Hypothesis: Optimizing interfacial positioning of crosslinkers within a reactive self-assembled hexagonal lyotropic liquid crystals (HLLC) system could assist in retaining the hexagonal structure during polymerization and thereby improving water filtration performances of the as-synthesized nanofiltration membranes.
Experiments: The positioning of the hydrophilic crosslinker, poly (ethylene glycol) diacrylate (PEGDA), within the reactive HLLC system was systematically investigated using H and C solid nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. The structural variation and water filtration performances of these HLLC systems with/without crosslinkers after polymerization were further studied using grazing incidence SAXS (GISAXS) and crossflow filtration tests, respectively.
Wearable electronic sensors have recently attracted tremendous attention in applications such as personal health monitoring, human movement detection, and sensory skins as they offer a promising alternative to counterparts made from traditional metallic conductors and bulky metallic conductors. However, the real-world use of most wearable sensors is often hindered by their limited stretchability and sensitivity, and ultimately, their difficulty to integrate into textiles. To overcome these limitations, wearable sensors can incorporate flexible conductive fibers as electrically active components.
View Article and Find Full Text PDFX-rays are a penetrating form of high-energy electromagnetic radiation with wavelengths ranging from 10 pm to 10 nm. Similar to visible light, X-rays provide a powerful tool to study the atoms and elemental information of objects. Different characterization methods based on X-rays are established, such as X-ray diffraction, small- and wide-angle X-ray scattering, and X-ray-based spectroscopies, to explore the structural and elemental information of varied materials including low-dimensional nanomaterials.
View Article and Find Full Text PDFMXene inks are promising candidates for fabricating conductive circuits and flexible devices. Here, MXene inks prepared from solvent mixtures demonstrate long-term stability and can be employed in commercial rollerball pens to write electronic circuits on flexible substrates. Such circuits exhibit a fast and accurate capacitive response for touch-boards and water level measurement, indicating the excellent potential of these MXene inks in electrical device fabrication.
View Article and Find Full Text PDFTi C T MXene (or "MXene" for simplicity) has gained noteworthy attention for its metal-like electrical conductivity and high electrochemical capacitance-a unique blend of properties attractive toward a wide range of applications such as energy storage, healthcare monitoring, and electromagnetic interference shielding. However, processing MXene architectures using conventional methods often deals with the presence of defects, voids, and isotropic flake arrangements, resulting in a trade-off in properties. Here, a sequential bridging (SB) strategy is reported to fabricate dense, freestanding MXene films of interconnected flakes with minimal defects, significantly enhancing its mechanical properties, specifically tensile strength (≈285 MPa) and breaking energy (≈16.
View Article and Find Full Text PDFFree-standing films that display high strength and high electrical conductivity are critical for flexible electronics, such as electromagnetic interference (EMI) shielding coatings and current collectors for batteries and supercapacitors. 2D Ti C T flakes are ideal candidates for making conductive films due to their high strength and metallic conductivity. It is, however, challenging to transfer those outstanding properties of single MXene flakes to macroscale films as a result of the small flake size and relatively poor flake alignment that occurs during solution-based processing.
View Article and Find Full Text PDFThe discovery of liquid crystalline (LC) phases in dispersions of two-dimensional (2D) materials has enabled the development of macroscopically aligned three-dimensional (3D) macrostructures. Here, we report the first experimental observation of self-assembled LC phases in aqueous TiCT MXene inks without using LC additives, binders, or stabilizing agents. We show that the transition concentration from the isotropic to nematic phase is influenced by the aspect ratio of MXene flakes.
View Article and Find Full Text PDFFiber-shaped supercapacitors (FSCs) are promising energy storage solutions for powering miniaturized or wearable electronics. However, the scalable fabrication of fiber electrodes with high electrical conductivity and excellent energy storage performance for use in FSCs remains a challenge. Here, an easily scalable one-step wet-spinning approach is reported to fabricate highly conductive fibers using hybrid formulations of Ti C T MXene nanosheets and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate.
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