| The micro-particle in the atmosphere can pollute the environment, cause many diseases, and adhere to the surfaces of many objects. It harms to the people life and industrial production. The surface propfdust and cleaning technology were investigated in the paper. These topics are very important both in theoretical study and practical operation. In the paper the micro-particle deposition, micro-particle adhesion mechanism and micro-particle removing from surface were studied, using theoretical analysis and experimental study. Main research contents and conclusions are as follows:1) Based on the literature search, it can be found:the research field of micro-particle consists of clean technology, mechanism research, instrument design and experimental testing. Fruits of clean technology are the largest, and the fruits of mechanism research are least of the proportion in these aspects. TiO2 catalytic oxidation technology was widely studied in the organic compound pollution, but the achievement of solid surface proofdust was few. Mechanism research mostly based on the classical contact mechanics, and it had rapidly developed in the Micro/Nano Electro-Mechanical Systems (MEMS/NEMS) and the semiconductor industry, solid surface dustproof and cleaning is still early stages of research.2) Several adhesion forces of the micro-particles adhering to solid surface were summarized, the physical adhesion mechanism of Van der Waals force, surface tension, static electricity and Casimir force were discussed. Several complex force models of particle adhesion were established considering different influencing factors, these factors including:surface adsorption layer, contact deformation, absorbed water, rough surface and surfactant, and detailedly listed the calculational expression of complex force models of particle adhesion.3) The results of sedimentation of micro-particles in air show that: the diameter of the particles is mainly between 20 and 80μm for tiles placed at the angle of 0°after 30 days, few particles with diameter great than 100μm or less than 0.5μm were found. By comparing the particles on the tiles with those on slides at the angle of 0°, it was found that the particle diameter varied from 10 to 40μm for the slides after one day while the diameter is mainly between 20 and 80μm for the tiles after 30 days. This indicates that the particle size distribution is affected by the sampling time, and it tends to be greater with the time. The size of the particle on the slides reduced as the placement angle increases. At the 10th day, the maximum size changes from 140μm,100μm to 80μm. The particle size mainly vary from 10 to 40μm for the angle of 0°or 45°, from 10 to 30μm for the angle of 90°. The particle average size does show strong correlation with the placement angle and the sampling time. However, the maximum size, the total area, the total perimeter, and the cover ratio increases with the sampling time. The increase was not significant within the first 10 days, while considerable from the 10th day to the 30th day during which they reduced with the placement angles. This indicates that, along with the time, the particles started to agglomerate from individuals, and physical and chemical changes occured.4) The experimental results of the pre-treated glass slide show that: the increment of adhesing quality of the micro-partilce on most slides surface treated by reagent is more obvious during the samping time 1d-5d than 5d-10d. The surface pre-treated by SDBS and Tween 60, the magnitude of micro-partilce quality is 5.0%> 1.0%> 0.5%, For the launder liquid, the order is 0.5%>5.0%>1.0%. These can be shown that it has difference for slides treated by different concentrations of reagents, for SDBS and Tween 60, before the magnitude exceed the concentration of 5.0%, the adhesing quality is increase with the concentration of reagent.5) The experimental results of the pre-treatment glass slide show that: the adhesing quality of the surface treated by the launder liquid is decrease with the samping time during 5d-10d, the reason included:a) the adhesing quality was close the maximum during 5d, and after that some mirco-particle remove from the surface because of the force came from airflow or other mirco-particle. b) every reagent has different property on physical chemistry, when the adhering quality exceed some value of micro-particle, the adhesion capacity will be declined under some concentration of reagent. 6) The experimental results of the pre-treated glass slide show that: the removal rate of the number of micro-particle adhering to the surface did not affect by samping time and the angle between the slide and the horizon very well. The removal rate of number was vary from 80%-100 %, but the change of removal rate of 0.5% Tween 60,5.0% Tween 60 and 0.5% launder liquid is obvious.7) The experimental results of the pre-treated glass slide show that: the experiment result does not show a strong correlation between the mirco-particle size, the placement angle, and the sampling time, the mirco-particle size tends to be greater with the time when the surface treated by 5.0% Tween 60 and 5.0% SDBS, and it tends to be smaller with the time for the untreated surface. The micro-particle size is smalles of the surface treated by the reagents AFC(0.5% SDBS+0.5% Fluocarbon), BFC(0.5% SDBS+0.5% Tween 60) and None, the value vary from 2μm to 3μm, the micro-particle size is largest for the surface treated by Tween 60, it vary from 4μm to 5μm.8) The experimental results of the pre-treated glass slide show that: the change of micro-particle size is not vary much for the surface treated by different reagents after cleaned, mostly of them were changed smaller, the average size is 3.285μm. The particle size change to 1μm for the particle on the surface treated by the single agents of SDBS, Tween 60, launder liquid and for the reagents of AFC and BFC had no significant change in particle size.9) The surface cleaning force was summaried in the paper, the work principle and remove mechanism of several common physical cleaning technology were analyzed, hydrophobic surface, outside force and remove pattern were discussed to study the physical remove mechanism, and chemical removal mechanism of surfactant was discussed in paper. |
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