Surface texturing modifies the optical characteristics of the surface because of scattering and diffusion of the incident UV-visible radiation by the textured pillars and fibrils. However, texturing of optically transparent surfaces requires special care towards keeping the optical properties, such as UV visible transmittance, reflection, and absorption. The desired surface texturing can be accomplished by many methods, including chemical processing, 9 laser ablation, 10 mechanical grinding/machining, 11 etc. 6–8 Hydrophobic wetting state is mainly associated with the surface texture composed of hierarchically distributed micro/nano pillars and low surface free energy. In general, sustainable self-cleaning requires a hydrophobic wetting state on surfaces. Consequently, investigation of the dust particle dynamics on inclined surfaces towards generating the self-cleaning effect on the surfaces becomes essential. The proper arrangement of the factors affecting the dynamics of dust particles can create the avalanche effect on the surface while enhancing dust particle removal from the surface. Size, shape, density, and electrostatic charge variation among the dust particles become key factors in determining the pinning forces. However, the pinning forces, some of which include the force due to dust particle adhesion on the surface, interlocking and interfacial forces among the accumulated dust particles on the surface, and frictional force play an important role in the dynamics of the dust particles on surfaces. Utilizing the gravitational force through tilting the dusty surfaces can contribute to the dust removal from surfaces. Because of the scarcity of clean water and shortage of electric power, adopting a self-sustainable mechanical method for dust particle removal becomes important, which is particularly true in the areas where electrical power is not readily available. 3–5 However, some of these methods and techniques require either clean water, 3 compressed air 4 or mechanical brushing, 5 and excessive energy use becomes unavoidable in these processes. Many methods and techniques have been developed to remove dust particles from surfaces. This contributes to dust particle accumulation on surfaces, which is mostly observed after the dust storms. These airborne particles cover the landscape surfaces when the influence of wind power diminishes. 2 However, some dust particles can suspend in air and are carried over long distances by strong winds. 1 In general, dust particles consist of various elements, and the particle composition changes from region to region depending on the regional geological characteristics. Dust accumulation has multi-fold effects on surfaces, and this is particularly true in humid ambient air. This is particularly important in regions where dust storms are affective due to the recent climate change. Introduction Optical transparency of glasses remains critical in dusty environments. The dust-removed surface, under the avalanche influence, improves the UV-visible transmittance of the hydrophobic glass. The size of the area where the dust particles are removed from the inclined surface increases with enlarging coverage area of the high density particles. Local insertion of the high density particles generates avalanche influence on the inclined surface while initiating the removal of the dust particles from the hydrophobic surface at small inclination angles. It is found that the predictions of velocity and acceleration of the dust particles agree well with the experimental data. The predictions of the dust particles' acceleration and velocity are compared to those obtained from the high speed camera data. The motion of the dust and high density particles on the inclined surface is monitored using a high speed camera. In order to increase the removal rate of the dust particles from the inclined hydrophobic glass surfaces, high density particles, which are higher than the density of the dust particles, are locally distributed on the dust particle-deposited surface while generating the avalanche influence on the inclined surface. A thin layer of environmental dust particles, collected from the local area of Dammam in the Kingdom of Saudi Arabia (KSA), is deposited on the surface while mimicking the dust accumulation on the surfaces in the dusty days of KSA. The glass surfaces are coated by functionalized nano-sized silica particles to create a hydrophobic wetting state on the surface. The removal of environmental dust particles from optically transparent glass surfaces is considered, and the dynamics of the dust particles on the inclined hydrophobic glass surface is examined.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |