Fabrication of super-hydrophobic nickel film on copper substrate with improved corrosion inhibition by electrodeposition process

Inspired by the famous “lotus effect”, we have fabricated the super-hydrophobic surfaces with nickel film on copper substrates using a one-step electrodeposition method. By adjusting processing time, water contact angle of as-prepared surfaces can reach as high as 160.3 ± 1.5° with small rolling angle of 3.0 ± 0.5°, showing excellent super-hydrophobicity. After the deposition of nickel coating, the pristine copper surfaces became much rough with packed cauliflower-/thorn-like clusters. This unique surface texture contributed to trapping large amount of air and forming the air cushion underneath the water droplet, which can prevent the liquids contacting the copper substrate. The examination of surface chemical compositions implied that the deposited super-hydrophobic coating consisted of nickel crystals and nickel myristate. In this research, the formation mechanism of the electrodeposited super-hydrophobicity was extensively explained based on the analyses of surface texture and surface chemistry. Moreover, the corrosion resistance of the as-fabricated super-hydrophobic surface was estimated by the potentiodynamic polarization tests as well as the electrochemical impedance spectroscopy (EIS) measurements. The results demonstrate that the super-hydrophobic nickel coating showed excellent corrosion inhibition in simulated seawater solution. The existence of the super-hydrophobic coating could be regarded as a barrier and thus provide a perfect air-liquid interface that inhibits the penetration of the corrosive ions. This facile and effective method of electrodeposition process offers a promising approach for mass production of super-hydrophobic surfaces on various metals

Insights into the wettability transition of nanosecond laser ablated surface under ambient air exposure

Super-hydrophobic surfaces are attractive due to self-cleaning and anti-corrosive behaviors in harsh environments. Laser texturing offers a facile method to produce super-hydrophobic surfaces. However, the results indicated that the fresh laser ablated surface was generally super-hydrophilic and then gradually reached super-hydrophobic state when exposed to ambient air for certain time. Investigating wettability changing mechanism could contribute to reducing wettability transition period and improving industrial productivity. To solve this problem, we have studied the bare aluminum surface, fresh laser ablated super-hydrophilic surface, 15-day air exposed surface, and the aged super-hydrophobic surface by time-dependent water contact angle (WCA) and rolling angle (RA), scanning electron microscopy (SEM), 3D profile and X-ray photoelectron spectroscopy (XPS). The origins of super-hydrophilicity of the fresh laser ablated surface are identified as (1) the formation of hierarchical rough structures and (2) the surface chemical modifications (the decrease of nonpolar carbon, the formation of hydrophilic alumina and residual unsaturated atoms). The chemisorbed nonpolar airborne hydrocarbons from air moisture contributed to the gradual super-hydrophobic transition, which can be proved by the thermal annealing experiment. Particularly, to clearly explore the wettability transition mechanism, we extensively discussed why the laser-induced freshly outer layer was super-hydrophilic and how the airborne hydrocarbons were chemisorbed. This work not only provides useful insights into the formation mechanism of laser ablated super-hydrophobic surfaces, but also further guides industry to effectively modify surface chemistry to reduce wettability transition period and rapidly produce stable and durable super-hydrophobic surfaces. [Abstract copyright: Copyright © 2018. Published by Elsevier Inc.

Preliminary Exploration of the Mental Health Education Competency Survey of Primary and Middle School Head Teachers

Despite a recent focus on the mental health of students, primary and middle school mental health education in China has been hampered by a lack of resources fand inadequate professional training. This study assessed the mental health education competency of primary and middle school head teachers using the Mental Health Education Competency Questionnaire, a measure based on data from documentary analysis, behavioral event interviews (BEIs), and expert judgment. Factor, reliability, and validity analysis of this questionnaire were conducted. Through these analyses, seven structural dimensions of mental health education competency were found: mental health education skill, career growth, personality charm, occupational tendency, achievement feature, student perspective, and professional knowledge. This questionnaire will improve hiring and evaluation processes and, therefore, improve mental health education

Na/K-ATPase Signaling and Salt Sensitivity: The Role of Oxidative Stress

Other than genetic regulation of salt sensitivity of blood pressure, many factors have been shown to regulate renal sodium handling which contributes to long-term blood pressure regulation and have been extensively reviewed. Here we present our progress on the Na/K-ATPase signaling mediated sodium reabsorption in renal proximal tubules, from cardiotonic steroids-mediated to reactive oxygen species (ROS)-mediated Na/K-ATPase signaling that contributes to experimental salt sensitivity