MXene has emerged as one of the most interest two-dimensional layered materials that has been extensively explored for various applications. In this work, a novel biomimetic method has been developed for the first time to fabricate Ti3C2 MXene based magnetic Fe3O4 composites that relied on the self-polymerization of dopamine and subsequent mild temperature pyrolysis. We demonstrated that many organic dyes could be rapidly degraded by the MXene-MNPs composites through Fenton reaction with extremely high efficiency. The degradation efficiency could be greater than 97 % under the optimized experimental conditions. Moreover, the catalysts displayed a good recyclable property after five continuous cycles. Electron paramagnetic resonance analysis and quenching results indicated that both (OH)-O-center dot and O-2(center dot-) were the reactive species and involved in the degradation process. Owing to the universality and mild reaction conditions of mussel-inspired biomimetic method, many other multifunctional composites with great research interest could also be fabricated. We also believe that this work will provide some new insights for fabrication of highly efficient catalysts for advanced oxidation processes and exploring the critical roles of polydopamine in advanced oxidation procedures.

Transition-metal carbides, nitrides or carbonitrides (named as MXenes) are a novel type of two-dimensional (2D) materials with the features of traditional 2D materials but more variable chemical compositions. MXenes and related materials have raised more and more research attention and been extensively explored for different applications. In this work, we developed a novel method to synthesize magnetic MXene composites (Ti3C2-MNPs) for the first time through a one-pot route, which relied on the incorporation of Fe3O4 nanoparticles into Ti3C2 nanosheets via thermal treatment. The potential utilization of these Ti3C2-MNPs for catalytic degradation of organic dyes through advanced oxidation processes (AOPs) were also evaluated in details. We demonstrated that Fe3O4 nanoparticles with size about 5 nm could be anchored onto Ti3C2 with well dispersed state. The catalytic degradation results demonstrated that Ti3C2-MNPs possess extremely high degradation efficiency towards different organic dyes under optimal conditions. The electron spin resonance (ESR) spectra identified that both hydroperoxyl radicals (center dot OH) and superoxide radicals (center dot O-2(-)) radicals were involved in the degradation process. This work reported a novel one-step method for fabrication MXenes based multifunctional composites, which show extremely high efficiency for AOPs. This method could also be extended for fabrication of many other multifunctional composites for various applications.

Herein a simple and novel approach has been developed for surface modification of delaminate MXene with nano-mixed silver oxide which combined with mussel-inspired chemistry. Surface modification with dopamine as a secondary reaction platform for loading nano-silver compounds for removal of iodine was achieved. The internal structure and morphology were characterized by SEM and TEM. The element content and distribution analysis of EDS and XPS proved that nano silver compounds were successfully supported and uniformly dispersed on the surface of MXene. Then the adsorption batch experiment was carried out, adsorption time, pH and other factors on the adsorption performance of the adsorbents were studied in details. By calculating the enthalpy change, Gibbs free energy and thermodynamic parameters, the adsorption reaction was found to be an exothermic process. The adsorption kinetics measured the maximum adsorption capacity of 80 mg/g and the removal efficiency is as high as 80% and the adsorption equilibrium time has also been improved. The adsorption kinetics were well fitted by pseudo first-order and second-order models. All the above results demonstrated that the composite from mussel-inspired chemistry has excellent adsorption properties towards iodine ions. This study not only deepens the research on the adsorption behavior of iodine adsorption, but also provides new research directions and experimental methods for pseudo-iodine adsorption. (C) 2020 Elsevier Inc. All rights reserved.

Halloysite nanotubes (HNTs) are a kind of aluminosilicate clay with a unique hollow tubular structure that has been intensively explored for various applications especially in biomedical fields owing to their excellent biocompatibility, biodegrading potential and low cost. Surface modification of HNTs with functional polymers will greatly improve their properties and endow new functions for biomedical applications. In this work, a light-induced reversible addition-fragmentation chain transfer (RAFT) polymerization was introduced to successfully prepare HNTs based fluorescent HNTs/poly(PEGMA-Fl) composites in the presence of oxygen using diacrylate-fluorescein and poly (ethylene glycol) methyl ether methacrylate (PEGMA) as the monomers. Without other catalysts, heating, and deoxygenation procedure, the polymerization process can take place under mild conditions. Besides, owing to the introduction of fluorescein and PEGMA on the surface of HNTs, the resultant HNTs/poly(PEGMA-Fl) composites display high water dispersibility and stable fluorescence. The results from cell viability examination and confocal laser scanning microscopy also demonstrated that HNTs/poly(PEGMA-Fl) composites could be internalized by L929 cells with bright fluorescence and low cytotoxicity. Taken together, we developed a novel photo-initiated RAFT polymerization method for the fabrication of HNTs based fluorescent polymeric composites with great potential for biomedical applications. More importantly, many other multifunctional HNTs based polymer composites could also be fabricated through a similar strategy owing to good designability of RAFT polymerization.

Here we report Ti3C2 MXene assisted LDI-LIFT-TOF/TOF for robust differentiation and relative quantitation of glycan isomers that differ in composition, connectivity and configuration. The improved sensitivity and background-free properties of this substrate combined with the special fragment profile produced by LDI-LIFT-TOF/TOF open a new door for nanomaterial assisted glycan structual analysis.

Two demensional nanomaterials have attracted increasing research interest for various applications ranging from environmental adsorption, biomedical applications, catalytic degradation and energy storage owing to their high surface areas, facile surface functionalization. In this work, we demonstrated the preparation and environmental adsorption applications of 2D material MXenes through extracting Al layer from Ti3AlC2 in a simpler and safer way. The surface of Ti3C2 was modified with sulfonic groups via aromatic coupling-diazotization. The adsorption behavior and capacity of the Ti3C2 and functionalized Ti3C2 towards methylene blue (MB) were also examined and compared. The successful preparation of Ti3C2 and modified Ti3C2 was characterized by a number of techniques, including scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The influence of different experiment conditions such as contact time, solution temperature, pH and initial MB concentrations on the adsorption behavior towards MB were also examined. The results demonstrated that sulfonic groups functionalized Ti3C2 (named as Ti3C2–SO3H) exhibited superior removal efficiency for MB. The maximum adsorption capacity of Ti3C2–SO3H towards MB is over four folds that of raw materials. The results of kinetics and isotherms studies demonstrated that experimental data were better described by pseudo-first-order model and Langmuir isotherm adsorption model, respectively. The process of MB onto surface of adsorbents was endothermic and spontaneous. Experimental details about pH indicated that the dye adsorption capability is favorable when the aqueous solution is alkaline. Based on the above results, cationic dye molecules were removed effectively by using Ti3C2–SO3H as adsorbent, which promotes the development of Ti3C2–SO3H for wastewater treatment.

Cellulose nanocrystals (CNCs) are a novel type of natural nanomaterials that have attracted tremendous research interest for various applications especially in the biomedical fields owing to their natural origin, biodegradable potential, remarkable biocompatibility and massive reactive hydroxyl groups. In this work, a novel strategy has been developed for fabrication of luminescent CNCs with aggregation-induced emission (AIE) feature for the first time through a facile one-step Ce(IV) redox polymerization for direct surface grafting of AIE dye (PhE) and hydrophilic monomer Poly(ethylene glycol) monomethyl ether acrylate (PEGMA) on CNCs. Various characterization techniques would demonstrate the successful preparation of resultant CNC-PhE-PEGMA with uniform nanoscale size, remarkable fluorescent properties and extremely low cytotoxicity. Furthermore, compared with conventional modification strategy of CNCs, Ce(IV) redox polymerization only need moderate temperature and can operate in aqueous solution utilizing surface hydroxyl groups of CNCs as polymerization activity sites. More importantly, CNC-PhE-PEGMA show desirable fluorescent properties and can be used for cell dyeing, indicating their potential for biomedical applications.

Fluorescent carbon nanoparticles (FCNs) have gradually become the most promising alternative candidates to other traditional fluorescent nanomaterials for biological applications on account of their excellent fluorescence property and remarkable biocompatibility. Although many methods have reported on the preparation of FCNs, to date, no studies have reported the preparation of polymers of functionalized FCNs. A high-efficiency method was developed in this work to synthesize high-quality poly(ethylene oxide) (PEG)-functionalized FCNs from cigarette ash and thiol group-containing PEG via a facile one-pot ultrasonic irradiation treatment. A series of characterization techniques demonstrated the uniform nanoscale size, good fluorescence stability, high water dispersibility and remarkable biocompatibility of the generated FCNs. Furthermore, cell imaging was easily achieved at high resolution using the synthetic FCNs as probes, which validates their potential for bioimaging applications. In summary, an efficient one-pot strategy is reported for the first time on the preparation of PEG-functionalized FCNs with the assistance of ultrasonic irradiation. This method should be of great research interest for the fabrication of other polymer-functionalized FCNs with designable properties and functions.