Magnetic Nanoparticle–Polymer Composites Loaded with Hydrophobic Sensitizers for Photodegradation of Azoic Dyes

Abstract

Oleate-protected iron oxide magnetic nanoparticles (MNPs) were encapsulated with amphiphilic comb polymer poly­(maleic anhydride alt-1-octadecene) (PMAO) in order to achieve the phase transfer to aqueous media and to load the resulting MNP–PMAO assemblies with phenalenone (PN), a hydrophobic photosensitizer with a quantum yield of singlet oxygen production close to unity. Steady-state fluorescence measurements complemented with density functional theory calculations, together with emission lifetime experiments, led us to conclude that PN molecules in the hybrid nanomaterial are indeed localized in a hydrophobic environment. In addition, laser flash-photolysis assays confirmed the generation of the triplet state of PN and its quenching by O2, an indication of the formation of singlet molecular oxygen (1O2). For monodisperse magnetic nanocubes (MNCs) 23 nm in edge length, the MNC–PMAO–PN nanohybrids can be efficiently removed by magnetic decantation. We performed photodegradation experiments of azoic derivative acid black 10B (AB10B), a dye commonly used in the cosmetic industry and which is found in wastewaters. Irradiation of a 0.01 mM AB10B solution for 120 min in the presence of the MNC–PMAO–PN assemblies (200 mg L−1, expressed as iron oxide concentration) led to a 76% decomposition of the dye at pH around 6. Unlike other methods based on Fenton processes, our strategy reaches a significant photodegradation efficiency without the addition of H2O2 or acids. Similar systems could be used to encapsulate hydrophobic photosensitizers for other purposes, such as bacterial inactivation and combined photodynamic and magnetic hyperthermia therapies.

Waste-Derived Iron Nanoparticles for Solvent-Free Single-Step Reductive Acetylation of Nitroarenes

“…After the optimization of the reaction parameters, the scope of the reaction on various derivatives of nitrobenzene was investigated, as depicted in Scheme 2. Overall, the reaction was found to be well tolerated for both the electron-withdrawing and electron-donating groups attached to the benzene ring, and good-to-excellent yield was recorded (74−90%) with various derivatives of nitrobenzene (Scheme 2, 1−11) and identified using 1 H and 13 C NMR analyses (see Supporting Information, Section 1− 1 H and 13 C NMR data of synthesized substrates). The electron-withdrawing functional groups like −Cl, −Br, and −CN, and attached at the para position of benzene ring reacted efficiently with acetic acid to form desired acetamide derivatives in significant amounts of 84−86% (Scheme 2, 2−4).…”

“…The morphology and geometry of FeO x -NPs were analyzed from the images taken from Tecnai G2 20 S-TWIN [FEI] transmission electron microscope. The 1 H, 13 C, and 1 H NMR spectra were recorded using a JEOL ECS-400 spectrometer (operating at 400 MHz for 1 H and 100 MHz for 13 C).…”

“…Characterization data of synthesized substrates; 1 H and 13 C NMR data of synthesized substrates; green metricsbased quantifications for the synthesis of paracetamol and phenacetin; and DOZN 2.0-based calculations for the quantitative determination of 12 principles of green chemistry (PDF)…”

“…The process related to the development of reduction methodologies involving the reduction of nitro compounds to medicinally important amide formation is always in demand. − Amide derivatives are known for various applications in agro- and pharmacy-related industries for making various surfactants, pesticides, polymers, dye precursors, and medicines. , For instance, acetanilide ( N -phenylacetamide) is used to produce 4-acetamidobenzene sulfonyl chloride (used for manufacturing sulfa drugs), paracetamol, and many more medicinally important drugs. However, their synthetic methodologies require two-step reduction of nitrobenzene to aniline, − followed by acetylation − for its preparation, which makes the reduction of nitro derivatives a multistep-complicated task. The multiple step procedures generally require expensive catalysts (platinum (Pt), , silver (Ag), lead (Pb), bimetallic catalysts, ,, etc.…”

Synthesis and Photophysical Characterizations of Pyrroloquinolone Photosensitizers for Singlet Oxygen Production†

“…The population of the triplet state occurs via a very efficient intersystem crossing between S 1 (n-π*) and T 1 (π-π*) which follows the El-Sayed's rule (20). In recent years, phenalenone photosensitizers have found valuable applications in the photodegradation of wastewater contaminants (21) and in photodynamic therapy for killing bacteria (22)(23)(24), fungi (25) and cancer cells (26,27). With the aim of uncovering new methods to prepare functionalized phenalenones, our group reported in 2020 a new class of phenalenone photosensitizers for singlet oxygen production (Scheme 1) (28).…”