Massive Preparation of Coumarone-indene Resin-based Hyper-crosslinked Polymers for Gas Adsorption

Construction of hydrophilic hypercrosslinked polymer based on natural kaempferol for highly effective extraction of 5-nitroimidazoles in environmental water, honey and fish samples

A series of novel hydroxyl-functional hypercrosslinked polymers (named as HCPs-Kae) were fabricated using natural and environmentally benign kaempferol as monomer via one-step Friedel-Crafts reaction. The prepared HCP-Kae1-24 h exhibited large surface area, good hydrophilicity and excellent adsorption performance to 5-nitroimidazoles (5-NDZs). Thus, by applying HCP-Kae1-24 h as a solid-phase extraction adsorbent, a sensitive method was developed for enrichment of 5-NDZs including metronidazole, ronidazole, secnidazole, dimetridazole and ornidazole prior to high performance liquid chromatography analysis. Under the optimum conditions, good linearities were achieved in the range of 0.10-100.0 ng mL^-1 for water, 1.3-500.0 ng g^-1 for honey, and 1.7-100.0 ng g^-1 for fish meat. The detection limits of the method were 0.03-0.05 ng mL^-1, 0.4-1.0 ng g^-1, 0.5-1.0 ng g^-1 for water, honey and fish meat, respectively. High method recovery was obtained in the range of 84-118% with relative standard deviations lower than 8.9%. The established method was successfully applied to the detection of 5-NDZs in environmental water, honey and fish samples. This work provides a new strategy for constructing hydroxyl-functional HCPs by using natural resource as robust adsorbent for adsorption/extraction applications.

New particle formation from the reactions of ozone with indene and styrene

This work reports the experimental study of the ozonolysis of indene in the presence of SO₂ and the reaction conditions leading to the formation of secondary aerosols. The reactions have been carried out in a Teflon chamber filled with synthetic air mixtures at atmospheric pressure and room temperature. As in the case of styrene, SO₂ plays a key role in the oxidation of the Criegee intermediates and enhances the formation of particulate matter. Thus, for the ozonolysis of indene, nucleation was observed for reacted indene concentrations above (4.5 ± 0.8) × 10¹¹ molecule cm^-3 in the absence of SO₂ while new particle formation was observed for concentrations one order of magnitude lower, (3 ± 1) × 10¹⁰ molecule cm^-3, in the presence of SO₂. Within the detection limit of the system, SO₂ concentrations remained constant during the experiments. The formation of secondary aerosols in the smog chamber was inhibited by H₂O and so the potential formation of secondary aerosols under atmospheric conditions depends on the concentration of SO₂ and relative humidity. Computational calculations have been performed for the ozonolysis of both indene and styrene in the presence of SO₂ and water to identify the reaction channels and species responsible for new particle formation. The release of SO₃ and its subsequent conversion into H₂SO₄ from the reaction of the Criegee intermediate H₂COO in the ozonolysis of styrene makes this aromatic have a high potential of aerosol formation in the atmosphere. On the other hand, quantitative conversion of SO₂ into SO₃ does not occur following the ozonolysis of indene.