Ring Opening Polymerization Used for the Production of VOC Free High-Performance Ecofriendly Novel PBZ/PDA/CeO2 Nanocomposites.

This study analyzed the fabrication and characterization of polybenzoxazine/polydopamine/ceria as tertiary nanocomposites. To this end, a new benzoxazine monomer (MBZ) was fabricated based on the well-known Mannich reaction of naphthalene-1-amine, 2-tert-butylbenzene-1,4-diol and formaldehyde under ultrasonic-assisted process. Polydopamine (PDA) was used as dispersing polymer nanoparticles and surface modifier for CeO2 by in-situ polymerization of dopamine with the assistance of ultrasonic waves. Then, nanocomposites (NC)s were manufactured by in-situ route under thermal conditions. The FT-IR and 1H-NMR spectra confirmed the preparation of the designed MBZ monomer. The FE-SEM and TEM results showed the morphological aspects of prepared NCs and illustrated the distribution of CeO2 NPs in the polymer matrix. The XRD patterns of NCs showed the presence of crystalline phases of nanoscale CeO2 in an amorphous matrix. The TGA results reveal that the prepared NCs are classified as thermally stable materials.

Inhibition of Rhodamine B-Ferricyanide Chemiluminescence by Gold Nanoparticles and Sensitive Determination of Hazardous Cyanide.

We describe a new turn off-on chemiluminescence (CL) method for the sensitive and selective determination of cyanide based on the inhibiting effect of gold nanoparticles (AuNPs) on rhodamine B (RohB)-ferricyanide (Fe(CN)6(3-)) reaction. Free RohB can generate strong chemiluminescence emission when oxidized with Fe(CN)6(3-), but undergoes an intense extinction in the presence of AuNPs. Energy transfer and collisions between RohB molecules and AuNPs are probably the reason for this decreasing effect. Furthermore, it was found that CL intensity gradually recovered in the presence of cyanide due to its interaction with the AuNPs. The relation between the decreased CL intensity and cyanide concentration was exploited to develop a method for the determination of cyanide in the 16.7 - 1333 nmol L(-1) concentration range, with a detection limit of 13.6 nmol L(-1). In comparison with other nanoparticle-based methods, the presented assay shows good sensitivity and reliability for the determination of cyanide. The method was satisfactorily applied to the determination of cyanide in environmental and biological samples.