarding thermal oxidative destruction of cellulose was confirmed by TGA and DTA methods. An increase in CeO2 content leads to a rise in the elastic modulus (1.27-fold rise caused by the introduction of 5 wt.% of the nanofiller into polymer) and strength of the films. This effect is explained by the formation of additional links between polymer macro-chains via the nanoparticles’ surface. The materials fabricated are characterized by a limited swellability in water. Swelling causes a 20-30-fold drop in the stiffness of the material, the mechanical properties of the films in a swollen state remaining germane to their practical use. The application of the composite films in cell engineering as substrates for the stem cells proliferation has been studied. The increase in CeO2 content in the films enhanced the proliferative activity of embryonic mouse stem cells. The cells cultured on the scaffold containing 5 wt.% of ceria demonstrated increased cell survival and migration activity. Analysis of gene expression confirmed the improved cultivation conditions on CeO2-containing scaffolds.

Green composites and their contribution toward sustainability: A review

The current world environment scenario demands new and more eco-friendly solutions to global problems that cover the demands for materials. This sector has included green polymer-based composites and natural reinforcers from origins of renewable sources, these Green Composites (GC), natural-fiber-reinforced bio-composites in which the matrix is a bio-based polymer, have shown attractive characteristics. Biodegradability is one of the most important attributes for these new “green” materials, in that this characteristic allows for their introduction into the world market as an environmental solution. The manufacturing processes for obtaining these materials have observed important improvements because each raw material exhibits different properties and characteristics and their eco-friendly character has facilitated its incorporation into diverse sectors, such as construction, automotive, packaging, and medicine, among others. At present, this segment represents an important income for some economies, especially those where these resources are available, enhancing the creation of green economies, strengthening the world’s efforts toward sustainability.