השוואת שיטות

	פיזור אור דינמי	שטח פנים BET	ניתוח תרמו-גרבימטרי
תחום	מדעי החומרים	מדעי החומרים	מדעי החומרים
משפחה	Process / pipeline	Process / pipeline	Process / pipeline
שנת המקור	1964	1938	1960s
הוגה השיטה	Robert Pecora	Brunauer, Emmett, Teller	William W. Wendlandt
סוג	Measurement method	Measurement method	Characterization method
מקור מכונן	Pecora, R. (1964). Spectral distribution of scattered light from a suspension of particles. Physica, 30(11), 2055-2070.	Brunauer, S., Emmett, P. H., & Teller, E. (1938). Adsorption of gases in multimolecular layers. Journal of the American Chemical Society, 60(2), 309-319.	Wendlandt, W. W. (1986). Thermal Analysis (3rd ed.). John Wiley & Sons.
כינויים	DLS, photon correlation spectroscopy, particle size measurement	BET analysis, nitrogen adsorption, surface area measurement	TGA, thermal gravimetry, thermogravimetry
קשורות	3	3	3
תקציר	Dynamic Light Scattering (DLS), also known as Photon Correlation Spectroscopy (PCS), is an analytical technique for determining the size and size distribution of particles suspended in fluids by analyzing the time-dependent intensity fluctuations of scattered laser light. Developed by Robert Pecora in 1964, DLS exploits the Brownian motion of particles: smaller particles move faster, causing faster intensity fluctuations; larger particles move slower, causing slower fluctuations. By correlating intensity over time, particle size is deduced. DLS is rapid, non-destructive, and requires minimal sample volume, making it the standard technique for characterizing nanoparticles, proteins, colloids, and emulsions.	Brunauer-Emmett-Teller (BET) Surface Area Analysis is a technique for measuring the specific surface area of solids by analyzing their nitrogen adsorption isotherms. Developed by Brunauer, Emmett, and Teller in 1938, BET theory extends monolayer adsorption (Langmuir) to multilayer adsorption, enabling quantification of surface area of porous and powdered materials. It is the industry standard for characterizing catalysts, adsorbents, pharmaceuticals, and porous materials, providing critical data for performance prediction and quality control.	Thermogravimetric Analysis (TGA) is a thermal characterization technique that continuously measures mass loss or gain of a material as a function of temperature (or time at constant temperature). Developed systematically by William Wendlandt and colleagues in the 1960s, TGA identifies thermal transitions (evaporation, decomposition, oxidation, reduction) and quantifies composition of polymers, pharmaceuticals, ceramics, and other materials. The derivative signal (DTG) highlights transition temperatures. When combined with gas analysis (MS, FTIR), decomposition products are identified.