ScannigElectronicMicroscop扫描电子显微镜原理.pptx

Scanning Electronic Microscope; Scanning electronic microscope (SEM) is an instrument used to magnify the fine details of material surfaces such as polymer splitting, polymer pull-out, debonding, matrix cracking and polymer matrix adhesion and determine its chemical composition. It is also used to check the morphology, and crystallization structure. Scanning electronic microscopy consists of: Electron gun Condenser lens Scan coil Objective lens Specimen and detector ; ;Principle of SEM ;Sample preparation Degrease sample using acetone- to ensure removal of hydrocarbon and volatile compound. Sample need to be dehydrated to make sure no water present in the sample. -Drying in the oven at 60 ?C for 24 hours. 3. Non conductive sample need to be converted by coating the sample thin layer of conductive material(e.g.gold) particle using sputter coater For PLA, system operated at 20 to 30 KV and the photo was recorded at 1000- 3000 x magnification ;