A Simple Way to Achieve Self-Cleaning Surfaces with Unique Antifouling Property

Self-cleaning surfaces may have wide applications such as microfluidic devices, lab-on-a-chip, sensors, microreactors, air purification, and antimicrobial fields. In this article, by using a combination of femtosecond (fs) laser irradiation and fluorination technique, self-cleaning stainless steel surfaces with unique antifouling property were obtained. New insight is developed through a detailed analysis of the antifouling behavior of the self-cleaning surfaces. The surface free energy and its polar and disperse components were calculated by using the Owens–Wendt-–Rabel–Kaelble (OWRK) method. X-ray photoelectron spectroscopy was employed to analyse the surface elemental compositions and functional groups. The antifouling property of the surface was recorded by using a high speed camera. Water sliding angles (SAs) were reduced by fluorination treatment, resulting in low adhesive superhydrophobic surfaces with the self-cleaning property. The influences of micro/nanostructures, fluorination, and their combination on the surface free energy were investigated. The interaction process between water droplets and pollutants (inorganic and organic particles) on the treated surface was explored. The antifouling property of an optimized specimen (CA = 162° and SA = 1°) was tested and compared with the untreated sample.</jats:p

Damage morphologies of Al₂O₃ and Fe particles attached on the input surface of fused silica after irradiation by a 355 nm laser

Particulate contamination on the optical surface can seriously degrade the performance of optics working in the high peak power laser system. In this study, we show that the nature of optical damages on the input surface induced by particles depends on the optical property of the particles. Ceramic A l 2 O 3 particles tend to cause micro-fractures to the optical surface, but metallic Fe particles mainly undergo ablation on the substrate. Different microscopes are used to characterize their damage morphologies, and the light distribution and thermal evolution of two different particles are simulated, focusing on better understanding their special damage morphologies.</jats:p

Cleaning of Graphite Particles Embedded in the Surface of Ductile Iron by Using a Novel Method

Ductile iron has unique mechanical property and has been widely used in many industrial applications, e.g., engine cylinder covers, crank axles, and machine tool beds and cams. The welding performance of ductile iron is normally influenced by graphite particles in the surface of ductile iron, which needs to be removed before welding. In this article, laser cleaning technique was developed to remove graphite particles implanted in the surface of ductile iron. Laser cleaning parameters and the damage threshold value of the substrate were investigated by using a pulsed Nd: YAG laser. The optimized laser cleaning parameters were obtained to achieve high-quality cleaning effect and avoid the formation of the oxide layer. Surface morphologies and elemental compositions of specimens before and after laser cleaning were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Results indicated that graphite particles implanted in the surface of ductile iron were removed completely and efficiently by using the pulsed laser without the protection of inert gas atmosphere, and surface oxidation was not observed during the laser cleaning process.</jats:p

A Simple Way to Achieve Self-Cleaning Surfaces with Unique Antifouling Property

Self-cleaning surfaces may have wide applications such as microfluidic devices, lab-on-a-chip, sensors, microreactors, air purification, and antimicrobial fields. In this article, by using a combination of femtosecond (fs) laser irradiation and fluorination technique, self-cleaning stainless steel surfaces with unique antifouling property were obtained. New insight is developed through a detailed analysis of the antifouling behavior of the self-cleaning surfaces. The surface free energy and its polar and disperse components were calculated by using the Owens–Wendt-–Rabel–Kaelble (OWRK) method. X-ray photoelectron spectroscopy was employed to analyse the surface elemental compositions and functional groups. The antifouling property of the surface was recorded by using a high speed camera. Water sliding angles (SAs) were reduced by fluorination treatment, resulting in low adhesive superhydrophobic surfaces with the self-cleaning property. The influences of micro/nanostructures, fluorination, and their combination on the surface free energy were investigated. The interaction process between water droplets and pollutants (inorganic and organic particles) on the treated surface was explored. The antifouling property of an optimized specimen (CA = 162° and SA = 1°) was tested and compared with the untreated sample

Study on micro-nano structures’ wettability transformation mechanism of femtosecond laser on aluminium alloy

In this work, superhydrophilic surfaces are obtained on LY12 aluminium alloy by irradiation of femtosecond (Fs). First, based on the theory of laser induced surface plasmon polariton, the formation mechanism of micro-nano structures is analyzed. Then the periodic change of the micro-nano structures with different wavelength and incident angle is calculated. According to the theoretical results, the structure period is 600 nm at the vertical incident and incident wavelength with 800 nm, and the experimental results agree with the theoretical results. Furthermore, two different kinds of postprocessing methods are employed to change the superhydrophilic surfaces to superhydrophobic surfaces. All the micro-nano structures are tested by scanning electron microscope (SEM), contact angle (CA) and Fourier transform infrared spectra (FTIR). By analyzing the function of the functional groups of C–H, C–F and C–O, the transition mechanism of the surface from superhydrophilicity to superhydrophobicity is also explored. </jats:p

Preparation and Recent Developments of Ti/SnO2-Sb Electrodes

Ti/SnO2-Sb electrode, which is one of the dimensionally stable anode (DSA) electrodes, offers high specific conductivity, excellent electrocatalytic performance, and great chemical stability. For these reasons, Ti/SnO2-Sb electrode has been extensively studied in the fields of wastewater treatment. This review covers essential research work about the advanced oxidation technology and related DSA electrodes. It gives an overview of preparation methods of SnO2 electrodes, including sol-gel method, dip-coating method, electrodeposition method, chemical vapor deposition method, thermal decomposition method, magnetron sputtering method, and hydrothermal method. To extend service life and improve electrocatalytic efficiency, the review provides comprehensive details about the modification technologies of Ti/SnO2-Sb electrode, such as doping modification, composite modification, and structural modification. In addition, the review discusses common problems in industrial applications of Ti/SnO2-Sb electrode and highlights the promising outlook of Ti/SnO2-Sb electrode.</jats:p