Covalent bonding of N-hydroxyphthalimide on mesoporous silica for catalytic aerobic oxidation of p-xylene at atmospheric pressure.

The surface of SBA-15 mesoporous silica was modified by N-hydroxyphthalimide (NHPI) moieties acting as immobilized active species for aerobic oxidation of alkylaromatic hydrocarbons. The incorporation was carried out by four original approaches: the grafting-from and grafting-onto techniques, using the presence of surface silanols enabling the formation of particularly stable O-Si-C bonds between the silica support and the organic modifier. The strategies involving the Heck coupling led to the formation of NHPI groups separated from the SiO surface by a vinyl linker, while one of the developed modification paths based on the grafting of an appropriate organosilane coupling agent resulted in the active phase devoid of this structural element.

Abiotic weathering of plastic: Experimental contributions towards understanding the formation of microplastics and other plastic related particulate pollutants.

The increasing use of plastic (synthetic polymers) results in the release of uncontrollable amounts of synthetic materials into the environment through waste, infrastructure, and essential goods. As plastic materials undergo weathering, a complex process unfolds, leading to the formation of pollutants, notably microplastics. This study employs multiple instrumental methods to explore the intricate abiotic degradation of the five most commonly used synthetic polymers in environmentally relevant conditions.

In Search of Factors Determining Activity of CoO Nanoparticles Dispersed in Partially Exfoliated Montmorillonite Structure.

The paper discusses a formation of Mt-PAA composite containing a natural montmorillonite structure partially exfoliated by poly(acrylic acid) introduced through intercalation polymerization of acrylic acid. Mt-PAA was subsequently modified by controlled adsorption of Co ions. The presence of aluminosilicate packets (clay) and carboxyl groups (hydrogel) led to the deposition of significant amounts of Co ions, which after calcination formed the CoO spinel particles.

Investigation on the low-temperature transformations of poly(furfuryl alcohol) deposited on MCM-41.

MCM-41-type mesoporous silica was used as a support for poly(furfuryl alcohol) deposition. This material was produced by precipitation-polycondensation of furfuryl alcohol (FA) in aqueous slurry of the SiO2 support followed by controlled partial carbonization. By tuning the FA/MCM-41 mass ratio in the reaction mixture, various amounts of polymer particles were introduced on the inner and outer surface of the MCM support.