Department | Scanning Electron Microscopy laboratory

Activities

The Scanning Electron Microscopy laboratory features various instruments for performing three-dimensional morphological analyses and dimensional studies on samples of various kinds from the Department of Pharmacy's multiple research groups. In addition, the laboratory is used for teaching exercises planned for students enrolled in DIFARMA's courses of study, doctoral courses, and the "Percorsi per le Competenze Trasversali e l’Orientamento" (PCTO), with the aim of expanding the technical knowledge and transversal skills of all learners.

In particular, the following activities are conducted:

Scanning Electron Microscopy (SEM).

This technique allows micrometer- and nanoscale imaging of samples of different morphology, size and composition. In particular, through the use of two different microscopes it is possible to perform:

• Surface morphological analysis through imaging with secondary and backscattered electron detector

• Analysis of conductive and insulating samples through the use of the variable pressure module

• Ultra-high resolution imaging with secondary and backscattered electron detectors for ultra-detailed analysis of samples used in the pharmaceutical field

• Imaging and microanalysis with Scanning Transmission Electron Microscopy (STEM) system

• Focused Ion Beam (FIB) sectioning and lamellae production for STEM analysis

• 3D FIB-SEM Tomographies

• Preparation of samples for performing scanning electron microscopy (SEM) analysis metallized

When imaging with an SEM, if the sample is non-conductive, the electron beam makes the image distorted due to charge buildup. In such cases, a very thin layer (a few nanometers) of a conductive metal, such as gold or platinum, must be applied, improving the quality and sharpness of the images obtained and protecting electron-sensitive samples.

• Particle characterization by Dynamic Light Scattering (DLS).

With this fast and well-established technique, it is possible to perform:

• Particle size measurement from the nanometer to micrometer range

• Determination of zeta potential

• Measurement of molecular mass

• Measurement of refractive index

Equipment

The laboratory features the following instruments:

• ZEISS EVO MA 10 microscope with tungsten source equipped with detectors for secondary and backscattered electrons. The electron microscope can work under high vacuum, variable pressure or ambient pressure conditions, depending on the type of sample and the type of imaging to be obtained

• TESCAN SOLARIS S9000G UHR FIB-SEM microscope with variable-pressure chamber (up to 500 Pa); with dual electron source (field emission source) and focused gallium ion source for FIB-SEM mode to enable deposition processes of various materials, cutting, excavation, and 3D-type tomographic reconstruction on a wide range of samples; with TriLens™ system for high resolution imaging; with TriSE™ (Triple SE) detection system to obtain images with extremely topographically detailed; with TriBE™ (Triple BSE) detection system to obtain high surface contrast images. The microscope is also equipped with STEM detector for Bright Field, Dark Field and High Angle Dark Field for studying composite and soft biological materials and biomaterials.

• LEICA EM SCD005 Metallizer

• Dynamic Light Scattering Litesizer DLS 500 from Anton Paar equipped with FM 10 flow module to use different types of cuvettes and Dosing System to perform titrations and p H modifications. The instrument features Kalliope TM Professional Software.