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Although surface terminations (such as ═O, –Cl, –F, and –OH) on MXene nanosheets strongly influence their functional properties, synthesis of MXenes with desired types and distribution of those terminations is still challenging. Here, it is demonstrated that thermal annealing helps in removing much of the terminal groups of molten salt-etched multilayered (ML) Ti3C2Tz. In this study, the chloride terminations of molten salt-etched ML-Ti3C2Tz were removed via thermal annealing at increased temperatures under an inert (argon) atmosphere. This thermal annealing created some bare sites available for further functionalization of Ti3C2Tz. XRD, EDS, and XPS measurements confirm the removal of much of the terminal groups of ML-Ti3C2Tz. Here, the annealed ML-Ti3C2Tz was refunctionalized by −OH groups and 3-aminopropyl triethoxysilane (APTES), which was confirmed by FTIR. The −OH and APTES surface-modified ML-Ti3C2Tz are evaluated as a solid lubricant, exhibiting ∼70.1 and 66.7% reduction in friction compared to a steel substrate, respectively. This enhanced performance is attributed to the improved interaction or adhesion of functionalized ML-Ti3C2Tz with the substrate material. This approach allows for the effective surface modification of MXenes and control of their functional properties. 

Abstract Formative asymmetric divisions produce cells with different fates and are critical for development. We show the maize (Zea mays) myosin XI protein, OPAQUE1 (O1), is necessary for asymmetric divisions during maize stomatal development. We analyzed stomatal precursor cells before and during asymmetric division to determine why o1 mutants have abnormal division planes. Cell polarization and nuclear positioning occur normally in the o1 mutant, and the future site of division is correctly specified. The defect in o1 becomes apparent during late cytokinesis, when the phragmoplast forms the nascent cell plate. Initial phragmoplast guidance in o1 is normal; however, as phragmoplast expansion continues o1 phragmoplasts become misguided. To understand how O1 contributes to phragmoplast guidance, we identified O1-interacting proteins. Maize kinesins related to the Arabidopsis thaliana division site markers PHRAGMOPLAST ORIENTING KINESINs (POKs), which are also required for correct phragmoplast guidance, physically interact with O1. We propose that different myosins are important at multiple steps of phragmoplast expansion, and the O1 actin motor and POK-like microtubule motors work together to ensure correct late-stage phragmoplast guidance.