Particle Stratification of Drying Bimodal Suspension Films

2016 Fiscal Year Final Research Report

• Project/Area Number: 26420766
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Properties in chemical engineering process/Transfer operation/Unit operation
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Yamamura Masato 九州工業大学, 大学院工学研究院, 教授 (90284588)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: drying / coating / suspension / fluorescence

Outline of Final Research Achievements

When nano-particle suspension films dry at too high a speed, the particles are trapped at the air-liquid interface to form a particle consolidation layer at the top surface. However, little attention has been paid to the drying of bimodal suspensions. This study aims at developing a new, in-situ measurement technique to capture the surface segregation of smaller particles in bimodal suspension films by means of fluorescence microscopy. The predictive model was newly built to predict the local particle volume fractions as a function of drying time. The results revealed that the measured emission intensity from the fluorescent nanoparticles well agreed with the model prediction. The increase in emission intensity was observed in two steps at different drying times. The secondary rise in emission intensity was attributed to the flow-induced transport of smaller particles through pore spaces between neighboring large particles.

Free Research Field

chemical engineering