Direct exfoliation and dispersion of two-dimensional materials in pure water via temperature control

The high-volume synthesis of two-dimensional (2D) materials in the form of platelets is desirable for various applications. While water is considered an ideal dispersion medium, due to its abundance and low cost, the hydrophobicity of platelet surfaces has prohibited its widespread use. Here we exfoliate 2D materials directly in pure water without using any chemicals or surfactants. In order to exfoliate and disperse the materials in water, we elevate the temperature of the sonication bath, and introduce energy via the dissipation of sonic waves. Storage stability greater than one month is achieved through the maintenance of high temperatures, and through atomic and molecular level simulations, we further discover that good solubility in water is maintained due to the presence of platelet surface charges as a result of edge functionalization or intrinsic polarity. Finally, we demonstrate inkjet printing on hard and flexible substrates as a potential application of water-dispersed 2D materials.close1

Standardising and advancing the quality of care in oral and maxillofacial surgery: role of education and training

Since first developed by Lemons and Quate in 1973 [1], scanning acoustic microscopy has been able to obtain images comparable to those from a high quality optical microscope [2]. In the meantime, many investigators [3–7] have developed that technology to determine the microscopic properties of materials. Among those developments, the line-focus-beam (LFB) acoustic microscopy work of Kushibiki and Chubachi [6–7] in the early 1980’s has been most widely recognized [8–10]. Since the LFB technique is a directional measurement, it can be used to study material anisotropy and stress

Validity and Correctness Before the OS: the Case of LEO I and LEO II

Efficient and reliable computing is based on validity and correctness. Techniques to ensure these essential features have been in place since the early days of computing. The present study focuses on the hardware testing, data validation and program correctness techniques designed and implemented for LEO I and II machines in the UK during the 1950s