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Surfactant-assisted algal flocculation has become a significant technique in the algal biodiesel industry. Generally, commercially available surfactants with longer chains are employed for algal flocculation owing to their lower critical micelle concentration (CMC). However, the efficiency of algal flocculation is unsatisfactory even at high concentrations of surfactants. In this work, an aggregation-induced emission surfactant, tetraphenylethene-dodecyltrimethylammonium bromide (TPE-DTAB), was used to flocculate Chlorella vulgaris C4 with high efficiency as a result of its ultralow CMC (24 μM) derived from the hydrophobic and rigid tetraphenylethene moiety. More interestingly, TPE-DTAB could generate fluorescence in its aggregation state in comparison with conventionally nonluminous surfactants. Therefore, the entire flocculation process of TPE-DTAB micelles with algae has been visualized. Our results would be helpful for scientists to design suitable surfactants with ultralow CMC for high-efficiency algal flocculation. [ABSTRACT FROM AUTHOR]

Chemiluminescence resonance energy transfer (CRET) efficiency can be enhanced by confining CRET donors and acceptors within nanoscale spaces. However, this enhanced efficiency is often affected by uncertainties stemming from the random distribution of CRET donors and acceptors in such confined environments. In this study, a novel confined nanospace was created through the surfactant modification of carbon dots (CDs) exhibiting aggregation-induced emission (AIE) characteristics. Hydrophobic CRET donors could be effectively confined within this nanospace. The distance between the CRET donors and acceptors could be controlled by anchoring the AIE-CDs as the CRET acceptors, resulting in significantly improved CRET efficiency. Furthermore, this AIE-CDs-based CRET system was successfully applied to the detection of hydrogen peroxide (H 2 O 2 ) in rainwater, showcasing its potential for practical applications., (© 2024 John Wiley & Sons Ltd.)

It is essential to probe the coordination number (CN) because it is a crucial factor to ensure the catalytic capability of single-atom catalysts (SACs). Currently, synchrotron X-ray absorption spectroscopy (XAS) is widely used to measure the CN. However, the scarcity of synchrotron X-ray source and complicated data analysis restrict its wide applications in determining the CN of SACs. In this contribution, we have developed a d-band center-regulated acetone cataluminescence (CTL) probe for a rapid screening of the CN of Pt-SACs. It is disclosed that the CN-triggered CTL is attributed to the fact that the increased CN could induce the downward shift of d-band center position, which assists the acetone adsorption and promotes the subsequent catalytic reaction. In addition, the universality of the proposed acetone-CTL probe is verified by determining the CN of Fe-SACs. This work has opened a new avenue for exploring an alternative to synchrotron XAS for the determination of CN of SACs and even conventional metal catalysts through d-band center-regulated CTL., (© 2024 Wiley‐VCH GmbH.)

The enhancement of chemiluminescence (CL) intensity is significant in the development of chemiluminescent detection systems with improved sensitivity. In this study, a cationic surfactant with an intrinsic aggregation-induced emission emitter (AIEgen) has been applied to boost the CL signal of the horseradish peroxidase-luminol-H 2 O 2 system. The formed cationic AIEgen micelles enhance the CL signal in two ways: the electrostatic attraction-mediated enrichment and approach of reactants and the high CRET efficiency between excited luminol radicals and AIEgen in the surfactant backbone. As a result, strong CL intensity is produced. Rapid and sensitive H 2 O 2 detection is realized through the proposed cationic AIEgen micelle-containing chemiluminescent system with a limit of detection of 100 nM. The favourable selectivity over other possible interferents including metal ions and anions is due to the specific chemical reaction. Practical H 2 O 2 analysis of thawing water samples with high accuracy using the proposed chemiluminescent platform is realized and is consistent with standard methods.

It is a considerable challenge to realize 3D fluorescence quantification of macrodispersion of clay fillers in a polymer matrix mainly owing to quenching of light emission in the solid state. Herein, a strong light emission is generated within the interlaminated clay as a result of a cation-π interaction between cationic surfactant and fluorescent polycyclic aromatic hydrocarbon when they are cointercalated into clay. Confocal laser scanning microscopy (CLSM) is applied for 3D imaging of macrodispersion of the fluorescence-labeled clay fillers in a silicone rubber matrix. More importantly, the quantification of macrodispersion of clay fillers in the overall polymer composite is established by a statistical model. The proposed method fills in an important gap in the standard for macrodispersion quantification of inorganic fillers in polymer composites.

The direct visualization of micelle transitions is a long-standing challenge owing to the intractable aggregation-caused quenching of light emission in the micelle solution. Herein, we report the synthesis of a surfactant with a tetraphenylethene (TPE) core and aggregation-induced emission (AIE) characteristics. The transition processes of surfactant micelles and the microemulsion droplets (MEDs) formed by the surfactant with a TPE core were clearly visualized by a high-contrast fluorescence imaging method. The fluorescence intensity of the MEDs decreased as the size of MEDs increased as a result of weakening of the restriction of intramolecular rotation (RIR). The results of this study deepen our understanding of micelle-transition processes and provide solid evidence in favor of the hypothesis that the AIE phenomenon has its origin in the RIR of fluorophores in the aggregate state., (© 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.)