Novel technique for measurement of coating layer thickness of fine and porous particles using focused ion beam

作     者：M. Goslinska I. Selmer C. Kleemann U.Kulozik I. Smirnova S. Heinrich 

作者机构：Hamburg University of TechnologyInstitute of Solids Process Engineering and Particle TechnologyDenickestr1521073 HamburgGermany Hamburg University of TechnologyInstitute of Thermal Separation ProcessesEiJ^endorfer Str. 3821073 HamburgGermany Technical University of MunichChair of Food and Bioprocess EngineeringWeihenstephaner Berg 185354 FreisingGermany 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2019年第17卷第1期

页      面：190-198页

核心收录：

学科分类：08[工学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：This IGF Project of the FEI was supported via AiF within the programme for promoting Industrial Collective Research (IGF) of the German Ministry of Economic Affairs and Energy (BMWi) based on a resolution of the German Parliament 

主　　题：Coating layer thickness Focused ion beam Microparticle Aerogel Spouted bed Dilute spouting 

摘      要：A novel technique for the measurement of the coating layer thickness of fine particles was developed in this work based on cross-sectioning of micrometre-sized single coated particles using focused ion beam (FIB) milling. This technique was tested on two batches of aerogel particles coated with thin coatings in a spouted bed. The FIB milling procedure consisted of two steps. First, the desired part of the coated particle was removed using a high ion beam current. The resulting cross-sectioned area was then polished using a lower ion beam current to make the cross-section clearly visible. The FIB milling process was controlled with simultaneous scanning electron microscopy (SEM). Afterwards, the coating layer thickness was evaluated using the SEM images. The coating layer was successfully applied on the porous aerogel microparticles in the spouted bed. The coating uniformity of the highly porous particles increased with increasing sprayed coating solution amount, with up to 91% of the particle pores being covered. The FIB-cross-sectioning technique using an ion beam of 2.50 nA for the first milling and 0.43 nA for polishing of the surface resulted in successful generation of cross-sections of representative particles with a visible particle core and coating layer. A coating layer thickness of approximately 700 nm was achieved on particles with sizes of below 45 μm.