The design of an antimicrobial coating materials becomes ideal in order to prevent infections caused by the transmision of pathogens coming from human’s contact with contaminated surfaces. In that aim layered single hydroxides (LSH) and layered double hydroxides (LDH) containing Zn and Cu, in nitrate form and intercalated with antimicrobial molecules, were synthe-sized and characterized. Cinnamate and salicylate anions were chosen to be intercalated in the fillers because of their well known antimicrobial activity. Several coatings based on polyvinyl alcohol (PVA) and LDH or LSH with increasing amounts of filler were prepared and filmed on a polyethylene terephthalate (PET) substrate. Coatings were characterized and their antimi-crobial activity was evaluated against pathogens critical in nosocomial infections, giving interesting results.

Composite membranes formed by sulfonated poly(ether ether ketone) (SPEEK) with embedded carbon quantum dots (CQDs) were used for detection and removal of heavy metal ions, such as lead and cadmium, from water. SPEEK is responsible for the capture of heavy metals based on the cation exchange mechanism, while CQDs detect their contamination by exhibiting changes in fluorescence. Water-insoluble “red” carbon quantum dots (rCQDs) were synthesized from p-phenylenediamine so that their photoluminescence was shifted from that of the polymer matrix. CQDs and the composites were characterized by several techniques: FTIR, Raman, UV/VIS, photoluminescence, XPS spectroscopies and AFM microscopy. The heavy metal ion concentration was analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES). The concentration ranges were 10.8 - 0.1 mM for Pb2+ and 10.0 - 0.27 mM for Cd2+. The composite achieved 100% removal efficiency for lead and cadmium if the concentration was below a half of the ion exchange capacity of SPEEK. The regeneration of membranes in 1 M NaCl was also studied. SPEEK/rCQDs showed a turn-off effect more pronounced for lead. A second order law was effective to describe the kinetics of the process.