Super-paramagnetic polymer composite-supported dendrimer–Mn catalyst: Fabrication, characterization and catalytic evaluation in selective aerobic oxidation of ethylbenzene and oximes derivatives

Enhanced PMS/O2 activation by self-crosslinked amine-gluteraldehyde/chitosan-Cu biocomposites for efficient degradation of HEPES as biological pollutants and selective allylic oxidation of cyclohexene

“…The CI (crystallinity index) value for the samples is measured using eqn (10):where K = shape factor, λ = wavelength, β = line broadening at 1/2 the maximum intensity, and θ = Bragg angle. 25 The results indicated that the CI of the MSNPs, and MS-(AgC)/Cu is ∼2.0 and 3.2, respectively. Since the CI value is inversely proportional to the degree of crystallinity, it can be concluded the MSNPs had higher crystallinity as compared to that of MS-(AgC)/Cu.…”

“…Presumably, the residual weight at ∼330–800 °C is related to the metal oxide and active center of MS-(AgC)/Cu. 25,27 To sum up, the amount of weight lost at 800 °C for MS-(AgC)–Cu was 5.956%. The weight loss of chitosan and MS-(AgC) was higher than that of MS/(AgC)–Cu, further proving the capping of Cu( ii ) ions with the polymeric network.…”

“…The appearance of peaks in MSNP spectra was related to the stretching vibration of –OH (3200–3600 cm −1 ), O–Si–O (472 cm −1 ), O–Si–O (790 cm −1 ) Fe–O–Fe (650 cm −1 ) and Si–O–Fe (1066 cm −1 ). 25 After network-modification, the characteristic peaks of overlappping N–H and O–H stretching (3477.3 cm −1 ), CO (1522.3 cm −1 ), –NH 2 bending (1580.1 and 1658.5 cm −1 ), C–H bending (1396.3 cm −1 ) and C–O–C stretching (1108.2 cm −1 ), appeared in the FT-IR spectra of MS/(AgC). Furthermore, after metal re-modification, the characteristic peaks were found to be around 616.4 cm −1 , which were ascribed to the vibration bands of Cu on chitosan-coated nanocomposites, which confirmed that Cu ions were capped with the polymeric network.…”

“…On the other hand, NAPI is more resistant to the generation of PINO than NHPI, because NHPI is produced as a result of hydrolysis of N-OAc in aqueous media. 25 It appears that the contained H 2 O in the solvent reduces the S CY-one (%) by NAPI. In the case of NDHPI, two NO–H groups on the benzene ring, as well as the electronic effect of each imide ring on each other are beneficial for X (%) and S CY-one (%).…”

“…5C), which entirely coincides with previous reports. 25,29 In the case of N (1s) and O (1s), the shift of N (1s) to a higher BE (from 399 eV in pure chitosan to 400.0 eV in MS-(AgC)/Cu) and the shift of O (1s) to a lower BE (from 530.03 and 531.32 eV to 531.19 and 533.52 eV, respectively, in MS-(AgC)/Cu) confirm the capping of Cu ions with a core shell scaffold (Fig. 5B).…”