121 research outputs found

    Effect of the incorporation of micro and nanocellulose particles on the anticorrosive properties of epoxy coatings applied on carbon steel

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    Polymeric coatings may act as a physical barrier between the aggressive ions and the metal substrate. However, prolonged exposure may cause damage to the polymer coating, leading to a continuous reduction of the barrier effect and consequently loss of the corrosion protection. The objective of this study is to determine the effect of aminopropyltriethoxysilane (APS), cellulose and polyaniline emeraldine-salt (PAni ES) in an epoxy coating on the corrosion protection of mild steel. Microcrystalline cellulose (MCC) and cellulose nanowhiskers (CNW) functionalized or not with PAni ES were used and compared. The coating properties were investigated by electrochemical impedance spectroscopy (EIS), salt spray test and scanning electron microscopy (SEM). The surface of the carbon steel, after 1000 h of exposure, did not present evidence of superficial corrosion. Polymer coatings using CNW and PAni ES showed improved corrosion protection properties even after 90 days of immersion in 3.5 wt% NaCl solution. The greatest increase in the corrosion resistance of the coating was found by EIS for the epoxy coating reinforced with CNW functionalized with PAni ES, revealing a synergistic effect of the electroactivity of a conducting polymer and nanosized cellulose particles

    CO2 adsorption by cryogels produced from poultry litter wastes

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    Poultry litter waste (PLW) is the main by-product generated by the Brazilian poultry industry. A sustainable approach for reusing this waste is the production of biochar to be further used aiming CO2 adsorption. In this work, biochars were produced by varying the N2 flow along the pyrolysis process of 150 (PLW-150) and 1000 (PLW-1000) mL min-1. PLW and biochars were characterized for their morphology, porosity, specific surface area, and CO2 adsorption capacity. From the biochars, carbon cryogels (CC) were produced aiming their use as CO2 adsorbents. The results of the cryogel adsorption test showed a CO2 adsorption capacity of 13.1±2.9 and 33.8±3.3 mg g-1 for the CC-PLW.150 and CC-PLW.1000 cryogels, respectively. Therefore, reusing this residue for cryogels production and its use in the CO2 adsorption signifies an attractive perspective to minimize the environmental damage caused by CO2 emissions
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