Materials in which photoluminescence is modulated by redox processes are known as electrofluorochromic. Intrinsically switchable fluorophores, incorporating both redox and fluorescent moieties, could be ideal electrofluorochromic materials if they possess high fluorescence quantum yields in at least one of their redox states. Fluorescent liquid crystals with redox active centres could combine the above requirements with the advantage to work in bulk anisotropic phases. However, electrofluorochromic liquid crystals have not been reported yet because their synthesis is challenging due to aggregation-caused fluorescent quenching. Here we show the first examples of electrofluorochromic π-conjugated ionic liquid crystals based on thienoviologens. These ordered materials, combining ionic and electronic functions, are highly fluorescence in the bulk state (quantum yield>60%). Their direct electrochemical reduction leads to fast and reversible bulk electrofluorochromic response in both columnar and smectic phases allowing for fluorescence intensity modulation and colour tuning.
The aim of this study is to examine the efficiency of biobased Spanish broom (SB) surface modified cellulose fibers to remove bisphenol A (BPA), a well-known endocrine disruptor, from water. Spanish brooms are flowering plants, which are native and abundant to Mediterranean regions. The functionalized fibers (FF) were found to have the best adsorption efficiency at pH 5, due to the optimal hydrophobic interaction between the FF fiber and BPA. Adsorption kinetics of BPA was found to fit well a pseudo-second order reaction. Equilibrium isotherm data were fitted by Langmuir and Freundlich models. A very fast and simple regeneration method was developed and it was observed that adsorption capacity of the fibers was kept almost unchanged after 3 consecutive uses. Bottled water and synthetic wastewater were also tested to assess the efficiency of the process under more realistic water and wastewater treatment conditions. It was found that BPA removal was slightly decreased from 77% in ultrapure water to 64% in synthetic wastewater matrix, indicating that FF has a high selectivity toward BPA, even in the presence of other organic compounds. Overall, it was observed that SB-modified fibers can be a new promising green biotechnology for water purification.
This review focuses on the ability of some natural antioxidant molecules (i.e., hydroxycinnamic acids, coumarin-3-carboxylic acid, quercetin, luteolin and curcumin) to form Al(III)- and Fe(III)-complexes with the aim of evaluating the coordination properties from a combined experimental and theoretical point of view. Despite the contributions of previous studies on the chemical properties and biological activity of these metal complexes involving such natural antioxidants, further detailed relationships between the structure and properties are still required. In this context, the investigation on the coordination properties of Al(III) and Fe(III) toward these natural antioxidant molecules might deserve high interest to design water soluble molecule-based metal carriers that can improve the metal’s intake and/or its removal in living organisms.