Sierra Particle Technologies (SPT) offers a wide range of tools and services for structural, chemical, and optical characterization of particles and powders.

i) Morphology characterization: We use both ex-situ and in-situ techniques to characterize particle morphology. Ex-situ characterization techniques include usage of Scanning and Transmission Electron Microscopy (SEM/TEM) along with Energy Dispersive X-ray Spectroscopy (EDS) for obtaining detailed images and elemental composition of the nanomaterials, followed by extraction of structural information from the images using both commercially available and proprietary image analysis and processing software. We specialize in performing both particle and powder related dimensional analysis, fractal analysis, shape analysis using various shape descriptors, particle identification, etc. We have access to state-of-the-art instrumentation such as Scanning Mobility Particle Sizer (SMPS) and Electrical Low Pressure Impactor (ELPI) for measuring particle size distribution and concentration. Ensemble particle analysis using SEM/EDS can be a slow and tedious process when performed in the manual mode. Therefore, SPT is currently developing an automated morphology analysis package for the analysis of SEM/TEM images using artificial intelligence (AI) algorithms. In-situ characterization techniques include Small Angle Scattering (SALS) and Dynamic Light Scattering (DLS) to extract structural information of ordered and partially-ordered systems like fractal-like materials, colloids of all types, metals, cement, oil, polymers, plastics, proteins, foods and pharmaceuticals.

ii) Inorganic and Carbon Particle Chemical Analysis: We have access to a full range of analytical capabilities for identifying and quantifying trace amounts of inorganic substances and carbon fractions in gaseous, particulate, and liquid (wet deposition) samples collected in containers and on filters. Samples and substrates are prepared under low contamination conditions to minimize dynamic and field blank levels to obtain the best Lower Quantifiable Limits (LQLs) possible. Positive-pressure air filtered by high-efficiency particle arresting (HEPA) filters in each laboratory area minimizes contamination, which is further controlled by sample handling in laminar flow hoods. Temperature and relative humidity are controlled for filter equilibration and gravimetric analysis. Standard operating procedures (SOPs), quality control (QC) performance tests, and inter-laboratory comparisons have been established for analyses of mass, carbon fractions, elements, and ions. Data processing and data validation procedures and software integrate field records and implement blank subtraction and error propagation. Capabilities include: 1) sample preparation, 2) gravimetric and light transmission analysis; 3) carbon measurements, and 4) elemental and ionic measurements.

iii) Organic Analysis: We have access to state-of-the-art instrumentation that provides a full range of analytical capabilities for identifying and quantifying trace organic contaminants in particulate, liquid and gaseous phases. Organic laboratory operations, quality assurance (QA), data management and validation are integrated into an interactive process that takes place throughout the measurement and analytical programs. To achieve this integration, software has been developed to automate the data processing and reporting functions.

iv) Optics and Acoustics Measurements: Available instrumentation includes innovative optical and acoustic instruments for the real-time quantification of particulate matter (PM) and its optical properties. Instruments have been developed to measure aerosol extinction and its scattering and absorption components, and are being used for ambient measurements in air quality studies and to improve emission factors for on- and off-road engines and biomass burning.