Q: What is Absorption?
A: Absorption refers to the incorporation of the sorbed molecule into the host material.
Q: Define Adsorbate.
A: Adsorbate denotes an adsorbed molecule; refer to adsorption for more details.
Q: What is Adsorbent?
A: Adsorbent is a solid or liquid capable of interacting with the adsorbate.
Q: Explain Adsorption.
A: Adsorption is the accumulation of molecules at the surface of a solid or liquid.
Q: Define Adsorptive.
A: Adsorptive is a molecule capable of being adsorbed.
Q: What does Barrett-Joyner-Halenda (BJH) Analysis determine?
A: BJH Analysis is a pore size distribution determination method, typically applied to nitrogen desorption data on mesoporous materials.
Q: Define BET.
A: BET is an acronym for the Brunauer-Emmett-Teller equation, used to determine the specific surface area of solids.
Q: What is the Buoyancy Effect?
A: The Buoyancy Effect, in the gravimetric method, is the change in measured weight due to the displacement of gas, following Archimedes’ Principle.
Q: Define Capillary Condensation.
A: Capillary Condensation is the process by which a liquid adsorbate phase is drawn into a pore.
Q: What is Chemical Adsorption?
A: Chemical Adsorption, also known as chemisorption, occurs due to chemical forces, such as hydrogen chemisorption on a catalytically active surface.
Q: Define Chemical Potential (μ).
A: Chemical Potential (μ) is the Gibbs Free Energy per mole of sorbate, expressing the work required to bring a sorbate molecule from a reference state to another state.
Q: What is Chemisorption?
A: Chemisorption is adsorption due to chemical forces, distinguishing it from physical forces.
Q: What are Coadsorption Equilibria or Equilibrium?
A: Coadsorption Equilibria refers to the equilibrium state of a system containing more than one adsorptive.
Q: What does Dead Volume Correction entail?
A: Dead Volume Correction is the correction in the volumetric method, equivalent to the buoyancy effect correction in gravimetry.
Q: Define Desorption.
A: Desorption is the generic term for the reverse process of either absorption or adsorption induced by lowering the chemical potential.
Q: What is Diffusion?
A: Diffusion is the process by which sorbate molecules move in the host material due to random molecular motion.
Q: Explain Dubinin-Astakhov (DA) Equation.
A: The DA Equation is based on the DR equation and effectively linearizes adsorption data.
Q: What is Dubinin-Radushkevich (DR) Analysis used for?
A: DR Analysis analyzes gas adsorption isotherms of microporous materials based on Polanyi's potential theory of adsorption.
Q: What does Dynamic Vapor Sorption (DVS) measure?
A: DVS is a technique for measuring vapor sorption isotherms using a dynamic mode gravimetric sorption analyzer with vapors.
Q: Define Equation of State.
A: The Equation of State is the relationship between sorbate pressure, temperature, and volume.
Q: What is Equilibration Time?
A: Equilibration Time is the time required for equilibrium to be obtained within a specified criterion.
Q: Define Equilibrium.
A: Equilibrium is the state when the net rate of sorption is zero, where the rates of sorption and desorption are equivalent.
Q: What is Excess Adsorption?
A: Excess Adsorption is the quantity determined in a gravimetric or volumetric adsorption experiment.
Q: Define Fick’s Law.
A: Fick’s Law is a relationship where the flux of diffusing sorbate is proportional to the sorbate concentration gradient.
Q: Explain Fickian Diffusion.
A: Fickian Diffusion is diffusion that obeys Fick’s Law.
Q: What is Fugacity?
A: Fugacity is the tendency of the sorbate to change phase or expand at constant temperature.
Q: What does GAB stand for?
A: GAB is an acronym for the Guggenheim-Anderson-de Boer isotherm model.
Q: Define Gas Sorption.
A: Gas Sorption is the adsorption or absorption of a fluid in its gas phase.
Q: What does Gravimetric pertain to?
A: Gravimetric pertains to the measurement of weight or weight change.
Q: What does Helium Density determine?
A: Helium Density is the skeletal density of a porous material determined with Helium using pycnometry.
Q: What is the Horváth-Kawazoe (HK) Method used for?
A: The HK Method determines the pore size distribution of graphitic slit pores in microporous carbons using nitrogen adsorption measurements at 77 K.
Q: What is a Hydride in adsorption terms?
A: Hydride is a chemical compound formed between hydrogen and an element or a compound.
Q: Define Hydrogenation.
A: Hydrogenation is the process of forming a metal hydride.
Q: What is Hysteresis in adsorption?
A: Adsorption hysteresis occurs when adsorption and desorption values deviate from one another.
Q: Define Isosteric Enthalpy of Adsorption.
A: Isosteric Enthalpy of Adsorption is the standard enthalpy of adsorption at a fixed surface coverage.
Q: What is an Isotherm in adsorption science?
A: Isotherm is the measurement of the amount sorbed as a function of sorbate pressure at constant temperature.
Q: What does Kinetic Selectivity refer to?
A: Kinetic Selectivity is the property shown by molecular sieve materials where differences in sorption kinetics are used to select one species over another.
Q: What is the Langmuir Isotherm?
A: Langmuir Isotherm describes the sorption of an adsorbate monolayer on a uniform surface in the absence of adsorbate-adsorbate interactions.
Q: Define Mesopore.
A: Mesopore is a pore with a diameter between 2 nm and 50 nm.
Q: What is a Micropore?
A: Micropore is a pore with a diameter or dimension below 2 nm.
Q: What is Moisture Sorption?
A: Moisture Sorption is the sorption of water in the liquid or vapor phase.
Q: What is a Molecular Sieve?
A: A Molecular Sieve is a porous material that exhibits molecular sieving properties.
Q: Define Monolayer.
A: Monolayer is an adsorbed film that is one molecule thick.
Q: What is Multilayer in adsorption?
A: Multilayer is adsorption on the monolayer.
Q: What does MVTR stand for?
A: MVTR stands for Moisture Vapor Transmission Rate, see permeation.
Q: Define Nanopore.
A: Nanopore is a pore in nanoporous materials with a diameter or dimension below 100 nm.
Q: What does PCI stand for?
A: PCI is a pressure-composition isotherm.
Q: What does PCT stand for in adsorption studies?
A: PCT stands for pressure-composition-temperature, commonly used for hydrogen absorption isotherms determined for metal hydrides.
Q: Define Permeation.
A: Permeation is the steady-state transfer rate of sorbate through a host material, a function of both solubility and diffusivity.
Q: What is Physical Adsorption?
A: Physical Adsorption, also known as physisorption, is weak adsorption due predominantly to dispersive (Van der Waals) intermolecular forces.
Q: What is Pore Size Distribution used to characterize?
A: Pore Size Distribution is used to characterize microporous materials, such as activated carbons, that have an amorphous skeletal structure.
Q: Define Pore Volume.
A: Pore Volume is the volume of the pores or voids within a porous material.
Q: What is a Porous Material?
A: Porous Material is any solid containing pores and voids.
Q: What is PSA in adsorption techniques?
A: PSA stands for Pressure Swing Adsorption, an adsorptive gas separation technique using changes in pressure to regenerate the adsorbent.
Q: What is Pycnometry used for?
A: Pycnometry is a technique for measuring volume.
Q: What does Relative Pressure signify?
A: Relative Pressure, denoted as P/Po, is the ratio of absolute pressure (P) to the saturation vapor pressure (Po) of the adsorptive at the experimental temperature.
Q: What is Sieverts’ Method (Apparatus)?
A: Sieverts’ Method, also known as volumetric, is used for measuring gas sorption.
Q: Define Skeletal Density.
A: Skeletal Density is the density of a solid calculated by excluding all open pores and internal void volume.
Q: Define Solubility in adsorption terms.
A: Solubility is the magnitude of absorption expressed as a concentration under defined conditions or as a solubility constant.
Q: What is Sorbate?
A: Sorbate is a molecule capable of being absorbed or adsorbed.
Q: What is Sorbent?
A: Sorbent is a solid or liquid material capable of interacting with the sorbate.
Q: What does Sorption encompass?
A: Sorption is the generic term for adsorption and absorption interactions proposed by J. W. McBain in 1909.
Q: Define Specific Surface Area (SSA).
A: Specific Surface Area (SSA) is the surface area of a unit mass of material.
Q: What does Temperature Swing Adsorption involve?
A: Temperature Swing Adsorption is an adsorptive gas separation technique that uses changes in temperature to regenerate the adsorbent.
Q: What is Temperature-Programmed Desorption (TPD)?
A: TPD is a thermal analysis technique that uses an applied temperature ramp to desorb adsorbed molecules from a solid.
Q: What is Thermal Decomposition?
A: Thermal Decomposition is the decomposition of a compound by heating.
Q: Define Thermal Stability.
A: Thermal Stability is the thermodynamic stability of a compound.
Q: What does Van ‘t Hoff Plot show for metal hydrides?
A: Van ‘t Hoff Plot is a plot of ln(P) against 1/T for metal hydrides, where P is the plateau pressure at a temperature, T.
Q: What is Vapor Sorption?
A: Vapor Sorption is the sorption of a fluid in its vapor phase.
Q: What does Volumetric pertain to in adsorption studies?
A: Volumetric pertains to the measurement of volume or volume change.
