Evaluation of the adhesion forces between dust particles and photovoltaic module surfaces

A new method, namely, force–distance curve mapping, was developed to directly measure the adhesion force of individual aerosol particles by atomic force microscopy. The proposed method collects adhesion force from multiple points on a single particle. It also takes into account the spatial distribution of the adhesion force affected by topography (e.g., the variation in the tip angle relative to the surface, as well as the force imposed upon contact), thereby enabling the direct and quantitative measurement of the adhesion force representing each particle. The topographic effect was first evaluated by measuring Polystyrene latex (PSL) standard particles, and the optimized method was then applied on atmospherically relevant model dust particles (quartz, ATD, and CJ-1) and inorganic particles (ammonium sulfate and artificial sea salt) to inter-compare the adhesion forces among different aerosol types. The method was further applied on the actual ambient aerosol particles collected on the western coast of Japan, when the region was under the influence of Asian dust plume. The ambient particles were classified into sea salt (SS), silicate dust, and Ca-rich dust particles based on individual particle analysis (micro-Raman or Scanning Electron Microscope/Energy Dispersive X-ray Spectroscopy (SEM-EDX)). Comparable adhesion forces were obtained from the model and ambient particles for both SS and silicate dust. Although dust particles tended to show smaller adhesion forces, the adhesion force of Ca-rich dust particles was larger than the majority of silicate dust particles and was comparable with the inorganic salt particles. These results highlight that the original chemical composition, as well as the aging process in the atmosphere, can create significant variation in the adhesion force among individual particles. This study demonstrates that force–distance curve mapping can be used as a new tool to quantitatively characterize the physical properties of aerosol particles on an individual basis.

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Dust Content and Adhesion Characteristics of Five Corn Samples

Transactions of the ASABE ◽

10.13031/trans.13747 ◽

2020 ◽

Vol 63 (2) ◽

pp. 495-499

Author(s):

Benjamin M. Plumier ◽

Yumeng Zhao ◽

Mark E. Casada ◽

Ronaldo G. Maghirang ◽

R. P. Kingsly Ambrose

Keyword(s):

Adhesion Force ◽

Bimodal Distribution ◽

Dust Concentration ◽

Dust Particles ◽

Dust Explosion ◽

Adhesion Forces ◽

Dust Generation ◽

Grain Handling ◽

Attachment Strength ◽

Grain Dust

HighlightsThe corn sample and centrifuge speed interactions were statistically significant predictors of dust generation.Attachment strengths of dust particles were calculated, with forces ranging from less than 4.6 × 10-10 N to 2.1 × 10-8 N.A sequential centrifuge experiment indicated a bimodal distribution of adhesion forces.Abstract. Grain dust explosions are a constant threat to the grain handling industry. Explosions occur when dust accumulates beyond the minimum explosion concentration in a confined area and is exposed to an ignition source. Handling and grain unloading conditions that generate dust, the minimum explosive dust concentration, overpressure from an explosion, and other factors that lead to grain dust explosion are well documented in the literature. The adhesion force that holds grain dust particles to the grain itself is an important factor in better understanding and mitigating dust separation from grain kernels and the resulting dust cloud generation. However, that adhesion force, how it is affected by grain quality, and how it is influenced by particle factors such as size and shape has not been adequately researched. A centrifuge separation technique was used to study the adhesion forces of grain dust. Results showed large variability in dust concentration between the five corn samples tested in this study. The dust particle attachment strength ranged from less than 4.6 × 10-10 N to 2.1 × 10-8 N. Only the sample and centrifuge speed interaction had a statistically significant effect on dust concentrations recovered at a 5% confidence limit. Under repeated centrifugations, the dust removed showed a bimodal distribution of attachment strengths, with three of four samples tested showing a local minimum at 2000 rpm, and the other at 3000 rpm. This study improves the understanding of the fundamental attachment strength behind dust separation from grain kernels. Investigating the size, shape, and surface characteristics of dust particles with varying attachment strengths is important to further understand their adhesion and separation mechanisms. Keywords: Adhesion strength, Dust explosion, Dust mitigation, Grain dust, Grain handling.

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Effects of Humidity on Dust Particle Removal during Solar Panel Cleaning

Surface Topography Metrology and Properties ◽

10.1088/2051-672x/ac4835 ◽

2022 ◽

Author(s):

E.Y. Chen ◽

Peter Renner ◽

K. Lee ◽

Bing Guo ◽

Hong Liang

Keyword(s):

Relative Humidity ◽

Dust Particle ◽

Energy Production ◽

Adhesion Force ◽

Solar Panel ◽

Dust Particles ◽

Particle Removal ◽

Adhesion Forces ◽

Ambient Conditions

Abstract Solar panel cleaning is important to maintain the efficiency of energy production. In this research, we investigated the effects of relative humidity and condensation on the effectiveness of cleaning. The dust particles are subjected to various forces once they are deposited on the surface of a solar panel. When the dust particles continue to build up, they are also subjected to the adhesion forces from the neighboring dust particles. The adhesion forces from the substrates and the neighboring particles are dependent on the ambient conditions. Fundamentally, the interaction between the adhesion force of particle-particle and particle-substrate under various conditions was discussed in this manuscript.

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