A superhydrophobic surface of lead dodecanethiolate with the water contact angle(CA) of 152.2°±1.2° and the sliding angle(SA) of 3.8°±1.0° was fabricated using a simple and relative inexpensive route based on our previous reported method. The procedure employed a one-pot reaction between lead salt and alkanethiolate to form a thermal stable superhydrophobic coating under mild conditions. SEM images revealed the lead dodecanethiolate surface morphology with packed aggregate “rice-like” particles of micrometer scale in length and nanometer scale in thickness. Also, Lead dodecanethiolate powder was investigated by TGA and XRD. 相似文献
Silicon nanocrystals (Si‐NCs) are emerging as an attractive class of quantum dots owing to the natural abundance of silicon in the Earth's crust, their low toxicity compared to many Group II–VI and III–V based quantum dots, compatibility with the existing semiconductor industry infrastructure, and their unique optoelectronic properties. Despite these favorable qualities, Si‐NCs have not received the same attention as Group II–VI and III–V quantum dots, because of their lower emission quantum yields, difficulties associated with synthesizing monodisperse particles, and oxidative instability. Recent advancements indicate the surface chemistry of Si‐NCs plays a key role in determining many of their properties. This Review summarizes new reports related to engineering Si‐NC surfaces, synthesis of Si‐NC/polymer hybrids, and their applications in sensing, diodes, catalysis, and batteries. 相似文献
The precise construction of a hierarchical complex pattern on substrates is required for numerous applications. Here, a strategy to fabricate well‐defined hierarchical three dimensional (3D) patterns on polymer substrate is developed. This technique, which combines photolithography and visible light‐induced surface initiated living graft crosslinking polymerization (VSLGCP), can effectively graft 3D patterns onto polymer substrate with high fidelity and controllable height. Owing to the living nature of VSLGCP, hierarchical 3D patterns can be prepared when a sequential living graft crosslinking process is performed on the first formed patterns. As a proof‐of‐concept, a reactive two layer 3D pattern with a morphology of lateral stripe on vertical stripe is prepared and employed to separately immobilize model biomolecules, e.g., biotin and IgG. This two component pattern can specifically interact with corresponding target proteins successfully, indicating that this strategy has potential applications in the fabrication of polymer‐based multicomponent biomolecule microarrays.
The voltammetry of various well-characterized aqueous and nonaqueous electrochemical systems has been studied at platinum and gold disk electrodes under illumination from a 10 Hz pulsed Nd:YAG laser frequency doubled to operate at 532 nm. A simple Nernst diffusion layer model is established to quantify the slight enhancement in mass transport observed as a function of laser intensity in the thermoelastic region where light energy absorbed by the metal is insufficient to cause localized melting or vaporization but does lead to a partial thinning of the diffusion layer thickness through surface heating/vibration. This leads to sigmoidal shaped voltammograms whilst maintaining a clean, reproducible electrode surface. Above the ablation threshold, the minimum laser intensity required to cause electrode damage, atomic force microscopy (AFM) is used to probe the nature of the surface damage and its relationship to the laser intensity. The Nernst-diffusion model is verified by means of potential step chronoamperometric measurements in water and acetonitrile where good agreement with theory is seen for transport across a diffusion layer of a thickness corresponding to that inferred from steady-state voltammetry. Applications of the laser activation technique are illustrated by three systems found to be passivating in aqueous media; the two electron reduction of toluidine blue dye, iodide oxidation and the oxidation of ferrocyanide in the presence of the blood protein, fibrinogen. In all cases clean, reproducible and quantitative voltammetry is seen in contrast to that observed in the absence of laser activation, demonstrating the excellent surface-cleaning effects of LAV. 相似文献