The adsorption isotherm
Adsorption theory and methods of extracting information
from the adsorption isotherm
Langmuir theory
BET theory
Standard isotherms, t- and alpha-plots
Thickness equations
Methods of characterization for microporous materials
-- MP Procedure
-- Dubinin-Radushkevich method
-- Dubinin-Astakhov analysis
-- Horvath-Kawazoe equation
The cylindrical pore model extension of Saito and Foley
The spherical pore model extension of Cheng and Yang
The method of Cheng and Yang in regard to nonlinearity
Methods of characterizing mesoporous and macroporous materials
-- Kelvin equation
-- BJH method
Density functional theory
Fitting model isotherms to experimental data by the method of deconvolution
Surface energy distribution
Rate of adsorption
Measurement of the isotherm
Application of gas laws
Standard volume
Nonideality
Instrumental methods and theory of instrument design
Static volumetric method
-- Determining the manifold volume
-- Determining the quantity of gas in the free space of the sample holder
Warm free space
Determining the quantity of gas at cryogenic temperature
Cold free space
-- Determining the quantity of gas adsorbed
-- Control of cryogen level during tests
-- Thermal transpiration
Single sample volumetric analyzer
The analysis gas manifold
Software control of the dosing and pressure equilibration routines
Dosing by pressure table
Incremental dosing
Fixed-quantity dosing
Dose-sensitive data collection
Equilibrium detection
-- Making a test
Saturation pressure measurement
Free-space determination
Determination of gas-adsorbed quantity
The multiple-port volumetric analyzer
The Gemini design
The flowing-gas (dynamic) analyzer
-- Design features
-- Applying Dalton's law of partial pressures
-- Calibration
-- Making a test
Recognition and avoidance of problems
Leaks
Instrument calibration
Connecting an adsorptive gas supply to the instrument
Sample preparation
Helium entrapment
Use of SealFrits and PrepSeals
Selecting the appropriate adsorptive
-- Krypton and argon vs. nitrogen for low surface area determinations
-- Nitrogen vs. argon for micropore analyses
Cryogen and adsorptive pairing
Sample temperature
Sample quantity
-- Free-space values
-- Thermal transpiration correction
-- Equilibrium time
-- Measured vs. entered saturation pressure
Evaluation of results
Inspection of the isotherm plot
Evaluating the isotherm tabular data set
Reduced data
-- Physical parameters
-- Guidelines and evaluation of data reduction methods
-- BET C-value
-- Data analyses by the BJH method
A systematic approach to sample analyses by physical adsorption
Sample preparation
Analysis temperature
Quantity of sample
Surface area determination
Porosity
Symbols used in this chapter