Search

A polyvinylimidazole-based cryogel is presented as a pioneering solution for efficient extraction and release of partially water-soluble polyphenols from olive byproducts. Specifically, oleuropein was used as model molecule to evaluate its recovery from water. The material merges the properties of interconnected cryogel structure in adsorbing molecules via fast diffusion flux, with the strong electrostatic interactions acted by imidazole moiety. Such cryogel achieves effective oleuropein binding likely through hydrogen bonding and π–π interactions. Comprehensive assessments of static adsorption kinetics, isotherms, and desorption kinetics underscore the cryogel's efficacy in oleuropein extraction and release, highlighting its pivotal role in valorizing olive wastewater through sustainable biotechnological applications. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs), recognized as hazardous air contaminants, prompt the exploration of sustainable air purification methods. Solar photocatalytic oxidation emerges as a promising solution, utilizing semiconductor photocatalysts like titanium dioxide (TiO2). However, the raw material crisis necessitates reduced TiO2 usage, leading to investigations into TiO2 modification techniques. The study introduces a novel approach by employing natural fibers, specifically loofah sponge, as a TiO2 support. This method aims to maintain photocatalytic activity while minimizing TiO2 content. The article explores using halloysite, a natural clay mineral, as a supportive material, enhancing mechanical strength and adsorption properties. The resulting TiO2/loofah-halloysite composites are evaluated for their efficacy in gas-phase photocatalytic oxidation of toluene and ethanol, chosen as representative VOCs. The conversion of toluene and ethanol on the composite was 88% and 39%, respectively, with high selectivity toward CO2. In addition to its high performance, the bio-composite was stable for several conversion cycles, keeping the conversion activity unchanged. The study contributes to developing green hybrid materials for VOC removal, showcasing potential applications across industries. [ABSTRACT FROM AUTHOR]

In recent decades, many efforts have been devoted to studying reactions catalyzed in nanoconfined spaces. The most impressive aspect of catalysis in nanoconfined spaces is that the reactivity of the molecules can be smartly driven to disobey classical behavior. A green and efficient three‐component aza‐Darzens (TCAD) reaction using a catalytic amount of γ‐cyclodextrins (CDs) in water has been developed to synthesize N‐phenylaziridines. CDs effectively performed this reaction in an environmentally friendly setting, achieving good yields. The same reaction was then performed using polymeric γ‐CD such as a γ‐cyclodextrin polymer crosslinked (GCDPC) with epichlorohydrin, a sponge‐like macroporous γ‐cyclodextrin‐based cryogel (GCDC), and a γ‐cyclodextrin‐based hydrogel (GCDH). The homogeneous and heterogeneous catalyst recovery was then studied, and it was proved to be easily recycled several times without relevant activity loss. Water, as a unique and eco‐friendly reaction medium, has been utilized for the first time, to the best of our knowledge, in this reaction. The inclusion of the reagents in CDs has been studied and rationalized by NMR spectroscopy experiments and molecular modeling calculations. The credit of the presented protocol includes good yields and catalyst reusability and precludes the use of organic solvents. [ABSTRACT FROM AUTHOR]

Using CO2 as feedstock to fabricate valuable products has become essential to green and sustainable chemistry and represents a rewarding challenge. Among the noticeable routes used to convert CO2 into synthetic polymers, this review highlights the reactions concerning the cycloaddition of epoxides with CO2 in cyclic carbonate as precursors for various forms of chemical synthesis, such as polycarbonates and polyurethanes (PUs). It is a fundamental challenge in polymer production to exploit biomass and CO2 as feedstock. PUs are one of the most versatile classes of polymeric materials that exhibit excellent properties. PUs are usually synthesized by a route involving the reaction of diols with diisocyanates derived from toxic phosgene gas. Non-isocyanate-derived polyurethane (NIPU) has been produced from cyclic carbonates and diamines without isocyanate. NIPU usually displays increased chemical resistance, lower permeability, improved water absorption, and thermal stability. In this review, we report the synthesis of several NIPUs for different applications in a more environmentally friendly manner, employing CO2 as a reagent and/or fully biobased reactants. [ABSTRACT FROM AUTHOR]

Advances in materials science and technology have prompted researchers to look to nature for new high-performance, low-cost materials. Among these, cyclodextrins have been widely used as a material in industrial applications. Inspired by previous work by our research group that led to the functionalization of cucurbit[6]uryl and its conversion into supramolecular nanospheres with good CO2 adsorption capacity, this work aims to improve the ability of cyclodextrins to capture CO2 by functionalizing them with amide groups. Carbon dioxide adsorption experiments on functionalized cyclodextrins showed an adsorption capacity similar to that of BEA zeolite, a material currently used in the industry for gas adsorption. Moreover, these adsorption properties could also be exploited to improve the adsorption capacity of drugs, a field in which cyclodextrins are widely used. The new cyclodextrin molecules were characterized by nuclear magnetic resonance spectroscopy and mass spectrometry, thanks to which we could determine the degree of functionalization of the new macrocycles. In addition, using Fourier-transform infrared spectroscopy, we demonstrated the presence and interaction of carbon dioxide adsorbed by the material, whereas an in silico study confirmed the chemisorption as the principal adsorption process, as experimentally inferred using the pseudo-second-order (PSO) kinetic model. [ABSTRACT FROM AUTHOR]

Fatty acid binding protein (FABP4) inhibitors are of synthetic and therapeutic interest and ongoing clinical studies indicate that they may be a promise for the treatment of cancer, as well as other diseases. As part of a broader research effort to develop more effective FABP4 inhibitors, we sought to identify new structures through a two-step computing assisted molecular design based on the established scaffold of a co-crystallized ligand. Novel and potent FABP4 inhibitors have been developed using this approach and herein we report the synthesis, biological evaluation and molecular docking of the 4-amino and 4-ureido pyridazinone-based series. [ABSTRACT FROM AUTHOR]

Correction for 'CO2-derived non-isocyanate polyurethanes (NIPUs) and their potential applications' by Rita Turnaturi et al., Green Chem., 2023, 25, 9574–9602, https://doi.org/10.1039/D3GC02796A. [ABSTRACT FROM AUTHOR]

Herein, a proof of concept is reported, concerning the formulation of methacrylic and styrene-based hydrogels with adsorption properties versus the emerging pollutants (dyes, pesticides, and pharmaceuticals). The synthesis of the hydrogels was achieved by functionalizing the HEMA monomer with specifically chelating groups, such as amino acids (lysine and histidine), cyclodextrins, and meglumine. The as-prepared monomers were polymerized in water at different temperatures to obtain macroporous samples. All the samples were characterized by chemical–physical and morphological analyses confirming the success of the reactions. The resulting systems were successfully tested to adsorb 2, 4 D, methylene blue, and lomefloxacin. In addition, up to five cycles of regeneration tests were performed, confirming the aptitude of the samples to be used several times without losing efficiency and maintaining their mechanical properties. [ABSTRACT FROM AUTHOR]