Chemical upcycling of polyethylene, polypropylene, and mixtures to high-value surfactants.

Conversion of plastic wastes to fatty acids is an attractive means to supplement the sourcing of these high-value, high-volume chemicals. We report a method for transforming polyethylene (PE) and polypropylene (PP) at ~80% conversion to fatty acids with number-average molar masses of up to ~700 and 670 daltons, respectively. The process is applicable to municipal PE and PP wastes and their mixtures.

A Generic Platform for Upcycling Polystyrene to Aryl Ketones and Organosulfur Compounds.

Polystyrene (PS) is one of the least recycled large-volume commodity plastics due to bulkiness of foam products and associated contaminants. PS recycling is also severely hampered by the lack of financial incentive, limited versatility, and poor selectivity of existing methods. To this end, herein we report a thermochemical recycling strategy of "degradation-upcycling" to synthesize a library of high-value aromatic chemicals from PS wastes with high versatility and selectivity.

Intermediate SrCoFeO Tetragonal Structure between Perovskite and Brownmillerite as a Model Catalyst with Layered Oxygen Deficiency for Enhanced Electrochemical Water Oxidation.

The generation of hydrogen in an environmentally benign way is highly essential to meet future energy demands. However, in the process of splitting water electrochemically, sluggish kinetics of the oxygen evolution reaction (OER) curtails its applicability, as it drags energy input. Herein, we synthesized Sr-Co-Fe-O oxides to optimize their OER activity by varying the Co/Fe ratio.

[Homicides in Medellín, Colombia, from 1990 to 2002: victims, motives and circumstances].

In Medellín, Colombia, homicide has been the first cause of morbidity and mortality for 20 years. Medellín has the highest homicide rates of all major cities in Latin America. This study describes the victims, motives, and circumstances in homicides in Medellín from 1990 to 2002.