The effect of microencapsulation of dihydrogen ammonium phosphate (MAP) in the generation of fire-resistant coatings was studied in the presence of tannins extracted from Pinus radiata. MAP was encapsulated to avoid interaction with sodium carbonate (Na₂CO₃), which, upon contact with fire, generates unwanted gases. Thus, a fireproof (or intumescent) protective film was produced in the presence of the tannins. Microcapsules were polymerized with melamine and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and scanning electron microscopy (SEM)-Energy-Dispersive X-ray Spectroscopy (EDS). The microcapsules were spherical with diameters between 0.7 and 1 µm. The as-produced microcapsules were mixed with tannin extract and the properties of their films were evaluated on wood and structural steel substrates; their fire resistance on medium density fiberboard was also evaluated. Flame resistance tests showed a carbonization index of 26.86% using microcapsules (3% w/w); this is better than commercial coatings. The film properties were similar to commercial coatings, but the adherence was slightly decreased due to agglomeration and also film flexibility.

Solvothermal synthesis and photocatalytic activity of BiOBr Microspheres with Hierarchical Morphologies

Currently, the cultivation and harvesting of mollusks is a crucial activity worldwide. However, this industry generates a large amount of mollusk shell waste disposed of in landfills, causing environmental pollution. In addition, the companies linked to this item allocate large sums of money to depositing the shells in authorized landfills. In South America, Chile is one of the leading producers worldwide of scallop shell (Argopecten purpuratus) waste, creating a growing environmental and financial problem in the country, especially considering that there has yet to be progress in the development of new technologies that may reuse this waste in Chile. This study used different techniques to completely characterize the northern Chile scallop shell waste’s physical and chemical properties for the first time. The XRD result corresponded with calcite crystal structures (CaCO₃), and the XFR showed 97.68% purity. Three particle sizes were obtained: BS (595–100 µm), MS (250–595 µm), and SS (<250 µm). In addition, the potential use of these wastes to remove contaminants present in water from the wine industry (caffeic acid) and some drinking water (arsenic(III)) was evaluated. The powder with the smallest particle size (SS), which has a surface area of 1 m²/g, 0.0050 m³/g of pore volume and pore diameter of 18.0 nm, removed 100.0% of CA and 23.0% As(III) in a pH condition of 4.6. The results show that scallop shell waste can be used to treat water and reinforce polymeric matrix composite materials to improve mechanical properties.