The size-dependent melting temperature and the size-dependent melting entropy of organic nanocrystals are predicted by use of our simple model being free of any adjustable parameter. The model predictions for the size-dependent melting temperature and the size-dependent melting entropy are supported by the experimental results on benzene, chlorobenzene, heptane, and naphthalene nanocrystals.

One‐dimensional nanomaterials and their assemblies attract considerable scientific interest in the physical, chemical, and biological fields because of their potential applications in electronic and optical devices. The interface‐assembly method has become an important route for the self‐assembly of nanoparticles, nanosheets, nanotubes, and nanorods, but the self‐assembly of ultralong nanowires has only been successful using the Langmuir–Blodgett approach. A novel approach for the spontaneous formation of highly aligned, ultralong Ag nanowire films at the oil–water–air interface is described. In this approach, the three‐phase interface directs the movement and self‐assembly process of the ultralong Ag nanowires without the effect of an external force or complex apparatus. The ordered films exhibit intrinsic large electromagnetic fields that are localized in the interstitials between adjacent nanowires. This new three‐phase‐interface approach is proven to be a general route that can be extended to self‐assemble other ultralong nanowires and produce ordered films.

1wileyonlinelibrary.com www.particle-journal.com www.MaterialsViews.com Uniform water-soluble monolayer MoS 2 quantum dots (MQDs) with lateral sizes of ≈2.1 nm, a clearly zigzag-terminated edge, and a hexagonal lattice structure are achieved using ammonium molybdate, thiourea, and N-acetyl-L -cysteine (NAC) as precursors and the capping reagent in a facile one-pot hydrothermal approach. MQDs have good dispersity and high stability in aqueous suspension and exhibit a signifi cantly larger direct bandgap (3.96 eV) compared to monolayer MoS 2 nanosheets (1.89 eV). Pronounced blue-shifts in the wavelengths of both the excitonic absorption and intrinsic state emission with activated strong luminescence at room temperature beyond monolayer MoS 2 nanosheets is demonstrated. Unusual upconversion photoluminescence is also observed and is caused by two successive transfers of energy from the near-infrared (NIR) absorption generated by the NAC capping reagent to the hexagonal structure of MQDs. Additional optical properties of MQDs may provide numerous exciting technological applications. Here, MQDs are demonstrated as a highly selective fl uorescent reagent for detecting tetracycline hydrochloride under UV and NIR irradiation. hydrogen storage, [ 10 ] nano-lubrication, [ 11 ] lithium ion batteries, [ 12 ] and biomedical imaging. [ 13 ] Few works emerged very recently concerning isolation and deposition of high-quality monolayer MoS 2 nanosheets by the top-down [ 14 ] and bottomup [ 9a , 15 ] approaches. Dramatic changes in the electronic structure and optical properties compared to the bulk counterparts were observed in these 2D ultrathin atomic layer structures. [ 16 ] When the lateral size of monolayer MoS 2 nanosheets further reduces to less than 10 nm leading to monolayer MoS 2 quantum dots (MQDs), extra fl uorescent property beyond singlelayer MoS 2 nanosheets might be obtained, since pronounced sizable bandgap in semiconducting TMDs has already been predicted. [ 17 ] However, rigorous control of the thickness and lateral size of these nanosheets is still a huge challenge. Exploitation of monolayer MQDs with extra optical properties has not been reported. In this paper, effective fabrication of uniform water-soluble monolayer MQDs of lateral size ≈2.1 nm by using a facile one-pot hydrothermal procedure is reported. These single-layer MQDs have good dispersity and high stability in aqueous suspension and possess unusual fl uorescence (especially near-infrared (NIR) excitation behavior). These attributes distinguish monolayer MQDs from single-layer MoS 2 nanosheets, which may offer going beyond fundamental pathways and open up numerous technological applications in catalysis, sensing, hydrogen storage, lithium ion batteries, photovoltaic devices, and microelectronics. Here, the fl uorescent properties of monolayer MQDs are demonstrated to be useful for highly selective detection of tetracycline hydrochloride under UV and NIR irradiation. Results and Discussion Synthesis and Characterization of MQDsMonolayer MQDs wer...

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