Lignin-Derivative Ionic Liquids as Corrosion Inhibitors

Corrosion is a significant problem that negatively affects a wide range of structures and buildings, resulting in their premature failure, which causes safety hazards and significant economic loss. For this reason, various approaches have been developed to prevent or minimize the effects of corrosion, including corrosion inhibitors. Recently, biobased inhibitors have gained a certain interest thanks to their unique properties, eco-friendliness, and availability. Among all the green precursors, lignin is of particular interest, being a natural polymer that can be obtained from different sources including agricultural residues. Corrosion inhibitors based on ionic liquids (ILs) also present interesting advantages, such as low volatility and high tunability. If combined, it may be possible to obtain new lignin-based ILs that present interesting corrosion inhibitor properties. In this work, the inhibition properties of new biobased lignin ILs and the influence of anions and cations on the corrosion of mild steel in an aqueous solution of 0.01 M NaCl were investigated by Potentiostatic Electrochemical Impedance Spectroscopy (PEIS) and Cyclic Potentiodynamic Polarization (CPP). Moreover, the surface was characterized using SEM, EDS, and optical profilometry. The IL choline syringate showed promising performance, reducing the corrosion current after 24 h immersion in 0.01 M sodium chloride, from 1.66 µA/cm2 for the control to 0.066 µA/cm2 with 10 mM of the IL present. In addition to its performance as a corrosion inhibitor, both components of this IL also meet or exceed the current additional desired properties of such compounds, being readily available, and well tolerated in organisms and the environment

PREPARATION OF POLYMER MATRIX COMPOSITE MATERIALS WITH NIR REFLECTIVE PROPERTIES

In this work, the dispersion of a NIR reflective organic black pigment in polymeric matrices and the influence of other additives on the film processing as well as its mechanical properties and thermal performances were investigated. Other factors such as the concentration of the reflecting material, distribution of the particles within the matrix, and film thickness were evaluated. The aim of the work is the preparation of an efficient NIR reflective polymeric composite for greenhouses or automotive applications

Modeling heavy metal release in the epiphytic lichen Evernia prunastri

In this study, the release of Cu2+ and Zn2+ was investigated and modeled in the epiphytic lichen Evernia prunastri. Samples were incubated with solutions containing these metals at ecologically relevant concentrations (10 and 100 μM) and then transplanted to a remote area and retrieved after 1, 2, 3, 6, 12, and 18 months. The results showed that, after 12 months, all samples faced similar metal reductions of ca. 80–85%, but after this period, all the involved processes seem to be no longer capable of generating further reductions. These results suggest that the lichen E. prunastri can provide information about environmental improvements after exposure to high or very high pollution levels in a relatively short period of time

Enhancing the cooling properties of low-density polyethylene films by combining near-infrared reflective additives

In the last years, the rising temperature caused by global warming brought the research to find new efficient solutions to lower the temperature of buildings and reduce the consumption of electrical energy for air conditioning. In this work, we propose the combined use of organic and inorganic near-infrared (NIR) reflective additives in low-density polyethylene (PE) films as an accessible plastic coating with enhanced cooling features. Two ‘cool’ pigments, the inorganic Sicopal® Black (Si Black) and the organic Paliogen® Black (Pa Black), were investigated for black-tinted coatings, while TiO2 (TI) and glass bubbles (GB) were tested for opaque white coatings. The additive's size and concentration influence the composite processing, and their ultimate optical properties were determined in terms of total solar reflectance (TSR) and cooling effect under solar radiation. TI and GB dispersed in PE showed the highest TSR, whereas the organic Pa Black confirmed its superior reflective features with respect to the traditional carbon black (CB). Moreover, a significant increase in the TSR occurred when TI or GB was added to the black pigments (12.7% and 13.6%, respectively). TSR increasing led to a cooler black-tinted PE film under solar irradiation. When using reflective pigments, a cooling effect of about 10°C was measured with respect to the traditional CB

Modeling heavy metal release in the epiphytic lichen Evernia prunastri

In this study, the release of Cu2+ and Zn2+ was investigated and modeled in the epiphytic lichen Evernia prunastri. Samples were incubated with solutions containing these metals at ecologically relevant concentrations (10 and 100 μM) and then transplanted to a remote area and retrieved after 1, 2, 3, 6, 12, and 18 months. The results showed that, after 12 months, all samples faced similar metal reductions of ca. 80–85%, but after this period, all the involved processes seem to be no longer capable of generating further reductions. These results suggest that the lichen E. prunastri can provide information about environmental improvements after exposure to high or very high pollution levels in a relatively short period of time