Biodegradable macroporous polyHIPEs with specific cavity sizes and selective interfacial functionalization of the inner surface with NHA are produced.

In this work, we have explored the use of hydrophobic deep eutectic systems (DESs) composed of d,l-menthol and different naturally occurring acids (acetic acid, lauric acid, lactic acid, and pyruvic acid) as an alternative green internal (dispersed) phase in the formulation of high internal phase emulsions (HIPEs). DES-in-water (DES/W) HIPEs were formulated using the hydrophilic monomer acrylamide and the cross-linker N,N′-methylenebis­(acrylamide) with water as the continuous phase and stabilized with a nonionic triblock copolymer surfactant (Pluronic F127). Furthermore, HIPEs formulated with tetradecane as the dispersed phase were comparatively studied. Surprisingly, stable DES/W HIPEs were obtained with the d,l-menthol/acetic acid (M:AA) DES and used as templates to obtain polyacrylamide macroporous materials (polyHIPEs) within a sustainable framework. The materials were coated with maghemite nanoparticles (γ-Fe2O3 Nps; synthesized in situ onto the porous structure by a coprecipitation method), allowing the formation of hydrophilic polyHIPEs with magnetic and electrostatic properties, which were satisfactorily used as methylene blue (MB) dye adsorbents. The use of the M:AA DES as the internal phase in HIPE formulation allowed the synthesis of macroporous materials with higher surface area (S BET) and γ-Fe2O3 Nps amount than those formulated with tetradecane because of the different porous structures obtained. Therefore, the magnetic polyHIPEs obtained with the M:AA DES presented higher MB dye maximum adsorption capacity (359.71 mg g–1) than those with tetradecane (264.55 mg g–1) in the same synthesis conditions, even higher than some commercial MB adsorbents. The materials were reused for more than six adsorption/desorption cycles without losing their adsorption capacity. Thus, the M:AA DES represents a green tool for the preparation of magnetic macroporous materials composed of polyacrylamide γ-Fe2O3 Nps with a promising and competitive performance as MB dye adsorbents.

A simple and direct method is described to prepare cationic bis(NHC)-Au(i) complexes containing N-alkyl or N-aryl NHC ligands to generate relevant gold complexes using metallic gold as the starting material.

In this work, we report a nonaqueous one-step method to synthesize polystyrene macroporous magnetic nanocomposites through high internal phase emulsions (HIPEs) formulated with the deep eutectic solvent (DES) composed of urea:choline chloride (U:ChCl, in a 2:1 molar ratio) as the internal phase and co-stabilized with mixtures of Span 60 surfactant and non-functionalized magnetite nanoparticles (Fe 3 O 4 NPs). The porous structure and the magnetic and lipophilic properties of the nanocomposite materials were easily tailored by varying the amount of Fe 3 O 4 NPs (0, 2, 5 and 10 wt %) and the surfactant Span 60 (0, 5, 10, and 20 wt %) used in the precursor emulsion. The resultant nanocomposite polyHIPEs exhibit high sorption capacity toward different oils (hexane, gasoline, and vegetable oil) due to their high porosity, interconnectivity, and hydrophobic surface. It was observed that the oil sorption capacity was improved when the amount of surfactant decreased and Fe 3 O 4 NPs increased in HIPE formulation. Therefore, polyHIPE formulated with 5 and 10 wt % Span 60 and Fe 3 O 4 NPs, respectively, showed the highest oil sorption capacities of 4.151, 3.556, and 3.266 g g –1 for gasoline, hexane, and vegetable oil, respectively. In addition, the magnetic monoliths were reused for more than ten sorption/desorption cycles without losing their oil sorption capacity.

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